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| Saturday, 11 May | Sunday, 12 May | Monday, 13 May | Tuesday, 14 May | Wednesday, 15 May | Thursday, 16 May |
| 8:00 | Fundamentals of Diffusion |
| Marco Palombo | |
This lecture introduces key concepts behind the physics of diffusion MRI (dMRI) signal contrast, and motivate why these concepts are relevant in the context of quantifying tissue microstructure. Following this lecture, researchers and clinicians who are interested in understanding the basics of molecular diffusion, will gain intuition about the diffusion process as conceptualised by random-walks of particles, familiarise with representing the diffusion process by the diffusion propagator, understand the regimes in which the diffusion can and cannot be considered Gaussian and understand how these concepts are relevant in the context of tissue microstructure. Hands-on exercises will give intuition into the concepts discussed. |
| 8:45 | Diffusion MRI Acquisition, Part I: From Propagator to Image |
| Jana Hutter | |
Single-shot Pulsed Gradient Spin Echo echo planar imaging remains the most commonly used sequence for diffusion MRI. However, recent years have seen numerous extensions. This lecture will introduce both the basic modular elements and more experimental novel approaches including modified diffusion preparations, read-out accelerations and combinations with additional contrasts such as relaxometry. |
| 9:30 | Break & Meet the Teachers |
| 10:00 | Image Artifacts & Processing Pipelines, Part I |
| Rita Nunes | |
Diffusion-weighted images (DWI) are corrupted by noise and various imaging artifacts such as Gibbs ringing, EPI and eddy current distortions, motion and other physiological artifacts. The correction of those artifacts is of utmost importance to improve the qualitative, quantitative and statistical inspection of the diffusion data. Here we will give an overview of the major image artifacts, explain how they might confound the DWI analysis, and how they can be corrected for or at least minimized at source or using image processing |
| 10:45 | Diffusion MRI Models & Representations |
| Chantal Tax | |
The lecture provides researchers and clinicians who use or are planning to use dMRI to quantify the diffusion process and/or tissue microstructure with the basic tools to extract relevant features from the diffusion-weighted signal. The language of the dMRI community regarding signal modelling and representation is introduced. Examples of both signal representations going beyond the Gaussian diffusion regime, and model parameter estimation, are used to give intuition of how these concepts are relevant in the context of tissue microstructure. By solving exercises, the audience will gain intuition into the concepts discussed in the lecture. |
| 11:30 | Lunch & Meet the Teachers |
| 8:00 | MRI for Surgical Planning |
| Priti Balchandani | |
This talk discusses the role of MRI in neurosurgical planning and guidance. Specific examples included are the application of ultrahigh field MRI and multi-modal MRI to improved surgical treatment of epilepsy and skull base tumors. |
| 8:25 | Self Assessment Module (SAM) |
| 8:30 | Temperature Measurement |
| Kagayaki Kuroda | |
Noninvasive thermometry is one of the unique features of MRI compared with the other imaging modalities. In this lecture, the basic principles, as well as the latest techniques of MR thermometry such as acquisition acceleration, motion and field change compensation, fat and bone thermometry are explained. |
| 9:00 | Laser Therapy in Epilepsy |
| Robert Watson | |
Epilepsy cannot be controlled by medications in 30-40% of patients, and in these patients, resection of the epileptogenic focus may be the only hope for a cure. Traditionally, epilepsy surgeries involve craniotomies with resection of substantial portions of the brain. MR-guided laser interstitial thermal therapy (MRgLITT) provides a minimally invasive alternative. MRgLITT is based on stereotaxic image-guided placement of a small laser fiber into the target and subsequent monitored heating and ablation of the epileptogenic lesion. The technique and advantages, as well as concerns and ways to mitigate them, will be discussed. |
| 9:30 | Break & Meet the Teachers |
| 10:00 | MR Image-Guided Therapy and Surgery |
| Jayender Jagadeesan | |
MR Image-Guided Therapy |
| 10:30 | Focused Ultrasound: Basics |
| David Schlesinger |
| 11:00 | MR-Guided Focused Ultrasound Therapy for Brain |
| Toshio Yamaguchi | |
This course is designed to provide an introduction of the current status of MRgFUS clinical application in the brain. |
| 11:30 | Lunch & Meet the Teachers |
| 8:00 | MR Systems Overview |
| Seung-Kyun Lee | |
This educational talk is designed to provide a broad overview of the functions and interactions of the subsystems of a modern clinical MRI scanner and explain various design constraints originating from engineering and physiological limitations. |
| 8:30 | Magnets: Design, Manufacturing, Installation, Present & Future Technology |
| Johannes Van Oort | |
An introduction to the design, manufacturing and installation of MR magnets is presented. Emphasis is placed upon current and future technology of superconducting magnets. Basic coil design is explained, with a brief introduction to the application of superconductivity in MR magnets. Current manufacturing techniques are illustrated with a brief photographic tour. Finally, future industry trends are discussed. |
| 9:00 | Magnetic Field Shimming |
| Robin de Graaf | |
Magnetic field inhomogeneity affects the performance of almost all MRI and MRS methods, leading to signal loss and image distortion in MRI and loss of spectral resolution in MRS. Spherical harmonics (SH) shimming is the standard tool to improve magnetic field homogeneity, but falls short on complex samples like the human head. The principles and practical aspects of SH shimming are discussed, together with more recent non-SH-based alternatives. |
| 9:30 | Break & Meet the Teachers |
| 10:00 | Gradient Coil Design Considerations, Manufacturing & Limitations |
| Blaine Chronik |
| 10:30 | Eddy Current Measurement & Compensation |
| Christoph Barmet |
| 11:00 | Peripheral Nerve Stimulation |
| Rebecca Feldman | |
Rapidly changing magnetic fields, such as those produced by a switched magnetic field gradient coil can activate nerve fibers in ways that can be perceived as sensation or even induce involuntary muscle contraction or twitching. Gradient induced peripheral nerve stimulation (PNS) will be discussed as well as the limits it imposes on the operation of gradient system. |
| 11:30 | Lunch & Meet the Teachers |
| 13:30 | MRI Transmitter Amplifier Systems |
| Michael Twieg | |
The RF power amplifier (RFPA) is one of several “black box” components in the MRI scanner. The implementation of the RF transmit chain has remained fairly consistent since the earliest clinical MRI scanners, but the advent of parallel transmission (pTX) provides a compelling opportunity to rethink not only the design of the RFPAs and coils, but of the entire MRI scanner. In this lecture we will review fundamental RFPA concepts such as linearity and efficiency. We will then explore advanced topics relating to pTX, including control, decoupling, local amplifiers, and switchmode amplifiers. |
| 14:00 | MR Receive Chain |
| Nicola De Zanche | |
This lecture covers the components of the RF chain from detection of the signal in the RF coil to its final representation as digital data. Each component is described and its effect on signal strength and quality is discussed. |
| 14:30 | RF Field Simulations & Safety Aspects |
| Simone Winkler | |
A major challenge that currently hinders the application of Ultra High-Field (UHF) MRI in clinical diagnostics is the non-uniform deposition of radiofrequency (RF) power in the body. Electromagnetic modeling has become a popular tool to assess SAR in simulation [10]-[14]. A diverse family of detailed body models can be used to estimate global SAR and peak local SAR. While SAR values can still vary from patient to patient, with patient position, and with other variables, these simulations provide a strong basis for novel approaches that tackle SAR prediction more accurately [15]-[17]. Given the strong incentive to develop UHF MRI into a clinical tool, it is paramount to find a viable and accurate method for monitoring the spatially varying SAR pattern, and therefore the actual ratio of peak local SAR to global SAR, as the key parameter in MRI safety. |
| 15:00 | Break & Meet the Teachers |
| 15:30 | MR Linac: Implementations & Challenges |
| Johan Overweg | |
Key hardware features and requirements of integrated MR-guided Linac-based radiotherapy systems and practical implementations are explained. |
| 16:00 | PET/MR: System Design Considerations |
| Floris Jansen | |
This talk is aimed at physicists, engineers, and others who would like a better appreciation of the challenges involved in integrating a PET detector inside a 3T MR scanner. The main challenges involved in integrating a PET detector inside an MR scanner will be explained, and various approaches will be discussed for solving them. |
| 16:30 | MR Guided Focused Ultrasound in the Brain: Systems & Applications |
| William Grissom | |
Focused ultrasound in the brain has recently been made possible by the advent of MRI monitoring and phased array transducers. The method is currently FDA-approved for ablation of the VIM for essential tremor, and BBB opening and neuromodulation are also being explored. In this talk I will review each of these applications and discuss how they drive the design of MR-guided FUS systems. |
| 17:00 | Adjournment & Meet the Teachers |
| 8:00 | Basic Principles of MRS (Chemical Shift, J-Coupling, Relaxation & Field Strength Effects) |
| Lars Hanson | |
The lecture provides a basic understanding of the mechanisms essential to in vivo MR spectroscopy, i.e. those that influence the time and frequency representations of the MR signal in the absence of imaging gradients. Topics include nuclear interactions, the free induction decay (FID), data representations,and signal characteristics in the time and frequency domains. An effort will be made to give intuitive insight and fresh perspectives on the very basics, including interpretations of math frequently appearing in MRS literature. |
| 8:30 | Acquisition Methods for Full Profile & Specific Metabolites (STEAM, PRESS, LASER, CSI & MEGA-PRESS) |
| Assaf Tal | |
This lecture will cover some of the popular and/or recent MRS localization schemes, including PRESS, STEAM, semi-LASER, LASER, STRESS, MEGA-PRESS and SPECIAL. We will outline the reasons for preferring one module over another. In particular, we will pay special attention to the effect of different modules on coupled resonances - such as those of glutamate, glutamine, GABA, glutathione and lactate - and discuss advantages and disadvantages of each module in detecting each type of metabolite. |
| 9:00 | Pre-Acquisition Adjustments (B0 Shimming, B1 Shimming & Water Suppression) |
| Vincent Boer | |
In this lecture, the most common pre-scan adjustments for MRS and MRSI will be discussed, as well as the most recent and upcoming developments. For MRS studies, the pre-scan adjustments are an important factor for achieving best quality and reproducability. Failing of even one of the adjustments can lead to severe loss in spectral quality.To perform a correct pre-scan adjustment, the user is required to monitor the different preparation steps before starting the actual experiment. Correct preparation of an MRS acquisition requires knowledge of the following steps:
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| 9:30 | Break & Meet the Teachers |
| 10:00 | Data Processing, Fitting & Quantification |
| Hélène Ratiney | |
This lecture tackles the main steps and concepts underlying the quantitative analysis of MR spectroscopic signal in an in vivo context. The goal is to obtain reliable metabolite concentrations from its analysis. |
| 10:30 | Matching MR Methods With Appropriate Applications |
| Robin de Graaf | |
This presentation will review the decision process to arrive at an optimal combination of MR sequence elements, such as spatial localization, water suppression and spectral editing. Examples of specific applications, metabolites and MR hardware limitations will be provided to demonstrate that an optimal choice for one condition may not necessarily be optimal for a different one. While guidelines and decision trees can help the user under most experimental conditions, an intimate knowledge of each specific MR method is required when straying off the beaten path. |
| 11:00 | Spectral Quality (How to Review Your Own & Judge Published Data) |
| Alexander Lin |
| 11:30 | Lunch & Meet the Teachers |
| 8:00 | Machine Learning & Deep Learning: Technical Introduction |
| Florian Knoll | |
This talk will provide an overview of the technical background of machine learning and deep learning in medical imaging. Common hurdles and pitfalls will be discussed via didactic examples from classification and reconstruction. Examples will be provided from a range of MRI applications, with special focus on body imaging. |
| 8:25 | Machine Learning & Deep Learning: Clinical Applications |
| Shigeru Kiryu | |
This talk will introduce the clinical applications of deep learning becoming a reality. It will also discuss the unique aspects of deep learning in clinical applications along with its limitations. |
| 8:50 | Radiomics: Technical Introduction |
| Mirabela Rusu | |
This course is an introduction to Radiomics approaches. The course summarizes the different steps required to pre-process the radiologic images, extract features, reduce the feature sets and the types of analysis that can be performed on these features. Pitfalls of Radiomics analysis are also discussed. |
| 9:15 | Radiomics: Clinical Applications |
| Masoom Haider | |
Although quantitative imaging biomarkers are used in clinical care, mining of MRI images to derive quantitative signature based on large feature sets (radiomics) as a distinct approach is primarily a research endeavor in 2019. Approaches to have maximal clinical impact should combine knowledge of MRI physics, biologic sciences, computer vision, medicine and health economics |
| 9:40 | Break & Meet the Teachers |
| 10:10 | Fast Imaging & Perfusion: Technical Introduction |
| Yong Chen | |
Fast imaging techniques are crucial for abdominal MRI. This presentation will first cover the basic concepts of parallel imaging techniques and their usage in accelerating abdominal scans. We will further discuss recent advances in fast imaging techniques and how these techniques enable quantitative perfusion measurement in the abdomen. |
| 10:35 | Understanding DCE MRI & Its Potential Clinical Applications |
| Choon Thng | |
Basic mathematical concepts and relationships such as convolution, arterial input function, impulse residue function (IRF), microcirculatory parameters such as flow and permeability, tumor concentration time curve are explained qualitatively to facilitate understanding of tracer kinetic modelling and derivation of microcirculatory parameters by curve fitting. Common DCE MRI parameters such as Ktrans is explained. More complex models are discussed along with their benefits and trade-offs. Unique microcirculatory properties of the liver are explained relating to zero fractional interstitial space in normal liver and a positive value for cirrhosis. Potential clinical applications are briefly discussed. |
| 11:00 | Advanced DIffusion Imaging: Technical Introduction |
| Amita Shukla-Dave | |
This lecture covers the advancement in the technical development of Diffusion Weighted Imaging (DWI). DWI depends upon the microscopic mobility of water. Water mobility within tissue is highly influenced by the cellular environment, allowing DWI mapping of the diffusion of molecules, mainly water, in biological tissue in vivo and non-invasively. Molecular diffusion in tissues is restricted and reflects interactions with macromolecules, fibers, membranes, etc., revealing details about tissue architecture, which could be either normal or in a diseased state. Thus, DWI has become a non-invasive tool of choice for many clinical applications from assessment of cerebral ischemia to tumor aggressiveness. A series of technical advances, such as developments of echo-planar imaging (EPI), high gradient amplitudes, multi-channel coils, navigator triggered acquisition for motion compensation, and parallel imaging, have been instrumental in extending the application of DWI to the body. However, primary challenges, such as multiple occurrence of motion, persist. |
| 11:25 | Clinical applications for advanced body diffusion imaging: challenges and opportunities |
| Dariya Malyarenko | |
Notwithstanding technological advances in body DWI acquisition and analysis, their clinical applications remain relatively sparse. Quantitative (q)DWI protocols enable evaluation of sophisticated tissue diffusivity models to derive Gaussian and non-Gaussian parameters (ADC, IVIM, kurtosis) and/or texture-based features (histogram moments and gray-level) of high potential relevance to pathology. Clinically viable qDWI metrics should reflect target pathology using practical acquisition protocol and analysis observing relevant biophysical constraints. By reviewing examples of successful qDWI implementations in clinical oncology studies (for prostate, liver, breast, and whole body metastasis), this lecture will highlight venues to balance existing disparities between research and unmet clinical need. |
| 11:50 | Adjournment & Meet the Teachers |
| 8:00 | MR Yesterday & Today: An Historic Perspective |
| Chris Boesch | |
We are standing on the shoulder of giants! The continuously surprising development of NMR in Chemistry and MR in Medicine is a perfect example how the early work of ingenious individuals enables the current community of researchers to go the next steps forward. This is in particular true if one considers the technical limitations of the early days. While engineers and companies are now providing almost ideal (as compared to the last century) tools with homogeneous high-field magnets, incredible gradient performance, multiple radiofrequency channels, and powerful data handling, many discoveries in the past were technically adventurous. |
| 8:30 | Spin Gymnastics: Phase Factor Begets MRI |
| Yi Wang | |
The proton spin phase factor of the gradient field is known to found the Fourier encoding system matrix for MR image formation. The phase factors of short-range proton magnetic field, long-range electron magnetic field, and movement in a gradient field also connect MR physics of relaxation, magnetism and transport with tissue biology of cellularity, biomolecularity and vascularity. Therefore, spin phase factors unify explanation of image formation and tissue contrasts. |
| 9:00 | The Classical Description & System Overview |
| Daniel Stäb | |
While the spin is an intrinsic quantum mechanical property of elementary particles, quantum mechanics are not necessarily required to describe many of the basic processes of NMR or MRI. This lecture aims at providing an intuitive understanding of the NMR phenomenon (including spin precession, RF excitation and relaxation) in conjunction with a brief overview of the basic components of MR systems. |
| 9:30 | Break & Meet the Teachers |
| 10:00 | MR Toolbox |
| Martin Krssák | |
This lecture will introduce and describe most of the “Tools” we are using as building blocks of MR imaging and spectroscopy sequences. It will start with radiofrequency (RF) excitation, use of the phase cycling and building up of spin echo. Principles of slice selection, use of the gradients for signal encoding and spoiling will also be described. A concept of the extended phase graph (EPG) theory, which is a tool for depicting and understanding the magnetization response of a broad variety of MR sequences will also be introduced. |
| 10:30 | The Physics of MR Spectroscopy |
| Uzay Emir | |
This presentation aims to provide insight into MR spectroscopy of humans and highlight the essential concepts of chemical shift, spectral dispersion associated with magnetic field strength, shimming, signal suppression, combination schemes for signal processing from phased array coils, sequence approach, and localization sequences. |
| 11:00 | Spatial Encoding & k-Space |
| Gigi Galiana | |
This course will cover the basic elements of spatial localization, with special focus on how the physics of spin evolution connect to k-space. This perspective will then be used to describe various phenomena in MRI, including PSFs, Nyquist relations, and non-Fourier encodings. |
| 11:30 | Lunch & Meet the Teachers |
| 13:30 | MRI Sequences |
| Jakob Assländer | |
Bringing together the previously learned building blocks, this course will discuss the basics of MRI pulse sequences with a focus on signal formation and contrast generation. We will shed some light on the overwhelming zoo of sequences (with an even larger number of acronyms) and discuss joint features, as well as the key differences. |
| 14:00 | Introduction to RF Pulses |
| Karl Landheer | |
The design of proper RF pulses for any magnetic resonance experiment is absolutely critical. Here we discuss basic properties of RF pulses such as the flip angle, duration, and amplitude, and extend into pulse design covering topics such as spatial localization, Shinnar Le-Roux pulses, adiabatic pulses, multi-band pulses and multi-dimensional pulses. Practical design and simulation is emphasized. |
| 14:30 | Magnetic Nanoparticles as MR Contrast Agent |
| Xiaoyuan Chen | |
Magnetic nanoparticles (MNPs) have been extensively explored as magnetic resonance imaging (MRI) contrast agents. Recent progress in probing MRI relaxivity of MNPs based on structural features at the molecular and atomic scales is reviewed, namely, the structure–relaxivity relationships, including size, shape, crystal structure, surface modification, and assembled structure. A special emphasis is placed on bridging the gaps between classical simplistic models and modern MNPs with elegant structural complexity. In the pursuit of novel MRI contrast agents, it is hoped that this talk will spur the critical thinking for design and engineering of novel MNPs for MRI applications across a broad spectrum of research fields. |
| 15:00 | Break & Meet the Teachers |
| 15:30 | The Physics of Artifacts |
| Pedro Ferreira |
| 16:00 | Fields in MR & the Physics of Tissue-Field Interactions |
| Jinfeng Tian | |
Electromagnetic (EM) fields are one of the fundamental forces in nature, which provide us an insight into the physics of MRI. In the presentation, we will have an overview of the interactions between the EM fields and human body. Audience are expected to understand the basic EM fields and Maxwell equations, the interaction variation with frequency, numerical method election and FDTD procedures to interpret the interactions qualitatively and quantitatively, and a summary of EM simulation applications in MRI. |
| 16:30 | Numerical Simulation of MR physics |
| Tony Stöcker | |
This course provides insight into practical implementation of computer simulations based on classical MR physics. Analytical solutions versus numerical implementations will be discussed. Based on pictorial examples, an introduction to various MRI simulator software packages will be given. Some code snippets will be presented in order to implement MRI physics simulation from scratch |
| 17:00 | Adjournment & Meet the Teachers |
| 8:00 | Best Practices & Pitfalls in Applying Machine Learning to Magnetic Resonance Imaging |
| Thomas Moreau |
| 8:30 | Challenging Conventional Segmentation Evaluation Metrics in Patient MRI |
| Tal Arbel |
| 9:00 | Questions |
| 9:10 | Applications for Machine Learning in Medical Imaging |
| Polina Golland |
| 9:40 | Experimental Design for Applications of Machine Learning in Magnetic Resonance in Medicine |
| Jean Baptiste Poline | |
This presentation is about the issues that arise from the use of machine learning techniques for the processing of magnetic resonance images in medicine and in particular brain images. It will discuss the issues of reproducitibility and propose a set of recommendations for setting experimental designs adapted to machine learning applications. |
| 10:10 | Break & Meet the Teachers |
| 10:30 | State of the Art & Current Problems in Deep Learning |
| Daniel Rueckert | |
We will give an overview of the current state-of-the-art in deep learning for medical imaging applications such as reconstruction, segmentation and classification. In particular, we will illustrate deep learning approaches based on Convolutional Neural Networks (CNN). We will focus on deep learning models taht use encoder-decoder networks and show these can be used for tasks such as image reconstruction and image segmentation. We show some applications of CNNs in the context of image classification. Finally, we will discuss some open challenges for deep learning approaches such as explainability and verification of deep learning. |
| 11:00 | Questions |
| 11:10 | Learning Image Reconstruction: AUTOMAP |
| Bo Zhu | |
In this educational talk we describe AUTOMAP, a generalized image reconstruction method utilizing machine learning end-to-end from raw k-space to the final image, enabling reconstruction of arbitrary spatial encoding schemes and encoding spaces (not limited to Fourier) and also featuring noise-robustness which is produced during the training process. |
| 11:30 | Machine Learning Applications to Diffusion MRI Microstructure |
| Marco Palombo | |
Diffusion MRI (dMRI) signal is sensitive to the tissue architecture at the microscopic scale. Modern machine learning and deep learning techniques can be used to learn the mapping between acquired dMRI signal and specific features of the tissue microstructure. However, experimental design and validation of training sets are essential for reliable supervised and semi-supervised learning and reproducibility and uncertainty of prediction are still open questions. This lecture provides the key concepts behind machine learning applications to dMRI signal analysis for tissue microstructure quantification and show the audience various techniques which have been recently used. |
| 11:50 | Questions |
| 12:00 | Lunch & Meet the Teachers |
| 8:00 | Basic BOLD Physiology |
| Avery Berman | |
Functional MRI (fMRI) based on the blood oxygenation level-dependent (BOLD) signal has been used by researchers over the last 25+ years to non-invasively map brain activity and to measure brain physiology. This lecture will explain the basic biophysical principles that enable the use of the BOLD signal as a surrogate measure of brain activity. Topics covered fall into the domains of BOLD-related cerebrovascular physiology (basics of neurovascular coupling) and BOLD MR physics (blood oxygenation-dependence of T2 and T2*). Building on this basic understanding will help us better interpret BOLD signals and |
| 8:25 | Data Acquisition Basics |
| Saskia Bollmann | |
This course gives an introduction to data acquisition for fMRI using echo planar imaging (EPI). Key sequence parameters (voxel size, repetition time, echo time, echo train length, flip angle, parallel imaging, simultaneous multislice) and typical artifacts (ghosting, distortions, signal loss) and their impact on contrast, geometry and speed of EPI time series will be discussed. |
| 8:50 | Preprocessing |
| Cesar Caballero-Gaudes | |
This talk will describe the main steps of functional MRI data preprocessing based on the blood-oxygenation level dependent (BOLD) contrast. The numerous methods available for each step, and corresponding parameter selection, causes that the amount of possible preprocessing workflows can be enormous, which may lead to substantial variability in the quality of the preprocessed data and final results. We will establish some simple guidelines for adequate preprocessing since there is no ‘optimal’ preprocessing pipeline, but there are incorrectly applied methods, emphasizing that the workflow must be decided according to the characteristics of each dataset and the research question. We will briefly introduce several platforms that can help researchers to design the preprocessing pipeline, automatize its execution, and facilitate data quality assessment. These tools can foster reproducibility, and ensure transparent reporting of methodological details. |
| 9:15 | Task-Based fMRI |
| Alessio Fracasso | |
Task-based fMRI data is often analysed using the General Linear Model (GLM). This talk introduces this analytical approach starting from its basic concepts, benefits and limitations. Examples will be given showing how it can be used in block and event-related paradigms. Furthermore, the discussion will cover an introduction to the flexible use of the GLM in forward (or encoding) modelling approaches of task-based fMRI as the population receptive field (pRF) analysis. |
| 9:40 | Break & Meet the Teachers |
| 10:10 | Resting-State fMRI |
| Ann Choe | |
In this educational course, basic concepts of the resting state fMRI (rsfMRI) will be outlined, and several widely used data-driven analysis approaches for resting state functional connectivity (rsFC) and their applications will be introduced. The course will also briefly describe the recent emergence of dynamic functional connectivity (dFC) and several of its widely used data analysis approaches. |
| 10:35 | High Spatial Resolution fMRI |
| Jeroen Siero |
| 11:00 | High Temporal Resolution fMRI |
| Laura Lewis | |
Whole-brain fMRI data can now be acquired at high temporal resolution – on timescales of hundreds of milliseconds. These ‘fast fMRI’ approaches have the potential to reveal new information about brain function. Both acquisition and analysis techniques need to be adapted for fast fMRI in order to exploit its full potential for neuroscience. This lecture will provide an overview of techniques for fast fMRI, how to design fast fMRI studies, and how to model and analyze fast fMRI data. Finally, we will discuss the advantages and limitations of fast fMRI, and highlight potential confounds in interpreting fast fMRI data. |
| 11:25 | Lunch & Meet the Teachers |
| 13:30 | Microstructure Models, Part I |
| Valerij Kiselev | |
We discuss the principles of accessing the tissue microstructure using diffusion MRI. This challenge is decomposed into the forward and inverse problems: the biophysical modeling of the diffusion-weighted MRI signal, and the model parameter estimation, respectively. We focus on the former and briefly discuss the latter. The central phenomenon for the biophysical modeling is the course-graning of the structural details by diffusion. It will be discussed for the regimes of short times (when diffusion reveals the interface surface per unit volume) to long times (when diffusion becomes sensitive to the overall structural organization of tissues). The case of impermeable compartments will be treated separately to clarify the sensitivity of diffusion measurements to the size of small cells |
| 14:15 | Diffusion MRI Acquisition, Part II: Adding Dimensions |
| Filip Szczepankiewicz | |
This lecture explores how diffusion-weighted experiment can be expanded to include correlations with T1 and T2 relaxation and multidimensional diffusion encoding. The exercises will include calculations relevant to the T2-dependent diffusion encoding, and to the design of non-conventional gradient waveforms. |
| 15:00 | Break & Meet the Teachers |
| 15:45 | Microstructure Models, Part II |
| Sune Jespersen | |
We discuss tissue microstructure from the point of view of biophysical modeling, using the so-called Standard Model of diffusion in the brain as our primary example. We review its assumptions, potential regimes of validity, validation studies, and approaches for parameter estimation. Prominent among these are “orthogonal measurements”, where e.g. diffusion pulse sequences employing generalized q-space trajectories may play an important role. |
| 16:30 | Image Artifacts & Processing Pipelines, Part II |
| Jelle Veraart | |
In the second part of this topic, we focus on more advanced image processing methods. We will give an overview of image denoising methods, Gibbs ringing removal, outlier detection, frequency stabilization, effects of gradient nonlinearity, and discuss challenges of pushing for higher spatial resolution. |
| 17:15 | Adjournment & Meet the Teachers |
| 13:30 | Get the Hype: The Physical Bases of Dynamic Nuclear Polarization for Medical Uses |
| Lucio Frydman | |
This talk will discuss the physical basis of the DNP NMR/MRI experiment. Attention will focus on alternatives to do the hyperpolarization component in either solutions or in the solid state, focusing in particular on the Overhauser, on the Solid and on the Cross Effects for the sake of maximizing the nuclear polarization. The parameters that each of these methods requires to work best –including their respective advantages and drawbacks– will be explained. On the basis of this, the procedures that may then enable their respective utilization in bioimaging settings will be introduced |
| 13:50 | Physics & Chemistry of d-DNP for Biomedical Imaging |
| Mikko Kettunen | |
Dissolution dynamic nuclear polarisation (d-DNP) method allows hyperpolarisation of a broad range of molecules, yielding >10,000-fold increase in 13C signal-to-noise ratio. Hyperpolarisation is achieved through microwave-induced polarisation transfer from electrons to nuclei at solid-state followed by rapid dissolution. d-DNP places some limitations to suitable marker molecules, however. In this talk, the basics of d-DNP and chemistry involved will be discussed. |
| 14:10 | MR/MRSI Acquisition Strategies |
| Angus Lau | |
Dynamic nuclear polarization and dissolution offer the exciting possibility of imaging biochemical reactions in vivo, including some of the key enzymatic reactions involved in cellular metabolism. For MR metabolic imaging using 13C‐labeled compounds and DNP, the desired information lies in both the spectral domain, with the relative amplitudes of the different chemical shift species, as well as in the spatial domain. This necessitates some form of spectral encoding together with the acquisition of imaging data, which strongly influences the design of pulse sequences for this application. We will discuss how to efficiently use the limited available hyperpolarized magnetization in conjunction with available imaging pulse sequences. |
| 14:30 | Applications of d-DNP in Pre-Clinical Research |
| Kerstin Timm | |
Dissolution dynamic nuclear polarization (d-DNP) has made possible the in vivo measurements of biochemical reactions using MR spectroscopy and different imaging strategies. This presentation will focus on the available pre-clinical models used for d-DNP as well as a range of hyperpolarized 13C-labelled substrates that have been employed thus far. The talk will furthermore outline the necessary steps that have to be taken when planning pre-clinical d-DNP studies, ranging from the choice of model system over practical considerations to the actual hyperpolarized probes and their chemical modifications. The presentation will conclude by pointing towards potential future applications and optimizations of d-DNP. |
| 14:50 | Break & Meet the Teachers |
| 15:20 | PHIP & SABRE Techniques |
| Thomas Theis | |
Parahydrogen Induced Polarization (PHIP) is a relatively new hyperpolarization technique, first described in 1986. PHIP has advanced to enable important applications including biomolecular imaging with hyperpolarized MRI markers. Compared to other hyperpolarization techniques, PHIP is particularly simple and easy to implement but also faces critical challenges that still need to be addressed for widespread use. In this tutorial, insight into fundamental PHIP spin physics is given and it will be illustrated how such fundamental insight can drive innovation towards broader adaption of the technology in medical applications. |
| 15:40 | Imaging Applications of PHIP & SABRE |
| Meghan Halse | |
In this presentation, the latest developments towards imaging applications of parahydrogen-based hyperpolarisation methods will be discussed. Recent advances of both the hydrogenative parahydrogen-induced polarisation (PHIP) and non-hydrogenative signal amplification by reversible exchange (SABRE) methods will be explored. In particular the talk will focus on developments in key aspects of clinical relevance including the optimisation of hyperpolarisation levels and lifetimes, strategies for increasing the range of agents amenable to hyperpolarisation, and developments that will allow for the delivery of biocompatible agents including both the solvent conditions and the removal of the transition metal catalyst. |
| 16:00 | SEOP & MEOP |
| Boyd Goodson | |
Once limited to the realm of fundamental physics experiments, hyperpolarized (HP) noble gases have been exploited to enhance magnetic resonance signals for a wide range of applications, including biomedical and clinical imaging. The purpose of this tutorial is to introduce the principles and practice of the primary methods of preparing hyperpolarized noble gases: spin-exchange optical pumping (SEOP) and metastability-exchange optical pumping (MEOP). Alternative approaches (e.g. dynamic nuclear polarization, DNP), will also be discussed. |
| 16:20 | Hyperpolarized Gas Imaging - A Focus on Ventilation |
| Jason Woods | |
Hyperpolarized-gas MRI has seen a steadily increasing, albeit tortuous, path toward relevance in pulmonary medicine. During the last 10 years, the field has seen an increased focus on 129Xe, which can be used to measure regional ventilation, to characterize the size of alveolar spaces (diffusion MRI), and to measure gas exchange between the airspaces, red blood cells, and interstitium/plasma. This presentation will focus on ventilation imaging and the relevance of ventilation imaging to sensitive detection of early, regional lung obstruction. Application to well-characterized patient populations has allowed detailed comparisons of hyperpolarized-gas MRI to clinically-accepted techniques, demonstrating high sensitivity. |
| 16:40 | Adjournment & Meet the Teachers |
| 13:30 | What Is Myelin & Why Is It Important to Image? |
| Samuel Ludwin |
| 13:50 | Magnetization Transfer Techniques |
| Guillaume Duhamel | |
The potential of Magnetization Transfer techniques (MTR, qMT and ihMT) for myelin imaging is presented |
| 14:10 | Myelin Water Imaging |
| Shannon Kolind | |
Myelin water imaging (MWI) provides quantitative measurements specific to myelin by separating the MRI signal into contributions from the various water pools present within a voxel. In central nervous system tissue these water pools generally correspond to intra- and extra-cellular water, which relaxes slowly, and water trapped between the myelin bilayers, which relaxes quickly. The fraction of water corresponding to the water trapped within the myelin sheath, the myelin water fraction (MWF), provides a quantitative measure related to myelin content. This course will discuss acquisition and analysis techniques as well as common artefacts and pitfalls. |
| 14:30 | T1 & T1w/T2w |
| Christine Tardif | |
This talk describes two methods used for imaging myelin content in vivo: T1 mapping and T1-weighted/T2-weighted (T1w/T2w) signal ratio imaging. Their advantages and limitations will be discussed in comparison to other techniques presented in the Myelin Imaging session. |
| 14:50 | Break & Meet the Teachers |
| 15:20 | Ultra Short TE |
| Mark Does | |
Magnetic resonance imaging (MRI) contrast can be highly sensitive to the presence of myelin; however, quantitative MRI approaches to measure myelin content remain a challenge. With ultra-short echo time (UTE) MRI, it may be possible to directly image the rapidly-relaxing non-aqueous protons in the phospholipid bilayers that comprise myelin. UTE-MRI brings with it technical challenges, and the MRI characteristics of the ultra-short T2 signal from myelin is not yet well understood. Several studies have presented UTE-MRI of brain thought to reflect myelin, but questions remain and further work is needed to validate this approach. |
| 15:40 | Synthetic Myelin Imaging |
| Marcel Warntjes | |
Synthetic MR imaging is a method that creates conventional T1W, T2W and FLAIR images by measuring the T1 and T2 relaxation times. The method can only resolve slow relaxation components, but by using a model for myelin including magnetization exchange, it can infer the presence of myelin. The advantage of the method is the short scan time, where typically full head coverage is obtained in 6 minutes. A new sequence is developed where even a 1 mm isotropic resolution can be obtained in that scan time. An overview is provided of the measurements, modeling and clinical application of myelin detection using synthetic MRI. |
| 16:00 | T2* |
| Dong-Hyun Kim | |
Recently, there has been numerous research on myelin water imaging via T2* contrast, e.g. based on multi gradient-echo imaging. In this talk, I will present the methodology of T2* based myelin water imaging. Acquisition and reconstruction methods will be presented. Also, the pros and cons of T2* based myelin water imaging and challenges will be discussed. |
| 16:20 | Exploring myelin content changes with Positron Emission Tomography: application to multiple sclerosis |
| Benedetta Bodini | |
Measuring myelin content changes in living patients is essential to understand the mechanisms underlying demyelinating diseases such as multiple sclerosis (MS). Several advanced MRI techniques have proven to be extremely sensitive for detecting microstructural changes affecting brain tissues of patients with MS. However, since similar changes in the physical properties of tissues detected by MRI can result from multiple pathological processes indistinguishable from each other, the interpretation of imaging data acquired with MRI remains challenged by an intrinsic suboptimal specificity. Being based on the use of radiolabeled compounds selectively binding to specific biological targets, positron emission tomography (PET) offers the highest possible specificity to explore myelin content changes in the human brain. |
| 16:40 | Panel Discussion |
| 17:00 | Adjournment & Meet the Teachers |
| 13:30 | Benign Primary Liver Tumors |
| Hero Hussain | |
Focal liver lesions are frequently encountered and represent a wide spectrum of pathologies. While most these lesions are benign, especially in the absence of history of malignancy and chronic liver disease, many will undergo MR imaging for characterization and reassurance. The radiologist must therefore be aware of typical and atypical imaging features of benign lesions on MR imaging, to avoid unnecessary extra tests and procedures. |
| 13:55 | Malignant Primary Liver Tumors |
| Takamichi Murakami | |
Malignant primary liver tumors are classified according to their origins in the 4th WHO classification. They mostly consist of epithelial tumors such as hepatocellular carcinoma and intrahepatic cholangiocarcinoma, which are the first and second most common liver malignancies. Although each malignancy has unique imaging features on CT and MRI that lead to differential diagnosis, they are sometimes difficult to distinguish due to similarities in the backgrounds or due to combined tumors which have features of both malignancies. In this lecture, typical and atypical imaging features of those liver malignancies with reference to the current topics and considerations will be presented. |
| 14:20 | Biliary Disease |
| Mi-Suk Park | |
Biliary disease: A pattern-based approach and differential diagnosis |
| 14:45 | Diffuse Liver Disease |
| Takeshi Yokoo | |
Recent advances in MRI for liver fat, iron, and fibrosis quantification has enabled “virtual liver biopsy” for patients with diffuse liver disease, and these technologies are now widely available for clinical care. The purpose of this educational session is to inform physicians and physicists of these new MRI capabilities and their potential value in clinical practice. |
| 15:10 | Break & Meet the Teachers |
| 13:30 | Foundations of Imaging Study Design |
| Chaya Moskowitz | |
This half-day Educational Course will provide an introduction to statistical methods for imaging studies. The course will focus on concepts of study design and data analysis that are frequently used in imaging studies. Topics to be covered include prospective and retrospective studies, error rates and hypothesis testing, ROC curves, basic sample size calculations, methods for evaluating quantitative imaging biomarkers, and statistical concepts in radiomics analysis. |
| 14:00 | Statistical Estimation & Hypothesis Testing |
| Mithat Gonen |
| 14:30 | Break & Meet the Teachers |
| 14:45 | Statistical Methods for Evaluating the Accuracy of Imaging Tests |
| Chaya Moskowitz |
| 15:10 | Power & Sample Size Calculation for Imaging Studies |
| Mithat Gonen |
| 15:35 | Break & Meet the Teachers |
| 15:50 | Concepts in Quantitative Imaging Biomarker Evaluation |
| Chaya Moskowitz |
| 16:15 | Radiomics from a Statistician’s Perspective |
| Mithat Gonen |
| 16:40 | Questions |
| 17:00 | Adjournment & Meet the Teachers |
| 13:30 | Neurovascular Coupling |
| Claudine Gauthier | |
The brain has a high energy demand, but cannot store energy. Consequently, it requires an uninterrupted and tightly controlled influx of blood to function. Neurovascular coupling comprises all mechanisms that determine cerebral blood flow (CBF) regulation following neuronal activity. The neurovascular unit is highly complex, involving excitatory neurons, interneurons, components of blood vessel walls such as smooth muscle cells and pericytes, as well as perivascular cells such as astrocytes and macrophages. All these cells can release molecules that can lead to vasodilation or vasoconstriction, and thereby determine the CBF response that accompanies neuronal activity, and therefore hemodynamic imaging signals. |
| 13:50 | HRF: Modeling & Transients |
| Martin Havlicek | |
Hemodynamic response measured with blood oxygenation level-dependent (BOLD) fMRI typically exhibit transients in the form of early-overshoot and post-stimulus undershoot. These transients originate from dynamic relationships between different physiological variables. They can be related to (1) active neuronal and metabolic processes reflecting changes in excitatory-inhibitory (E-I) balance; or (2) passive vascular venous blood volume changes due to vessel viscoelasticity. In this lecture, I will explain how dynamic physiological models, accounting for both active and passive mechanisms underlying BOLD response (BR) transients, can help us to study dynamic changes in E-I balance using fMRI data. |
| 14:10 | Laminar Physiology |
| Laurentius Huber | |
Recent methodological advancements of fMRI allow researchers to approach the mesoscopic regime of cortical layers and columns. This revolutionizes the ability to tackle cortical information processing within brain systems. In order to interpret the layer-dependent fMRI signal, however, the underlying laminar physiology must be understood. In this educational lecture, I will give an overview of the physiology of blood vessels within GM and discuss how this physiology affects the interpretation of layer-fMRI signal changes. I will give an overview of the corresponding fMRI analysis challenges. And finally, I will discuss how intra-cortical blood vessels can differently affect fMRI contrasts of BOLD and non-BOLD sequences. |
| 14:30 | Cardiovascular Response |
| Kevin King | |
We will discuss how new MRI techniques allow us to identify various stages of brain response to cardiovascular disease. |
| 14:50 | Break & Meet the Teachers |
| 15:20 | Calibrated BOLD |
| Daniel Bulte | |
Blood oxygenation level dependent (BOLD) functional MRI is a powerful tool for localising neural activity, but it provides an ambiguous physiological signal. A number of methods exist for calibrating the BOLD signal in order to provide either relative changes in a physiological parameter such as CBF and CMRO2 during the performance of a task, or to produce quantitative maps of physiological parameters at rest. This session will introduce the basic science behind some of the most popular methods of BOLD calibration. |
| 15:40 | MRI Measurement of OEF and CMRO2 |
| Felix Wehrli | |
The cerebral metabolic rate of oxygen (CMRO2) is fundamental to tissue metabolism. Determination of CMRO2 demands knowledge of the arterio-venous difference in hemoglobin-bound oxygen concentration, typically expressed as oxygen extraction fraction (OEF), and cerebral blood flow rate (CBF). MRI is uniquely suited for measurement of both these quantities, yielding CMRO2 in absolute physiologic units of µmol O2 min-1/100g tissue. Two approaches will be discussed, both relying on hemoglobin magnetism. The first is based on measurement of blood water T2, which is modulated by diffusion and exchange in the local induced fields in the vicinity of erythrocytes. The second exploits the blood’s bulk magnetic susceptibility, which can be derived from field maps. |
| 16:00 | Understanding Baseline: Arterial Compliance |
| Esther Warnert | |
Understanding Baseline: Arterial Compliance. |
| 16:20 | Understanding Baseline: Non-Gd BBB |
| Jack Wells | |
Alterations to the integrity of the blood brain barrier (BBB) appear to be mechanistically important in the development of neurodegenerative disease. Traditionally, BBB integrity is measured by investigating the transfer of intravascular contrast agents, such as gadolinium or evans blue, into the brain parenchyma. Alternative, non-invasive, MRI techniques have been proposed that harness arterial spin labelling sequences to assess the permeability of the BBB to water, potentially yielding a sensitive marker of subtle pathological changes. In this lecture I will review these non-invasive techniques and how they have been applied to investigate abnormalities to BBB integrity in disease. |
| 16:40 | Adjournment & Meet the Teachers |
| 15:40 | Imaging for Biopsy Planning |
| Leonardo Bittencourt | |
In this presentation, we will discuss about imaging and clinical variables that may help achieve a better performance on MR-TRUS fusion-guided biopsies of the prostate. |
| 16:05 | Imaging for Surgery, Focal Therapy & Radiation Treatment Planning |
| Satoru Takahashi | |
Basis, characteristics and indication of potential definitive therapy for the prostate cancer; including radical prostatectomy, radiotherapy, local ablation therapy, will be demonstrated for better understanding of the appropriate management of newly diagnosed prostate cancer. Surgical and radiological anatomy of crucial structures for preventing complications of radical prostatectomy, as well as tips, trick and pitfalls for visualizing and evaluating vital structures will be discussed. |
| 16:30 | Imaging in the Post-Treatment Setting |
| Sadhna Verma | |
Learning Objectives Describe prostate cancer treatment options (active surveillance, surgery, radiation, and focal therapies) and their imaging findings. Recognize the importance of new MRI and PET techniques in the detection of recurrence after hormone, radiation, prostatectomy and focal therapies. Understand the importance of MR imaging in surveillance after focal therapy and its role in triage and follow-up of patients who undergo active surveillance. |
| 16:55 | Adjournment & Meet the Teachers |
| 8:00 | Quantitative Magnetization Transfer Imaging for Characterizing Pathology |
| Seth Smith | |
The purpose of this presentation is to provide an overview of the basics of quantitative magnetization transfer (qMT) MRI acquisition, analysis, and implementation. We will additionally provide an overview of the application of qMT in health and disease and examine the opportunities for qMT in characterizing pathology. |
| 8:35 | CEST MRI for Beginners |
| Eleni Demetriou | |
What is the origin of CEST contrast in tissues? What are the basic steps for generating CEST contrast maps including acquisition and post-processing of CEST MRI data? What are its current applications and its limits? The purpose of this talk will be to outline the basic mechanisms of CEST either through MRS or imaging. To discuss the progress of CEST imaging towards clinical practise and to highlight extraordinary developments within this field. |
| 9:10 | Bringing It All Together: Relaxation, T1rho, T2rho & CEST |
| Elena Vinogradov | |
Spin-lock experiments employ RF to probe dynamic processes in molecules. CEST also employ RF to create contrast and explore spin dynamics. In all these cases, in the presence of RF, an effective field is formed and the relaxation processes are governed by the constants parallel and perpendicular to the effective field – T1rho and T2rho. We will dwell in more details on the basic principles, equations and features governing relaxation and dynamics processes in these methods. |
| 9:45 | Break & Meet the Teachers |
| 10:15 | Exploiting Relaxation Along Fictitious Fields |
| Silvia Mangia | |
The SNR increase of high fields needs to be leveraged with the challenge of maintaining the flexibility of tuning the MRI contrast to the molecular dynamics of interest. Relaxation methods based on frequency-modulated pulses, including T1ρ and T2ρ using adiabatic pulses, and the non-adiabatic method entitled relaxation along a fictitious field (RAFF) in the rotating frame of rank 'n' (RAFFn), offer sensitivity to molecular dynamics in intermediate and slow regimes. The reduced power deposition of RAFFn, along with the opportunity of enhancing sensitivity to exchange by tuning the periodicity of irradiation, are distinct and compelling advantages of the methodology. |
| 10:50 | C’est La Vie: Selected Topics on In Vivo CEST |
| Lucio Frydman | |
This talk will center on analyzing the potential associated with CEST-based MRI, based on both the method’s physical principles and on experiences with in vivo rodent experiments. Following an initial description on how molecular-based information can be extracted based on chemical exchanges of labile molecular protons with the solvent, attention will be focused on methods to improve the resolution and specificity of the method. Various acquisition modes, pulse sequences and acquisition conditions, will be introduced. On the basis of these procedures, applications geared at observing dynamic processes related to tumor progression, to biochemical metabolism and to functional stimuli, will be discussed. |
| 11:25 | Role of Molecular Dynamic Imaging in Musculoskeletal Applications |
| Mikko Nissi | |
This course part covers the applications of molecular dynamic imaging, or more precisely, MT/CEST, T2, T1rho, adiabatic T1rho and T2rho, and RAFF relaxation times in the musculoskeletal applications. The lectures will briefly cover possible musculoskeletal targets for the methods, focusing mostly on articular cartilage which is most frequently studied and affected in musculoskeletal disorders. Furthermore, the methods will be briefly overviewed with respect to the musculoskeletal application, followed by their potential uses. |
| 12:00 | Lunch & Meet the Teachers |
| 8:00 | Muscle Disorders: Diagnosis & Clinical Biomarkers |
| Pierre Carlier | |
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| 8:25 | Muscle Disorders: Emerging Biomarkers |
| Eric Sigmund | |
Outcomes/Objectives · Summarize quantitative biomarkers of skeletal muscle function (specifically relaxometry and diffusion-weighted imaging) that access novel physiologic properties · Describe the role of quantitative modeling for increased specificity · Describe examples of exercise as a controlled clinical challenge |
| 8:50 | MSK Complications of Diabetes: Present |
| Mark Schweitzer | |
1. Pathophysiology of DM 2. Why MSK system? 3. tendons 4. ligaments 5. joints 6. osteomyelitis |
| 9:10 | Self Assessment Module (SAM) |
| 9:15 | MSK Complications of Diabetes: Future |
| Prodromos Parasoglou | |
Individuals with long-standing diabetes are at high risk for developing devastating musculoskeletal complications including plantar ulcers, and Charcot arthropathy that can lead to amputation. A major obstacle for the development of effective treatments for musculoskeletal complications of diabetes is the lack of objective and reproducible tests to detect small changes in symptoms and signs seen in intervention studies. In this lecture, we will discuss how quantitative MRI methods can be help delineate the specific pathophysiological mechanisms that mediate the effectiveness of a treatment and identity patients who are responsive to an intervention. |
| 9:40 | Break & Meet the Teachers |
| 10:10 | Inflammatory Arthropathy: Present |
| Tamotsu Kamishama | |
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| 10:35 | Inflammatory Arthropathy: Future |
| Chiara Giraudo | |
This lecture is for radiologists and clinicians, technologists, and scientists interested in musculoskeletal imaging with a special focus on inflammatory rheumatic diseases. The presentation will address how we may improve the diagnostic process in adults and pediatric patients affected by this heterogeneous group of inflammatory arthropathies. It will be discussed not only how the MR protocols can be further optimized considering the constant new technological improvements but also the role of hybrid imaging applying PET/MR. Indeed, PET/MR combining specific tracers and sequences via a whole-body approach may provide simultaneously acquired metabolic, functional and anatomical information characterizing the injured areas at diagnosis and after treatment. Furthermore, the role and application of qualitative and quantitative analyses will be addressed, including the use of machine learning and the assessment of radiomics features in the era of biological therapy.In conclusion, after this presentation, the audience should have a comprehensive overview about promising novel MR and PET/MR applications and the research aspectsthat should be further investigated in inflammatory arthropathies. |
| 11:00 | Osteoarthritis: Present |
| Alissa Burge | |
Osteoarthritis is an extremely common cause of morbidity, affecting an estimated 30.8 million adults in the united states, and is cited as the 5th most common cause of disability and the most prevalent form of musculoskeletal pathology worldwide, contributing to tremendous human and economic burden. MR imaging can provide valuable information regarding a variety of characteristics relevant to the natural history of osteoarthritis, including risk factors, diagnosis and severity of disease, and complications of both disease and treatment, thereby facilitating clinical decision making. |
| 11:25 | Osteoarthritis: Future |
| Stefan Zbyn | |
Compositional MRI techniques have gained increasing attention in Osteoarthritis (OA) research over the recent years, as they allow detection of early biochemical alteration in musculoskeletal tissues prior to appearance of the morphological changes. This presentation will provide an overview of basic technical principles, biochemical correlates, recent technical developments and in vivo applications of compositional MRI techniques for early detection, monitoring and prediction of OA progression in the knee joint. |
| 11:50 | Lunch & Meet the Teachers |
| 8:00 | Basics of RF Theory, Transmission Lines & Power Transfer |
| Steven Wright | |
This talk will cover the basics of RF transmission lines and wave guidance. While two-conductor transmission lines are ubiquitous in MRI today, other forms of wave guidance are becoming increasingly popular with the emergence of high and ultra-high field MRI systems. An electromagnetic approach to transmission lines, as opposed to a circuit-theory approach, covers all cases. The talk will discuss the Smith Chart, applications of transmission lines beyond interconnects, and discuss practical issues of transmission line selection. |
| 8:30 | Volume & Surface Coils |
| Özlem Ipek | |
This talk will cover the basic theory and design of a RF coil, characterization of the RF coil on the bench including tuning, matching and quality factor with a vector network analyzer, on the scanner with B1 maps and signal-to-noise ratio measurements and electromagnetic field simulations. Various types of RF coils as well as the recent RF coil concepts will be addressed. |
| 9:00 | Multi-Tuned Coils |
| Ryan Brown | |
· Dual-tuned coils provide metabolic information (x-nuclei module) and co-registered anatomical images and B0 shim settings (1H module) without repositioning the subject or coil · X-nuclei signal strength is typically less than 1/1,000× that of 1H (1). Therefore it is important to maximize x-nuclei receive sensitivity while simultaneously providing adequate 1H sensitivity · We will discuss prevalent dual-tuning techniques and considerations for performance characterization and interfacing dual-tuned coils |
| 9:30 | Break & Meet the Teachers |
| 10:00 | Receive Arrays & Circuitry |
| Arne Reykowski | |
Transmit antennas are typically design with a strong focus on homogeneity. In contrast, receive antennas (also referredto as local coils) are optimized for high signal-to-noise ratio (SNR) within a certain region of interest (ROI) andtypically do not offer homogeneous sensitivity. |
| 10:30 | Transmit Arrays & Circuitry |
| Roberta Frass-Kriegl | |
RF transmission in MR measurements relies on RF coils, the transmit system (typically part of the MR scanner), and RF pulse design. In this educational presentation, basic principles of transmit coil arrays and related circuitry will be explained for single channel as well as multi-channel transmit systems. The potential of static B1+ shimming and full parallel RF transmission will be discussed including the aspect of more complicated safety evaluation in terms of specific absorption rate (SAR) with increased degrees of freedom. |
| 11:00 | RF Modeling |
| Bastien Guerin | |
In this talk, I will present the basics of the three main electromagnetic simulation approaches for assessment of MRI RF coils: finite difference time domain, finite element modeling and integral equations. The strengths and weaknesses of these techniques will be compared. I will introduce the co-simulation approach to fast coil analysis. Finally, I will talk about the availability of body models for each technique as well as major applications such as RF coil safety assessment, design optimization and calculation of ultimate metric bounds. |
| 11:30 | Lunch & Meet the Teachers |
| 13:30 | RF Coils & Materials at High Fields |
| Andrew Webb | |
This talk concentrates on the similarities and differences in designing RF coils for high field MRI. In particular the effects of sample loading, coil losses, coil decoupling, travelling wave effects and near field/far field effects are considered. Examples of loop, dipole and combined loop/dipole configurations are shown. Finally the role of high permittivity materials, alone or in combination with high field MRI coils is discussed. |
| 14:00 | Emerging Technologies: Flexible, Lightweight, Optical & Wireless |
| Fraser Robb | |
Phased coil arrays have changed dramatically since their earliest inception with increasing complexity and channel density. These changes have led to the development of an innovative fully flexible coil design with highly integrated electronics, which can be placed easily within todays modern coil arrays to reduce the design complexity associated with the large number of channels. Recently, research has been done to improve the interface between RF coils and MRI systems by transferring the data over wireless or optical connections within the scanner bore. The evolution of all of these new technologies can provide a fully wireless, or lightly tethered, future for coil arrays and allow potential the realization of a patient-friendly phased array. |
| 14:30 | Break & Meet the Teachers |
| 15:00 | Live Construction of Receive Arrays |
| Kyle Gilbert | |
This course will focus on the construction of a four-channel receive array for small-animal imaging at 9.4 T. Although this demonstration is geared toward a specific application, the construction methods are applicable to receive arrays for both humans and animals, and with any number of elements. The demonstration will cover the basic steps of constructing a receive array: the design of a former, tuning and matching, preamplifier decoupling, active detuning, geometric decoupling, and cable management. This course is intended for the student, technician, or researcher who wants to learn the basic steps on how to build a receive array. |
| 15:00 | Live Construction of Receive Arrays |
| Omer Oran |
| 16:00 | Adjournment & Meet the Teachers |
| 8:00 | Basic CNS Fluid Physiology |
| Andreas Linninger | |
Keywords: cerebrospinal fluid flow, intrathecal drug delivery, intracranial dynamics, |
| 8:25 | Interacting Fluid Compartments of the Central Nervous System: A Holistic Mathematical Modelling Approach |
| Eleuterio Toro | |
We first describe all major fluid compartments of the central nervous system, their connections and their relevance to understand some neurological diseases. We then present a full-body, global mathematical model for the fluid dynamics includind heart, pulmonary circulation, respiration, arterial and venous trees, miscrovasculature, brain parenchyma and cerebrospinal fluid, We outline the equations and algorithms to solve these on a computer to produce subject-specific predictions. Validation of predictions against MRI measurements and is presented. We then apply the methods to study intra and extracranial venous outflow anomalies and their impact on cerebral haemodynamics in terms of increased intracranial pressure, reverse flow, altered shear stresses, altered fluid transport, altered perfusion. |
| 8:50 | Role of Fluid Dynamics in Neurological Diseases |
| E. Mark Haacke |
| 9:15 | MR Imaging of CSF Spaces |
| Shigeki Yamada | |
We have studied how to visualize “neurofluids” three-dimensionally by using transparency and perspective technologies with shading and texture mapping from volumetric magnetic resonance imaging. The mean volume of the intracranial cerebrospinal fluid (CSF) in healthy individuals aged ≥70 years was estimated at more than 300 mL. CSF movement with cardiac pulsation was reduced with increasing age, although the dynamics of neurofluids has not been elucidated. By developing fluid dynamics-related technology, the 3D movement of CSF can be measured quantitatively. CSF dynamic theory has been renewed; the CSF does not exhibit unidirectional bulk flow and moves in a pulsatile fashion. |
| 9:40 | Break & Meet the Teachers |
| 10:10 | Mechanisms of Brain Drain: Glymphatics |
| Helene Benveniste | |
The glymphatic system (GS) is described as a perivascular transit passageway for cerebrospinal fluid (CSF) and interstitial fluid exchange that facilitate metabolic waste drainage from the brain in a manner dependent on aquaporin 4 (AQP4) water channels on glial cells and vascular pulsatility. In this presentation I will present the fundamentals of the GS concept (including current controversies) and focus on MRI methods to quantify GS transport in normal and diseased brain. Evidence for its existence in human brain will also be highlighed. |
| 10:35 | Drainage of fluids from the brain |
| Roxane Carare | |
Interstitial fluid of the brain drains along the walls of capillaries and arteries as intramural periarterial drainage (IPAD). This process fails with ageing and possession of APOE4 genotype, resulting in cerebral amyloid angiopathy (CAA). There is convective influx/glymphatic entry of cerebrospinal fluid (CSF) along the pial glial basement membranes into the brain parenchyma. |
| 11:00 | From Magnetic Resonance to Mathematical Models for Flow Dynamics |
| John Vardakis |
| 11:25 | Imaging Brain Lymphatics |
| Toshiaki Taoka | |
In recent years, mass transport system in the brain by cerebrospinal fluid or interstitial fluid has been clarified from the researches until now. Glymphatic system is the waste clearance pathway system by cerebrospinal fluid through perivascular space and interstitial space in the brain. To visualize or evaluate the waste clearance system of the brain, tracer studies are mostly applied and findings on the system has been accumulated. There are several approaches other than tracer studies to evaluate the dynamics of the interstitial fluid within the brain including diffusion images. Findings from these studies will be discussed in this lecture. |
| 11:50 | Lunch & Meet the Teachers |
| 8:00 | Contrast Agents |
| Tim Leiner |
| 8:30 | Non-Contrast Enhanced |
| Mitsue Miyazaki | |
Various established non-contrast enhanced MRA techniques such as time-of-flight (TOF), quiescent interval single-shot (QISS), fresh blood imaging (FBI), and a flow-in spin labeling are discussed with their characteristic features. In addition, recent on-going research techniques are introduced such as flow-sensitive dephasing (FSD), velocity-selective inversion preparation with 3D bSSFP, radial QISS, and radial fast interrupted steady-state (FISS). |
| 9:00 | Contrast-Enhanced |
| Jeremy Collins | |
Contrast-enhanced MR angiography is an adaptable imaging technique that can be tailored to the clinical question posed. CE-MRA relies on subtracted and unsubtracted techniques applied to single station, multi station, and time-resolved CE-MRA. CE-MR Angiography is considered a reference standard for arterial evalation. More recent developments rely on imaging in the steady state with ECG-gating, applying acceleration schema to shorten imaging time without compromising the spatial resolution. |
| 9:30 | Flow Hemodynamics |
| Susanne Schnell | |
Phase contrast MRI and its utilization to measure blood flow will be explained. Spins that move during an MRI acquisition exhibit different imaging characteristics compared to stationary spins. Flowing spins, for example from flowing blood, appear as an artifact in the image. However, by understanding these characteristics of flowing spins, their appearance can be utilized for angiographic purposes. 2D Phase contrast imaging is sensitized to flow by using a series of bipolar gradients to affect the phase signal of spins that flow with a uniform velocity in the direction parallel to the gradients. By utilizing ECG gating, blood flow velocities can be measured in a time-resolved manner. 2D phase contrast can be extended to a time-resolved 3D volume acquisition with 3-directional velocity encoding, which is called 4D flow MRI. This encoding of velocity enables quantification of flow hemodynamics. Furthermore, some potential sources of error will be discussed, such as misalignment of flow, velocity aliasing and phase offset errors. |
| 10:00 | Break & Meet the Teachers |
| 10:30 | Supraaortic & Intracranial |
| Bum Soo Kim | |
This talk will describe the sequences used for MRA of intracranial and supraaortic vessels, and clinical application to cerebrovascular diseases, focusing on the contributions that MRA can make to diagnosis and follow-up. |
| 11:00 | Chest & Abdominal |
| Mark Schiebler | |
This syllabus and the accompanying slides serve as an introduction to the use of pulmonary MRA for the primary diagnosis of pulmonary embolism. It is our hope that you will be able to start up a program at your institution based on this information. |
| 11:30 | Peripheral |
| Trisha Roy | |
This peripheral arterial educational session will review the pathophysiology and management of peripheral arterial disease, current imaging modalities, gaps in knowledge and opportunities for MRI to address the many remaining questions in this field. |
| 12:00 | Lunch & Meet the Teachers |
| 8:00 | RF Excitation & Parallel Transmission |
| William Grissom | |
RF excitation is a necessary ingredient to all pulse sequences. This lecture will introduce common RF pulse types, the mechanics behind their function, and practical uses for them. The goal of this lecture is to give the pulse sequence designer the knowledge necessary to make appropriate RF pulse selections in a wide variety of applications. |
| 8:30 | Signal Generation & Spatial Encoding |
| David Higgins | |
Basic MR physics will be reviewed, to provide a foundation for discussion of more advanced concepts in the course. The process of spatial encoding of the MR signal, from signal generation to image reconstruction, will be described. The the information content of k-space will be illustrated and discussed. Routine adjustments which are made to k-space data will be introduced. |
| 9:00 | Encoding Basic Physiological Processes into the MRI Signal: Motion & Flow |
| Pelin Aksit Ciris | |
MRI can be used to non-invasively encode and quantify different biophysical aspects of tissue including flow and motion. In this presentation, we will review methods that generate motion related image contrast, through manipulation of longitudinal magnetization prior to excitation, such as Time-of-flight MR Angiography, Arterial Spin Labeling, Myocardial Tagging; as well as through manipulation of transverse magnetization between excitation and acquisition, such as Phase Contrast MR Angiography, Diffusion Imaging, and MR Elastography. |
| 9:30 | Break & Meet the Teachers |
| 10:00 | Single-Shot Sequences |
| Xiaohong Joe Zhou | |
Single-shot pulse sequences are a class of sequences that can rapidly traverse k-space in a single repetition time (TR), producing sufficient k-space data for image reconstruction. In this lecture, we will highlight four single-shot pulse sequences, including echo planar imaging (EPI), turbo-spin echo (TSE) or fast spin echo (FSE), gradient and spin echo (GRASE), and spiral. For each pulse sequence, we will describe the spin physics involved, discuss several “tricks” in practical implementation, present strategies to mitigate image artifacts, and provide examples in clinical and research applications. |
| 10:30 | Multi-Shot & Multi-Echo Techniques |
| Daniel Herzka |
| 11:00 | Faster & Higher Quality MRI Through Tailored Undersampling |
| Kawin Setsompop | |
Various image reconstruction approaches (e.g. parallel imaging, CS, ML) have been developed to enable k-space under-sampling. Optimal performance for these reconstruction approaches at high accelerations requires a tailored sampling scheme. In this course, we will examine these sampling strategies and how to adopt them effectively in a wide variety of imaging sequences under various constraints. Insights on how to flexibly take advantage of the undersampling for either scan time reduction and/or artifact mitigation will be discussed. Examples will be provided to demonstrate the benefit of a synergistic design approach on sampling, sequence, and reconstruction. |
| 11:30 | Lunch & Meet the Teachers |
| 8:00 | Bloch Simulation & Pulse Sequences Tools |
| Maxim Zaitsev |
| 8:25 | Designing Reusable Software Components for Computational MRI |
| Martin Uecker | |
Computational techniques play an important part in the development of new methods for Magnetic Resonance Imaging (MRI). Based on our experience developing software for computational MRI, this talk will explain how to develop reusable software components that preserve our scientific knowledge in a reproducible, useful, and sustainable way. |
| 8:50 | Usinig cloud computing for exploration and scale |
| Eric Jonas | |
The rise of “cloud computing” offerings has enabled many recent advances in data science, simulation, and data analytics. Current cloud providers offer a previously-unimaginable combination of scale, storage, and compute capabilities but it can be difficult for a newcomer to navigate the ecosystem. This tutorial session is targeted at developers and users who have not used cloud computing infrastructure before, or have only recently started experimenting. I will outline the offerings from the various providers, compare and contrast their capabilities, and show how they can enable rapid experimentation and analysis at very low cost. I will highlight several open-source projects, developed by my research group and others, to make this onboarding process easier. I will point out some common pitfalls from migrating existing workloads to the cloud, and suggest means of avoiding them. |
| 9:15 | Open-Source Reconstruction Systems |
| Adrienne Campbell-Washburn | |
This talk will summarize the features of open source MR image reconstruction software projects and provide illustrative examples of software usage. |
| 9:40 | Break & Meet the Teachers |
| 10:10 | MRiLab: Realistic MRI Simulations Based on Parallel Computing & Generalized Tissue Model |
| Fang Liu |
| 10:18 | JEMRIS: A General-Purpose MRI Simulator |
| Daniel Pflugfelder |
| 10:27 | The KSFoundation Abstraction Layer for EPIC |
| Stefan Skare |
| 10:35 | gammaSTAR: Platform-Independent MR Sequence Development |
| Cristoffer Cordes |
| 10:43 | Live Cross-Vendor Sequence Programming with Pulseq |
| Maxim Zaitsev |
| 10:52 | RF & Gradient Optimization Tools |
| John Pauly |
| 11:00 | Yarra Framework: Open-Source Toolkit for Clinical-Translational MRI Research |
| Roy Wiggins |
| 11:08 | Automated Reconstruction Handling |
| Eric Borisch |
| 11:17 | MRIReco.jl: An Extensible Open-Source Image Reconstruction Framework Written in Julia |
| Tobias Knopp |
| 11:25 | BART Reconstruction Toolbox / Iterative Reconstruction Toolbox in Python |
| Jonathan Tamir |
| 11:33 | Gadgetron |
| Hui Xue |
| 11:42 | GPILAB |
| Nicholas Zwart |
| 11:50 | Lunch & Meet the Teachers |
| 13:30 | Hands - On Demonstrations |
| 16:00 | Adjournment & Meet the Teachers |
| 8:00 | ASL Acquisition methods |
| Luis Hernandez-Garcia | |
This segment of the course will introduce the audience to the main varieties of arterial spin labeling schemes, as well as the practical considerations and options for image readouts. The technical details and practical considerations for implementation will be discussed from an engineering point of view. |
| 8:25 | ASL: Analysis |
| Laura Parkes | |
ASL acquisition produces perfusion-weighted images through the subtraction of label and control images. These may be collected at a single post-labelling delay time or at multiple delay times. How do we extract quantitative CBF from these subtraction images? Quantification is important as the signal in the perfusion-weighted images will be affected by parameters other than blood flow, principally arterial transit time, labelling efficiency and the T1 and equilibrium magnetisation of blood. These may vary on an individual and/or regional basis. In this talk I will describe the most widely used method for quantification (Alsop et. al. 2015) and explain which parameters are most important for CBF accuracy. |
| 8:50 | ASL: Advances |
| Lirong Yan | |
Multiple physiological parameters other than CBF can be derived from ASL signal when the magnetically labeled blood passes through arterial trees and freely diffuses across the blood-brain barrier in capillaries, such as dynamic MR angiography, arterial cerebral blood volume (aCBV), vascular compliance (VC), and water permeability. This lecture will cover these recently developed advanced ASL techniques. |
| 9:15 | ASL: Reproducibility, Multi-Site & Validation |
| Henk Mutsaerts | |
This lecture focuses on the reproducibility of arterial spin labeling (ASL). Several interconnected factors influence the reliability of ASL. Mainly, investigators should strive to keep sequence parameters as identical as possible between different ASL datasets, whether this concerns a single-center scanner software update or pooling of different multi-center ASL datasets. Second, the consistency of ASL quantification parameters between sequences should be validated, for which the ASL-BIDS format is introduced. Third, it is important to acknowledge how (patho-)physiology determines the reliability of ASL. Finally, the definition of ASL image quality and recognition of artifacts should be standardized. |
| 9:40 | Break & Meet the Teachers |
| 10:10 | DSC-MRI: Acquisition |
| Jerrold Boxerman | |
DSC-MRI has been used in the brain since the early 1990s, (1,2) with multiple applications to gliomas, including treatment response assessment. (3) However, incorporation into multi-center clinical trials has been limited. This presentation briefly summarizes DSC-MRI acquisition methodology; the need for standardizing DSC-MRI for multi-site trials, as illustrated by application to pseudoprogression (PsP) and pseudoresponse (PsR); (4-6) and ongoing efforts to achieve this goal. |
| 10:35 | DCE-MRI: Acquisition |
| Chad Quarles | |
The overall purpose of this educational lecture is to discuss conventional and state-of-the-art acquisition methods for DCE-MRI. Topics will include protocol design informed by contrast mechanisms, sensitivity and spatiotemporal demands and advances in DCE-MRI acquisition methods based on technological advances (e.g. novel sampling schemes) and designed to enhance sensitivity to a greater range of physiologic properties. |
| 11:00 | DSC-MRI: Analysis |
| Ona Wu | |
Learn how to make perfusion maps and understand potential confounds. |
| 11:25 | DCE-MRI: Analysis |
| Linda Knutsson | |
This educational presentation gives an overview how to analyse data obtained from a Dynamic Contrast Enhanced (DCE) MRI experiment in order to retrieve perfusion and/or perfusion-related parameters. |
| 11:50 | Lunch & Meet the Teachers |
| 13:30 | Congenital Anomaly |
| Aki Kido | |
Müllerian duct anomalies (MDAs) are broad spectrum of developmental anomalies and its classification system is proposed by American Society for Reproductive Medicine. Ultrasound and Hysterosalpingography are the initial modalities, but MRI is superior by its high soft tissue contrast and multiplanar imaging capabilities. Accurate classification of MDAs is important as surgical treatment may varies among MDA subtypes. In this lecture, each type of MDAs are overviewed with embryological aspect and imaging findings will be explained with actual cases with MR images. |
| 13:50 | Cervical & Endometrial Cancer |
| Caroline Reinhold | |
This presentation will review the role of MRI in the staging of endometrial and cervical carcinoma, present the 2018 FIGO staging updates for cervical carcinoma, review the imaging protocol and briefly present future directions. |
| 14:10 | Acute Gynecologic Disease |
| Victoria Chernyak | |
This presentation will review MRI appearance of acute gynecologic conditions, both in pregnant and nonpregnant patients. |
| 14:25 | Self Assessment Module (SAM) |
| 14:30 | Endometriosis |
| Nicole Hindman | |
Endometriosis is a common but occult cause of chronic pelvic pain in women. Being able to recognize the appearance and spectrum of endometriosis, particularly deep infiltrating endometriosis, on MR imaging offers incredible value to referring physicians. This talk will review the typical and unusual appearances of deep infiltrating endometriosis on MRI. |
| 14:50 | Break & Meet the Teachers |
| 13:30 | Sports Injuries: Present |
| Haron Obaid | |
This talk will focus on MRI imaging techniques as related to sports injuries, role of MRI in sports imaging-problem solving tool, pitfalls and limitations of MRI in sports imaging. There will be a review of imaging findings of common injury patterns affecting the tendons, ligaments, cartilage, muscles and bones. |
| 13:55 | Sports Injuries: Advanced Imaging Methods for Injuries to Short-T2 Tissues |
| Ashley Williams | |
Sprains, strains, tears and stress fractures are unfortunately common occurrences in athletes and weekend warriors alike. Detection and quantitation of subtle and, in some cases, subclinical damage to short-T2 tissues using advanced MRI methods, like ultrashort echo time (UTE) and zero echo time (ZTE) imaging, may help to guide the clinical management of injured patients as they recover and return to sport. Audience members will be introduced to common sports injuries involving short-T2 tissues and new and upcoming MRI techniques to diagnose, stage, and monitor tissue injury and recovery by assessing short-T2 tissue properties. |
| 14:20 | Break & Meet the Teachers |
| 14:50 | Osteonecrosis & Osteochondrosis: Present |
| Mihra Taljanovic | |
This talk reviews the pathophysiology, clinical findings, imaging findings and treatment options of epiphyseal osteonecrosis, bone infarcts and various types of osteohondroses with emphasis on magnetic resonance imaging (MRI). Specifically, osteonecrosis of the femoral head, humeral head, talar dome, lunate and proximal scaphoid pole will be discussed. Steinberg modified FICAT classification of the femoral head osteonecrosis and Lichtman staging of Kienbock Disease will be presented in tables. Following osteochondroses will be addressed: Legg-Calvé-Perthes disease, osteochondritis dissecans (OCD), osteochondrosis of the capitellum (Panner disease), Blount disease (tibia vara) Osgood-Schlatter disease, Sinding-Larsen-Johansson disease (jumper’s knee), Freiberg infraction, Köhler disease and Scheuermann’s disease. |
| 15:15 | Osteochondrosis & Osteonecrosis: Future Musculoskeletal Imaging Applications for Pediatric and Young Adult Patients |
| Jutta Ellermann | |
Advanced qualitative and quantitative MRI methods can be utilized to study unique aspects of the developing skeleton that are important for diagnosis and better treatment of musculoskeletal diseases of pediatric and young adult patients. |
| 15:40 | Adjournment & Meet the Teachers |
| 13:30 | The WHO 2016 Classification of Brain Tumors |
| Ulrike Löbel | |
Major restructuring occurred in the 2016 classification of brain tumors. All diffuse astrocytic and oligodendroglial tumors are now grouped together and oligodendrogliomas are defined by a 1p/19q-codeletion. The new entity of diffuse midline glioma predominates in children and is characterized by a very poor outcome. Within the group of embryonal tumors, the current classification defined medulloblastoma WNT–activated and medulloblastoma SHH–activated as tumor entities and the new entity of embryonal tumour with multilayered rosettes (ETMR), C19MC-altered was defined. On the other hand, the term primitive neuroectodermal tumor (PNET) was removed from the tumor classification. |
| 13:55 | Use of Intraoperative MRI for Improvement of Neurosurgical Intervention |
| Akira Matsumura | |
Intraoperative MRI (i-MRI) is a powerful tool in improving the surgical intervention for brain and skull base surgery. We would like to share our experience of tha advantage of using i-MRI for better treatmet results. |
| 14:20 | Spinal Cord Tumors |
| Carlos Torres |
| 14:45 | Break & Meet the Teachers |
| 15:15 | Pediatric Tumors |
| Benita Tamrazi | |
Advanced imaging of pediatric brain tumors will be discussed with emphasis on clinical scenarios. |
| 15:35 | Self Assessment Module (SAM) |
| 15:40 | Radiomics in Gliomas |
| Yoon Seong Choi |
| 16:05 | Molecular Imaging |
| Georges El Fakhri |
| 16:30 | Tumor Therapy |
| Marco Essig | |
Brain tumours are among the top causes of cancer related deaths both in Europe and North America. The goals and requirements for neuroimaging in brain tumours are multiplex and involve making a diagnosis and a differential diagnosis, while accurate lesion grading is needed in the case of the overall patient management. Imaging is also involved in the decision-making process for therapy and later for precise planning of surgical or radio-therapeutic interventions. After therapy neuroimaging techniques have shown to be mandatory for monitoring of disease and detection as well as management of possible therapy related side effects. |
| 16:55 | Adjournment & Meet the Teachers |
| 13:30 | Cardiac Physiology & Electrophysiology: Beginners' Guide |
| Saman Nazarian | |
Summary slide set for Dr. Nazarian's talk on: "CARDIAC MR: LINKING PHYSIOLOGY TO IMAGING". |
| 13:55 | Cardiac & Myocardial Function |
| Ru San Tan | |
Cardiac MR images contain rich 4-D spatio-temporal information that have been largely unexploited in routine image interpretation. Feature-tracking as well as other novel post-acquisition analyses of these images have potential to yield clinical meaningful readouts that can allow detailed dissection of heart chamber global and regional, systolic and diastolic, function. |
| 14:20 | Imaging of Myocardial Perfusion & Scar |
| Kate Hanneman | |
Imaging of Myocardial Perfusion & Scar |
| 14:45 | Break & Meet the Teachers |
| 15:15 | Advanced Contrast Mechanisms: Diffusion & DTI of the Heart |
| Christopher Nguyen | |
Diffusion MRI is powerful tool to interrogate the myocardial microstructure revealing fiber architecture. Technical advances in the past 5 years have enabled in vivo free breathing diffusion MRI of the heart and is primed to make new discoveries in patient populations as an orthogonal quantitative tool alongside conventional methods such as relaxometry mapping and function. |
| 15:35 | Self Assessment Module (SAM) |
| 15:40 | Augmented Intelligence & Radiomics in Cardiac MRI |
| Bettina Baessler | |
Augmented intelligence and radiomics will play an important role in future cardiac MR. Techniques like machine learning or deep learning will influence all aspects of cardiac MR, from patient management and workflow over image acquisition and reconstruction up to image analysis and prognostic assessment. This presentation will focus on current applications of AI and radiomics in cardiac MR and address the limitations of these techniques before their integration into routine clinical practice becomes reality. |
| 16:05 | Benefits & Challenges of Cardiac Relaxometry |
| Donnie Cameron | |
Cardiac relaxometry permits quantitative characterisation of myocardial tissue. Over the past fifteen years, it has grown from obscure research method to routine clinical tool, offering strong diagnostic and prognostic utility in some conditions. The goals of this session are to: (i) outline the key benefits of cardiac relaxometry methods with respect to clinical applications; (ii) describe the methodological details of cardiac relaxometry techniques, including T1, T2, T2*, and T1-rho mapping; and (iii) summarise current pitfalls of relaxometry methods in terms of acquisition, processing, and interpretation. |
| 16:30 | Adjournment & Meet the Teachers |
| 13:30 | Spatial Encoding & Direct Inversion of Cartesian & Non-Cartesian Data |
| Nicole Seiberlich |
| 13:55 | Parallel Imaging |
| Tolga Cukur | |
A brief survey of the fundamental approaches to parallel imaging will be presented, followed by recent application to multi-acquisition or multi-parametric MRI. |
| 16:05 | Compressed Sensing |
| Jonathan Tamir | |
Compressed sensing takes advantage of sparsity, incoherent sampling, and non-linear reconstruction algorithms to reduce acquisition requirements far below the Nyquist rate. This talk will provide an overview of these concepts and show how they can be used to accelerate MRI. Compressed sensing MRI examples will be discussed, including its combination with parallel imaging and application to dynamic imaging. |
| 14:45 | Break & Meet the Teachers |
| 14:20 | Low Rank Plus Sparse Reconstruction |
| Jong Chul Ye | |
In this course, we will review the recent MR researches using low rank and sparse reconstruction. First, basic compressed sensing theory for MR reconstruction method is first reviewed, after which the low-rank image model is described. Finally, sparse + low rank model is introduced as an novel image modeling for accelerated MRI and artifact removal. |
| 15:15 | Using Machine Learning for Image Reconstruction |
| Florian Knoll | |
This talk will provide an introduction to the use of machine learning and convolutional neural networks (CNNs) in the area of MR image reconstruction from undersampled acquisitions. We will discuss approaches that are based on iterative reconstruction methods that are commonly used in compressed sensing (CS) as well as purely data driven approaches. Using selected examples, we will discuss both advantages and challenges, covering topics like reconstruction time, design of the training procedure, error metrics and training efficiency and validation of image quality. |
| 15:40 | Practical Implementation of Efficient Off-Line Image Reconstruction Pipelines |
| Hui Xue |
| 16:30 | Adjournment & Meet the Teachers |
| 13:30 | How the Brain Is Connected |
| David Van Essen | |
Recent studies of long-distance connections in the cerebral cortex reveal that they are remarkably complex, but major insights have been learned using anatomical tracers in monkeys and mice and noninvasive neuroimaging in humans and monkeys. |
| 13:55 | Introduction to Functional Connectivity |
| Zhongming Liu | |
This talk will serve as an introduction to functional connectivity. The primary focus is on spontaneous brain activity observed with functional magnetic resonance imaging. In this talk, I will cover the origins of resting state fMRI signals, analysis methods to map large-scale functional brain networks based on fMRI (or MEG/EEG), dynamics of functional connectivity, variation of functional connectivity across brain states, diseases, or individuals, as well as some recent work of using deep learning to map or analyze functional connectivity. |
| 14:20 | Introduction to Structural Connectivity |
| Maxime Descoteaux | |
Introductory course for people seeking to learn about the fundamental of structural connectivity and building the “connectome” using diffusion MRI tractography. |
| 14:45 | Break & Meet the Teachers |
| 15:15 | Connectomics: Data Analysis |
| Sarah Genon | |
Connectomics analyses play a major role in our understanding of the human brain organization and function. In this talk, I will present the concepts, methods |
| 15:40 | Linking Structural & Functional Connectivity: Methods & Modeling |
| Richard Betzel | |
The human brain can be modeled as a set of white-matter fibers (structural connectivity; SC) that constrain inter-regional interactions and shape the correlation structure of brain activity (functional connectivity; FC). Though SC and FC capture distinct connectional modes, they can both be modeled as networks. Understanding their relationship to one another is critical for if we wish to deepen our knowledge of the role networks place in cognition, health, and development. In this talk I will review current approaches for linking SC with FC, emphasizing that there exists a spectrum of approaches, each suited for answering specific research questions. |
| 16:05 | Multimodal Fusion: Exploiting links among enriched types of imaging, cognitive and behavioral information |
| Jing Sui | |
Psychiatric imaging is struggling with identifying robust biomarkers. Existing approaches do not fully leverage the power of multimodal data, despite evidence that such information is highly informative. We will draw on advances and ideas from fields of supervised learning，data fusion and deep learning, to capture rich information from imaging, cognitive, behavioral and genetic data, in order to integrate a whole picture to deepen our understanding of neural mechanism of cognitive impairment, and to identify replicable biomarkers that are able to predict individual clinical measures and help for differential diagnosis and intervention. |
| 16:30 | Adjournment & Meet the Teachers |
| 15:20 | Rectal Cancer Staging |
| Akira Furukawa | |
MRI diagnosis of rectal cancer will be reviewed regarding 1) Anatomy of the rectum and per-rectal structure, 2)MR imaging technique for preoperative assessment of rectal cancer, 3) Important MR findings in preoperative assessment of rectal cancer, 4) Diagnostic accuracy of MR in rectal cancer. |
| 15:40 | Rectal Cancer Post-Treatment Assessment |
| Gina Brown | |
TARGET AUDIENCE Radiologists with an interest in cancer imaging who would benefit from: · Understanding the role of high-resolution MRI reassessment following chemoradiotherapy. · How this information can improve outcomes by providing important prognostic and therapeutic information. |
| 16:00 | Perianal Fistula MRI |
| Mukesh Harisinghani | |
MRI is |
| 16:20 | MR Enterography |
| Jonathan Dillman | |
MR enterography is critical to the diagnosis and continued assessment of children and adults with Crohn’s disease. In this talk, we will review how radiologists can maximize value when performing MR enterography through: 1) Standardized reporting, including meaningful impression statements, 2) Accurate assessment of intestinal inflammatory activity and therapy response, and 3) Detection and accurate characterization of Crohn’s disease-related complications and extra-intestinal manifestations. |
| 16:40 | Adjournment & Meet the Teachers |
| 17:00 | Welcome |
| Pia Maly Sundgren |
| 17:30 | My Life in Magnetic Resonance: Sense & Serendipity |
| Peter van Zijl |
| 7:00 | fMRI Applications in Brain Diseases |
| Nicolas Ramsey |
| 7:30 | fMRI in Surgical Planning |
| Joshua Shimony |
| 8:00 | Adjournment |
| 7:00 | ASL: Technique |
| Matthias J.P. van Osch |
| 7:30 | Clinical Applications of ASL in the Brain |
| Marion Smits |
| 8:00 | Adjournment |
| 7:00 | Understanding & Selecting Acquisition Methods for 23Na or 39K-MRI |
| Guillaume Madelin |
| 7:30 | Clinical Applications of 23Na-MRI |
| Matilde Inglese |
| 8:00 | Adjournment |
| 7:00 | Basic Brain MRI Methods |
| Kevin Chan |
| 7:30 | Advanced Brain MRI: Functions & Circuits |
| Joanes Grandjean |
| 8:00 | Adjournment |
| 7:00 | Beyond the Phenemenological Single Compartment Model |
| Sean Deoni |
| 7:30 | Implementation Considerations in Relaxometry |
| Martina Callaghan |
| 8:00 | Adjournment |
| 7:00 | New Developments in Coils for Cardiovascular MR |
| Martijn Froeling |
| 7:30 | Opportunities of Low-Field MR |
| Rizwan Ahmad |
| 8:00 | Adjournment |
| 7:00 | Machine Learning: Research Perspective |
| Fang Liu |
| 7:30 | Machine Learning: Clinical Perspective |
| Richard Kijowski |
| 8:00 | Adjournment |
8:15
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Physicist's Perspective: Reduction of Imaging for Value in MRI | |
1Mayo Clinic, United States |
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MRI technology is extremely powerful but relatively expensive, somewhat unreliable, complex to operate, and (thus) often poorly utilized. While most institutions attempt to optimize MRI for specific use cases, the variations in “optimal” protocols across institutions (and radiologists) reflect a lack of objective criteria for diagnosis. Arguably, even the standardization of exam slot times reflects institutions’ need for efficient scheduling, rather than optimal allocation of resources to individual patient care. This all presents great opportunity for increasing the impact of MRI on patient care while simultaneously reducing the cost of healthcare with more efficient, targeted, accurate and actionable diagnostic scans. |
8:45
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Radiologist's Perspective: Reduction of Imaging for Value in MRI | |
9:15
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Radiographer's Perspective: Reduction of Imaging for Value in MRI | |
1Austin Health, Australia |
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MRI is of high diagnostic value but it is historically slow and expensive. Reducing imaging can diminish these obstacles and create value through access. Advances in technology and working smarter with existing resources can significantly reduce examination times. Improved access to imaging and better patient tolerance of examinations will see MRI become a front line imaging modality. As more patients benefit from quicker diagnosis, timely treatment and better outcomes the clinical demand for MRI will only continue to grow. The ongoing challenges within this field will be maintaining adequate levels of patient care and Radiographer job satisfaction |
9:45
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Neurosurgeon's Perspective: Reduction of Imaging for Value in MR | |
1Sainte Justine University Hospital, Montreal, QC, Canada |
10:15
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Adjournment |
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Pitch: 8:15 Poster: 9:15 Plasma 1
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FEV1/FVC Mapping with Dynamic MRI - A New Regional Lung Function Test |
1Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany, 2Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany |
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Pulmonary function parameters like the ratio of expiratory volume in one second (FEV1) and forced vital capacity (FVC) are the current gold standard for disease diagnosis and monitoring. However, early disease detection remains limited due to missing regional information. In this study the forced expiratory maneuver was captured with a dynamic MRI acquisition, as used in Fourier decomposition or phase-resolved functional lung imaging (PREFUL), for FEV1/FVC mapping. Results were compared with spirometry, PREFUL and hyperpolarized MRI in four healthy subjects and one patient with cystic fibrosis and suggest a potentially increased sensitivity in comparison with the tidal breathing approach. |
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Pitch: 8:15 Poster: 9:15 Plasma 2
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3D Magnetic Resonance Spirometry |
1IR4M, CNRS, Orsay, France, 2IR4M, Univ. Paris-Sud, Orsay, France, 3IR4M, Université Paris-Saclay, Orsay, France, 4Applications & Workflow, GE Healthcare, Buc, France, 5Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States |
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Spirometry is a routine tool in pulmonology to challenge lung function. It is sensitive and specific to several common lung diseases. Nevertheless, spirometry provides a global measurement at the mouth that only characterizes the pulmonary response as a whole, and cannot specifically address regional affections. We developed a 3D MRI-based technique to non-invasively perform local spirometry throughout the lung. The final outcome is a 3D map with voxel-wise flow-volume loops over the organ. The potential of this technique is demonstrated by its sensitivity to normal, thoracic, and diaphragmatic breathings and its related regional specificity in a healthy subject. |
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Pitch: 8:15 Poster: 9:15 Plasma 3
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Improved lung imaging and oxygen enhancement at 0.55T |
1National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States |
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Signal dephasing at high field and low proton density, has limited the use of MRI for lung imaging. We revisit the problem, using a low field (0.55T) scanner which, due to low magnetic susceptibility, improves the signal at air-tissue boundaries like lung. Moreover, because oxygen has increased r1 relaxativity at low field, oxygen inhalation can be used to significantly increase lung signal at 0.55T. Combined, these advantages makes lung MRI lucrative at low field. In this abstract we demonstrate oxygen-enhanced lung MRI at 0.55T in healthy volunteers and Lymphangioleiomyomatosis (LAM) patients. |
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Pitch: 8:15 Poster: 9:15 Plasma 4
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Using 129Xenon MR Imaging and Spectroscopic Signatures to Differentiate Pulmonary Arterial Hypertension from Other Cardiopulmonary Diseases |
1Biomedical Engineering, Duke University, Durham, NC, United States, 2Center for In Vivo Microscopy, Duke University, Durham, NC, United States, 3Department of Medicine, Duke University Medical Center, Durham, NC, United States, 4Electrical and Computer Engineering, Duke University, Durham, NC, United States, 5Radiology, Duke University Medical Center, Durham, NC, United States, 6Biostatistics & Bioinformatics, Duke University Medical Center, Durham, NC, United States, 7Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, NC, United States |
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This work sought to identify a non-invasive means to detect pulmonary arterial hypertension (PAH). 129Xenon MRI and dynamic spectroscopy were acquired in healthy volunteers and subjects with chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), left heart failure (LHF), and PAH. COPD was differentiated from PAH by increased ventilation and barrier defects, while IPF was differentiated by increased barrier uptake. PAH and LHF subjects had similar imaging features but could be differentiated by their RBC signal oscillation amplitudes. 129Xe MR imaging and spectroscopy appears capable of differentiating PAH from COPD, IPF, and LHF. |
| 5
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Pitch: 8:15 Poster: 9:15 Plasma 5
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Hyperpolarised xenon-129 MR spectroscopy and diffusion-weighted xenon-129 MRI at baseline in patients with interstitial lung disease |
1The University of Sheffield, Sheffield, United Kingdom, 2Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, United Kingdom, 3The University of Manchester, Manchester, United Kingdom, 4The University of Manchester NHS Foundation Trust, Manchester, United Kingdom, 5Bioxydyn Ltd, Manchester, United Kingdom |
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Preliminary findings are presented from a prospective, longitudinal, multicentre MRI biomarker study of patients presenting with interstitial lung disease (ILD) including drug induced ILD, hypersensitivity pneumonitis, idiopathic pulmonary fibrosis and connective tissue disease ILD. At the time of writing, 27 patients have undergone baseline hyperpolarised xenon-129 (129Xe) MR spectroscopy (MRS) and 129Xe diffusion-weighted MRI. Our findings suggest significant differences in mean 129Xe apparent diffusion coefficient between the ILD subtypes at baseline but no significant differences in the red blood cell / tissue plasma ratio from dissolved 129Xe MRS. We also demonstrate correlation between pulmonary function tests and 129Xe MRI measures. |
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Pitch: 8:15 Poster: 9:15 Plasma 6
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Comparison of Phase-Resolved Functional Lung (PREFUL) MRI and Hyperpolarized 129Xe MRI in Pediatric Cystic Fibrosis |
1Translational Medicine Program, The Hospital for Sick Children, Toronto, ON, Canada, 2Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada, 3Division of Respiratory Medicine, British Columbia Children’s Hospital, Vancouver, BC, Canada, 4MR Application Predevelopment, Siemens Healthcare, Erlangen, Germany, 5Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany, 6Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany, 7Division of Respiratory Medicine, The Hospital for Sick Children, Toronto, ON, Canada |
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Hyperpolarized 129Xe MRI provides robust measurements of ventilatory function through the measurement of the ventilation defect percent (VDP). Recent progress in 1H-based free-breathing techniques (phase-resolved functional lung; PREFUL) allows for the calculation of fractional ventilation maps, which can be similarly processed to calculate VDP. While hyperpolarized 129Xe is an established research technique, PREFUL MRI is simple to implement on any MRI scanner and therefore has good potential for use in future clinical trials in cystic fibrosis (CF). In this study, VDP measurements performed using hyperpolarized 129Xe and PREFUL MRI were compared and correlated with pulmonary function tests in pediatric CF. |
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Pitch: 8:15 Poster: 9:15 Plasma 7
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Differences Between 3He and 129Xe Ventilation Heterogeneity Explained Using Oscillometry |
1Robarts Research Institute, London, ON, Canada, 2Department of Medical Biophysics, Western University, London, ON, Canada, 3School of Biomedical Engineering, Dalhousie University, Halifax, NS, Canada, 4Division of Respirology, Department of Medicine, Western University, London, ON, Canada |
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129Xe MRI ventilation defects were previously shown to be greater and more numerous than 3He MRI ventilation defects in patients with chronic obstructive pulmonary disease (COPD) and asthma, however the underlying biomechanical explanation for these differences has not been determined. Here we evaluated the relationships of 3He and 129Xe MRI ventilation defect percent (VDP) with oscillometry measurements acquired in patients to better understand the lung biomechanical constraints that lead to such differences. 129Xe VDP was significantly related to total respiratory-system resistance whereas 3He was not which may suggest increased sensitivity of 129Xe to resistance throughout the entire airway tree. |
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Improved Pulmonary 129Xe Ventilation Imaging via 3D-Spiral UTE MRI |
1Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States, 2Philips, Cincinnati, OH, United States, 3University of Cincinnati, Cincinnati, OH, United States, 4Phoenix Children’s Hospital, Phoenix, AZ, United States, 5Mayo Clinic, Rochester, MN, United States, 6University of Cincinnati Medical Center, Cincinnati, OH, United States |
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Functional lung imaging via inhaled hyperpolarized 129Xe MRI has been shown to provide sensitive regional maps of ventilation and gas-exchange. Traditionally, ventilation images are acquired via standard Cartesian or less commonly radial sequences. Previously reported results have shown promise for 2D-spiral sequences with increased SNR and/or shorter acquisition lengths. In this study, a 3D-spiral sequence (FLORET) was implemented and compared to Cartesian, radial, and 2D-spiral acquisition techniques. This is the first implementation and comparison of a 3D-spiral UTE technique to acquire hyperpolarized gas images. |
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The Accuracy of Hyperpolarized 129Xe Ventilation Derived from 3D Radial Gas Exchange MRI versus Multi-Slice Gradient Echo Imaging |
1Department of Electrical Engineering and Computer, Duke University, DURHAM, NC, United States, 2Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, United States, 3Department of Biomedical Engineering, Duke University, DURHAM, NC, United States, 4Department of Medical Physics, Duke University, DURHAM, NC, United States |
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Both multi-slice GRE and 3D-radial acquisitions can image regional ventilation in the lungs. Here, we sought to evaluate the accuracy of the ventilation images acquired as part of a 3D-radial gas-exchange acquisition by comparing them with those acquired with a standard GRE acquisition. Linear-binning quantification was applied on both acquisitions to derive the quantitative metrics, through which we found good qualitative and modest pixel-wise agreement between the two ventilation scans. With further reconciliation of bias-field correction and threshold-setting for the 3D-radial pipeline, it could become a one-stop shop for single-breath ventilation and gas exchange imaging. |
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MR radiomics analysis in predicting the pathological classification and TNM staging of thymic epithelial tumors |
1Tangdu Hospital, Xi’an, China, 2GE Healthcare, Shanghai, China, 3GE Healthcare, Beijing, China |
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To explore the performance of MR radiomics in predicting the pathological classification and staging of thymic epithelial tumors (TETs), we built two radiomics models based on support vector machine. Besides, we developed a radiomics nomogram for predicting risk stratification of advanced TETs. The models achieved an area under the curve of 77.1% or 90.8% in the test cohort in distinguishing low-, high-risk thymomas and thymic carcinomas or early and advanced TETs. The radiomics model, symptom, and pericardial effusion constituted a radiomics nomogram, with a C-index of 0.957 in the test cohort. Thus, MR radiomics can be useful for assessing TETs. |
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Evaluation of automatic methods for arterial input function extraction for perfusion quantification in the lung. |
1Bioxydyn Limited, Manchester, United Kingdom, 2Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom, 3POLARIS, Academic Radiology, University of Sheffield, Sheffield, United Kingdom, 4The University of Manchester, Manchester, United Kingdom, 5Royal United Hospitals Bath NHS Foundation Trust, Bath, United Kingdom, 6The University of Manchester NHS Foundation Trust, Manchester, United Kingdom, 7Central Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom, 8Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, United Kingdom, 9Quantitative biomedical Imaging Lab, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, United Kingdom |
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We developed automatic methods to extract the AIF for lung first pass perfusion DCE and compared their performance with manual selection of an ROI in the pulmonary artery (PA). Dynamic enhancement was calculated by simple subtraction and with a shuffle subtraction. Early enhancing voxels with the highest enhancing values were selected. We demonstrated that the shuffle subtraction is a more robust method, since it avoids including the early enhancing subclavian vein. Our results suggest obtaining the AIF automatically from pixels within the RV may be more robust against partial volume effects and removes inter-reader variability. |
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3D UTE Yarn Ball Acquisition MRI for Quantification of Lung Water Content |
1Biomedical Engineering, University of Alberta, Edmonton, AB, Canada |
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The goal of this study was to develop and validate a fast, robust and quantitative MRI method for the evaluation of lung water density, for the detection of pulmonary edema. Short lung T2* necessitates ultrashort TE (UTE) acquisitions. We propose a novel optimized UTE Yarn-Ball k-space trajectory that uses ~15% of the pure radial readouts arms required to achieve full sampling. Phantom studies validated accurate water density quantification. A dual-echo approach enabled automated lung tissue segmentation. An optimized Yarn-Ball k-space trajectory yields three-dimensional spin-density weighted lung water images (2.5mm isotropic resolution), without the need for breath-holding, in ~2 minutes. |
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Combined ventilation and perfusion imaging using dynamic susceptibility contrast 19F-MRI of inhaled perfluoropropane |
1Newcastle Magnetic Resonance Centre, Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom, 2Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom |
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19F-MRI of inhaled perfluoropropane (PFP) can be used to assess pulmonary ventilation. PFP has a short in vivo T2* (~2ms) arising from magnetic field inhomogeneity in the lung, reflecting the different magnetic susceptibilities of adjacent alveolar walls and gas components. Intravenous injection of a paramagnetic contrast agent to the pulmonary circulation can transiently reduce these magnetic susceptibility gradients, raising the T2* of inhaled PFP in regions directly adjacent to well-perfused lung. We present the first in man demonstration of combined pulmonary ventilation and perfusion assessment using 19F-MRI of inhaled PFP with concurrent administration of a gadolinium-based contrast agent. |
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Investigating the relationship between free-breathing 1H and breath-hold 3He MRI in patients with cystic fibrosis |
1POLARIS, Academic Radiology, University of Sheffield, Sheffield, United Kingdom, 2Institute for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany, 3Sheffield Children's Hospital, Sheffield, United Kingdom |
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Free-breathing non-contrast enhanced 1H MRI techniques show promise as a surrogate for ventilation imaging but more validation against methods which directly image lung ventilation is needed in patients. The aim of this work was to investigate the relationship between 1H free-breathing and 3He breath-hold ventilation images in patients with CF. Phase-resolved functional lung (PREFUL) 1H and 3He ventilation images were compared in 10 patients with CF. Qualitative similarities were observed between techniques to varying degrees. Ventilation defect percentage showed strong correlation between methods and with FEV1, although median and inter-quartile range fractional ventilation values were not related. |
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Oxygen-enhanced UTE MRI for Quantification of Dynamic Lung Function |
1Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 2Radiology, University of Wisconsin-Madison, Madison, WI, United States, 3Pediatrics, University of Wisconsin-Madison, Madison, WI, United States, 4Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States |
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Three-dimensional dynamic imaging using free-breathing oxygen-enhanced (OE) ultrashort echo time (UTE) MRI can measure change of partial pressure of oxygen (ΔPO2) and wash-in/out time constants. Nine healthy subjects underwent the dynamic OE MRI protocol at 1.5T. A subset of 4 subjects underwent repeated exams and 2 of these 4 underwent the same protocol at 3.0T on the same day. The inter-exam variations at 1.5T suggest good quantitative measurements of lung function and wash-in/out dynamics with variations observed in ΔPO2max. The parametric maps imply comparable wash-in/out time constants and normal ventilation measured at 1.5T vs. 3.0T. |
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Synthetic MRI through a Deep Neural Network Based Relaxometry and Segmentation |
1University of California at San Francisco, University of California at San Francisco, San Francisco, CA, United States |
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This study demonstrated a method for 3D synthetic MRI through a deep neural network Based Relaxometry and Segmentation. Ranges of T1 and T2 values for gray matter, white matter and cerebrospinal fluid (CSF) were used as the prior knowledge. The proposed method can directly generate brain T1 and T2 maps in conjunction with segmentation based bias field correction and synthetic MRI. |
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High-resolution 3D MR Fingerprinting using parallel imaging and deep learning |
1Radiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, 2Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States |
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In this study, a high-resolution 3D MR Fingerprinting technique, combining parallel imaging and deep learning, was developed for rapid and simultaneous quantification of T1 and T2 relaxation times. Our preliminary results show that, with the integration of parallel imaging and deep learning techniques, whole-brain quantitative T1 and T2 mapping with 1-mm isotropic resolution can be achieved in ~6 min, which is feasible for routine clinical practice. |
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AUTOMATED BRAIN TISSUE SEGMENTATION USING DEEP LEARNING AND IMPERFECT LABELING |
1Radiology, University of Texas Southwestern Medical Center, Dallas, TX, United States |
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This work presents a deep learning pipeline to perform brain tissue segmentation on T1w Magnetic Resonance images (MRI). Two separate 3D-Dense-Unets were designed: GW-net to segment the gray matter (GM) and white matter (WM) and CSF-net to segment the cerebrospinal fluid (CSF). The network was trained on T1w MRI from 785 datasets in the iTAKL study with their corresponding SPM12 segmentations as ground truth and tested on 50 held-out subjects from the iTAKL study, 50 subjects from the AADHS study and 131 subjects from the Human Connectome project (HCP). Our pipeline showed improved segmentations when tested on simulated data with known ground truth as compared to the existing neuroimaging packages including SPM12, FSL and CAT12. |
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MR IMAGE RECONSTRUCTION FROM UNDERSAMPLED k-SPACE USING DEEP LEARNING |
1Radiology, University of Texas Southwestern Medical Center, Dallas, TX, United States |
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This work presents a deep learning approach to reconstruct MR images from undersampled k-space on 3D-FLAIR MR images. IR-net, a patch based 3D-Dense U-net, was designed to achieve this. 600 [JM1] [CGBY2] 3D-FLAIR MR images were used for training and testing. Aliased images were created by undersampling the high resolution 3D-FLAIR images in k-space using a Poisson distribution filter. The network was trained on patches from 550 aliased k-space data with their corresponding high resolution 3D-FLAIR MR images as ground truth and 50 images were held out for testing. IR-net successfully reconstructed the aliased images with significant improvement in SSIM and PSNR. [JM1]Are these 600 image slices, or 600 3D image volumes? [CGBY2]600 3D images. |
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Fully-Automated Glioma Volumetric Segmentation and Treatment Response Assessment in MRI using Deep Learning |
1Radiology, Massachusetts General Hospital, Boston, MA, United States, 2Hospital of the University of Pennsylvania, Philadelphia, PA, United States, 3Massachusetts General Hospital, Boston, MA, United States, 4Xiangya Hospital, Changsha, China, 5Brigham and Women’s Hospital, Boston, MA, United States, 6Yale School of Medicine, New Haven, CT, United States, 7The Second Xiangya Hospital, Changsha, China, 8Beijing Tiantan Hospital, Beijing, China, 9Dana-Farber Cancer Institute, Boston, MA, United States |
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Longitudinal assessment of glioma burden is important for evaluating treatment response and tumor progression. Delineation of tumor regions is typically performed manually but is time-consuming and subject to inter-rater and intra-rater variability. Therefore, there has been interest in developing automated approaches to calculate 1) glioma volume and 2) the product of maximum diameters of contrast-enhancing tumor (the key measure used in the Response Assessment for Neuro-Oncology (RANO) criteria). We present a fully automated pipeline for brain extraction, tumor segmentation, and RANO measurement (AutoRANO). We show the utility of this pipeline on 713 MRI scans from 54 post-operative glioblastoma patients, demonstrating capacity for tumor burden measurement. |
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Automatic detection and classification of brain tumors using deep learning and based on conventional MRI and clinical information |
1Sagol Brain Institute, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel, 2Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel, 3Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel, 4The Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel |
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Automatic detection and classification of brain tumors was performed using deep learning based on conventional MRI and clinical information. A total of 441 patients where included: 202 patients with high grade glioma and 239 patients with brain metastases. Classification was performed using resnet34 architecture. The input data for classification were FLAIR images, post contrast T1W images and patients’ clinical information. Classification results showed high accuracy=89%, specificity=91% and sensitivity=86%. For lesion localization the mean intersection over union (IoU) score was 0.64±0.17. Our results indicate the promising potential of a deep learning approach for automatic non-invasive diagnosis of patients with brain tumors. |
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Automatic segmentation and follow-up of optic pathway gliomas using deep learning and based on conventional MRI |
1Sagol Brain Institute, Tel Aviv Sourasky Medical Center, Tel - Aviv, Israel, 2Sackler Faculty of Medicine, Tel Aviv University, Tel - Aviv, Israel, 3Sagol School of Neuroscience, Tel Aviv University, Tel - Aviv, Israel, 4The Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Tel - Aviv, Israel, 5Division of Radiology, Tel Aviv Sourasky Medical Center, Tel - Aviv, Israel, 6The Gilbert Israeli Neurofibromatosis Center, Tel - Aviv, Israel, 7Department of Pediatric Neurosurgery, Tel - Aviv, Israel |
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Optic pathway gliomas (OPG) are heterogeneous tumors with complex shape. The aim of this study was to implement a deep-learning approach for automatic segmentation and follow-up of patients with OPG based on conventional MRI. A total of 354 MRI scans from 53 patients where included. A neural-network with a U-net architecture was trained for segmentation of lesion area. The similarity coefficient score between segmentation results and ground truth was 0.812±0.159, with sensitivity=0.799±0.188, specificity=0.999±0.002 and correlation of r=0.987 (p<0.001) between lesion volumes. These results demonstrate the potential applicability of the proposed method for automatic radiological follow-up of patients with OPG. |
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Predictive and discriminative localization of IDH genotype in high grade gliomas using deep convolutional neural nets |
1Symbiosis Centre of Medical Image Analysis, Symbiosis International University, Pune, India, 2National Institute of Mental Health and Neurosciences, Bangalore, India, 3Department of Neuroimaging & Interventional Radiology, National Institute of Mental Health and Neurosciences, Bangalore, India |
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Radiomics and state-of-art convolutional neural networks (CNNs) have demonstrated their usefulness for predicting genotype in gliomas from brain MRI. However, these techniques rely on accurate tumor segmentation and do not facilitate insights into the critical discrimative features. To mitigate this, we employ a novel technique called CNNs with discriminative localization (DL-CNN) on a clinical T2 weighted MRI dataset of IDH1 mutant and wild-type tumor patients, which is not only free of tumor segmentation with high classification accuracy of 86.7% but also demonstrates that the tumoral area is discriminative in mutants while in IDH1 wildtype the peri-tumoral edema is also involved. |
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Deep Learning for Identification of Active Lesions in Multiple Sclerosis Without Administration of Gadolinium Based Contrast Agent |
1Diagnostic and Interventional Imaging, University of Texas Health Science Center at Houston, Houston, TX, United States, 2Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 3Neurology, University of Texas Health Science Center at Houston, Houston, TX, United States |
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Gadolinium based contrast agents (GBCA) are routinely administered for identifying active lesions in multiple sclerosis (MS). Because of the safety concerns with GBCA, alternative methods are highly desirable to identify active lesions without GBCA. We used Deep Learning, specifically multi-layered VGG16 network, to identify active MS lesions on the pre-contrast images. The network was trained using a large number of annotated multi-modal magnetic resonance image volumes (792) acquired as a part of phase 3 clinical. The DL results look quite promising as judged by the accuracy, sensitivity, and specificity of 0.729, 0.861, 0.598, respectively. |
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Thalamic Connectome Based Machine Learning for Predicting Individual Symptoms after Mild Traumatic Brain Injury |
1Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan, 2Neuroscience Research Center, Taipei Medical University, Taipei, Taiwan, 3Translational Imaging Research Center, Taipei Medical University Hospital, Taipei, Taiwan, 4Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan, 5Department of Medical Imaging, Taipei Medical University Hospital, Taipei, Taiwan |
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Mild traumatic brain injury (mTBI) can cause persistent post-concussion symptoms in 15-20% patients, however the presented type and severity of symptoms differ largely between patients. This study recruited 53 mTBI patients and 44 healthy controls to demonstrate the feasibility in using the imaging features of thalamic connectome combined with machine-learning regression models for the individualized prediction of clinical symptoms. |
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A Machine Learning approach to Predict Age-Related Motor Performance using MRI-MRS data |
1University of Leuven, leuven, Belgium, 2Philips UK, Belfast, United Kingdom, 3icometrix, leuven, Belgium |
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Aging is associated with gradual alterations in structural and neurochemical characteristics of the brain, which can be assessed in vivo by MRI and MRS modalities. The process of brain aging occurs in accord with a general decline in cognitive-motor performance and increases the risk of neurodegeneration. We used MRI-MRS data from 86 individuals as inputs for machine learning models5 to predict motor performance in healthy individuals. Our analysis shows that application of machine learning algorithms on combination of age, gender and MR data can accurately predict motor performance and has potential to be used as a biomarker for neuro related diseases. |
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A deep learning framework with redundancy removal and its diagnostic performance of Parkinson's disease |
1Medical Imaging and Radiological Sciences, Chang Gung University, Taoyuan, Taiwan, 2School of Information and Communication Engineering, University of Electronic Science and Technology of China, Chengdu, China, 3Neurology, Chang Gung Memorial Hospital, Taoyuan, Taiwan, 4Diagnostic Radiology, Keelung Chang Gung Memorial Hospital, Keelung, Taiwan |
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Computer-aided diagnosis using deep learning methods shows its potential in medical images classifications. This study aims to examine the diagnostic performance of diffusion tensor imaging using a 4-steps framework for deep learning to differentially diagnose patients with Parkinson's disease(PD) and normal controls(NC). |
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Hippocampal segmentation for brains with extensive atrophy using three-dimensional convolutional neural networks |
1Sunnybrook Research Institute, Toronto, ON, Canada |
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Obtaining hippocampal volumes through manual segmentation requires an expert and is time consuming. Automated segmentation techniques would benefit from user-friendly and publicly accessible to tools, and robust results in the face of brain diseases. To accomplish these objectives, we trained a 3D convolutional neural network to segment the hippocampus automatically. Our algorithm was more accurate and time efficient compared to 4 publicly available state-of-the-art methods when considering a wide range of patient groups. Thus, we present a new method for obtaining hippocampal volumes, an important biomarker in aging, disease, and dementia. |
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Functional MRI-based Deep Learning Classification between Temporal Lobe Epilepsy Patients and Healthy Controls |
1Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States, 2Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States, 3Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States, 4Neurology, Medical College of Wisconsin, Milwaukee, WI, United States, 5Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States, 6Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States |
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Common machine learning approaches to differentiate between Temporal Lobe Epilepsy (TLE) and healthy controls often include extensive preprocessing techniques that often entail feature extraction, resulting in a more time-intensive and variable approach. Utilizing data from both the Epilepsy Connectome Project (ECP) and Human Connectome Project (HCP), this study attempts to develop, train, and validate a deep learning classifier to automatically differentiate between TLE patients and healthy subjects using resting-state fMRI (rs-fMRI) and task fMRI (t-fMRI) data alone without advanced preprocessing steps or feature extraction. |
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Using convolutional neural networks to predict infarct development in acute ischemic stroke patients: does reperfusion status matter? |
1Stanford University, Stanford, CA, United States |
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Convolutional Neural Network has shown promising results in stroke treatment outcome predictions. Our study explores the hypothesis of whether training a CNN model with patients who have similar treatment outcomes can improve the model prediction of day 5 stroke lesion. |
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Increased brain perfusion in neonatal hypoxic ischemic injury with negative reading of DWI, T1/T2-weighted images: Implications of perfusion MRI for reperfusion response monitoring and prognostication |
1Children's Hospital of Philadelphia, Philadelphia, PA, United States, 2Yantai University, Yantai, China, 3University of Pennsylvania, Philadelphia, PA, United States |
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Brain perfusion plays an important role in the diagnosis and prognosis of neonatal hypoxic ischemic injury (HII). However, the studies on perfusion changes in HII neonates with negative reading in conventional magnetic resonance imaging (MRI) (HII-) are rarely reported. Here, we used arterial-spin-labeled perfusion MRI to compare cerebral blood flow among health controls, HII neonates with positive reading of conventional MRI images (HII+) and HII- neonates. The results demonstrate that perfusion is altered in HII neonates even with negative reading of conventional MRI images, suggesting importance of inclusion of perfusion MRI for evaluating HII in clinical practice and research. |
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Music in preterm infants enhances maturation of neural pathways involved in emotion processing |
1Division of Development and Growth, Department of Pediatrics, University of Geneva, Geneva, Switzerland, 2Division of Development and Growth, Department of Pediatrics, Geneva University Hospitals, Geneva, Switzerland, 3Psychology, Yale University, New Haven, CT, United States, 4Center of BioMedical Imaging (CIBM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland, 5Wellcome Centre for Integrative Neuroimaging (WIN) - Oxford Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB), University of Oxford, Oxford, United Kingdom, 6Sir Peter Mansfield Imaging Centre, School of Medicine, University of Nottingham, Nottingham, United Kingdom, 7Center of BioMedical Imaging (CIBM), University of Geneva, Geneva, Switzerland |
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Prematurity disrupts brain maturation during a critical period of development and music potentially enhances cognitive-socio-emotional pathways affected by prematurity. Using multi-modal MRI, we evaluated the structural impact of a music intervention during NICU stay in preterm infants’ brains, namely in WM through DTI ROI and tractography analysis and in amygdala through volumetric analysis. Overall, WM microstructural maturity was decreased in preterm control vs full-term newborns. In comparison to preterm control, preterm exposed to music demonstrate improved WM maturation in uncinate fasciculus, external capsule/claustrum/extreme capsule and larger amygdala volumes, proving a structural effect of music intervention on emotional processing neural pathways. |
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Early Language and Motor Functional Network Connectivity from Infancy to Early Childhood |
1Warren Alpert School of Medicine, Brown University, Providence, RI, United States, 2Women and Infants Hospital of Rhode Island, Providence, RI, United States, 3MNCHD & T, Bill & Melinda Gates Foundation, Seattle, WA, United States |
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While childhood is a period of rapid brain development defined by early motor and language milestones, very little is known about the development of functional networks with increasing milestone abilities. We investigated correlation patterns between resting state functional MRI network connectivity and standardized scores for motor and language milestone functions in a large cohort of typically developing children spanning from 3 months to 6 years of age. We demonstrate distinct functional network connectivity patterns for major motor and language milestone functions, which increase in number with task complexity. |
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Variations in tract-specific fibre density and morphology with puberty and behaviour across childhood |
1Department of Paediatrics, University of Melbourne, Parkville, Australia, 2Developmental Imaging, Murdoch Children's Research Institute, Parkville, Australia, 3Department of Medicine, University of Melbourne, Parkville, Australia, 4School of Pschology, Deakin University, Geelong, Australia |
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Microstructural development is dynamic throughout childhood and adolescence. Modelling these profiles requires statistical flexibility to understand complex interplays between related phenotypes such as sex, pubertal stage, and age. We leverage the fixel-based analysis framework and compute fibre density and morphology metrics in selective white matter tracts, to enable longitudinal mixed-effects modelling of multiple phenotypes. We show that longitudinal development of white matter fibre properties in children aged 9–14 dominates in posterior fibres. Increases in fibre density are associated with increases in pubertal stage and attention dysfunction, and protracted increases in fibre density are associated with greater internalising behaviours. |
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Changes in functional brain connectivity associated with the development of executive functions during early childhood |
1Warren Alpert Medical School, Department of Pediatrics, Brown University, Providence, RI, United States, 2Women and Infants Hospital of Rhode Island, Providence, RI, United States, 3MNCHD&T, Bill & Melinda Gates Foundation, Seattle, WA, United States |
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Task-based functional MRI (fMRI) has been commonly used to study executive functions but may be difficult to implement for children younger than 5-year-old. In this work, resting sate fMRI is combined with in-house tablet-based tasks which evaluate reaction and inhibition control in children from 2 to 5 years of age. The aim is to determine differences in brain connectivity related to the children’s performance of these two tasks. Preliminary results demonstrated the importance of the language, visual and attention networks during the reaction task and asymmetrical changes in frontal parietal and sensorimotor network connectivity associated with the development of inhibition control. |
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Development-based Joint Parcellation of Human and Macaque Brains during Infancy |
1Department of Computer Science and Technology, Shandong University, Jinan, China, 2Department of Radiology and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States |
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Joint cortical parcellation maps of human and macaque infant brains with corresponding regions are highly desirable, since they provide basic common cortical parcels for both region-based and network-based studies of two closely-related species. Developmental patterns of infants indicate underlying rapid changes of microstructures, which determine the molecular and functional principles of the cortex. Leveraging 210 longitudinal human infant MRI scans and 140 longitudinal macaque infant MRI scans, we develop a novel method to generate the first joint parcellation maps of human and macaque infants based on their developmental patterns. |
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Differences in Brain Development in a High and Low Economic Setting |
1MNCHD&T, Bill & Melinda Gates Foundation, Seattle, WA, United States, 2Pediatrics, Brown University, Providence, RI, United States, 3University of Wisconsin at Madison, Madison, WI, United States |
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Adverse environmental conditions throughout infancy and childhood have potential to result in neurodevelopment delays and impaired cognitive outcomes. Children born in low and middle income countries (LMICs) often experience significant malnutrition, inadequate sanitation, and are exposed to poor water and air quality, all of which can affect brain and cognitive development. However, there are limited reports of brain growth in LMICs, with cognitive development often assessed indirectly through measures of physical growth (child height and weight). Here we present the first reports of brain volume growth in children from a low resource area of India. Relative to reference brain growth charts derived from a large cohort of healthy children in Providence RI, we find significant brain growth delay, particularly amongst girls. These results shine new light on the importance of living conditions on child brain health. |
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Grey matter changes in adolescents participating in a meditation training |
1Department of Radiology & Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States, 2Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL, United States, 3Department of Clinical Science/Child- and Adolescent Psychiatry, Umeå University, Umeå, Sweden, 4Department of Psychiatry, University of California, San Francisco, San Francisco, CA, United States |
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Meditation is a popular mind-body practice with numerous benefits, but its neural mechanism remains unclear. Previous MRI studies have shown morphometric changes associated with meditation, such as increased grey matter volume (GMV). However, these findings were in adults and adolescents remained understudied. Using voxel-based morphometry, we assessed GMV changes in adolescents participating in a training containing elements from mindfulness meditation and yoga-based practices. We found a significant GMV decrease in the left posterior insula, a key homeostatic awareness and interoception region. The decreasing GMV opposes previous findings of structural increase in adults, which may be due to adolescence-specific developmental processes. |
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Cortical Thickness and White Matter Connectivity in preschool Children with Autism Spectrum Disorder |
1PLA General Hospital, Beijing, China, 2Tsinghua University, Beijing, China, 3Center for MRI Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China, 4Beijing Jishuitan Hospital, Beijing, China |
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Structural magnetic resonance imaging (MRI) is suitable to describe brain anatomy, and altered cortical thickness and connectivity are the keys feature of autism spectrum disorder (ASD) pathophysiology. By processing T1-weighted imaging and diffusion-tensor imaging data from same subjects, cortical thickness and white matter connectivity were shown respectively, and some differences of brain areas were found between typically developing (TD) preschool children group and ASD, which might be related to the behaviors of ASD preschool children. Compared with TD, the thickness of right middle post cingulada gyrus and sulcus increased and its close white matter's fractional anisotropy (FA) of right superior frontal area decreased (P<0.01) in ASD group. These findings may be the morphological biomarkers, which will help guide the precise intervention or treatment in preschool children with ASD as some new neural circuits. |
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Multimodal Stratification Biomarkers: Unravelling Electrophysiological Latency Differences in Autism Spectrum Disorder with the help of DTI and MEGAPRESS |
1Radiology, Children's Hospital of Philadelphia, Philadelphia, PA, United States |
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Electrophysiological delays in sensory (e.g. auditory) evoked responses are hallmarks of ASD. However, their magnitude is heterogeneous across the autism spectrum. This study approaches latency delay from a biophysical standpoint, focusing on axonal conduction velocity and synaptic transmission speed as potential mediators of ultimate latency. Combining MEG measures of cortical response latency with MR surrogates of conduction velocity (thalamocortical white matter diffusion fractional anisotropy) and synaptic transmission (MRS estimates of the neurotransmitter GABA) allows the stratification of children with ASD into subgroups dominantly dependent on conduction velocity vs synaptic transmission respectively. Such biological stratification may offer promise for targeted intervention. |
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Regional and Lateralized Cortical Thickness Measurement in Children and Adolescents with Complex Congenital Heart Disease: Effects of Age, Gender, and Ciliary Dysfunction |
1Department of Pediatric Radiology, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, United States, 2Developmental Biology, University of Pittsburgh, Pittsburgh, PA, United States, 3Department of Biomedical Informatics, University of Pittsburgh, Pittsburgh, PA, United States |
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Both regional and lateralized differences in cerebral cortical thickness were noted in CHD patients compared to controls during a protracted period of critical brain development during childhood and adolescent period. The regional vulnerability was localized to important known cognitive control network including the prefrontal region, salience network and the default mode network . Importantly, ciliary motion abnormalities accounted for most of these regional and lateralized differences in cortical thickness between CHD and controls, underscoring the importance of ciliary mutations/genetic abnormalities underlying cortical dysmaturation in CHD patients. |
| 42 | Pitch: 8:15 Poster: 9:15 Plasma 42
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Brain Microstructural Changes Support Cognitive Deficits in Normal Children Born to HIV-infected Mothers |
1Division of Translational Medicine, Sidra Medicine, Doha, Qatar, 2Department of Radiology and Imaging, Fortis Memorial Research Institute, Gurgaon, India, 3Department of Neurology, King George Medical University, Lucknow, India, 4Department of Microbiology, King George Medical University, Lucknow, India, 5Department of Psychiatry, Sidra Medicine, Doha, Qatar, 6Laboratory Animal Research Center, Qatar University, Doha, Qatar |
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In the current study, we evaluated the brain integrity [by mapping the fractional anisotropy (FA) and mean diffusivity (MD)] and neurocognitive performance (NP) in normal children (NCI) born to HIV-infected mother compared to normal children (NCH) born to healthy mother and HIV-infected children (HI). Reduced FA in multiple brain sites of HI and NCI children suggests loss of tissue integrity while altered MD indicates presence of cerebral edema. Presence of tissue changes and abnormal cognition in absence of HIV-infection in NCI children advice that ART may have detrimental effects on brain. |
| 43 | Pitch: 8:15 Poster: 9:15 Plasma 43
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Anomalous relationship between sensorimotor GABA levels and cortical excitability in children with Attention-deficit/hyperactivity disorder |
1Radiology, University of Calgary, Calgary, AB, Canada, 2Child and Adolescent Imaging Research Program, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada, 3Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada, 4Division of Pediatric Neurology, Cincinnati Children's Hospital Medical Center and University of Cincinnati, Cincinnati, OH, United States, 5Department of Radiology, Cincinnati Children's Hospital Medical Center and University of Cincinnati, Cincinnati, OH, United States, 6Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins School of Medicine, Baltimore, MD, United States, 7F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States, 8Center forNeurocognitive and Imaging Research, Kennedy Krieger Institute, Baltimore, MD, United States, 9Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, United States, 10Department of Behavioral Science and Psychiatry, Johns Hopkins School of Medicine, Baltimore, MD, United States |
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Reduced inhibition as shown though GABA-edited MRS and TMS measures have been suggested to underlie some of the symptomology of ADHD. In this study we apply GABA-MRS and single- and paired-pulse TMS in ADHD and typically developing cohorts to better understand altered inhibition in ADHD. We show that SICI approaches 1 with increasing GABA across both groups. Secondly, we show a convergence in SICI and single-pulse TMS responses with increasing GABA. Last, we show different factors modulate the TMS responses between ADHD and control suggesting there are additional differences in GABAergic inhibition between these two groups. |
| 44 | Pitch: 8:15 Poster: 9:15 Plasma 44
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The Relation Between Nasal Nitric Oxide and Neurocognitive Outcome is Mediated by Regional Cerebral Blood Flow in Healthy Adolescents and Adolescents with Congenital Heart Disease |
1Radiology, UPMC Pittsburgh Children's Hospital, Pittsburgh, PA, United States, 2UPMC Pittsburgh Children's Hospital, Pittsburgh, PA, United States |
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Nasal nitric oxide (nNO) may be a proxy for NO or NO synthase (NOS) availability in the brain, while NO/NOS availability is likely related to metabolism and downstream to neurocognitive function. We tested this hypothesis using a mediation analysis with nNO the independent variable, regional CBF (rCBF) as measured by ASL the mediator, and neurocognitive outcome (NIH Toolbox) the dependent variable in a cohort of normal adolescents and adolescents with congenital heart disease. Anterior and posterior default mode network regions positively mediated all NIH Toolbox composite scores, especially crystallized cognition. Results indicate nNO may be a powerful biomarker for brain function and metabolism. |
| 45 | Pitch: 8:15 Poster: 9:15 Plasma 45
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Investigating the effects of an early intervention in preterm newborns: A resting-state functional connectivity study |
1Division of Development and Growth, Department of Pediatrics, University of Geneva, Geneva, Switzerland, 2Institute of Bioengineering, Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne, Switzerland, 3Institute of Mathematics, Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne, Switzerland |
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In this |
8:15
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MRS in Tissue: What Are We Measuring? | |
1MPI for Biological Cybernetics, Germany |
| 47 | 8:35
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Dynamic Deuterium MRS Imaging for Studying Rat Heart Energy Metabolism in vivo – Initial Experience |
1Center for Magnetic Resonance Research,Department of Radiology, University of Minnesota, Minneapolis, MN, United States, Minneapolis, MN, United States, 2Department of Radiology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China |
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Assessment of myocardial energy metabolism is crucial for understanding heart function and viable myocardium after myocardial infarction. Based on our recently developed in vivo Deuterium (2H) MR spectroscopic (DMRS) approach, we further exploited the DMRS and imaging (DMRSI) methods for dynamic measurement of the myocardial energy metabolism in rat heart at 16.4 T. This work demonstrates the feasibility of in vivo DMRS for assessing myocardial energy metabolisms, and its potential to directly image the viable myocardium in hearts under conditions such as myocardial infarction. |
| 46
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8:47
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Novel methods to record MR spectra in human brain without suppressing or exciting the water signal to investigate exchange-sensitive protons. |
1Departments of Radiology and Biomedical Research, University Bern, Bern, Switzerland, 2Department of Biomedical Imaging and Image-guided Therapy, Medical University Vienna, High-field MR Center, Vienna, Austria |
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Non-water-suppressed MR spectroscopy in the form of metabolite-cycled MRS and longitudinal-relaxation-enhanced MRS (also termed non-water-excitation, NWE) has come into focus when studying compounds with exchanging protons (observed in the downfield region) or compounds like NAD+ that seem to be affected by cross relaxation from water. Here, we strive to implement new NWE techniques that can be used at 3T and allow for very short TE and observation of fast exchanging protons. 2D I-CSE, a combination of 2D ISIS and slice-selection with chemical shift selective excitation, fulfills this profile and first human brain applications show large signal contributions from exchanging protons. |
8:59
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CEST in Tissue: What Are We Measuring? | |
1Vanderbilt University Medical Center, United States |
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In CEST, specificity is the key issue. |
| 48
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9:19
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High-resolution phosphocreatine mapping of human skeletal muscle by artificial neural network-based chemical exchange saturation transfer MRI at 3T |
1F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, MD, United States, 2Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 3Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 4Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China |
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The creatine kinase reaction provides energy for cells by reversibly regenerating adenosine triphosphate from a phosphocreatine pool. Functional impairment of this system is observed in many neurodegenerative and muscle diseases. In this study, we developed a high-resolution phosphocreatine (PCr) mapping approach that can be used on standard magnetic resonance clinical scanners by specifically detecting PCr via the water proton signal using a chemical exchange saturation transfer (CEST) method. An artificial neural network was employed to achieve absolute quantification of PCr concentration. Such a mapping method offers a non-invasive, rapid imaging tool to quantify abnormalities in PCr content and distribution in musculoskeletal diseases. |
| 49 | 9:31
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Translating pH-sensitive PROgressive saturation for Quantifying Exchange using Saturation Times (PRO-QUEST) MRI to a 3T Clinical Scanner |
1Department of Brain Repair and Rehabilitation, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom, 2Queen Square MS Centre, Department of Neuroinflammation, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom, 3Philips Healthcare, Surrey, United Kingdom, 4UCL Centre for Medical Imaging, University College London, London, United Kingdom, 5Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy, 6Brain MRI 3T Research Centre, IRCCS Mondino Foundation, Pavia, Italy |
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In this work, a recently developed method called PRO-QUEST (PROgressive saturation for Quantifying Exchange using Saturation Times) is translated to a 3T clinical scanner for assessing pH-sensitive indices in phantoms and a healthy volunteer. Our results demonstrate that quantification of pH sensitive indices using PRO-QUEST is feasible at 3T within clinically acceptable acquisition times. Our initial findings suggest that PRO-QUEST has the potential to provide a new biomarker to study neurological disorders associated with brain tissue acidosis. |
9:43
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CEST & MRS: Biochemistry (Breast Cancer) | |
1Johns Hopkins University SOM, United States |
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CEST & MRS: Biochemistry (Breast Cancer) |
| 50 | 10:03
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Self-adapting Multi-peak Water-fat Separation for Removing Lipid Artifacts in Breast Chemical Exchange Saturation Transfer (CEST) Imaging |
1Shanghai Key Laboratory of Magnetic Resonance, Shanghai, China |
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Chemical exchange saturation transfer (CEST) MRI show potential for breast lesion characterization. However, artifacts caused by strong lipid signals hinder its widespread application. To remove the artifacts, water-fat separation based on multipoint Dixon acquisition is used to obtain water-only images. Considering that RF pulses with various frequency offset in CEST preparation saturate each fat peak at different level, relative amplitudes of fat peaks are updated for building fat signal model by the numerical simulation. Based on this self-adapting multi-peak model (SMPM), a method combining nonlinear least-squares fitting and R2 *-IDEAL is used to perform the water-fat reconstruction. Phantom and in vivo breast experiments demonstrate that the proposed method successfully removes lipid artifacts. |
10:15
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Adjournment |
8:15
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Multi-Modal Imaging: From Animal Models to Human | |
1Vanderbilt University, United States |
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Integrating fMRI with complementary neurophysiological measurements can provide a more comprehensive understanding of brain function, and help to clarify the neural basis of BOLD fMRI signals. Here, we will discuss multi-modal imaging studies of the human brain using simultaneous EEG-fMRI, along with studies in animal models, which allow for more direct, invasive monitoring and manipulation of neural circuits. This talk will also briefly discuss technical challenges and methodology involved in acquiring and analyzing simultaneous fMRI-electrophysiological data. |
| 51 | 8:45
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Optogenetic fMRI reveals ventral hippocampal modulatory effects on large-scale visual processing |
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, China, 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China |
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Hippocampus has been traditionally associated to learning, memory, navigation and emotional behaviors. However, little is known regarding whether and how it influences the processing of large-scale visual sensory information. In this study, we combined optogenetic stimulation and visual fMRI to investigate the influence of the ventral hippocampus on visual processing across the central visual pathway, including superior colliculus, lateral geniculate nucleus and visual cortex. Our optogenetic fMRI results reveal for the first time the differential influences of high and low frequency ventral hippocampal activities on visual processing along the central visual pathway. |
| 52 | 8:57
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Neurovascular coupling in task and resting state using simultaneous calcium fiber photometry and fMRI in rats |
1Institution of Medical Information, Sourthern Medical University, Guangzhou, China, 2Institution of Neuroscience, Shanghai, China |
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Neurovascular coupling is the foundation of functional brain imaging. We developed a dual site, dual color simultaneous GCaMP6-based fiber photometry and fMRI recording system in rats, to simultaneously record calcium and BOLD signals. Our results revealed the strong couplings in the task condition, and much weaker but still significant coupling in the resting state. We also showed that in the resting state such coupling was susceptible to different preprocessing steps. Our results provided a novel perspective on neurovascular coupling in task and resting state conditions. |
| 53
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9:09
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LFP-triggered Co-activation Patterns Show That the Relationship between LFP and BOLD Is Driven by a Few Distinct Events |
1Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States |
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To gather electrophysiological evidence of time-varying functional networks, we developed a new method to analyze simultaneous fMRI and LFP data, which averages the fMRI frames at LFP power higher or lower than a threshold. The results not only show that the correlation between LFP power and BOLD is driven by a few distinct instead of a continuous interaction, but also suggests that the non-stationary resting state networks found in fMRI studies represent the time-varying behavior of LFPs. |
9:21
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Multi-modal Imaging in Epilepsy Research | |
1MGH Martinos, United States |
| 54
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9:51
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Exploration of the spatial and temporal characteristics of sensorimotor neural activity in the preterm human brain with simultaneous EEG-fMRI |
1Centre for the Developing Brain, Kings College London, London, United Kingdom, 2Department of Neuroscience Physiology and Pharmacology, University College London, London, United Kingdom, 3Department of Bioengineering, Imperial College London, London, United Kingdom |
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In the developing animal brain, different patterns of neural activity have distinct roles in the establishment of brain networks at different scales. Although studies suggest that the human preterm period is a crucial time for establishing brain connectivity, the role of different frequencies of neural activity has not been studied. We therefore used simultaneous EEG-fMRI and a robotic somatosensory stimulus to study the temporal and spatial characteristics of evoked neural activity in a group of preterm infants. Specific types of neural activity were associated with different BOLD responses, suggesting that these methods offer new insights into developing brain activity. |
| 55 | 10:03
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Identifying focal thalamic activity underlying sleep and wake states through EEG-fMRI at 7 Tesla |
1Boston University, Boston, MA, United States, 2Massachusetts General Hospital, Boston, MA, United States, 3Massachusetts General Hospital/Harvard Medical School, Boston, MA, United States, 4BIDMC/Harvard Medical School, Boston, MA, United States |
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The thalamus plays an important role in regulating brain states, but remains poorly understood due to the technical challenges in imaging small brain structures with simultaneous electrophysiology. We implemented simultaneous fast fMRI and EEG at 7 Tesla to achieve high-SNR imaging of thalamic dynamics during human sleep. We found that we could detect selective activity within a focal set of thalamic nuclei that preceded the moment of awakening. These results identify potential network mechanisms engaged in regulating brain states, and demonstrate the potential for multimodal 7T imaging to identify new roles for deep brain structures in regulating cortical function and cognition. |
10:15
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Adjournment |
| 56
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8:15
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Estimating compartment- and cell-specific microscopic anisotropy in the human brain using double-diffusion encoding spectroscopy at 7T |
1Radiology, C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden, Netherlands, 2Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark |
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Double diffusion encoding spectroscopy (DDES) offers the unique ability to estimate compartment and cell-specific micro-anisotropy (μFA) in vivo. Recently, this method allowed the estimation of intracellular micro-anisotropy in the white matter. Here, we propose to measure the μFA in different diffusion weighting settings to explore intra- and extracellular μFA in both white (WM) and grey matter (GM). We show that intracellular μFA is similar in both WM and GM, but extracellular space in WM is significantly more anisotropic compared to GM. |
| 57
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8:27
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MRS Extended by Oscillating Diffusion Gradients as a Probe for Investigation of Human Brain Tissue Microstructure |
1Depts. Radiology and Biomedical Research, Bern, Switzerland |
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Pulsed diffusion and oscillating diffusion gradients implemented in a semi-Laser sequence for measuring at long and short diffusion times were tested in a phantom and applied in vivo. Metabolite diffusion constants measured in human gray matter in 6 healthy volunteers at short diffusion times were significantly higher than those determined at long diffusion times, suggesting an enhanced sensitivity to diffusion on the cellular and subcellular level. |
| 58 | 8:39
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Oscillating-gradient diffusion-weighted MRI provides accurate cell radii in tumor spheroids |
1Translational Research Imaging Center (TRIC), University Hospital Muenster, Muenster, Germany, 2Institute of Physiological Chemistry and Pathobiochemistry, University Hospital Muenster, Muenster, Germany, 3Bruker BioSpin, Ettlingen, Germany |
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Diffusion weighted MRI using oscillating gradients has previously been shown to provide microstructural information on celllularity in tumors, which may serve as marker for monitoring therapy response. Which geometrical model for analysis of such data provides most reliable results, is, however, a matter of debate. Here, we used the IMPULSED approach, and show that cell radii in tumor spheroids of three different cell lines can be determined with high accuracy. In an in vivo model, however, deviations from radii determined by laser scanning microscopy were found. |
| 59
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8:51
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In-vivo Neural Soma Imaging Using B-tensor Encoding and Deep Learning |
1Centre for Medical Image Computing, University College London, London, United Kingdom, 2Great Ormond Street Institute of Child Health, University College London, London, United Kingdom, 3Siemens Healthcare Ltd, Frimley, United Kingdom |
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Diffusion MRI is successfully used to map white matter in the brain. In this work we develop a new clinically viable technique with particular focus on grey matter microstructure. To capture the heterogeneous morphology of grey matter, it is imperative to disentangle cylindrical and spherical geometries commonly attributed to neurites and neural soma. We achieve this by leveraging the latest advances in B-tensor encoding and deep learning techniques and present microstructural feature maps of neurites and neural soma in-vivo in the human brain. |
| 60
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9:03
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COMPARISON OF DIFFERENT TENSOR ENCODING COMBINATIONS IN MICROSTRUCTURAL PARAMETER ESTIMATION |
1Cardiff University Brain Research Imaging Center (CUBRIC), School of Psychology, Cardiff University, Cardiff, United Kingdom, 2School of Psychology, Faculty of Health Sciences, Australian Catholic University, Melbourne, Victoria, 3065, Australia |
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Diffusion-weighted imaging provides information to study the brain microstructure. Several studies in the literature have shown that there is degeneracy in the estimated parameters for a commonly used microstructural model. B-tensor encoding is one of the strategies that has been proposed to solve the degeneracy. The combination of linear-spherical tensor encoding (LTE+STE) and linear-planar (LTE+PTE) have been utilized in previous works. In this paper, we compare different combinations of b-tensor encoding, (LTE+STE), linear-planar (LTE+PTE), planar-spherical (PTE+STE) and linear-planar-spherical (LTE+PTE+STE). We also compare the results of fit using a nonlinear least square algorithm and microstructure imaging of crossing (MIX) method. The results show that the combination of tensor encodings with MIX fitting algorithm leads to lower bias and higher precision in the parameter estimates than single tensor encoding. |
| 61
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9:15
|
Beyond the Standard Model in Spinal Cord |
1Center of Functionally Integrative Neuroscience (CFIN) and MINDLab, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark, 2Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark, 3Champalimaud Neuroscience Programme, Lisbon, Portugal |
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A prevalent model for the diffusion signal from |
| 62 | 9:27
|
Tangential and radial diffusion in human primary somatosensory and motor cortex: evidence from in-vivo line-scan acquisitions at 7T with 250–500 micron radial resolution |
1Harvard Medical School, Boston, MA, United States, 2Department of Radiology, Boston Children's Hospital, Boston, MA, United States, 3Department of Radiology, Brigham and Women's Hospital, Boston, MA, United States, 4Department of Radiology, Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden, 5Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, United States, 6Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States |
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Eight healthy volunteers were scanned at 7T using a line-scan diffusion sequence with each line prescribed perpendicularly to primary somatosensory (S1) and motor (M1) cortex, and with 250–500 micron resolution along the line. We observed tangential diffusion in S1 and radial diffusion in M1, consistent with prior reports, but with the high radial resolution used here enabling us to identify the deep layers of S1—where high diffusion anisotropy was seen—as the source of the tangential diffusion, with low anisotropy in the upper layers. In M1, radial diffusion with moderate anisotropy was seen at nearly all cortical depths. |
| 63 | 9:39
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Multi-Dimensional Diffusion MRI of the Human Sciatic Nerve |
1Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, 2Radiology, Harvard Medical School, Boston, MA, United States, 3Radiology, Brigham and Women's Hospital, Boston, MA, United States, 4Random Walk Imaging AB, Lund, Sweden, 5Philips Healthcare, Markham, ON, Canada, 6Philips Healthcare, Dallas, TX, United States, 7Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States |
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Multi-dimensional diffusion MRI is a promising new tool to assess tissue microstructure. Here, we developed a high-resolution protocol that overcomes the challenges of nerve imaging in humans (e.g., the influence of fat, short-T2s) and translated the method to the sciatic nerve in the thigh. Preliminary results showed that measures of microscopic fractional anisotropy in sciatic nerve were 1) similar to reported measures in white matter and 2) were repeatable across scans in the same subject. Additional comparisons to conventional diffusion encodings of the sciatic nerve suggest that multi-dimensional diffusion MRI may yields more specific measures of nerve microstructure. |
| 64 | 9:51
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Temporal Diffusion Ratio (TDR): A Diffusion MRI technique to map the fraction and spatial distribution of large axons in the living human brain |
1NatBrainLab, King's College London, London, United Kingdom, 2Department of Physics and Geology, University of Perugia, Perugia, United Kingdom, 3CUBRIC, Cardiff University, Cardiff, United Kingdom |
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This work presents a new approach to mapping the fraction and spatial distribution of large axons (d>3μm) across white matter (WM) in the living human brain. By collecting high b-value (b=8000 s/mm2) diffusion MRI data at two diffusion times on a Connectome scanner, we were able to generate a new contrast specific to the characteristic signal decay of large axons at different diffusion times. Using this approach, we were able to identify and discriminate consistently some of the major WM pathways expected to carry the largest axons within the human brain. WM characterisation using TDR can offer important and practical clinical applications. |
| 65
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10:03
|
Combined Diffusion-Relaxometry MRI to Identify Dysfunction in the Human Placenta |
1Centre for Medical Image Computing, University College London, London, United Kingdom, 2Biomedical Engineering, Kings College London, London, United Kingdom, 3Centre for the Developing Brain, King's College London, London, United Kingdom, 4Women's Health Department, King's College London, London, United Kingdom |
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We demonstrate simultaneous diffusion-relaxometry in the in-vivo human placenta. Two MRI measures widely used for characterizing the placenta, T2* relaxometry and diffusion, are combined into a single scan. We estimate the T2*-ADC spectrum, which enables study of the coupling between these complementary MR contrasts by disentangling joint effects. This gives new potential for improved characterisation of placental dysfunction compared to single contrast MRI and/or ultrasound, and hence could inform improved evaluation of pregnancy complications. |
| 66
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8:15
|
Wireless motion tracking with short-wave radiofrequency |
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland |
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For robust and high-quality brain imaging rigid body motion correction plays an increasingly important role. We propose a wireless motion tracking method based on short-wave RF signal transmission that does not require a direct line of sight and can penetrate tissue and plastics between detector and marker providing a unprecedented degree of freedom in marker placement and fixation. Single digit micrometer precision during an EPI sequence could be demonstrated even at high tracking bandwidth of 100 Hz with minimal latency and operating independently from the scanner. |
| 67
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8:27
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Prospective motion correction using a wireless device that combines vector observations of the static magnetic field and the rate of change of the gradient fields. |
1Human Biology, University of Cape Town, Cape Town, South Africa, 2Cape Universities Body Imaging Centre (CUBIC), University of Cape Town, Cape Town, South Africa, 3Athinoula A. Martinos Center, Massachusetts General Hospital, Charlestown, MA, United States, 4Radiology, Harvard Medical School, Boston, MA, United States |
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Using external hardware to track patient motion allows for high frequency, accurate prospective motion correction that is robust to changes in coil set-up and subject anatomy. However, this typically comes at the expense of increased hardware complexity, difficulties in marker placement and in some cases cross-calibration. To address some of these challenges, we have developed a small, battery powered marker that uses the three-dimensional gradient spatial encoding, visible through Faraday induction, for vector-based position and orientation estimates. The device enables wireless, calibration-free prospective motion correction that can be used on an ad-hoc basis in an unmodified scanner. |
| 68
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8:39
|
Enhanced reliability of NMR marker localization using real-time field tracking |
1Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland, 2Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland |
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Tracking head mounted NMR markers enables to carry out prospective motion correction for brain MRI. In this work, a NMR marker tracking method that facilitates easy deployment is characterized with respect to tracking reliability in the presence of hardware drift and other imperfections. The method is then applied to a high-resolution in-vivo scan with long scan duration. |
| 69
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8:51
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Intra echo train correction for constant flip angle Turbo Spin Echo sequence |
1Department of Radiology, Medical Physics, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany |
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Turbo spin echo (TSE) sequence is one of the “workhorses” used in routine clinical applications for MR imaging [1]. However, long scan time and segmented k-space acquisition make it particularly susceptible to |
| 70
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9:03
|
Free-breathing placental and fetal MR angiography using continuous stable state acquisition (Sweep) |
1Biomedical Engineering,School of Biomedical Engineering & Imaging Sciences, Kings College London, London, United Kingdom, 2Department of Women and Children’s Health, School of Life Course Sciences, Kings College London, London, United Kingdom, 3Centre for the Developing brain, School of Biomedical Engineering & Imaging Sciences, Kings College London, London, United Kingdom |
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Major obstetric complications such as pre-eclampsia and intrauterine growth restriction can result from malformations in the circulation of the fetus and placenta. Robust, high resolution in-utero MR angiography has the potential to be a valuable tool in identification and monitoring of these disorders but is hampered by the presence of complex motion, ineffective breath holds and lack of safe contrast agents. Here we present a motion compensated method for visualising the vascular networks in the fetus and placenta using respiration resolved 2D inflow angiography with efficient and dense spatiotemporal sampling and retrospective correction. |
| 71 | 9:15
|
Propeller Echo-Planar Time-resolved Imaging with Dynamic Encoding (PEPTIDE) |
1A.A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, United States, 2Harvard-MIT Health Sciences and Technology, MIT, Cambridge, MA, United States |
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Echo-Planar Time-resolved Imaging (EPTI) is a recent multi-shot EPI-based approach that allows extremely rapid acquisition of distortion and blurring free multi-contrast imaging and mapping. In this work, a motion robust extension to EPTI, termed PEPTIDE, is presented. Combining Propeller-like rotations into the EPTI sampling strategy, this technique brings significant tolerance to shot-to-shot motion and B0 phase variations, as well as opening up opportunities for further acceleration. |
| 72 | 9:27
|
Motion-insensitive 3D T2*-weighted MRI using a motion- and B0 field-navigator |
1National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States |
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The ability of T2*-weighted (or susceptibility-weighed) MRI to provide structural and functional information about the brain is affected by B0 field fluctuations associated with head motion, which are inadequately accounted for in current correction approaches. Here, a 3D EPI navigator was developed to measure head motion, map the associated complex B0 field changes and correct their effects in T2*-weighted GRE MRI. Adequate temporal resolution of the navigator was achieved by implementing 2D parallel imaging with controlled aliasing. A fast reconstruction strategy is proposed to retrospectively correct the motion artifacts, overcoming limitations of prospective B0 corrections inadequately dealing with the spatially complex B0 changes. |
| 73
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9:39
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Pilot tone-based prospective respiratory motion correction for 2D cine cardiac MRI |
1Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany, 2Siemens Healthcare, Erlangen, Germany |
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Respiratory motion during data acquisition can introduce strong motion artefacts in 2D cine cardiac MR images. The commonly used breathhold method minimizes these artefacts, but also limits achievable image resolution and requires patient cooperation. Here we present a prospective motion correction technique using RF pilot tone signals with high temporal resolution. A calibration scan was carried out to convert signal intensity changes of the pilot tone to displacements of the heart due to breathing. The proposed approach was evaluated in four healthy volunteers and allowed for free-breathing 2D cine MR with high image quality. |
| 74
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9:51
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Network Accelerated Motion Estimation and Reduction (NAMER): Accelerating forward model based retrospective motion correction using a convolutional neural network |
1A.A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States, 2Program in Biophysics, Harvard University, Cambridge, MA, United States, 3Harvard Medical School, Boston, MA, United States, 4Siemens Healthineers AG, Erlangen, Germany, 5Harvard-MIT Division of Health Sciences and Technology, MIT, Cambridge, MA, United States |
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Retrospective motion correction techniques have the potential to improve clinical imaging without altering the workflow or acquisition sequence. Yet, they suffer from long reconstruction times and poor conditioning. To address these problems, we developed a Network Accelerated Motion Estimation and Reduction method (NAMER) within a data-consistency based forward model approach to motion parameter estimation. The neural net accelerates convergence up to 15-fold as well as improving final image quality. The ML+MR physics motion correction method combines the speedup provided by fast convolutional neural networks with the robustness of a forward model-based data-consistency reconstruction. |
| 75
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10:03
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Retrospective motion correction using deep learning |
1School of Biomedical Engineering & Imaging Sciences, King's College London, London, United Kingdom, 2Department of Radiology, University Hospital Tübingen, Tübingen, Germany, 3Institute of Signal Processing and System Theory, University of Stuttgart, Stuttgart, Germany |
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Motion is the main extrinsic source for imaging artifacts which can strongly deteriorate image quality and thus impair diagnostic accuracy. Numerous motion correction strategies have been proposed to mitigate or capture the artifacts. These methods have in common that they need to be applied during the actual measurement procedure with already a-priori knowledge about the expected motion type and appearance. We propose the usage of deep neural networks to perform retrospective motion correction in a reference-free setting, i.e. not requiring any a-priori motion information. Feasibility and influences of motion type and origin as well as optimal architecture are investigated. |
| 76 | 8:15
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Metabolic Imaging of Traumatic Brain Injuries Using Ultrahigh-Resolution 1H-MRSI |
1Radiology Department, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, China, 2Institute for Medical Imaging Technology, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China, 3Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 4Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 5Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States |
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Traumatic brain injury (TBI) is a significant public health problem that contributes to a large number of injury-induced deaths each year. MRSI has long been recognized as a powerful tool for detection of neurometabolic alterations induced by TBI; however, most existing MRSI studies of TBI are limited by low resolution which severely reduce the detection sensitivity. In this study, we performed MRSI scans on TBI patients using a newly developed ultrahigh-resolution 1H-MRSI technique. Our experimental study yielded very encouraging results and showed that ultrahigh-resolution MRSI can capture neurometabolic alterations induced by TBI effectively. |
| 77 | 8:27
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Connectivity Reorganization after Repetitive Mild Traumatic Brain Injury is Impact Site Associated |
1Neuroscience Research Center, Taipei Medical University, Taipei, Taiwan, 2Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan, 3Translational Imaging Research Center, Taipei Medical University Hospital, Taipei, Taiwan, 4Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan, 5Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, Taiwan, 6Department of Medical Imaging, Taipei Medical University Hospital, Taipei, Taiwan |
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Different degrees of functional reorganization associated with |
| 78 | 8:39
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Free water elimination is necessary to characterize Diffuse Axonal Injury in moderate Traumatic Brain Injury |
1Penn Patho-Connectomics Lab, Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Molecular, Cellular, and Biomedical Sciences, CUNY School of Medicine, The City College of New York, New York, NY, United States |
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As the prevalence of diffusion MRI for clinical use grows, it is important to address the influence of injury-related extracellular water on the clinical interpretation of diffusion measures in conditions such as traumatic brain injury (TBI). The presence of extracellular free water from edema pollutes the estimation of diffusion measures, leading to flawed conclusions about the microstructure of the white matter. We demonstrate that Fernet, a robust single-shell free-water elimination method, can be used to decouple the effects of extracellular edema and tissue damage, to improve clinical understanding of the effects of injury on underlying white matter structure. |
| 79 | 8:51
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White matter changes caused by mild traumatic brain injury in mice |
1Neurosciences and Mental Health, Hospital for Sick Children, Toronto, ON, Canada, 2Physiology, University of Toronto, Toronto, ON, Canada, 3Mouse Imaging Centre, Hospital for Sick Children, Toronto, ON, Canada, 4Medical Biophysics, University of Toronto, Toronto, ON, Canada |
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White matter pathology following mild traumatic brain injury (mTBI) is complex and unlikely to be characterized by a single neuroimaging metric. DTI has been used to probe white matter microstructure, but is known to be non-specific. We show that the orientation dispersion index from the NODDI model may be more sensitive to white matter damage following mTBI in a mouse closed-skull impact model. Combined with quantitative susceptibility mapping, our data suggest minimal overt myelin loss, but progressive white matter injury, which may include myelin disruption, up to 6 weeks post-mTBI. |
| 80
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9:03
|
Exploring static and dynamic functional connectivity differences between cognitively impaired and non-impaired active professional fighters |
1Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV, United States, 2University of Colorado Boulder, Boulder, CO, United States |
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Both static and dynamic FC differences between cognitively impaired and non-impaired active fighters were explored using resting-state fMRI. Reduced network strength in anterior default mode network and cerebellar network were observed in impaired fighters, as compared to the non-impaired fighters. Four dynamic FC states were identified with k-means clustering and abnormities in state 2 were observed in impaired fighters. Higher classification accuracy was obtained using dynamic FC matrices as input features to a non-linear classifier, as compared to using static FC matrices as input features, which demonstrates that the time-varying brain activities carry richer cognitive impairment-related information. |
| 81 | 9:15
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In vivo magnetic resonance imaging demonstrates that subcutaneous administration angiotensin-(1-7) is neuroprotective following severe traumatic brain injury in mice |
1Pharmacology and Molecular Therapeutics, Program in Molecular and Cell Biology, Uniformed Services University, Bethesda, MD, United States, 2Radiology and Radiological Sciences, Uniformed Services University, Bethesda, MD, United States, 3Center for Neuroscience and Regenerative Medicine, Henry M. Jackson Foundation, Bethesda, MD, United States, 4Center for Neuroscience and Regenerative Medicine, Uniformed Services University, Bethesda, MD, United States |
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The effectiveness of angiotensin-(1-7), a novel peptide derivative of angiotensin II, for the treatment of traumatic brain injury in mice have been investigated using non-invasive MRI techniques. Our results demonstrate that treatment of mice with angiotensin-(1-7) after control cortical impact reduced lesion volume compared to saline-treated mice. The MRI data are validated by histological results. The observed data show for the first time that angiotensin-(1-7) has potential therapeutic use for TBI. |
| 82 | 9:27
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Advanced diffusion-weighted imaging reveals distinct neuropathological processes in concussed youth |
1Neurology and Neurosurgery, McGill University, Montreal, QC, Canada, 2Computer Science, University of Sherbrooke, Sherbrooke, QC, Canada, 3Pediatrics, Montreal Children's Hospital, Montreal, QC, Canada |
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Because concussions are undetectable by conventional medical imaging, their diagnosis is dependent on symptoms, which can be unreliable. Conventional diffusion-weighted imaging (DWI) can detect abnormalities in concussed individuals, but lack specificity and hence cannot provide information about the underlying neuropathology, especially during the sub-acute stage of concussions where different neuropathologies occur simultaneously. In this study, we used emerging DWI methods to disambiguate the neuropathological basis of a common concussive symptom, memory problems. We found evidence of different white-matter neuropathologies in concussed youth which contributed differently to memory problems. This study is an important step towards developing neuropathologically-informed biomarkers of concussion. |
| 83 | 9:39
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Traumatic Brain Injury fast-forwards Alzheimer's parthenogenesis: A radiological-pathological investigation in a mouse AD model. |
1The Queensland Brain Institute, The University of Queensland, Brisbane, Australia |
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Traumatic brain injury (TBI) today is the strongest epigenetic risk factor for Alzheimer's disease (AD) . To date, the underlying mechanisms of these comorbidities are still unclear, which has hindered diagnosis and monitoring. We have investigated the effect of TBI in a PR5 tauopathy model using Diffusion Tensor Imaging and histology. We concluded that neuroinflammation is a key trigger in worsening taupathy accumulation and MRI can detect this cascade of events at an early stage. This study will enhance our understanding, not only of the effect of TBI progression in AD, but the potential of MRI for translational purposes. |
| 84 | 9:51
|
Mild traumatic brain injury accelerates progressive brain ageing |
1Department of Medical Imaging, the First Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710061, China, Xi'an, Shaanxi, China, 2The Key Laboratory of Biomedical Information Engineering, Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi’ an Jiaotong University, Xi’ an, 710049, China, Xi'an, Shaanxi, China |
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To analyze mild traumatic brain injury (mTBI) accelerating brain ageing, we trained a brain age prediction model based on diffuse tensor image (DTI) data by using machine learning method. Conducting a longitudinal observation from acute to chronic stages, we found that mTBI accelerated brain age process from acute stage to chronic stage. This prolonged abnormal brain ageing level could be predicted by information processing speed. In conclusion, mTBI persistently induces brain ageing process deviating from normal trajectory, and this process can be revealed by information processing speed at very early period after injury. |
| 85 | 10:03
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Changes In White Matter Microstructure In Relation To Working Memory After Mild Traumatic Brain Injury: Multi-Shell Diffusion MRI Study |
1Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, NYU School of Medicine, New York, NY, United States, 2Bernard and Irene Schwartz Center for Biomedical Imaging, NYU School of Medicine, New York, NY, United States, 3Department of Rehabilitation Medicine, NYU School of Medicine, New York, NY, United States |
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Working memory is a critical cognitive functions affected after mild traumatic brain injury (MTBI). We investigate associations between white matter (WM) microstructure and working memory, using multi-shell diffusion MRI and WAIS-IV subtests. The significant positive correlations observed in normal controls (NC) between tissue microstructure markers (fractional anisotropy (FA) and axonal water fraction (AWF)) with letter-number sequencing (LNS) were not present in MTBI. For MTBI, a significant positive correlation was observed between axial kurtosis (AK) and digit span backward (DSB), not seen in NC. These results show clear differences in the relationship between WM microstructure and working memory performance after injury. |
| 86
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8:15
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Acute effects of nicotine-free e-cigarette aerosol inhalation on vascular function detected by multi-parametric quantitative MRI |
1Radiology, Laboratory for Structural, Physiologic and Functional Imaging, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States, 2Institute for Environmental Medicine and Department of Phisiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States |
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Electronic cigarette (e-cig) vaping has been causally associated with arterial stiffening, oxidative stress, and impaired vasodilatory capacity. Here we investigated acute effects of nicotine-free e-cig vaping in terms of aortic pulse-wave velocity, a marker of arterial stiffness, and measures of peripheral and neurovascular reactivity to induced hypoxia, by means of a quantitative MRI protocol. Flow mediated dilation, a marker of endothelial function, was significantly impaired after vaping; moreover, the peripheral vascular response to cuff-induced ischemia and neurovascular reactivity were altered. Considering the increasing use of e-cig among youth, these results underscore the urgency of further investigation. |
| 87
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8:27
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Stochastic Flow Co-expression Signatures: A novel concept for volumetric 4D flow assessment with application to aortic valve disease |
1Radiology, Northwestern University, Chicago, IL, United States, 2University of Colorado, Anschutz Medical Campus, Aurora, Colo., CO, United States, 3Cardiac Surgery, Northwestern University, Chicago, IL, United States, 4Mayo Clinic, Rochester, MN, United States, 5Cardiology, Northwestern University, Chicago, IL, United States |
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Studies have shown an impact of aortic valve disease, as |
| 88
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8:39
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Machine learning for automatic three-dimensional segmentation of the aorta in 4D flow MRI |
1Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 2Department of Cardiothoracic Surgery, Amsterdam University Medical Centers, AMC, Amsterdam, Netherlands, 3Department of Radiology & Nuclear Medicine, Amsterdam University Medical Centers, AMC, Amsterdam, Netherlands |
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In this study we present a machine learning convolutional neural network (CNN) for automatic segmentation of the aorta used for peak systolic wall shear stress (WSS) assessment from 4D flow MRI data. The automated three-dimensional WSS profiles (WSSMACHINE) were compared with WSS calculated using manually (WSSMAN) created segmentations. Bland-Altman and orthogonal regression analysis revealed good agreement between WSSMAN and WSSMACHINE in terms of small mean differences and slopes and intercepts close to unity and zero respectively. The CNN has the ability to drastically accelerate aortic segmentation from 4D flow MRI data, which will greatly improve the clinical applicability of WSS. |
| 89
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8:51
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5D Flow Tensor MRI for Mapping Reynolds Stresses in the Aorta |
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland |
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We present a 5D Flow MRI approach for mapping the Reynolds stress tensor in the in-vivo aorta within 6 minutes. First and second statistical moments of fluctuating velocities are encoded using six different velocity encoding gradient directions embedded in a Cartesian Golden angle undersampling scheme with data-driven motion detection and locally low-rank imaging reconstruction. It is demonstrated that this approach permits a time-efficient assessment of velocity vector fields, turbulent kinetic energy and Reynolds shear stresses of the aorta in-vivo. |
| 90
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9:03
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5D flow MRI: A free-running, fully self-gated, radial imaging framework for cardiac and respiratory motion-resolved assessment of 3D blood flow dynamics |
1Radiology, Northwestern University, Chicago, IL, United States, 2Biomedical Engineering, Northwestern University, Evanston, IL, United States, 3Radiology, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, 4Advanced Clinical Imaging Technology, Siemens Healthcare AG, Lausanne, Switzerland |
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Recent advances have enabled fully self-gated high resolution imaging using a Free-running framework, where data is continuously collected, retrospectively binned into cardiac and respiratory phases, and reconstructed using multi-dimensional compressed sensing (CS) for efficient functional and anatomical imaging of the heart. Here, we propose a novel expansion of this framework to cardiac and respiratory motion-resolved 3D flow imaging— or 5D flow MRI. The findings of this study show that 5D flow MRI is feasible in-vitro and in-vivo and can depict cardiac and respiratory-resolved 3D hemodynamics. |
| 91
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9:15
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Chronological 4D Flow MRI Assessment of Pulmonary Artery Stenosis Stent Treatment |
1Biomedical Engineering, University of Wisconsin - Madison, Madison, WI, United States, 2Mechanical Engineering, University of Wisconsin - Madison, Madison, WI, United States, 3Pediatrics, University of Wisconsin - Madison, Madison, WI, United States, 4Radiology, University of Wisconsin - Madison, Madison, WI, United States |
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Branch pulmonary artery stenosis, a common complication after surgical repair of congenital heart disease, is treated with intravascular stenting. As the acute and chronic effects of stenting are unknown this study uses 4D Flow MRI to serially monitor hemodynamics in a porcine model of pulmonary artery stenosis. Intervention increases flow through the stenosed artery, but not to a normal value. Chronologically, stenosis flow is found to increase immediately after stenting and then remain constant. |
| 92 | 9:27
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4D Flow MRI Quantification of Congenital Shunts: Comparison to Invasive Catheterization |
1Cardiovascular Medicine, Univeristy of California San Diego, San Diego, CA, United States, 2Radiology, University of California San Diego, San Diego, CA, United States |
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When used for quantification of intracardiac and extracardiac shunts, 4D Flow MRI has been shown to have high reproducibility between measurement location and observers, and high consistency with MRI measurements of stroke volume. However, there has been little data showing its relationship to invasive measurements obtained during catheter angiography, which serves as the clinical reference standard at many institutions. We retrospectively evaluated patients who underwent 4D Flow MRI and invasive right heart catheterization during clinical work-up of congenital heart disease. 4D Flow measurements correlated extremely well with invasive measurements of shunt fraction by oximetry and cardiac output by Fick calculation in patients without a shunt. |
| 93 | 9:39
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Comprehensive hemodynamic assessment in non-sedated neonates with CHD using motion-robust 3D radial phase-contrast MR |
1Translational Medicine, The Hospital for Sick Children, Toronto, ON, Canada, 2Physiology, University of Toronto, Toronto, ON, Canada, 3Medical Biophysics, University of Toronto, Toronto, ON, Canada, 4Heart Centre, The Hospital for Sick Children, Toronto, ON, Canada, 5Paediatrics, University of Toronto, Toronto, ON, Canada |
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The complex hemodynamics in congenital heart disease (CHD) are difficult to visualize and quantify in neonates and young infants. Here we present a novel motion robust and respiratory-resolved acquisition and reconstruction pipeline that addresses the need for rapid, high spatial resolution imaging in these patients. 3D cardiac flow is visualized and quantification comparison with 2D PC measurements is exhibited. This technique opens the door for more comprehensive investigations into the wealth of hemodynamic information not normally considered in surgical planning and follow-up evaluations of CHD. |
| 94
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9:51
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Sensitivity Study of 4D flow Left Ventricular Hemodynamics Parameters in Healthy Volunteers and Dilated Cardiomyopathy Patients |
1Millennium Nucleus for Cardiovascular Magnetic Resonance, Santiago, Chile, 2Biomedical Imaging Center, Pontificia Universidad Católica de Chile, Santiago, Chile, 3Electrical Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile, 4Biomedical Engineering, King's College London, London, United Kingdom, 5Structural and Geotechnical Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile, 6Institute for Biological and Medical Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile, 7Radiology Department, Pontificia Universidad Católica de Chile, Santiago, Chile |
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Segmentation of the Left Ventricle (LV) from MRI and 4D flow datasets is an essential step for quantifying clinical indices and hemodynamic parameters. Automatic methods for heart segmentation are generally validated using cardiac volumetric and global ejection fraction. However, little is known about the changes |
| 95
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10:03
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Simultaneous Measurement of Myocardial and Blood Flow Velocities using a Dual Echo Dual Velocity Encoding (DEDV) Phase-Contrast MRI (PC-MRI) Approach for Evaluating Left Ventricular (LV) Diastolic Function |
1Department of Physics, University of Houston [Main Campus], Houston, TX, United States, 2Department of Diagnostic and Interventional Radiology, Baylor St. Luke's Medical Center, Houston, TX, United States, 3Philips Healthcare, Gainesville, FL, United States, 4Physics and Texas Center for Superconductivity, University of Houston [Main Campus], Houston, TX, United States |
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PC-MRI based Left ventricular (LV) diastolic indices such as E/Em ratio are conventionally estimated from two separate PC acquisitions: One sensitive to myocardium and the other to blood velocities. This ensures optimal velocity to noise ratio and zero velocity aliasing. A rapid single acquisition (dual echo dual VENC PC-MRI method) sensitive to both low and high velocities was developed. Preliminary result on 7 healthy subjects demonstrated a high agreement of LV diastolic indices obtained from the proposed and conventional method. |
| 96 | 8:15
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Technical Feasibility of Three-Dimensional Magnetic Resonance Elastography for Assessing Endometrial Carcinoma |
1Department of Radiology, The third affiliated hospital of Sun Yat-sen University, Guangzhou, China, 2Department of Radiology, Mayo Clinic, Rochester, MN, United States, 3MR Research China, GE Healthcare, Beijing, China |
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Endometrial carcinoma (EC) is one of the most common primary malignant tumors in women worldwide. Tumor grades, International Federation of Gynecology and Obstetrics (FIGO) stage and myometrial invasion of EC are important factors for treatment planning and prognosis. We explored the potential value of MR elastography (MRE) for the prediction of tumor grades, FIGO stage and myometrial invasion of EC. Our study showed that mean tumor stiffness may be a useful metric for differentiating well or moderately differentiated EC from poorly differentiated EC and for differentiating superficial invasion from deep myometrial invasion in EC. |
| 97 | 8:27
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Value of R2* and T2* in differential diagnosis of uterine sarcoma and degenerated hysteromyoma |
1The First Affiliated Hospital of Dalian Medical University, DaLian, China, 2GE Healthcare, MR Research, Beijing, China |
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To investigate the clinical value of enhanced T2 star weighted angiography (ESWAN) quantitative parameters in differential diagnosis of uterine sarcoma and degenerated hysteromyoma. |
| 98 | 8:39
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High b-value diffusion-weighted MRI in cervical cancer detection: Preliminary results |
1Center for MR Research,University of Illinois at Chicago, Chicago, IL, United States, 2Department of Diagnostic Radiology, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China, 3Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, United States, 4Departments of Radiology and Neurosurgery, University of Illinois at Chicago, Chicago, IL, United States |
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Cervical cancer remains one of the leading causes of cancer-related deaths in women. High b-value DWI with non-Gaussian modeling has made it possible to probe tumor tissue complexity, microstructures, and heterogeneity. We employed a non-Gaussian diffusion model based on continuous-time random walk (CTRW) theory to differentiate normal from cancerous cervical tissues. The CTRW parameters (Dm and β) exhibited a statistically significant difference between cancerous cervical tissue and normal. Our preliminary results illustrate the added value of high b-value DWI for cervical cancer detection, and point to a possible direction of diagnosing or staging cervical cancer using non-Gaussian diffusion models. |
| 99 | 8:51
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Three-Dimensional Amide Proton Transfer MR Imaging for Cervical Cancer: Initial Experience |
1Peking Union Medical College Hospital, Beijing, China, 2Philips Healthcare China, Beijing, China |
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The present study demonstrates the feasibility of 3D APT MR imaging for uterine cervix on the largest sample size to our knowledge. As the clinical robustness of APT imaging in the pelvis is what researchers concerned, our study investigated and revealed the excellent agreement in both image quality assessment and APT values measurement, even on small cervical lesions with maximum diameter less than 2cm. Our studies demonstrated that APT imaging could differentiate cervical cancer from normal cervix. Cervical cancer showed significant higher APT values than that of normal cervix. |
| 100 | 9:03
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Radiomics Analysis of tumor and peri-tumor tissue on T2-Weighted Imaging Improves Diagnostic Performance of Lymph Node Metastasis in Patients with Cervical Cancer |
1Department of Radiology, Henan Provincial People's Hospital, Zhengzhou, China, 2CAS Key Laboratory of Molecular Imaging, Institute of Automation, Beijing, China, 3School of Information and Electronics, Beijing Institute of Technology, Beijing, China, 4Cooperative Innovation Center of Internet Healthcare & School of Software and Applied Technology, Zhengzhou University, Zhengzhou, China |
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The tumor margin and peritumoral tissue play an important role in the process of LN metastasis. The aim of this study was to utilize radiomics analysis of tumor and peri-tumor tissue on T2 weighted image (T2WI) to improve LNM prediction ablility in cervical cancer patients. We found that peritumoral tissue of cervical cancer on T2WI showed favorable value in predicting LNM. The decision tree we proposed which incorporates the radiomics features of intratumoral and peritumoral tissue on T2WI and c-LN status can be potentially used for personalized preoperative evaluation of LNM and optimal treatment regimen selection in cervical cancer patients. |
| 101 | 9:15
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Prediction of Neoadjuvant Chemoradiation Therapy Response in Rectal Cancer Using Radiomics Compared to Deep Learning Based on Pre-Treatment and mid-RT MRI |
1Department of Radiological Sciences, University of California, Irvine, CA, United States, 2Department of Radiation Oncology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China, 3Department of Radiation Oncology, Rutgers-The State University of New Jersey, New Brunswick, NJ, United States, 4Department of Radiology, E-Da Hospital and I-Shou University, Kaohsiung, Taiwan |
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The capability to predict patients’ response to neoadjuvant chemoradiation therapy is important for improving their management. The multi-parametric MRI (T2, DWI, DCE) performed before treatment and after 3-4 weeks of radiation were analyzed to predict final pathological response. Quantitative radiomics was performed using GLCM texture and histogram parameters, and also ROI and deep learning using convolutional neural network (CNN) were performed. Combining quantitative radiomics features with tumor volume and diffusion coefficient could achieve accuracy of 0.86 for pCR vs. non-pCR and 0.93 for GR vs. non-GR, and adding follow-up to pre-treatment MRI could improve accuracy, especially for CNN analysis. |
| 102
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9:27
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The feasibility of matching lymph nodes detected on USPIO-enhanced MRI with histopathology in rectal cancer |
1Radiology, Radboudumc, Nijmegen, Netherlands, 2Pathology, Radboudumc, Nijmegen, Netherlands, 3Surgery, Cansius-Wilhelmina hospital, Nijmegen, Netherlands, 4Surgery, Radboudumc, Nijmegen, Netherlands, 5Pathology, Cansius-Wilhelmina hospital, Nijmegen, Netherlands, 6Radboudumc, Nijmegen, Netherlands |
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Lymph node staging in rectal cancer based on imaging is a major challenge. Node-to-node matching is crucial to determine the histopathology of lymph nodes that are detected on in-vivo MRI. A workflow of in-vivo MRI, ex-vivo MRI and MR-guided pathology was set up for lymph nodes that were characterized on USPIO-enhanced MRI. Difficulties were seen in the node-to-node matching, in despite of the use of high-resolution 3D ex-vivo MRI to link in-vivo detected nodes to final pathology. |
| 103 | 9:39
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Enhanced T2 Star-Weighted Angiography (ESWAN) for Differentiating Borderline From Malignant Epithelial Ovarian Tumors |
1First Affiliated Hospital of Dalian Medical University, Dalian, China, 2GE Healthcare, Beijing, China |
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The aim of this study is to assess the fitted parameters of ESWAN in ovarian tumors and to investigate their potential in distinguishing borderline from malignant epithelial ovarian tumors, which can provide detailed information for clinical treatment. R2* and T2* in ESWAN were the key parameters for distinguishing borderline from malignant epithelial ovarian tumors. MR-ESWAN sequence can be used as non-enhancement quantitative indexes, which has a good application prospect. |
| 104 | 9:51
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Ex-vivo MR-guided pathology to improve lymph node staging in rectal cancer |
1Radiology, Radboudumc, Nijmegen, Netherlands, 2Pathology, Canisius-Wilhelmina hospital, Nijmegen, Netherlands, 3Surgery, Radboudumc, Nijmegen, Netherlands, 4Pathology, Radboudumc, Nijmegen, Netherlands |
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Pathological lymph node yield can be influenced by multiple factors. The use of ex-vivo MR guided pathology of rectal specimens could provide insight in the number and size of lymph nodes present in a rectal specimen and aid in an increased pathological lymph node yield. Therefore two series of rectal specimens were examined, one control group and one MR-guided group. Ex-vivo MRI revealed significantly more and significantly smaller lymph nodes without increasing the pathological yield. Small nodes appear to be difficult to harvest, presumably requiring a 3D approach for further improvement of pathological evaluation. |
| 105 | 10:03
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Using Amide Proton Transferto indentify Cervical Squamous Carcinoma/Adenocarcinoma and Evaluate its Differentiation Grade |
1Department of MR, the First Affiliated Hospital，Xinxiang Medical University, Weihui, China, 2MR Research China, GE Healthcare, Beijing, China |
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Amide proton transfer (APT) weighted imaging provides information about concentration of proteins/peptides with amide backbones. At present, there is no report on whether APT can be applied to cervical cancer. Our results show that APT can be used to preliminarily identify cervical squamous carcinoma, cervical adenocarcinoma and evaluate its differentiation grade. |
| 106 | 8:15
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3D R2* Mapping of the Placenta During Early Gestation Using Free-Breathing Multiecho Stack-of-Radial MRI at 3 T |
1Radiological Sciences, University of California Los Angeles, Los Angeles, CA, United States, 2Physics and Biology in Medicine, University of California Los Angeles, Los Angeles, CA, United States, 3Obstetrics and Gynecology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States, 4Pediatrics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States |
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Ischemic placental disease can lead to hypoxia and abnormal pregnancy outcomes. R2* mapping using MRI can characterize placental hypoxia. However, conventional Cartesian MRI requires breath-holding which limits volumetric coverage, resolution, and signal-to-noise ratio. In addition, little is known about the nominal range of placental R2* at 3T and during early gestation. Therefore, we developed and evaluated a new free-breathing 3D stack-of-radial (free-breathing radial) technique for full volume placental R2* mapping at 3T. Free-breathing radial demonstrated good repeatability and established a nominal range of placental R2* in pregnant subjects during early gestation at 3T. |
| 107 | 8:35
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5-Minute Double-Echo in Steady-State with Separated Echoes for Comprehensive Whole-Joint Knee MRI Assessment with and without a Proton-Density-Weighted Sequence |
1Department of Radiology, Stanford University, Stanford, CA, United States, 2Department of Bioengineering, Stanford University, Stanford, CA, United States, 3LVIS Corporation, Palo Alto, CA, United States, 4Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 5Department of Radiology, Harvard Medical School, Boston, MA, United States, 6Department of Orthopaedic Surgery, Stanford University, Stanford, CA, United States, 7Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center, Rotterdam, Netherlands, 8Department of Electrical Engineering, Stanford University, Stanford, CA, United States, 9Department of Neurology & Neurological Sciences, Stanford University, Stanford, CA, United States, 10Department of Neurology, Stanford University, Stanford, CA, United States |
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Most knee MRI protocols require 20+ minutes of scan time, leading to interest in expedited protocols. Here, we first demonstrate in a study with 35 patients and 5 readers that for diagnostic knee MRI, a 3D 5-minute quantitative double-echo steady-state (qDESS) sequence has high agreement with the conventional sequences, where the addition of a proton-density-weighted sequence engenders near-perfect agreement. In a second study with 51 patients and 2 readers, we demonstrate that qDESS with two-fold enhanced slice resolution using deep-learning-based super-resolution and T2 maps has high agreement with the conventional sequences, where both methods have similar agreement with arthroscopic findings. |
| 108 | 8:55
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3D chemical shift-encoded MRI for volume and composition quantification of abdominal adipose tissue during an overfeeding protocol in healthy volunteers |
1Univ Lyon, INSA‐Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, F69621, Lyon, France, 2Centre de Recherche en Nutrition Humaine Rhône-Alpes (CRNH-RA), Centre Hospitalier Lyon Sud, Pierre-Bénite, Lyon, France, 3Institut National de la Santé et de la Recherche Médicale Unit 1060, CarMeN Laboratory, Lyon 1 University, Oullins, France, 4Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, France, 5Hospices Civils de Lyon, Département d'imagerie digestive, CHU Edouard Herriot, Lyon, France |
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The aim of this work was to assess chemical shift-encoded MRI (CSE-MRI) method to quantify content and composition changes of fat storage in healthy volunteers during a 31 days overfeeding protocol while comparing CSE-MRI results with DEXA, MRS and Gas chromatography measurements. A total of 21 volunteers underwent a NMR protocol at 3T with an axial 3D CSE-MRI on abdominal region and spectroscopy acquired on subcutaneous adipose tissue, visceral adipose tissue and liver. The NMR protocol was used to analyze the volume and the fatty acid composition of abdominal adipose tissues, and the fat content in the liver. |
| 109 | 9:15
|
Prediction of Peripheral Nerve Stimulation Thresholds of MRI Gradient Coils using Coupled Electromagnetic and Neurodynamic Simulations |
1Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany, 2Dept. of Radiology, A.A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 3Harvard Medical School, Boston, MA, United States, 4Siemens Healthcare, Erlangen, Germany, 5Harvard-MIT Division of Health Sciences Technology, Cambridge, MA, United States |
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Peripheral Nerve Stimulation (PNS) has become the major limitation in many fast MRI sequences for state-of-the-art gradient systems. We present the first (to our knowledge) full PNS model for assessing magnetostimulation thresholds and a method to incorporate these thresholds as constraints in the coil-winding design phase. Our model consists of comprehensive female and male body models for EM simulations, co-registered atlases of peripheral nerves, and a neurodynamic model describing the nerve responses to induced electric fields. We validated our framework based on three commercial MR gradient systems and found close resemblance between simulated thresholds and experimentally obtained group PNS thresholds. |
| 110 | 9:35
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SPARKLING: variable-density k-space filling curves for accelerated MRI |
1NeuroSpin, CEA Saclay, Gif-sur-Yvette, France, 2Université Paris, Saclay, France, 3Parietal, INRIA, Palaiseau, France, 4ITAV USR3505 CNRS, Toulouse, France, 5IMT UMR 5219 CNRS, Toulouse, France, 6Université de Toulouse, Toulouse, France, 7Siemens Healthineers, Saint‐Denis, France, 8Université François‐Rabelais de Tours, INSERM, Imagerie et Cerveau UMR 930, Tours, France |
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This work reports the use of new non-Cartesian k-space trajectories whose improved efficiency allows to significantly reduce MR scan time with minimum deterioration of image quality. Instead of using simple geometrical patterns, we introduce an approach inspired from stippling techniques, which automatically designs optimized sampling patterns along any desired density by taking full advantage of the hardware capabilities. We use our strategy to accelerate the acquisition time of T2*-weighted scans acquired at 7T on in vivo human brains. We compare our method to standard non-Cartesian trajectories (spiral, radial) and demonstrate its superiority regarding image quality and robustness to system imperfections. |
| 111 | 9:55
|
Echo Planar Time-resolved Imaging (EPTI) |
1Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 2Harvard-MIT Health Sciences and Technology, MIT, Cambridge, MA, United States, 3Department of Electrical Engineering and Computer Science, MIT, Cambridge, MA, United States, 4Department of Radiology, Harvard Medical School, Boston, MA, United States |
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A new technique, termed Echo Planar Time-resolved Imaging (EPTI), was developed to address EPI’s geometric distortion and blurring, and to provide temporal signal evolution information across the EPI readout window. Using a small number of EPTI-shots, a time-series of multi-contrast images can be created free of distortion and blurring (up to 100 T2- and T2*-weighted images). This should make EPTI useful for numerous applications. Here, we demonstrated EPTI in brain to provide i) rapid simultaneous quantitative mapping of T2, T2*, proton density and tissue phase, as well as ii) multi-echo and quantitative T2* fMRI. |
8:15
|
Let's Exchange: CEST | |
8:35
|
Salty Treat: Sodium MRI | |
1NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, London, United Kingdom |
8:55
|
Look at All These Different Protons: 1H MRSI | |
1MPI for Biological Cybernetics, Germany |
9:15
|
Energizing Oncology: 31P MRSI | |
9:35
|
Drink the Tracer: Deuterium MRI | |
1MRRC, Yale University, New Haven, CT, United States |
9:55
|
Get Down with 2HG (Yeah You Know Me) | |
1Brigham and Women's Hospital, United States |
8:15
|
The Link to Biology & Renal Physiology: The Physiologist’s Perspective | |
8:30
|
Renal Diseases & Pathophysiology: The Nephrologist’s Perspective | |
8:45
|
Emerging Renal MR Imaging Biomarkers or Measurement Approaches: The MR Physics Perspective | |
1Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom |
9:00
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Technical Validation: Demonstrating Accuracy, Precision & Quality Assurance of Renal MR Biomarkers | |
1Radiology, Leiden University Medical Center, Voorburg, Netherlands |
9:15
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Computational Models, Predictive Analytics & Machine Learning for Advancing Renal Diagnostics & Theranostics | |
9:30
|
Potential Added Value of Novel Renal MR Biomarkers in Drug Development or Patient Management | |
9:45
|
Practical Challenges & Outcome of Multi-Center Studies & Clinical Renal MR Imaging Trials | |
| 11:15 | Introduction |
| 11:20 | Disruptors to the Way We Gather Data |
1Leiden University Medical Center, Netherlands |
| 11:38 | Disruptors to the Way We Visualize Data |
1Case Western Reserve University |
| 11:57 | Disruptors to the Way We Interpret Data |
| 106 | 13:45
|
3D R2* Mapping of the Placenta During Early Gestation Using Free-Breathing Multiecho Stack-of-Radial MRI at 3 T |
1Radiological Sciences, University of California Los Angeles, Los Angeles, CA, United States, 2Physics and Biology in Medicine, University of California Los Angeles, Los Angeles, CA, United States, 3Obstetrics and Gynecology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States, 4Pediatrics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States |
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Ischemic placental disease can lead to hypoxia and abnormal pregnancy outcomes. R2* mapping using MRI can characterize placental hypoxia. However, conventional Cartesian MRI requires breath-holding which limits volumetric coverage, resolution, and signal-to-noise ratio. In addition, little is known about the nominal range of placental R2* at 3T and during early gestation. Therefore, we developed and evaluated a new free-breathing 3D stack-of-radial (free-breathing radial) technique for full volume placental R2* mapping at 3T. Free-breathing radial demonstrated good repeatability and established a nominal range of placental R2* in pregnant subjects during early gestation at 3T. |
| 107 | 14:05
|
5-Minute Double-Echo in Steady-State with Separated Echoes for Comprehensive Whole-Joint Knee MRI Assessment with and without a Proton-Density-Weighted Sequence |
1Department of Radiology, Stanford University, Stanford, CA, United States, 2Department of Bioengineering, Stanford University, Stanford, CA, United States, 3LVIS Corporation, Palo Alto, CA, United States, 4Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 5Department of Radiology, Harvard Medical School, Boston, MA, United States, 6Department of Orthopaedic Surgery, Stanford University, Stanford, CA, United States, 7Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center, Rotterdam, Netherlands, 8Department of Electrical Engineering, Stanford University, Stanford, CA, United States, 9Department of Neurology & Neurological Sciences, Stanford University, Stanford, CA, United States, 10Department of Neurology, Stanford University, Stanford, CA, United States |
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Most knee MRI protocols require 20+ minutes of scan time, leading to interest in expedited protocols. Here, we first demonstrate in a study with 35 patients and 5 readers that for diagnostic knee MRI, a 3D 5-minute quantitative double-echo steady-state (qDESS) sequence has high agreement with the conventional sequences, where the addition of a proton-density-weighted sequence engenders near-perfect agreement. In a second study with 51 patients and 2 readers, we demonstrate that qDESS with two-fold enhanced slice resolution using deep-learning-based super-resolution and T2 maps has high agreement with the conventional sequences, where both methods have similar agreement with arthroscopic findings. |
| 108 | 14:25
|
3D chemical shift-encoded MRI for volume and composition quantification of abdominal adipose tissue during an overfeeding protocol in healthy volunteers |
1Univ Lyon, INSA‐Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, F69621, Lyon, France, 2Centre de Recherche en Nutrition Humaine Rhône-Alpes (CRNH-RA), Centre Hospitalier Lyon Sud, Pierre-Bénite, Lyon, France, 3Institut National de la Santé et de la Recherche Médicale Unit 1060, CarMeN Laboratory, Lyon 1 University, Oullins, France, 4Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, France, 5Hospices Civils de Lyon, Département d'imagerie digestive, CHU Edouard Herriot, Lyon, France |
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The aim of this work was to assess chemical shift-encoded MRI (CSE-MRI) method to quantify content and composition changes of fat storage in healthy volunteers during a 31 days overfeeding protocol while comparing CSE-MRI results with DEXA, MRS and Gas chromatography measurements. A total of 21 volunteers underwent a NMR protocol at 3T with an axial 3D CSE-MRI on abdominal region and spectroscopy acquired on subcutaneous adipose tissue, visceral adipose tissue and liver. The NMR protocol was used to analyze the volume and the fatty acid composition of abdominal adipose tissues, and the fat content in the liver. |
| 109 | 14:45
|
Prediction of Peripheral Nerve Stimulation Thresholds of MRI Gradient Coils using Coupled Electromagnetic and Neurodynamic Simulations |
1Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany, 2Dept. of Radiology, A.A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 3Harvard Medical School, Boston, MA, United States, 4Siemens Healthcare, Erlangen, Germany, 5Harvard-MIT Division of Health Sciences Technology, Cambridge, MA, United States |
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Peripheral Nerve Stimulation (PNS) has become the major limitation in many fast MRI sequences for state-of-the-art gradient systems. We present the first (to our knowledge) full PNS model for assessing magnetostimulation thresholds and a method to incorporate these thresholds as constraints in the coil-winding design phase. Our model consists of comprehensive female and male body models for EM simulations, co-registered atlases of peripheral nerves, and a neurodynamic model describing the nerve responses to induced electric fields. We validated our framework based on three commercial MR gradient systems and found close resemblance between simulated thresholds and experimentally obtained group PNS thresholds. |
| 110 | 15:05
|
SPARKLING: variable-density k-space filling curves for accelerated MRI |
1NeuroSpin, CEA Saclay, Gif-sur-Yvette, France, 2Université Paris, Saclay, France, 3Parietal, INRIA, Palaiseau, France, 4ITAV USR3505 CNRS, Toulouse, France, 5IMT UMR 5219 CNRS, Toulouse, France, 6Université de Toulouse, Toulouse, France, 7Siemens Healthineers, Saint‐Denis, France, 8Université François‐Rabelais de Tours, INSERM, Imagerie et Cerveau UMR 930, Tours, France |
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This work reports the use of new non-Cartesian k-space trajectories whose improved efficiency allows to significantly reduce MR scan time with minimum deterioration of image quality. Instead of using simple geometrical patterns, we introduce an approach inspired from stippling techniques, which automatically designs optimized sampling patterns along any desired density by taking full advantage of the hardware capabilities. We use our strategy to accelerate the acquisition time of T2*-weighted scans acquired at 7T on in vivo human brains. We compare our method to standard non-Cartesian trajectories (spiral, radial) and demonstrate its superiority regarding image quality and robustness to system imperfections. |
| 111 | 15:25
|
Echo Planar Time-resolved Imaging (EPTI) |
1Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 2Harvard-MIT Health Sciences and Technology, MIT, Cambridge, MA, United States, 3Department of Electrical Engineering and Computer Science, MIT, Cambridge, MA, United States, 4Department of Radiology, Harvard Medical School, Boston, MA, United States |
||
A new technique, termed Echo Planar Time-resolved Imaging (EPTI), was developed to address EPI’s geometric distortion and blurring, and to provide temporal signal evolution information across the EPI readout window. Using a small number of EPTI-shots, a time-series of multi-contrast images can be created free of distortion and blurring (up to 100 T2- and T2*-weighted images). This should make EPTI useful for numerous applications. Here, we demonstrated EPTI in brain to provide i) rapid simultaneous quantitative mapping of T2, T2*, proton density and tissue phase, as well as ii) multi-echo and quantitative T2* fMRI. |
13:45
|
Understanding Cardiac Microstructure | |
1Biomedical Engineering, King's College London, London, United Kingdom |
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Detailed information can now be obtained on the microstructural architecture of the heart from MRI data. Changes in microstructure in disease have significant impacts on cardiac performance. This talk will give course participants an overview of our current understanding of the relationships between cardiac microstructure and cardiac function. Recent clinical applications will be reviewed and areas of productive future research will be highlighted. |
14:15
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Cardiac DTI: Acquisition Techniques | |
1University and ETH Zurich, Switzerland |
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The two most commonly used approaches to overcome motion induced signal dephasing in cardiac diffusion weighted imaging rely on stimulated echo acquisition mode and motion compensated spin echo diffusion weighted imaging. Both sequences employ different strategies to generate diffusion contrast. In recent in-vivo imaging as well as Monte Carlo simulations it has become apparent that the quantitative parameters such as mean diffusivity and fractional anisotropy substantially differ between the two imaging approaches. The aim of this educational is to explain motion compensation strategies and discuss the resulting differences in measurements. |
14:45
|
Cardiac DTI: Processing Techniques | |
1University of Oxford, Oxford, United Kingdom |
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This talk will outline how the diffusion tensor is calculated from the diffusion weighted images. Tensor-derived invariants (mean diffusivity and fractional anisotropy) as well as cardiac-specific directional parameters will be discussed. |
15:15
|
Cardiac DTI: Current & Future Clinical Applications | |
1Royal Brompton Hospital, United Kingdom |
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Only one tool exists to perform in-vivo, human non-invasive assessment of the myocardium at the microstructural level, namely diffusion tensor (DT) cardiac magnetic resonance (CMR). DT-CMR quantifies water diffusion in the myocardium, which is constrained by the myocardial micro-architecture. This talk examines potential clinical applications of DT-CMR. |
15:40
|
Self Assessment Module (SAM) |
15:45
|
Adjournment |
13:45
|
Idiopathic Normal Pressure Hydrocephalus: Definition & Imaging | |
1Johns Hopkins University, Baltimore, MD |
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During this presentation we will review the imaging features of adult hydrocephalus and the current limitations in our ability to provide diagnostic and prognostic information for this disease process. |
14:15
|
MRI for Selection of Patients for Shunt Surgery & Follow-up | |
1Östersund Hospital, Umeå University, Östersund, Sweden |
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Brain MRI has a key role in the diagnosis of idiopathic Normal Pressure Hydrocephalus and is supportive in the selection of shunt candidates. This course will present an overview of the diagnostic and prognostic value of imaging features. A systematic approach to imaging evaluation and structured reporting of the findings enables comparison between sites and longitudinal follow-up of patients. |
14:45
|
Aqueductal Flow in iNPH | |
1Lund University Bioimaging Center, Lund University, Lund, Sweden |
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Idipathic Normal Pressure Hydrocephalus (iNPH) is a debilitating diesease without known cause. The symptoms are similar to those of vascular dementia, Alzheimers disease (AD) and Parkinsons (PD), making it difficult to diagnose. iNPH can be surgically treated with good results in at least a subset of patients, making a correct diagnosis crucial to the patient. Quantitative flow measurements of the cerebrospinal fluid (CSF) through the cerebral aqueduct has been suggested as a means of supporting the diagnosis of iNPH, differentiating it from AD or other forms of dementia, and for predicting outcome of ventriculoperitoneal shunting. |
15:15
|
CSF dynamics Imaging with ASL | |
1Kugayama Hospital, Japan |
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I will talk about Cerebrospinal fluid dynamics observation using MRI arterial spin labeling (ASL) technique in normal brain and it’s alteration in hydrocephalic brain. Observation of CSF flow by ASL is quite different from that is described in the textbook. |
15:45
|
Adjournment |
| 112
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Pitch: 13:45 Poster: 14:45 Plasma 1
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3D Inversion Recovery Ultrashort Echo Time (3D IR-UTE) Magnetic Resonance Imaging of Myelin in Traumatic Brain Injury – a Feasibility Study |
1University of California, San Diego, San Diego, CA, United States, 2VA San Diego Healthcare System, San Diego, CA, United States |
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Reduced myelination has been observed in rodents and humans after mild traumatic brain injury (mTBI). However, conventional MR imaging sequences cannot directly detect any signal from myelin. In this study, we aimed to evaluate a 3D IR-UTE sequence for selective imaging of myelin in mice using a standard controlled cortical impact (CCI) model of mTBI with histological confirmation. To demonstrate the clinical feasibility, a translational 3D IR-UTE technique was developed and applied to healthy volunteers and mTBI patients at 3T. The preliminary results demonstrate the feasibility of volumetric myelin mapping using the 3D IR-UTE sequences at 7T and 3T. |
| 113
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Pitch: 13:45 Poster: 14:45 Plasma 2
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Volumetric Imaging of Myelin in Vivo using 3D Inversion-Recovery Ultrashort Echo Time Cones (3D IR-UTE-Cones) Magnetic Resonance Imaging |
1Radiology, University of California, San Diego, San Diego, CA, United States, 2VA San Diego Healthcare System, San Diego, CA, United States, 3Neurosciences, University of California, San Diego, San Diego, CA, United States |
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To image myelin directly for whole brain on clinical scanners which would provide better characterization of multiple sclerosis (MS) lesions at diagnosis and in response to therapy, we propose a 3D adiabatic inversion recovery prepared ultrashort echo time cones (3D IR-UTE-Cones) sequence for volumetric myelin imaging in vivo with a clinical feasible scan time. The myelin imaging show clearly signal loss in MS lesions for both ex vivo and in vivo brain studies. |
| 114 | Pitch: 13:45 Poster: 14:45 Plasma 3
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Comparison of Myelin- and Axon-Specific Imaging Modalities in Multiple Sclerosis |
11Division of Biomedical Engineering, Hankuk University of Foreign Studies, Yongin, Korea, Republic of, 2Lerner Research Institute, The Cleveland Clinic, Cleveland, OH, United States, 3Neurological Institute, The Cleveland Clinic, Cleveland, OH, United States, 4The Cleveland Clinic, Cleveland, OH, United States |
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Multiple sclerosis (MS) is a chronic disease characterized by demyelination and neuronal/axonal pathology. Based on postmortem MRI-pathology correlations lesions found on conventional MRI do not exhibit expected demyelination. There is a need for imaging modalities that have better specificity for myelin, axonal density and axonal health. We compare the properties of fast variants of myelin-specific modalities (myelin water imaging, quantitative magnetization transfer and visualization of short transverse relaxation component) and of axon-specific measures from neurite orientation dispersion and density imaging. These comparisons constitute steps toward developing better imaging biomarkers for MS pathology. |
| 115 | Pitch: 13:45 Poster: 14:45 Plasma 4
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Reproducibility of Practical Imaging-Based Myelin Biomarkers |
1Division of Biomedical Engineering, Hankuk University of Foreign Studies, Yongin, Korea, Republic of, 2Imaging Institute, The Cleveland Clinic, Cleveland, OH, United States |
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Remyelination therapies are an emerging approach for treating multiple sclerosis, but development of these therapies is hampered by a lack of imaging biomarkers. Imaging with improved specificity to myelin, as compared to conventional MRI, have the potential to act as biomarkers, but current implementations can be time consuming. We examine the performance of fast version of myelin imaging from the perspective of reproducibility, a necessary prerequisite for use in proof-of-concept clinical trials of remyelinating agents. |
| 116
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Pitch: 13:45 Poster: 14:45 Plasma 5
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Chronic MS lesions with hyperintense appearance on QSM demonstrate more myelin damage and are long-lasting |
1Radiology, Tongji Hospital, Tongji Medical College, HUST, Wuhan, China, 2Radiology, Weill Cornell Medical College, New York, NY, United States, 3Biomedical Engineering, Cornell University, Ithaca, NY, United States, 4Neurology, Weill Cornell Medical College, New York, NY, United States |
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We assessed longitudinal QSM and MWF changes in 307 chronic MS lesions from 41 patients over four years. Lesions were stratified into three groups: hyperintense rim on QSM (rim+), no rim (rim-) and isointense on QSM (QSM-). Rim+ lesions were found to have the lowest MWF. QSM lesions showed a decreasing trend while MWF remains relatively stable over the same period. |
| 117
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Pitch: 13:45 Poster: 14:45 Plasma 6
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Concurrent remyelination and susceptibility increase in new active MS lesions indicate early iron accrual |
1Radiology, Tongji Hospital, Tongji Medical College, HUST, Wuhan, China, 2Radiology, Weill Cornell Medical College, New York, NY, United States, 3Biomedical Engineering, Cornell University, Ithaca, NY, United States, 4Neurology, Weill Cornell Medical College, New York, NY, United States |
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We reported initial results of an ongoing longitudinal study of new enhancing lesions using quantitative MRI including QSM, MWF and DTI. MS patients were followed five times during the first three months of lesion formation. We found a subset of lesions in which QSM rises rapidly and simultaneously with MWF and FA measurements, suggesting increasing iron accumulation within this period. |
| 118 | Pitch: 13:45 Poster: 14:45 Plasma 7
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A pediatric brain template for myelin water fraction and diffusion tensor imaging. |
1Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada, 2International Collaboration on Repair Discoveries, Vancouver, BC, Canada, 3Radiology, University of British Columbia, Vancouver, BC, Canada, 4Educational and Counseling Psychology, and Special Education, University of British Columbia, Vancouver, BC, Canada, 5Phillips Healthcare, Hamburg, Germany, 6Medicine, University of British Columbia, Vancouver, BC, Canada, 7Biomedical Engineering, University of Alberta, Edmonton, AB, Canada, 8Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada |
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Measuring pediatric brain myelination can provide insights into normal brain development as well as many pediatric brain disorders. We have created a myelin water and diffusion tensor template for healthy children aged 9-10 years to be used as a reference in imaging studies. Our template was produced using ANTs software to provide high-quality anatomical alignment of brain structures. ROI analysis revealed significant differences in myelin water fraction between children and adults. We found no significant correlation between myelin water fraction and diffusion tensor metrics across the ROIs investigated, highlighting the complementary information these two techniques provide. |
| 119 | Pitch: 13:45 Poster: 14:45 Plasma 8
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A comparison between diffusion metrics, macromolecular proton fraction, and g-ratio for quantitative in vivo myelin mapping |
1New York University School of Medicine, New York, NY, United States, 2Department of Radiology, New York University School of Medicine, New York, NY, United States, 3Department of Radiology, University of Wisconsin at Madison, Madison, WI, United States, 4Bernard and Irene Schwartz Center for Biomedical Imaging, New York, NY, United States |
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Myelination as one of the most reliable indicators of postnatal brain maturation and cognitive ability, supports white matter function by facilitating efficient neural signaling and pathway remodeling. The current study aimed to compare in healthy young adults several recently developed myelin mapping metrics including g-ratio, macromolecular proton fraction, and metrics from diffusion tensor/kurtosis imaging. Relationships between these individual metrics and their specific sensitivity to different aspects of white matter microstructure are discussed. |
| 120 | Pitch: 13:45 Poster: 14:45 Plasma 9
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Test-retest Reliability of Myelin-Sensitive MRI Techniques |
1Health Sciences Progam, University of Calgary, Calgary, AB, Canada, 2Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada, 3Biomedical Engineering Graduate Program, University of Calgary, Calgary, AB, Canada, 4Department of Radiology, University of Calgary, Calgary, AB, Canada, 5GE Healthcare, Calgary, AB, Canada |
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This project evaluated the reliability of quantitative inhomogeneous magnetization transfer (qihMT), a novel myelin-sensitive measure, compared to more common measures, magnetization transfer ratio (MTR) and fractional anisotropy (FA), in 10 healthy adults. A repeated measures ANOVA revealed no significant differences in measure means between scans in 18 white matter regions. Coefficients of variation (CV) demonstrated that FA had the highest reliability, followed by MTR and qihMT. The reduced reliability of qihMT observed here may be mitigated by further optimization of this novel sequence. |
| 121
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Pitch: 13:45 Poster: 14:45 Plasma 10
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Remyelination is less efficient in periventricular white matter lesions in Multiple Sclerosis |
1ICM - Brain & Spine Institute, Paris, France, 2Neurology Department, Pitie-Salpetriere Hospital, Paris, France, 3IMIV, CEA, Inserm, CNRS, Univ. Paris-Sud, Université Paris Saclay, CEA-SHFJ, Paris, France, 4Neurology Department, St Antoine Hospital, Paris, France |
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The objective of this study was to investigate the relationship between the extent of spontaneous remyelination and the distance from ventricular cerebrospinal fluid (CSF) in a group of multiple sclerosis patients. Dynamic remyelination was measured using longitudinal [11C]PiB positron emission tomography and found to be significantly reduced in periventricular white matter lesions, while becoming progressively more extensive with increasing distance from ventricles. Moreover, we found a positive correlation between periventricular remyelination and cortical thickness. These results suggest that CSF-linked factors might interfere with the spontaneous remyelination process in multiple sclerosis patients. |
| 122 | Pitch: 13:45 Poster: 14:45 Plasma 11
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Early life Myelination Mediates the Effects of the APOE Genotype on Cognitive Development |
1Neurosurgery, Westchester Medical Center, Valhalla, NY, United States, 2Pediatrics, Women and Infant's Hospital, Providence, RI, United States, 3Pediatrics, Brown University Warren Alpert School of Medicine, Providence, RI, United States, 4University of Wisconsin, Madison, WI, United States |
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A growing focus in Alzheimer’s Disease (AD) research is understanding the earliest preclinical structural changes associated with the disorder. In prior studies our group has shown differences in early myelin content based on APOE genotype and we recently have shown preliminary results that APOE effects early longitudinal myelin and cognitive development. Nevertheless, these results fail to explain how differences in early brain anatomy lead to differences in cognitive development. This is the first study to explore and analyze if differences in early cognitive development based on APOE genotype is explained by differences in early myelin development in a large cohort of healthy neurotypical infants and young children stratified by presence or absence of at least one APOE ε4 allele. |
| 123 | Pitch: 13:45 Poster: 14:45 Plasma 12
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Pitching the Cuprizone Mouse Model for Testing (re-) myelination therapies: robustness and reproducibility |
1Roche Pharma Research & Early Development, Neuroscience, Ophthalmology and Rare Diseases Discovery & Translational Area, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland |
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We assessed robustness and reproducibility of the cuprizone mouse model of de- and remyelination for its use in testing novel pharmacological treatments of demyelinating disorders such as multiple sclerosis. In several multimodal MRI studies using independent batches of animals, increases in T2, decreases in MTR and FA and biphasic responses in MK upon cuprizone feeding, as well as partial recoveries after cuprizone withdrawal, showed huge effect sizes and high cross-study consistency, especially in the corpus callosum. Our results substantiate the suitability of the cuprizone mouse model for longitudinal monitoring of the pathology using multimodal MRI. |
| 124 | Pitch: 13:45 Poster: 14:45 Plasma 13
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Multi-parameter quantitative MRI reveals common distribution of myelin in ex-vivo chimpanzee and in-vivo human brains |
1Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom, 2Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, Netherlands |
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Post-mortem investigations of tissue properties can dramatically extend the biological information that can be obtained from bodies or tissue that cannot be easily investigated in-vivo, as is the case for the majority of species of interest to comparative neuroscience. Here, we show the potential of a quantitive MRI method, multi-parameter mapping, to obtain high-resolution information about tissue properties of large non-human primates that generally cannot be studied anatomically. We compare myelination indices, derived from ex-vivo chimpanzee data at 7T to those derived from in-vivo human data at 3T. |
| 125 | Pitch: 13:45 Poster: 14:45 Plasma 14
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Effects of myelin on the water resonance line-shape in postmortem mouse brain |
1Department of Radiology, University of Chicago, Chicago, IL, United States, 2Department of Neurology, University of Chicago, Chicago, IL, United States, 3Department of Radiology, Harvard Medical School, Boston, MA, United States, 4Gordon Center for Medical Imaging, Massachusetts General Hospital, Boston, MA, United States, 5Department of Neurobiology, University of Chicago, Chicago, IL, United States |
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Dysmyelinating diseases are characterized by abnormal myelin formation and function. Such microstructural abnormalities in myelin have been demonstrated to produce measurable effects on the MR signal. This work examines these effects from post-mortem fixed control and shiverer mouse brains on voxel-wise, high-resolution water spectra acquired using a multi-gradient echo pulse sequence. Results demonstrate that components of the spectra are differentially affected by myelin concentration. This suggests that water proton spectra may be sensitive to the tissue microenvironment, specifically myelin, and could serve as potential MRI based biomarkers of dysmyelinating diseases. |
| 126 | Pitch: 13:45 Poster: 14:45 Plasma 15
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Quantitative multiparametric mapping assessment of the rat brain through adolescence into adulthood |
1Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom, 2Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom, 3University of Cambridge, Cambridge, United Kingdom |
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We demonstrate high-resolution quantitative multiparametric mapping in the rat: scanning animals before and after adolescence and comparing them to the adult. We produce maps sensitive to myelin signal throughout the brain that complement volumetric information normally used in developmental studies. The aim is to better exploit models of neuropsychiatric disorders, particularly those with developmental components. |
| 127
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Pitch: 13:45 Poster: 14:45 Plasma 16
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Multi-vendor multi-site T1ρ and T2 quantification of knee cartilage |
1Program of Advanced Musculoskeletal Imaging (PAMI), Cleveland Clinic, Cleveland, OH, United States, 2University of California, San Francisco (UCSF), San Francisco, CA, United States, 3University of Kentucky, Lexington, KY, United States, 4Albert Einstein College of Medicine, Bronx, NY, United States, 5Arthritis Foundation, Atlanta, GA, United States, 6Siemens Medical Solution Inc, Malvern, PA, United States, 7GE Healthcare, Milwaukee, WI, United States, 8Philips Healthcare, Andover, MA, United States |
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T1ρ and T2 relaxation times are promising biomarkers for early detection of osteoarthritis due to its sensitivity to cartilage degeneration. Good reliability is essential for these quantitative measures to be widely applicable in clinical trials. We implemented MAPSS T1ρ and T2 imaging on multiple platforms (Siemens, GE, Philips) and evaluated the intra-site repeatability and inter-site reproducibility of T1ρ and T2 data in a multi-site multi-vendor setting. |
| 128
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Pitch: 13:45 Poster: 14:45 Plasma 17
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GagCEST at 3T Can Detect Cartilage Differences Between Healthy and OA Subjects |
1Department of Radiology, Stanford University, Stanford, CA, United States, 2Department of Bioengineering, Stanford University, Stanford, CA, United States, 3Musculoskeletal Research Laboratory, VA Palo Alto Healthcare System, Palo Alto, CA, United States, 4Department of Mechanical Engineering, Stanford University, Stanford, CA, United States, 5Orthopaedic Surgery, Stanford, Stanford, CA, United States |
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Chemical exchange saturation transfer of GAG (gagCEST) is a quantitative MR technique that is a useful biomarker for assessing GAG content at 7T. However, its utility at 3T remains unclear. In this study, we compare gagCEST asymmetry values of healthy and osteoarthritic subjects scanned at 3T. Comparisons between healthy and OA subjects indicate a significant difference in the average gagCEST signal across the medial and lateral anterior and medial weight-bearing regions of the femoral cartilage. The results of this study suggest that there is potential for use of gagCEST in the study of OA at 3T. |
| 129 | Pitch: 13:45 Poster: 14:45 Plasma 18
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Deep Learning Pipeline for Automated Identification of Osteoarthritic Degenerative Changes in the Hip |
1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States |
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Manual identification of bone and cartilage abnormalities in MR images can be laborious and time consuming. The goal of this study was to develop a fully automated deep learning pipeline to identify morphological and degenerative changes in patients with hip osteoarthritis (OA). It included an object detection deep convolutional neural network (DCNN) that generated cropped images of the hip joint and a classification DCNN that identified the presence of morphological bone and cartilage changes. |
| 130 | Pitch: 13:45 Poster: 14:45 Plasma 19
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Added Clinical Value of Isotropic MAVRIC SL Acquisitions of Total Hip Arthroplasties |
1Hospital for Special Surgery, New York, NY, United States, 2MR Applications and Workflow, GE Healthcare, Waukesha, WI, United States |
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MAVRIC SL, a multi-spectral MRI imaging sequence, reduces metallic susceptibility artifact to improve visualization near joint arthroplasty by acquiring 24 spectral bins of off-resonance data. Many implants require fewer bins, and this study uses a calibration scan to determine the number of bins necessary to permit an isotropic MAVRIC acquisition and a reduced TR isotropic MAVRIC acquisition. The isotropic MAVRIC images decreased blurring and improved visualization of the periprosthetic bone and synovium while retaining image quality. Lowering the TR decreased scan time but affected image interpretation. Isotropic MAVRIC acquisitions may improve the diagnostic capability of MAVRIC SL images. |
| 131
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Five-minute single sequence comprehensive 4D pediatric ankle MRI with T2 Shuffling |
1Electrical Engineering and Computer Sciences, University of California, Berkeley, Berkeley, CA, United States, 2Radiology, Stanford University, Stanford, CA, United States |
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The use of volumetric acquisitions for musculoskeletal MR in clinical settings has been limited due to blurring artifacts from T2 decay. T2 Shuffling (T2Sh), a redesigned 3D fast spin-echo technique that mitigates blurring, has been successfully applied to pediatric knee MRI in a clinical setting and used to streamline the pediatric knee exam. This work assesses a shortened T2Sh scan for pediatric ankle MRI with total scan time under 5 minutes. Our results show that T2Sh has the potential to provide a comprehensive diagnostic protocol in place of the conventional long 2D exam. |
| 132 | Pitch: 13:45 Poster: 14:45 Plasma 21
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Denoising of Diffusion MRI Improves Peripheral Nerve Conspicuity and Reproducibility |
1GE Healthcare, New York, NY, United States, 2Hospital for Special Surgery, New York, NY, United States, 3GE Global Research, Niskayuna, NY, United States |
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This study evaluated q-space-based (genSD) and principal component analysis (PCA) denoising techniques to enhance SNR for peripheral nerve diffusion MRI of 10 healthy knees. The combination of both methods (PCA+genSD) was compared with a PCA-only method as well as the average of 10 repetitions. The combined denoising method showed improved performance with respect to SNR, peripheral nerve conspicuity and reproducibility. |
| 133 | Pitch: 13:45 Poster: 14:45 Plasma 22
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Robust Motion-Compensated Lumbar Spine Bone imaging using 3D UTE with Broadband Inversion Recovery Pulse and k-space Weighted Navigator Gating |
1Philips Japan, Tokyo, Japan, 2Philips Australia & New Zealand, North Ryde, Australia, 3Qscan Radiology Clinics, Brisbane, Australia, 4Radiology, Eastern Chiba Medical Center, Chiba, Japan, 5General Medical Services, Chiba University Graduate School of Medicine, Chiba, Japan, 6Orthopaedic Surgery, Eastern Chiba Medical Center, Chiba, Japan, 7Philips Healthcare, Tokyo, Japan |
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We proposed a new technique for the lumbar spine MR bone imaging based on broadband inversion recovery prepared segmented multispoke UTE sequence with k-space weighted navigator gating (3D BoneVIEW) for assessment of low back pain. 3D BoneVIEW provided robust bone imaging with sufficient background suppression and without respiratory artifacts. This sequence has a great potential to help more accurate assessment of the low back pain as an alternative to CT imaging. |
| 134 | Pitch: 13:45 Poster: 14:45 Plasma 23
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Self-navigated, rapid 3D UTE for motion-robust skull imaging |
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Plastic Surgery, University of Pennsylvania, Philadelphia, PA, United States |
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Solid-state MRI via 3D UTE or ZTE methods has potential for bone-selective imaging as a radiation-free alternative to computed tomography, particularly for children with craniofacial abnormalities. However, relatively long scan times make the technique vulnerable to artifacts from involuntary subject movements, thereby impairing image quality. Here, we developed a self-navigated, rapid 3D UTE technique by combining a retrospective motion detection and correction approach with sparsity-constrained image reconstruction. Results from in vivo studies demonstrate the proposed method's feasibility in achieving motion-corrected whole-skull images at 1 mm isotropic resolution in 2.1 minutes scan time. |
| 135
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Fat Suppression in UTE Imaging of Short T2 Tissues Using a Novel Soft-hard Composite RF Pulse |
1Radiology, University of California, San Diego, San Diego, CA, United States, 2VA San Diego Healthcare System, San Diego, CA, United States |
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Fat suppression is very important for both high contrast morphological imaging and accurate quantitative MR imaging. However, the conventional fat suppression methods such as chemical shift-based fat saturation are not well-suited for short T2 imaging due to the large direct saturation of short T2 tissues with broad spectra. The purpose of this study was to design a novel fat suppression pulse for ultrashort echo time (UTE) imaging of short T2 tissues with well-preserved short T2 signals using a soft-hard composite pulse. |
| 136
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Cortical bone quantifications using ultrashort echo time MR imaging (UTE-MRI) correlate well with histomorphometric assessment of bone microstructure |
1Radiology, University of california, San Diego, San Diego, CA, United States, 2Radiology Service, VA San Diego Healthcare System, San Diego, CA, United States |
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Ultrashort echo time magnetic resonance imaging (UTE-MRI) has been used to assess cortical bone porosity, as validated routinely with high resolution micro computed tomography (μCT). This study investigated the correlations between UTE-MRI-based quantifications and histomorphometric measures, as well as between UTE-MRI-based quantifications and μCT results. MRI properties showed strong correlations with both histomorphometric and μCT-based porosities. Only UTE-MRI could assess small pore (<40 μm) variations with moderate correlations. Major porosity changes were from large pores in studied specimens; therefore, μCT employment is likely adequate to validate UTE-MRI biomarkers. However, UTE-MRI techniques can assess pores below the detectable range by μCT, porosities which might contribute differently to bone mechanics. |
| 137 | Pitch: 13:45 Poster: 14:45 Plasma 26
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A Quantitative, Multiparametric Method for Bone Edema and Adiposity Characterisation in Inflamed Trabecular Bone |
1Centre for Medical Imaging, University College London, London, United Kingdom, 2Arthritis Research UK Centre for Adolescent Rheumatology, University College London, London, United Kingdom, 3Magnetic Resonance Imaging Physics, University College London Hospitals, London, United Kingdom |
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MRI is increasingly used to identify and monitor inflammation in patients with inflammatory diseases involving the skeleton, such as spondyloarthritis. However, conventional image interpretation by radiologists provides only indirect information about the inflammatory process and lacks reproducibility. Here, we describe a partially-automated multiparametric MRI tool for quantifying and characterising both active and chronic inflammation in spondyloarthritis, relying on histographic analysis of apparent diffusion coefficient (ADC) and proton density fat fraction (PDFF) maps. We show that histographic analysis improves performance compared to simple averaging, and, further, that ADC and PDFF provide distinct, complementary information regarding active inflammation and structural damage respectively. |
| 138 | Pitch: 13:45 Poster: 14:45 Plasma 27
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Texture analysis based on diffusional kurtosis imaging for the differentiation of benign and malignant bone tumors |
1First affiliated hospital of Zhengzhou university, Zhengzhou, China, 2Clinical Science, Philips Healthcare, Beijing, China |
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This work investigated and evaluated the role of textures extracted from magnetic resonance (MR) diffusion kurtosis imaging (DKI) in characterizing the bone tumors, and furtherly evaluate the ability of these textures to differentiate benign and malignant tumors by using support vector machine classifiers (SVM), which might be helpful for clinical diagnosis and studies. The texture parameters have the ability to character the bone tumor and SVM classifier showed good performance in the differentiation of benign and malignant bone tumors. |
| 139 | Pitch: 13:45 Poster: 14:45 Plasma 28
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Pilot study on facioscapulohumeral muscular dystrophy patients with dynamic phase contrast imaging of electrically stimulated quadriceps muscles |
1Department of Radiology/Division of Radiological Physics, University Hospital Basel, Basel, Switzerland, 2Department of Biomedical Engineering, University of Basel, Basel, Switzerland, 3Unità Operativa Complessa di Neurologia, Dipartimento di Scienze dell’Invecchiamento, Neurologiche, Ortopediche e della Testa-Collo, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy, 4Neuroradiology Department, IRCCS Mondino Foundation, Pavia, Italy, 5University of Pavia, Pavia, Switzerland, 6Radiology Department, Desio Hospital ASST, Monza, Italy |
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Facioscapulohumeral muscular dystrophy is characterized by a peculiar non-linear muscle-by-muscle involvement and is very hard to predict. The purpose of this study was to use dynamic phase contrast MR imaging of electrically stimulated quadriceps muscle to characterize the elastic potential of the muscle in FSHD patients and contribute to the understanding of this challenging disease. Velocity, strain, and strain rate were analyzed and compared to the results of physical examination. |
| 140 | Pitch: 13:45 Poster: 14:45 Plasma 29
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Quantitative MRI Measurements can Distinguish Myositis From Healthy Control Muscle. |
1Leeds Institute of Rheumatic and Musculoskeletal Medicine, Leeds, United Kingdom, 2NIHR Leeds Biomedical Research Centre, Leeds, United Kingdom |
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Myositis is an autoimmune inflammatory muscle disease which can decrease quality of life and increase mortality. Clinical presentation includes muscle weakness, changes in muscle microstructure, myosteatosis and myalgia. Current diagnosis is reliant on subjective clinical examinations, blood tests and invasive biopsies. Quantitative MRI techniques such as diffusion and fat fraction measurements are sensitive to changes within the muscle. 10 myositis patients and 16 healthy controls underwent scans of the thigh. Significant differences were found in fat fraction and diffusion measurements between myositis patients and healthy controls, implying these measures have potential as biomarkers in the diagnosis and management of myositis. |
| 141 | Pitch: 13:45 Poster: 14:45 Plasma 30
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Imaging of calf muscle contraction in pediatric patients with cerebral palsy and healthy children by dynamic phase contrast MRI |
1Department of Radiology, Division of Radiological Physics, University of Basel Hospital, Basel, Switzerland, 2Department of Biomedical Engineering, University of Basel, Basel, Switzerland, 3Laboratory for Movement Analysis, University Children's Hospital Basel, Basel, Switzerland, 4Department of Orthopedic Surgery, University Children's Hospital Basel, Basel, Switzerland, 5Department of Radiology, Division of Neuroadiological Physics, University of Basel Hospital, Basel, Switzerland |
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Aim of this study is to investigate the feasibility of phase contrast imaging for assessment of muscle function in children with cerebral palsy (CP). Time-resolved cine phase contrast MRI was synchronized with electrical muscle stimulation of the calf muscle at a clinical 3T MRI scanner. 11 healthy and 4 children with hemiparetic CP were scanned. Dynamic velocity, strain, and strain rate maps were reconstructed. Synchronous dynamic PC MRI of electrically stimulated muscle is feasible in children, even in CP patients and might provide further insight into the health status of their muscles. |
| 142 | Pitch: 13:45 Poster: 14:45 Plasma 31
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Accelerate Parallel CEST Imaging with Dynamic Convolutional Recurrent Neural Network |
1Institute for Medical Imaging Technology, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China, 2Philips Research, Hamburg, Germany, 3Radiology, University of Texas Southwestern Medical Center, Dallas, TX, United States, 4Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States |
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CEST is a new contrast mechanism in MRI. However, a successful application of CEST is hampered by its slow acquisition. This work investigates accelerating parallel CEST imaging using dynamic convolutional recurrent neural networks. This work is the first try to apply recurrent neural networks to accelerate CEST imaging, which jointly learns the spatial and Z-spectral features. The in vivo brain results show that the proposed method demonstrates a much better reconstruction quality of the human brain MTRasym maps than the traditional dynamic compressed sensing method, while the reconstruction time is one hundred times shorter. |
| 143 | Pitch: 13:45 Poster: 14:45 Plasma 32
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Denoising of Z-spectra for stable CEST MRI using principal component analysis |
1Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Faculty of Physics and Astronomy, University of Heidelberg, Heidelberg, Germany, 3Max Max Planck Institute for Nuclear Physics, Heidelberg, Germany, 4High-field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany, 5Faculty of Medicine, University of Heidelberg, Heidelberg, Germany, 6Department of Biomedical Magnetic Resonance, Eberhard-Karls University Tübingen, Tübingen, Germany |
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Chemical exchange saturation transfer (CEST) MRI allows for the indirect detection of low-concentration biomolecules by their saturation transfer to the abundant water pool. However, reliable quantification of CEST effects remains challenging and requires a high image signal-to-noise ratio. In this study, we show that principle component analysis can provide a denoising capability which is comparable or better than 6-fold averaging. Principle component analysis allows identifying similarities across all noisy Z-spectra, and thus, extracting the relevant information. The resulting denoised Z-spectra provide a more stable basis for quantification of selective CEST effects, without requiring additional measurements. |
| 144 | Pitch: 13:45 Poster: 14:45 Plasma 33
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Homogenous Excitation in Whole Brain CEST: Combination of Snapshot CEST and Multiple Interleaved Mode Saturation |
1Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany, 2Max Planck Institute for Biological Cybernetics, Tuebingen, Germany, 3Siemens Healthcare GmbH, Erlangen, Germany, 4Department of Neuroradiolohy, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany |
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To perform Chemical Exchange Saturation Transfer MRI of the whole brain a homogeneous saturation and fast readout are required. To achieve a fast and robust 3D acquisition a spiral-centric-reordered GRE readout was used. In addition, a Multiple Interleaved Mode Saturation scheme was applied to mitigate B1+-inhomogeneity effects of the CEST saturation. Combination of these two methods allows acquiring a homogenous CEST contrast in a volume of approximately 220x220x45mm3 within an acquisition time of 7 min 26s. |
| 145
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A Novel Approach for Improved CEST Imaging with Real-Time Frequency Drift Correction |
1Key Laboratory for Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, China, 2Department of Radiology, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, China, 3Philips Healthcare, Shanghai, China, 4Clinical Research Board, Philips Research China, Shanghai, China, 5Department of Radiology, Johns Hopkins University, Baltimore, MD, United States |
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Chemical Exchange Saturation Transfer (CEST) imaging is highly sensitive to temporal B0 drift. Here, we proposed a novel frequency-stabilized CEST (FS-CEST) imaging sequence by adding a frequency stabilization module to the conventional non-frequency-stabilized CEST (NFS-CEST) sequence for correcting artifacts due to B0 drift in real time. The FS-CEST sequence was implemented in phantoms and 26 human volunteers, and generated substantially more stable magnetization transfer ratio asymmetry (MTRasym) spectra and amide proton transfer weighted (APTw) images than the conventional NFS-CEST sequence. The FS-CEST sequence provides an effective approach for B0 drift correction without additional scan time. |
| 146 | Pitch: 13:45 Poster: 14:45 Plasma 35
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Z-Spectral Water-Fat Separation for APTw MRI in the Body using efficient Single-Echo Acquisitions |
1Philips Research, Hamburg, Germany, 2University of Texas Southwestern Medical Center, Dallas, TX, United States |
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An APTw/CEST-MRI technique to obtain water-only Z-spectra in the presence of fat is described. Water-fat separation in CEST is complicated by partial saturation of spectral fat components. Here, the saturation frequency-dependent water-fat phases are calculated using a multi-peak saturation model. A Z-spectrum acquisition with a single echo-shift is combined with a reference acquisition (S0) using 3 echo-shifts for water-fraction and B0-mapping. A B0-corrected, water-only Z-spectrum is obtained by complex rotations and weighted subtraction according to the water-fat phase. Volunteer examinations at 3T are shown (breast and abdominal). The single echo-shift technique offers a time-efficient means for water-fat separation in APTw/CEST-MRI. |
| 147 | Pitch: 13:45 Poster: 14:45 Plasma 36
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Amide proton transfer (APT) imaging of uterine cervical cancer; prediction of histological findings |
1Department of Clinical Radiology, Kyushu university, Fukuoka, Japan, 2Department of Anatomic Pathology, Kyushu university, Fukuoka, Japan, 3Department of Obstetrics and Gynecology, Kyushu university, Fukuoka, Japan, 4Philips Research, Hamburg, Germany |
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It is important to diagnose histological type and existence of parametrial invasion in uterine cervical cancer as correctly as possible because these factors are important in choosing treatment strategies or predicting prognosis. The objective of our study is to investigate whether amide proton transfer (APT) imaging is useful for evaluation of uterine cervical cancer. We compared the APT signal of uterine cervical cancer with different histological findings (histological type and existence of parametrial invasion) using three different durations of presaturation pulse. |
| 148 | Pitch: 13:45 Poster: 14:45 Plasma 37
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Fat corrected APT-CEST in the human breast at 7 Tesla: application to mamma carcinoma and dependency on menstrual cycle |
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Department of Physics and Astronomy, University of Heidelberg, Heidelberg, Germany, 3Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 4Max Planck Institute for Nuclear Physics, Heidelberg, Germany, 5High‐field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany, 6Department of Gynecology and Obstetrics, University Hospital Heidelberg, Heidelberg, Germany |
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The fat correction method enables robust APT-CEST quantification in the human breast and proved its suitability for examinations in vivo. We present to the extent of our knowledge the first APT-CEST contrast corrected for fat signal contribution, spillover, B1 field inhomogeneities and T1 relaxation in a breast cancer patient. The CEST contrast increased threefold compared to the measurement of a healthy volunteer. Repeated CEST imaging over the course of one menstrual cycle in one healthy woman did not reveal a hormonal correlation of APT contrast. A clinical study in healthy premenopausal volunteers will now investigate the dependency on menstrual cycle. |
| 149 | Pitch: 13:45 Poster: 14:45 Plasma 38
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NaSA-CEST MRI: comparison with Gd-enhanced contrast for imaging brain inflammation |
1Russell H. Morgan Dept. of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States, 2Cellular Imaging Section, Institute for Cell Engineering, Johns Hopkins University, Baltimore, MD, United States, 3Dept. of Information Sciences and Technology, Northwest University, Xi'an, China |
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Sodium salicylate (NaSA), a nonsteroidal anti-inflammatory drug and the main metabolite of aspirin, accumulates specifically in inflamed tissue. Since NaSA can be detected with CEST-MRI at millimolar concentrations, we investigated the use of NaSA-enhanced CEST MRI for in vivo mapping of brain inflammation, induced by intracerebral injection of lipopolysaccharide in mice. NaSA-CEST shows signal enhancement in the inflamed LPS-injected hemisphere, which was not observed in two control groups. NaSA-CEST exhibits distinct signal kinetics and enhanced regions from that of Gd-enhanced MRI, and shows correlations with histological staining of inflammatory markers, indicating its potential as a new platform for imaging neuroinflammation. |
| 150 | Pitch: 13:45 Poster: 14:45 Plasma 39
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Proton exchange rate increases in MS lesions |
1Radiology, University of Illinois, Chicago, IL, United States, 2Department of Radiology, Huazhong University of Science & Technology, China, China, 3Radiology, University of Illinois at Chicago, Chicago, IL, United States, 4Bioengieering, University of Illinois at Chicago, Chicago, IL, United States, 5Huazhong University of Science & Technology, Wuhan, China, 6Bioenginnering, University of Illinois at Chicago, Chicago, IL, United States |
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We have evaluated the performance of magnetic resonance proton exchange (Kex) imaging in vivo in characterization of gray matter, white matter as well as MS lesions. With informed consent, 10 control and 8 MS diagnosed subjects underwent a brain MRI on a 3T clinical-scanner. Kex maps were generated by pixel-wise fitting of the omega plot constructed from four different saturation power (B1=1, 2, 3 & 4 µT). Kex values from gray matter (GM), white matter (WM) and lesions were calculated, and two-tailed paired Student’s T-test was used to classify each group. Kex was able to demarcates each region. The combined use of Kex mapping has potential to improve the early and specific diagnosis of MS. |
| 151 | Pitch: 13:45 Poster: 14:45 Plasma 40
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Multicolor metabolic quantitative CEST (mmqCEST): high resolution imaging of brain metabolites |
1University Medical Center Utrecht, Utrecht, Netherlands, 2Max Planck Institute for Biological Cybernetics, Tübingen, Germany, 3Eberhard-Karls University, Tübingen, Germany, 4Eberhard-Karls University Tübingen, Tübingen, Germany |
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Multicolor metabolic quantitative CEST (mmqCEST): high resolution imaging of brain metabolites |
| 152 | Pitch: 13:45 Poster: 14:45 Plasma 41
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150× acceleration of myelin water imaging data analysis by a neural network |
1Physics & Astronomy, University of British Columbia, Vancouver, BC, Canada, 2International Collaboration on Repair Discoveries, Vancouver, BC, Canada, 3Radiology, University of British Columbia, Vancouver, BC, Canada, 4Biomedical Engineering, University of British Columbia, Vancouver, BC, Canada, 5Kinesiology, University of British Columbia, Vancouver, BC, Canada, 6Pathology & Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada |
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In-vivo information of myelin content is desirable for studying many brain diseases and injuries which damage myelin. Myelin water imaging (MWI) is a validated and quantitative MR method to myelin. However, the data post-processing of MWI is mathematically complex and computationally demanding. The analysis typically takes several hours for a whole brain analysis, which limits its clinical applications. Our objective was to train a neural network as an alternative method for the MWI data analysis. We found this novel approach can accelerate MWI data analysis by over 150 times. |
| 153 | Pitch: 13:45 Poster: 14:45 Plasma 42
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Contrasting frequency shifts and QSM in a longitudinal analysis of MS lesions to determine the nature of MR frequency and QSM signal changes |
1Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada, 2Pediatrics, University of British Columbia, Vancouver, BC, Canada, 3UBC MRI Research Centre, University of British Columbia, Vancouver, BC, Canada, 4Radiology, University of British Columbia, Vancouver, BC, Canada, 5Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada, 6International Collaboration on Repair Discoveries (ICORD), Vancouver, BC, Canada, 7Medicine (Neurology), University of British Columbia, Vancouver, BC, Canada |
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Magnetic susceptibility and MR frequency shifts in MS lesions are sensitive measures of tissue damage. However, the sensitivity of FS and QSM to magnetic susceptibility effects as well as changes in tissue microarchitecture complicate data interpretation in biological systems. By contrasting QSM and resonance frequency shift maps these two mechanisms may be differentiated. We observed that the signal shifts at enhancement are reflective of microstructural changes indicating formation of myelin debris, as similar FS and QSM changes were observed. Signal reductions in MS lesions 5yrs-post-enhancement however are only present on QSM, suggesting removal of myelin debris and axonal loss as the underlying mechanisms. |
| 154 | Pitch: 13:45 Poster: 14:45 Plasma 43
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Impact of unilateral carotid artery stenosis on white matter fiber orientation effects of mq-BOLD derived oxygen extraction fraction |
1Department of Neuroradiology, Technical University of Munich, Munich, Germany, 2MRRC, Yale University, New Haven, CT, United States, 3Clinic for Radiology, Technical University of Munich, Munich, Germany, 4Philips Healthcare, Hamburg, Germany, 5Clinic for Neurology, Technical University of Munich, Munich, Germany |
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Assessment of relative oxygen extraction fraction (rOEF) in white matter (WM) by multiparametric quantitative-BOLD (mq-BOLD) has highest clinical relevance, but was so far limited due to known WM anisotropy effects. Here, we present data from a clinical study in 29 internal carotid artery stenosis (ICAS) patients and 30 age-matched healthy controls (HC). The major aim was to characterise the ICAS impact on T2*, T2, R2’, rCBV and rOEF orientation dependencies in WM. Our results show very similar rOEF orientation dependencies for ICAS-patients compared to HC and low average rOEF orientation errors of 4.5% indicating potentially meaningful rOEF evaluations in WM. |
| 155 | Pitch: 13:45 Poster: 14:45 Plasma 44
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Quantitative assessment of the degeneration of the superior cerebellar peduncle in Friedreich’s ataxia at 7 T: susceptibility, diffusion anisotropy, and T2 and T1 relaxometry |
1Division of Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany, 2Faculty of Physics and Astronomy, Heidelberg University, Heidelberg, Germany, 3Department of Neuroradiology, Medical University Innsbruck, Innsbruck, Austria, 4Department of Neurology, Medical University Innsbruck, Innsbruck, Austria, 5Faculty of Medicine, Heidelberg University, Heidelberg, Germany |
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Friedreich’s ataxia is a rare disease involving degenerative processes within white matter fiber tracts, spinal nerves and the cerebellum. A correlation of patients’ clinical status and superior cerebellar peduncle atrophy has been shown in MR volumetry studies. The ongoing ultra-high field study presented here assesses the degeneration of the superior cerebellar peduncle in Friedreich’s ataxia with quantitative MR parameters – susceptibility, diffusion anisotropy, and T2 and T1 relaxometry. Statistically significant differences between fractional anisotropy as well as T2 values in patients and healthy controls could be observed, indicating that these quantitative MRI methods potentially provide valuable biomarkers to assess the course of Friedreich’s ataxia. |
| 156
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Glucose Uptake in Mouse Brain Detected by MRI Frequency Shifts with a Jump-Return Sequence |
1Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University, Baltimore, MD, United States, 2F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, MD, United States, 3Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China |
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Neuronal activity relies on glucose metabolism for energy maintenance and abnormalities in glucose uptake and metabolism constitute a potential biomarker for many disorders, including neurodegenerative diseases. Existing MRI techniques for monitoring glucose uptake and transportation often suffer from insufficient detection sensitivity. Here, we demonstrate a jump-return MRI (JR-MRI) method with high sensitivity for monitoring glucose uptake via tracing the water-frequency shift induced by chemical exchange. Conventional MRS was performed to validate the delivery of glucose to the brain. |
13:45
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Technical Development | |
1University of Wisconsin-Madison, Madison, WI, United States |
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This presentation will describe MRI-based techniques for quantification of fat and iron deposition in the liver. Specifically, this presentation will cover: 1) the relevant MR contrast mechanisms related to the presence of fat and iron, 2) the types of pulse sequences used to probe these contrast mechanisms, 3) the main challenges for quantification of fat and iron, 4) the technical solutions to these challenges, and 5) the state of the art of development and validation of MRI-based techniques for quantification of fat and iron deposition in the liver. |
14:15
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Clinical Applications | |
1Seoul National University |
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New advances in liver MRI including T1- |
| 157 | 14:45
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Evaluating the clinical efficacy of magnetic resonance elastography in patients with Budd-Chiari syndrome |
1Affiliated Hospital of Xuzhou Medical University, Xuzhou, China, 2GE Healthcare, MR Research China, Beijing, China, 3GE Healthcare, MR Enhanced Application China, Beijing, China |
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Budd-Chiari syndrome (BCS) is a rare disorder with an obstruction of the hepatic venous outflow tract. Previous studies reported that liver stiffness (LS) was associated with liver function in some chronic liver diseases. In this study, magnetic resonance elastography was for the first time applied to investigate the LS levels of BCS patients staged with different Child-Pugh grades. As a result, significant correlation between LS levels and liver function properties was shown in BCS patients. In addition, higher LS levels were found in BCS patients with higher grades and lower LS levels were observed for patients after receiving treatment. |
| 158 | 14:57
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Quantification and Repeatability of the Collagen Signal Fraction in the Healthy Liver Using Ultrashort Echo Time (UTE) MRI |
1Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom |
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Liver injury can lead to fibrosis, i.e. an accumulation of collagen. Fibrosis is clinically assessed via biopsy. Due to the health risks and unrepresentative sampling associated with biopsy, a non-invasive method of quantifying collagen would be beneficial. Here, an ultrashort echo time (UTE) pulse sequence was employed to quantify the collagen signal fraction in 10 subjects with healthy livers in a test-retest study at 3 T. The collagen signal fraction was repeatable, with a mean of 14 ± 3 %. |
| 159 | 15:09
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Feasibility Study of MRI IDEAL-IQ Sequence in Evaluating Liver Function of Patients with Liver Cirrhosis |
1The First Affiliated Hospital of Dalian Medical University, Dalian, China, 2GE Healthcare, BeiJing, China |
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Liver biopsy is the gold standard for the diagnosis of liver cirrhosis, but because the biopsy is invasive, and liver tissue sampling is insufficient and sampling error (puncture location) exists. IDEAL-IQ sequence can be used to analyze liver fat fraction and iron content (R2*) simultaneously, and it is easy to operate. |
| 160 | 15:21
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Can Intravoxel Incoherent Motion Diffusion-weighted Imaging Be used for Preoperative Assessment of Microvascular Invasion in Hepatocellular Carcinoma ? |
1West China Hospital, Sichuan University, Chengdu, China, 2GE Healthcare China, MR Research, Beijing, China |
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Microvascular invasion (MVI) is one of the most important factors for the recurrence of hepatocellular carcinoma (HCC), however, accurate preoperative evaluation of MVI is quietly difficult because of the controversy results caused by the conventional imaging features. Compared with diffusion-weighted imaging (DWI), Intravoxel incoherent motion (IVIM) diffusion-weighted MR imaging could better characterize heterogeneity and irregularity of tissue components, and thus may have the potential to better evaluate MVI. In this study, we prospectively determine the usefulness of IVIM parameters and conventional radiologic features for preoperative prediction of MVI in patients with HCC. |
| 161 | 15:33
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In vivo mapping of liver microstructure using quantitative Temporal Diffusion Spectroscopy Imaging |
1Vanderbilt University Institute of Imaging Science, nashville, TN, United States |
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Architectural and morphological changes of hepatocytes (the major parenchymal cells carrying out most of the metabolic functions of the liver) are key diagnostic findings for liver diseases and are associated with important biological events. However, such information can currently only be assessed by liver biopsy. Quantitative temporal diffusion spectroscopy imaging (qTDSI), which uses different modulated gradient waveforms to measure ADC values equivalent to the use of multiple diffusion times (Δ), has been shown to provide accurate, high-resolution maps of cell size in solid tumors. In this study, we demonstrated that qTDSI can map hepatocyte sizes in mice in vivo. |
15:45
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Adjournment |
| 162
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13:45
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Mapping of fibre-specific relaxation and diffusivities in heterogeneous brain tissue |
1Physical Chemistry, Department of Chemistry, Lund University, Lund, Sweden, 2Random Walk Imaging AB, Lund, Sweden, 3Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, United Kingdom, 4Harvard Medical School, Boston, MA, United States, 5Radiology, Brigham and Women’s Hospital, Boston, MA, United States |
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While diffusion MRI tractography has provided important insights on the human brain connectome, fibre-tracking through heterogeneous voxels has proven to be a challenging endeavour. Recently, we devised MRI acquisition- and processing methods to resolve sub-voxel heterogeneity with nonparametric 5D relaxation-diffusion distributions where contributions from distinct tissues are separated while circumventing the use of limiting assumptions. The separation between tissue-signals provides a clean mapping of nerve fibres that can then be used as an input in fibre-tracking algorithms. Additionally, values of relaxation rates and diffusivities are estimated for each distinct fibre bundle, potentially giving tract-specific information on chemical composition and microstructure. |
| 163
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13:57
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Estimation of multiple fiber orientation distributions (mFODs) from diffusion MRI data using spherical deconvolution |
1Image Sciences Institute, UMC Utrecht, Utrecht, Netherlands |
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Fiber orientation distributions (FODs) of white matter (WM) are commonly estimated from brain diffusion MRI data with spherical deconvolution (SD) approaches. Typically, only WM is considered to be anisotropic in SD, relying on suboptimal isotropic modeling of grey matter (GM). Here we present a general framework to reconstruct multiple anisotropic FODs (mFODs) from multiple response functions, allowing for the investigation of anisotropy in GM. The estimated mFODs were evaluated on a dataset from the HCP project with five response functions generated with the diffusion kurtosis and NODDI approaches, and their performances compared to state-of-the-art SD approaches. |
| 164 | 14:09
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Diffusion MRI in the unfolded hippocampus |
1Centre for Functional and Metabolic Mapping, Robarts Research Institute, Western University, London, ON, Canada, 2Neuroscience Graduate Program, Western University, London, ON, Canada, 3The Brain and Mind Institute, Western University, London, ON, Canada, 4Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, 5School of Biomedical Engineering, Western University, London, ON, Canada |
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The hippocampus is of high interest to the research community due to its involvement in many neurological disorders. However, in-vivo imaging, particularly diffusion weighted imaging, is challenging due to the hippocampus’ complicated curved geometry and small size. We address these challenges with an approach that ‘unfolds’ the hippocampus into a thin sheet. This allows migration of the diffusion data into this unfolded hippocampus, which enables visualization of microstructural sensitive diffusion parameters in a space where hippocampal subfields can be readily distinguished. |
| 165
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14:21
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Towards validation of diffusion MRI tractography: bridging the resolution gap with 3D Polarized Light Imaging |
1Athena Project-Team, Inria Sophia Antipolis Méditerranée, Université Côte d'Azur, Sophia Antipolis, France |
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Three-dimensional Polarized Light Imaging (3D-PLI) is an optical approach presented as a good candidate for validation of diffusion Magnetic Resonance Imaging (dMRI) results such as orientation estimates (fiber Orientation Distribution Functions) and tractography. We developed an anlytical approach to reconstruct fiber ODFs from 3D-PLI datasets. From these fODFs, here we compute brain fiber tracts via dMRI-based probabilistic tractography algorithm. Reconstructed fODFs at different scales proves the ability to bridge the resolution gap between 3D-PLI and dMRI, demonstrating, therefore, a great promise to validate diffusion MRI tractography thanks to multi-scale fiber tracking based on 3D-PLI. |
| 166
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14:33
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On the intrahemispheric connectivity of the monkey: a diffusion tractography and tract tracing analysis |
1Radiology Department, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland, 2Signal Processing Lab (LTS5), École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 3Department of Physiology and Pharmacology, University of Rome SAPIENZA, Rome, Italy, 4Department of Anatomy, Histology, Forensic Medicine, and Orthopedics, University of Rome SAPIENZA, Rome, Italy, 5Sherbrooke Connectivity Imaging Lab, Computer Science Department, Université de Sherbrooke, Sherbrooke, QC, Canada, 6Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kongens Lyngby, Denmark, 7Danish Research Centre for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark, 8Center of Functionally Integrative Neuroscience, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark, 9Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom, 10Department of Applied Mathematics an Computer Science, Technical University of Denmark, Kongens Lyngby, Denmark, 11Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden, 12Brain and Mind Institute, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland |
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In this work, we compare diffusion tractography with neuronal retrograde tract tracing of the frontal, cingulate and parietal areas of the monkey. We analyze the agreements between the tractography and the tracing for connected and not connected regions. We report an accuracy of 0.71 across all pairs of regions, with twice the number of true positive than false positive connections. Some regions show accuracy higher than 0.80, while other regions show accuracy lower than 0.6. A further analysis of the location of false positive and false negative connections will help understand the limitations and improve diffusion tractography algorithms. |
| 167
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14:45
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SUper-REsolution TRACTography (SURE-TRACT) pipeline using self-similarity between diffusional and anatomical images |
1Center for Biomedical Imaging, New York University School of Medicine, New York, NY, United States, 2Center for Advanced Imaging Innovation and Research (CAI2R), New York University School of Medicine, New York, NY, United States |
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Here, we propose a model-free, self-similarity based SUper-REsolution TRACTography (SURE-TRACT) pipeline to increase the resolution of diffusion weighted images (DWIs) by translating the high spatial frequency details from the co-registered high-resolution anatomical image of the same subject. The generated high-resolution DWIs enable to identify fiber tracks and estimate biophysical parameters with greater anatomical detail. Validating our pipeline using Human Connectome Project data, we showed that the SURE-TRACT pipeline resolves partial volume effects, and is more flexible to different acquisition protocols than other recent machine-learning based algorithms. |
| 168 | 14:57
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A novel fiber-tracking algorithm using parallel transport frames |
1Department Neuroscience and Biomedical Engineering, Aalto University, Helsinki, Finland, 2Laboratory of NeuroImaging (LONI), Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, United States |
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White matter fiber-tracking algorithms have remarkably improved during the last two decades. However, multiple validation studies warn about the reliability and reproducibility of results, and point out to the need for better algorithms. In propagation based tracking, connections are typically modeled as piece-wise linear segments. In this work, we propose a novel propagation based probabilistic tracker using parallel transport frames which is capable of generating geometrically smooth curves. Moreover, our tracker has a mechanism to reduce noise related propagation errors. Our experiments on FiberCup and Human Connectome Project data show visually and quantitatively superior results compared to three algorithms in MRtrix3. |
| 169
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15:09
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Mapping short association fibres in the human visual system with ultra high resolution and high sensitivity diffusion MRI |
1Neurophysics, Max Planck Institute for Human cognitive and Brain Sciences, Leipzig, Germany, 2International Max Planck Research School on Neuroscience of Communication: Function, Structure, and Plasticity, Leipzig, Germany, 3Neurocomputation and Neuroimaging Unit, Department of Education and Psychology, Free University Berlin, Berlin, Germany, 4Felix Bloch Institute for Solid State Physics, Faculty of Physics and Earth Sciences, Leipzig University, Leipzig, Germany |
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Short association fibres connect proximal cortical areas over short distances. These fibres are highly underrepresented in the current MRI-derived human brain connectome. We combined sub-millimetre resolution diffusion MRI, acquired with a 300 mT/m gradient system and high sensitivity coil for imaging the occipital cortex, with fMRI-driven retinotopic maps of V1/V2. These maps were used to identify the short V1-V2 connections in the human visual processing stream. V1-V2 connectivity was in agreement with previously reported anatomical and functional connectivities. Our results provide an important step towards the construction of a more complete MRI-derived human brain connectome via robust short fibre mapping. |
| 170 | 15:21
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Metrics that Matter: Improved statistical power to detect differences in tissue microstructure through dimensionality reduction |
1School of Psychology, Cardiff University Brain Research Imaging Centre, Cardiff, United Kingdom, 2Department of Paediatrics, The University of Melbourne, Parkville, Australia, 3Developmental Imaging, Murdoch Childrens Research Institute, Parkville, Australia, 4Computer Science, University of Sherbrooke, Sherbrooke, QC, Canada, 5School of Psychology, Australian Catholic University, Victoria, Australia |
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Various diffusion metrics have been proposed for characterising tissue microstructure. However, it is unclear which metric best captures individual microstructural differences. One possible approach is to explore all available metrics. However, this increases the chance of Type I error and makes interpretation difficult. Using data-reduction approaches, we identified two principal components that capture 85% of the variance in diffusion measurements. The first captures properties related to hindrance, while the second reflects tissue complexity. We demonstrate the utility of this approach by showing significant correlations with age of these new metrics, whereas little to no effects were observed with any individual metric. |
| 171 | 15:33
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Improving the inter-subject reproducibility of diffusion MRI connectivity analysis by controlling the bundle reliability of individual streamlines at the group-level connectome. |
1Translational Neuroscience Program, Wayne State University, Detroit, MI, United States, 2Department of Pediatrics, Wayne State University, Detroit, MI, United States, 3Department of Neurology, Wayne State University, Detroit, MI, United States, 4Department of Neurological Surgery, Wakayama Medical University, Wakayama, Japan |
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Identifying true positives from diffusion weighted imaging (DWI)-based tractography is not trivial, and no universal gold standard has yet been developed. In this study, we introduce a method which utilizes the group-level streamline pathway distribution to determine inter-subject reproducibility of streamline bundles. At the participant level, streamlines that do not correspond to reproducible bundles are removed, resulting in improved reproducibility and increased fidelity when identifying differences between pathways. Additionally, we utilized electrical stimulation-based cortico-cortical evoked potentials to assess how well reliable bundles reflect underlying connectivity. Cleaned structural connectivity data was found to better correlate with electrophysiological connectivity. |
| 172
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13:45
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Antibiotic rifaximin for treatment of chronic liver disease-induced HE: a longitudinal in vivo 1H-MRS study of brain metabolism |
1LIFMET, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 2CIBM, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 3Service of Biomedecine, University Hospital of Lausanne, Lausanne, Switzerland, 4Swiss Center for Liver Disease in Children, Department of Pediatrics, University Hospitals Geneva, Geneva, Switzerland |
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Rifaximin is a commonly-used antibiotic to treat hepatic encephalopathy(HE), a complex neuropsychiatric syndrome caused by hepatic dysfunction. Rifaximin reduces the production of gut ammonia, the main toxin in HE pathogenesis. We hypothesized that the effect of rifaximin on neurometabolic profile is dose-related. Therefore, in this study, the effects of rifaximin administered at 6x human-dose were assessed, in vivo and longitudinally on brain metabolites in bile-duct ligated(BDL) rats using 1H-MRS at 9.4T, biochemical and behavioral tests. They were compared with non-treated and human-dose treated rats. We showed that higher-dose rifaximin treatment was associated with positive effects on brain Gln,Glu and osmoregulation. |
| 173
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13:57
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The neurometabolic correlates of motor performance across the adult lifespan: a study on the effects of age |
1University of Leuven, Leuven, Belgium, 2icometrix, Leuven, Belgium, 3University of Leuven, leuven, Belgium, 4University Hospital Leuven, Leuven, Belgium |
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Aging is associated with alterations in neurochemistry of the brain, which can be assessed by MR spectroscopy. However, it’s unclear which metabolites are critical for function of the motor network. We explored whether changes in the neurometabolites of the aging brain account for motor-declines in bimanual coordination. We focused on neurochemistry of motor-occipital cortices as both regions are nodes of sensorimotor network underlying bimanual control. Myo-inositol was relevant for predicting Perdue test, which examine manual dexterity and general bimanual skills whereas N-acetylaspartate was associated with bimanual coordination task. Findings indicate NAA and mI could serve as biomarkers for integrity of motor network. |
| 174 | 14:09
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An MRS investigation of superior visual search abilities in children with autism spectrum disorder: Evidence for enhanced top-down attentional filtering |
1School of Health Sciences, Purdue University, West Lafayette, IN, United States, 2Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States, 3Department of Speech, Language, & Hearing Sciences, Purdue University, West Lafayette, IN, United States |
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Processing strengths or “islets of ability” associated with autism spectrum disorder (ASD), especially in visual search, have been of continued interest as they provide insight into how those with ASD perceive the world around them. In typically-developing (TD) individuals, region-specific concentrations of GABA are associated with differences in attention and perception. ASD may be associated with an excitatory-inhibitory imbalance, however, it remains unclear how this may contribute to superior search abilities. To test this, 37 ASD and TD children participated in a magnetic resonance spectroscopy study using MEGA-semi-LASER to detect GABA concentrations in cortical regions associated with attention and perception. |
| 175
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14:21
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Glial and axonal changes in mouse models of disease investigated with diffusion-weighted magnetic resonance spectroscopy at 11.7 T |
1Centre de NeuroImagerie de Recherche (CENIR), Institut du Cerveau et de la Moelle épinère (ICM), Paris, France, 2Sorbonne Université, UMR S 1127, Inserm U 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle épinère (ICM), Paris, France, 3Department of Computer Science and Centre for Medical Image Computing, University College of London (UCL), London, United Kingdom, 4Institute of biomedical imaging, Atomic Energy and Alternative Energies Commission (CEA), Fontenay-aux-Roses, France, 5Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown, Lisbon, Portugal, 6Core Facility ICM.Quant, Institut du Cerveau et de la Moelle épinère (ICM), Paris, France |
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The goal of this study was to evaluate the alterations of white matter microstructure in two different mouse models of white matter disease: the cuprizone (CPZ) model of multiple sclerosis and the Plp1 overexpressing (PLP-tg66) model of Pelizeaus-Merzbacher disease. To this end, we employed diffusion-weighted MR spectroscopy (DW-MRS) to measure concentrations and apparent diffusion coefficients of several metabolites in the corpus callosum of wild-type, CPZ and PLP-tg66 mice at 11.7 T. DW-MRS markers of axonal and glial degeneration were compared with histological measures. |
| 176 | 14:33
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Elevated brain glutamate levels in type 1 diabetes |
1Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, Netherlands, 2Internal Medicine, Radboud university medical center, Nijmegen, Netherlands, 3Pediatrics, Radboud university medical center, Nijmegen, Netherlands |
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Type 1 diabetes affects the structure and functioning of the brain, but the neurochemical mediators that may accompany these negative effects are largely unknown. We investigated brain metabolite levels with 1H MRS in patients with type 1 diabetes and normal awareness of hypoglycemia, patients with impaired awareness of hypoglycemia (IAH) and non-diabetic controls. Brain glutamate levels were elevated in type 1 diabetes and correlated with glycemic control and age of disease onset, but not with burden of hypoglycemia as reflected by IAH. This suggests a potential role for glutamate as early marker of hyperglycemia-induced cerebral decline in type 1 diabetes. |
| 177 | 14:45
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Remote metabolic profile changes in subacute spinal cord injury |
1Department of Radiology, Swiss Paraplegic Centre, Nottwil, Switzerland, 2Institute for Biomedical Engineering, ETH and University of Zurich, Zurich, Switzerland, 3Max-Planck Institute for Biological Cybernetics, Tuebingen, Germany |
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Not a single MR marker has been identified to predict patient outcome in spinal cord injury (SCI) rehabilitation. Therefore, we applied magnetic resonance spectroscopy (MRS) to examine metabolite concentration in the pons around 10 weeks after injury and identify group differences in complete and incomplete SCI at the time of the MRS acquisition. |
| 178 | 14:57
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In vivo cystathionine detection in gliomas by edited 1H magnetic resonance spectroscopy |
1Centre de NeuroImagerie de Recherche (CENIR), Institut du Cerveau et de la Moelle épinère (ICM), Paris, France, 2Sorbonne Université, UMR S 1127, Inserm U 1127, CNRS UMR 7225, Paris, France, 3Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, MN, United States, 4AP-HP, Hôpital de la Pitié-Salpêtrière, Service de Neurologie 2, Paris, France, 5Department of Neurology, Foch Hospital, Suresnes, Paris, France, 6Onconeurotek tumor bank, Institut du Cerveau et de la Moelle épinère (ICM), Paris, France |
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This study reports the first measurement of cystathionine in vivo. Cystathionine was measured using the edited magnetic resonance spectroscopy (MRS). The identification of cystathionine was confirmed by comparing in vivo spectra acquired in gliomas with the cystathionine spectrum measured in a phantom at physiological pH and temperature and with a simulated spectrum generated using accurate chemical shifts and J-coupling constants. The noninvasive detection of cystathionine by MRS may represent a new in vivo marker of glioma subtypes which will benefit diagnosis and treatment of patients with gliomas. |
| 179 | 15:09
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Importance of early spectral variations during 48 months of longitudinal follow-up MRI and MRS in 100 patients treated glioblastoma |
1Radiology, CHU et Université Picardie Jules Vernes, Amiens, France, Amiens, France, Metropolitan, 2CHU et Université Picardie Jules Vernes, Amiens, France, Amiens, France, Metropolitan, 3Tsinghua University, Beijing, China, Beijing, China, 4Université de Rouen, France, Rouen, France |
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MRS with Cho/Cr, Lac/Cr, CH2/Cr and NAA/Cr ratios, could be more sensitive than MRI and could, in some cases, be predictive of worsening in glioblastomas follow-up. These spectroscopic changes occurred well before clinical deterioration. There is a large variability, but repetition and modelisation of spectroscopic measurements during longitudinal follow-up could allow us to diminish it and to improve glioblastomas prognostic evaluation especially at and after relapses. Studying the relationship between MRS measures, segmentation and perfusion parameters could lead to better understanding of therapeutic response and patients selection, especially with regard to chemotherapy and antiangiogenic molecules and in future stress modulators. |
| 180 | 15:21
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Metabolite relaxation and diffusion abnormalities in the white matter of first-episode schizophrenia: a longitudinal study |
1McLean Hospital, Belmont, MA, United States, 2Harvard Medical School, Boston, MA, United States |
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Microstructural abnormalities in the white matter are important in the pathophysiology of schizophrenia. Unlike to unspecific nature of water, MRS can probe the brain's intracellular microenvironment through the measurement of transverse relaxation and diffusion of neurometabolites and even providecell-specific information. In this study, we worked with first episode schizophreniapatients so as to obviate the effects of medications and toxic effects of chronic psychosis. A combination of the T2-MRS and DTS techniques were applied in a longitudinal study. NAA T2 and ADC showed more sensitive changes compared to water at the early stage of disease. |
| 181
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15:33
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Spiral-MRSI and tissue segmentation of normal-appearing white matter and white matter lesion load in relapsing remitting Multiple Sclerosis. |
1School of Health Sciences, University of Newcastle, Newcastle, Australia, 2Hunter Medical Research Institute, Newcastle, Australia, 3Department of Neurology, John Hunter Hospital, Newcastle, Australia, 4School of Medicine and Public Health, University of Newcastle, Newcastle, Australia, 5Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia, 6Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States |
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The study evaluated a novel Fast-MRSI technique with tissue segmentation in determining metabolic alterations in NAWM and WM-lesions in MS compared to healthy controls. 3D-MPRAGE and 3D-Spiral-MRSI covering 70% of total brain on 16 RRMS and 9 HCs (aged 22-55yrs) were used. MRSI was processed using MATLAB and LCModel. Findings revealed that (NAA/tCr) in WM-lesions was significantly lower than NAWM-MS and HCs. Volumetric segmentation using SIENAX, revealed a significant WBV reduction and CSF increase in RRMS compared to HCs. Fast-MRSI may enhance diagnosis and clinical monitoring of MS patients, and is sensitive in diagnosing MS even in NAWM. |
| 182
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13:45
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Anatomic alterations in amygdala subregions in medication-free patients with obsessive-compulsive disorder |
1Department of Radiology, Huaxi MR Research Center (HMRRC), Sichuan University, Chengdu, China, 2Department of Psychiatry, Sichuan University, Chengdu, China, 3Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, OH, United States |
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Most previous human neuroimaging studies measured the volume of amygdala as a whole, however, the amygdala consists of several functionally distinct subnuclei. Recent advances in structural MR image segmentation technique have made it possible to study amygdala subnuclei volumes with a robust, automatic approach using a Bayesian inference-based atlas building algorithm. Using this algorithm, we for the first time provide a distinctive profile of amygdala subnuclei volume abnormality in a relatively large sample of drug-free obsessive-compulsive disorder patients, and provide an insight that these subnuclei contribute to different aspect of neuropathology in the disorder. |
| 183 | 13:57
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Mediators of the real-time fMRI amygdala neurofeedback training effect on PTSD symptom reduction: a whole brain structural equation model mapping analysis |
1Laureate Institute for Brain Research, Tulsa, OK, United States, 2Neuroscience Department, George Mason University, Fairfax, VA, United States, 3Department of Psychological Science, University of Arkansas, Fayetteville, AR, United States, 4Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, OK, United States |
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We determined mediators of the real-time fMRI neurofeedback (rtfMRI-nf) amygdala training inducing PTSD symptom reduction in combat veterans. Thirty-six veterans with PTSD (25 experimental group and 11 control group receiving a feedback from a control region) completed three rtfMRI-nf training sessions in separate days. We employed a novel whole brain structural equation model mapping (SEMM) analysis to identify brain regions that mediated the effects of the rtfMRI-nf procedure on PTSD symptoms. Results revealed that PTSD symptom reduction in the experimental group was mediated by lower activation than the control group in default mode network regions during the neurofeedback training. |
| 184 | 14:09
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Imaging hippocampal glutamate alterations in a 22q11.2 deletion syndrome mouse model of schizophrenia |
1Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, United States, 3Department of Pediatrics, University of Pennsylvania, Philadelphia, PA, United States |
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Schizophrenia (SZ) is a common, severe mental illness caused by neurobiological disturbances in glutamate and dopamine. Glutamate is the major excitatory neurotransmitter in the brain and can be detected using MR spectroscopy and glutamate-weighted chemical exchange saturation transfer (GluCEST) MRI. In this study, we performed high-resolution GluCEST MRI in the 22q11.2 deletion syndrome (22q11.2DS) mouse model of SZ to evaluate glutamatergic alterations in the dorsal and ventral hippocampus. The GluCEST contrast was found to be lower in the hippocampus of 22q11.2DS mice compared to that in the age-matched control mice indicating the lower hippocampal glutamate level in the preclinical model of SZ. |
| 185 | 14:21
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Emotion Self-Regulation Training with Simultaneous Real-Time fMRI and EEG Neurofeedback in Major Depression |
1Laureate Institute for Brain Research, Tulsa, OK, United States, 2Electrical and Computer Engineering, University of Oklahoma, Tulsa, OK, United States, 3Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, OK, United States |
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We report a study of emotion self-regulation training in patients with major depressive disorder (MDD) using simultaneous real-time fMRI and EEG neurofeedback (rtfMRI-EEG-nf). Emotion-relevant target nf measures included fMRI activities of the left amygdala and left rACC, and frontal EEG asymmetries in the alpha and high-beta bands. MDD patients successfully learned to upregulate all four measures simultaneously using rtfMRI-EEG-nf during a happy emotion induction task. EEG-fMRI data analyses provided new insights into mechanisms of rtfMRI-EEG-nf. These findings may lead to development of more efficient neurotherapies for MDD. |
| 186 | 14:33
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Discrete Regions of Gray Matter Loss Underlie Major Depressive Disorder: A Replication and Expanded Investigation |
1Sydney Translational Imaging Laboratory, Heart Research Institute, Charles Perkins Centre, University of Sydney, Sydney, Australia, 2General Electric Healthcare, Melbourne, Australia, 3The Brain Dynamics Centre, Westmead Millennium Institute and Sydney Medical School, Sydney, Australia, 4Department of Psychiatry and Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL, United States, 5Sierra-Pacific Mental Illness Research, Education, and Clinical Center (MIRECC), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, United States, 6Brain Resource Ltd, Sydney, Australia, 7Duke-National University of Singapore, Singapore, Singapore, 8Department of Psychiatry, Duke Medical School, Durham, NC, United States, 9Department of Radiology, Royal Prince Alfred Hospital, Sydney, Australia |
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The aims of this study were to construct a biomarker based on anatomical regions of profoundly reduced gray matter volume in subjects with major depressive disorder. Our biomarker successfully discriminated MDD subjects from controls at an accuracy of 73%, suggesting a possible role for network measurements of GM susceptibility in MDD. |
| 187 | 14:45
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Neural Correlates of Rumination in Normal and Major Depressive Disorder: A Brain Network Analysis |
1Icahn School of Medicine at Mount Sinai, New York, NY, United States |
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Major depressive disorder (MDD) patients exhibit higher rumination levels; repetitive thinking and focus on negative states. Rumination is known to be associated with brain cortical midline and limbic structures, yet, the underlying brain network topological organization remains unclear. Implementing a graph-theory analysis we tested whether whole brain network connectivity hierarchies during fMRI resting state are associated with rumination. We found a significant correlation between right caudal anterior cingulate (cACC) connectivity strength and subjective rumination tendency. This result emphasize the cACC impact during self-reflective processing, which might serve as biomarker for clinical diagnosis. |
| 188 | 14:57
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PET derived Raphe Nuclei [11C]-CUMI binding potential is associated with MR derived diffusion entropy in the frontal and temporal lobes |
1Biomedical Engineering, Stony Brook University, Stony Brook, NY, United States, 2Psychiatry, Stony Brook Medicine, Stony Brook, NY, United States, 3Radiology, Stony Brook Radiology, Stony Brook, NY, United States |
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Using a new DTI processing technique, named diffusion entropy, and dynamic PET data we observed a statistically significant inverse correlation between diffusion entropy and [11C]-CUMI binding potential (BPF) in a dataset with bipolar, major depressive disorder patients and controls. This newfound analysis can give rise to further understanding the pathophysiology that undermines psychiatric diseases and, also, a non-invasive, non-ionizing radiation procedure to estimate [11C]-CUMI BPF. |
| 189 | 15:09
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Thalamic Substructures in Alcoholism: Volume Deficits and Functional Correlates |
1Neuroscience, SRI International, Menlo Park, CA, United States, 2Stanford University, Stanford, CA, United States, 3Department of Medical Imaging, The University of Arizona Health Sciences, Tucson, AZ, United States |
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Volumes of 5 thalamic substructures—mediodorsal (MD), anterior (AV), ventral lateral posterior (VLp), ventral posterior lateral (VPl), pulvinar (Pul))—were quantified using a novel automated segmentation algorithm in 40 individuals with Alcohol Use Disorder (AUD) and 60 controls (Con). Multiple regressions on supratentorial-volume-corrected measures revealed that volumes of AV, VLp, VPl, and Pul were smaller with older age, and volumes of AV, VLp, Pul, and MD were smaller in the AUD than Con group. Functional ramifications of thalamic substructures indicated relations between back pain and smaller Pul and VLp volumes, and poor ataxia scores with smaller VPI volumes. |
| 190 | 15:21
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Mapping atypical functional connectome organization and hierarchy in autism spectrum disorders |
1Multimodal Imaging and Connectome Analysis Lab, Montreal Neurological Institute, Montreal, Quebec, QC, Canada, 2Center for the Developing Brain, Child Mind Institute, New York, NY, United States, 3Autism Research Centre, Department of Psychiatry, University of Cambridge, Cambridge, United Kingdom, 4Institute of Systems Neuroscience, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany, 5Autism Center, Child Mind Institute, New York, NY, United States, 6Institut de Cerveau et de la Moelle épinière, Hôpital Pitié Salpêtrière, Paris, France, 7Center for Biomedical Imaging and Neuromodulation, Nathan S. Kline Institute for Psychiatric Research, New York, NY, United States, 8Department of Psychology, University of York, York, United Kingdom |
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One paradox of autism is the co-occurrence of deficits in sensory and higher-order socio-cognitive processing. The current work examined whether these phenotypical patterns may relate to abnormal macroscale hierarchy affecting both unimodal and |
| 191 | 15:33
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Modulation of dorsolateral prefrontal cortex GABA and Glx (glutamate + glutamine) levels following repetitive magnetic stimulation therapy of major depressive disorder |
1Imaging Institute, Cleveland Clinic, Cleveland, OH, United States, 2Radiology, Cleveland Clinic Lerner College of Medicine, Cleveland, OH, United States, 3Neurological Institute, Cleveland Clinic, Cleveland, OH, United States |
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Abnormalities of Gamma Amino Butyric Acid (GABA), the major inhibitory neurotransmitter, and Glx (glutamate, major excitatory neurotransmitter + glutamine) have been implicated in the pathology of depression. Modulation of GABA and Glx at left dorsolateral prefrontal cortex, the site of application of repetitive transcranial magnetic stimulation (rTMS) to treat major depressive disorder for patients not adequately responsive to medication treatment, was investigated using MEGA-PRESS spectroscopy. No change in GABA level was observed, while Glx/creatine level increased with rTMS therapy. Patients with higher Glx/Creatine level tended to respond better to rTMS, and the response was inversely correlated with increase in Glx/Creatine. |
| 192
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13:45
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Model-free denoising of multi b-value diffusion-weighted MR images using principal component analysis: simulations and in vivo results |
1The Institute of Cancer Research and the Royal Marsden NHS Foundation Trust, London, United Kingdom, 2Cancer Research UK Cancer Imaging Centre, The Institute of Cancer Research and the Royal Marsden NHS Foundation Trust, London, United Kingdom, 3Cancer Center Amsterdam, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands |
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We present a principal component analysis (PCA) toolkit for mode-free denoising of multi b-value diffusion-weighted images for clinical use. In simulations, PCA-denoising suppressed the random noise equally well (up to 55%) as synthetic MRI. Contrary to synthetic MRI (systematic error up to 29% of total signal intensity), PCA-denoising did not introduce any systematic errors (<2%). In volunteer and patient image data, PCA-denoising resulted in sharper and less noisy images than synthetic MRI, which resulted in sharper and clearer tumour boundaries. In conclusion, our PCA-denoising toolkit is promising for denoising b-value images for clinical use. |
| 193
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13:57
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DCE MRI-Based Computational Modeling of Interstitial Fluid Pressure and Velocity in Head and Neck Cancer: Initial Analysis |
1Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, United States, 2Radiology, Medical College of Wisconsin, Milwaukee, WI, United States, 3Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, United States, 4Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, United States, 5Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, United States |
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We applied computational fluid modeling to head-and-neck cancer patients' DCE-MRI data using permeability maps from extended Tofts' model and tumor geometry from imaging. Interstitial fluid pressure (IFP) maps generated from computational fluid modeling depict heterogeneous distribution of elevated IFP and velocity in tumor tissue. We found significant correlation between tumor volume and IFP. |
| 194
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14:09
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Deep residual learning of radial under sampling artefacts for real-time MR image guidance during radiotherapy |
1Radiotherapy, University Medical Center Utrecht, Utrecht, Netherlands, 2MR Code B.V., Zaltbommel, Netherlands, 3Biomedical Engineering, University of Technology Eindhoven, Eindhoven, Netherlands, 4Medical Natural Sciences, VU Amsterdam, Amsterdam, Netherlands |
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MRI-guided radiotherapy using hybrid MR-Linac systems, requires high spatiotemporal resolution MR images to guide the radiation beam in real time. Here, we investigate the concept of deep residual learning of radial undersampling artifacts to decrease acquisition time and minimize extra reconstruction time by using the fast forward evaluation of the network. Within 8-10 milliseconds most streaking artifacts were removed for undersampling rates between R=4 and R=32 in the abdomen and brain, facilitating real-time tracking for MR-guided radiotherapy. |
| 195 | 14:21
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Amid Proton Transfer-Weighted Imaging vs. Diffusion-Weighted Imaging vs. FDG-PET/CT: Capability for Management of Solitary Pulmonary Nodules |
1Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan, 2Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe, Japan, 3Canon Medical Systems Corporation, Otawara, Japan, 4Center for Radiology and Radiation Oncology, Kobe University Hospital, Kobe, Japan, 5Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan |
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We hypothesized that APTw imaging had equal or better potential for diagnosis of SPNs and prediction of postoperative recurrence prediction in postoperative lung cancer patients, when compared with DWI and FDG-PET/CT. In addition, multiparametric approach among all three methods had better potential than single-parametric approach on each method in this setting. The purpose of this study was to compare the diagnosis and prediction capabilities of pulmonary nodules among single- and multi-parametric approaches by APTw imaging, DWI, and FDG-PET/CT. |
| 196
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14:33
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A Noninvasive Comparison Study between Human Gliomas with IDH1 and IDH2 Mutations by MR Spectroscopy |
1Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States, 2University of Oxford, Oxford, United Kingdom, 3Oxford University Hospitals NHS Trust, Oxford, United Kingdom, 4School of Health Sciences, Purdue University, West Lafayette, IN, United States |
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The oncogenes that are expressed in gliomas reprogram particular pathways of glucose, amino acid, and fatty acid metabolism. Mutations in the isocitrate dehydrogenase genes (IDH1/2) in diffuse gliomas are associated with abnormally high 2-hydroxyglutarate (2-HG) levels. Non-invasive measurement of 2-HG via in vivo 1H magnetic resonance spectroscopy (MRS) can be used to differentiate mutant cytosolic IDH1 from mitochondrial IDH2 in gliomas. |
| 197 | 14:45
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Cystathionine as a marker for 1p/19q codeleted gliomas by in vivo magnetic resonance spectroscopy |
1Centre de NeuroImagerie de Recherche (CENIR), Institut du Cerveau et de la Moelle épinère (ICM), Paris, France, 2Sorbonne Université, UMR S 1127, Inserm U 1127, CNRS UMR 7225, Paris, France, 3Centre de Référence des Maladies Métaboliques, Service de Biochimie Métabolique, Hôpital Necker and Université Paris Descartes, Paris, France, 4AP-HP, Hôpital de la Pitié-Salpêtrière, Service de Neurologie 2, Paris, France, 5Department of Neurology, Foch Hospital, Suresnes, Paris, France, 6Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, MN, United States, 7Onconeurotek tumor bank, Institut du Cerveau et de la Moelle épinère (ICM), Paris, France |
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Molecular markers such as mutation in isocitrate dehydrogenase (IDH) and codeletion of chromosome arms 1p and 19q (1p/19q codeletion) have highly benefited diagnosis and prognosis in brain gliomas. However, the biological effects of 1p/19q codeletion are still not clear. We report selective accumulation of cystathionine in IDH-mutated, 1p/19q codeleted gliomas observed by edited 1H magnetic resonance spectroscopy. Noninvasive detection of cystathione enables identification of glioma subtypes in vivo and opens up the possibility of investigating nonivasively cancer-specific metabolic pathways. |
| 198
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14:57
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The effects of neoadjuvant chemotherapy on axillary lymph node volume and compacity in breast cancer patients: an MRI study |
1Stony Brook University, Stony Brook, NY, United States |
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Axillary lymph node involvement in breast cancer is associated with higher risk of distant metastasis and recurrence. This study evaluated whether MRI can be used to longitudinally monitor effects of neoadjuvant chemotherapy on axillary lymph nodes in situ. Nodal volume and compacity were analyzed with respect to treatment responders and non-responders. Comparisons with unaffected nodes were made. Neoadjuvant chemotherapy significantly reduced nodal volume of the affected nodes in both responders and non-responders. Nodal volumes of the responders normalized whereas those of the partial-responders did not normalize completely. This approach may prove useful for monitoring cancer treatment effects on nodal morphology. |
| 199 | 15:09
|
Lymphovascular invasion correlates with elevated tumor pressure as quantified by MR Elastography: initial results from a breast cancer trial |
1School of Biomedical Engineering & Imaging Sciences, King's College London, London, United Kingdom, 2Guy's and St.Thomas' NHS Foundation Trust, London, United Kingdom, 3Division of Cancer Studies, King's College London, London, United Kingdom, 4Department of Radiology and Nuclear Medicine, Amsterdam UMC, Amsterdam, Netherlands, 5King's College Hospital, London, United Kingdom, 6Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States, 7U1148, INSERM, Paris, France |
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Gauging metastatic propensity is crucial as it impacts decision making in oncology (e.g. whether a patient should receive surgery immediately or neoadjuvant chemotherapy). Interstitial fluid pressure (IFP) is known to correlate with microvascular invasion, a proxy for metastatic potential. However, no current imaging biomarkers correlate with this. We present a method to noninvasively calculate a total tumor pressure (which IFP contributes to). The method reconstructs pressure via nonlinear biomechanics and MR Elastography and is validated in simulations and phantoms. Elevated pressure values from a cohort of 16 breast cancer patients correlate with lymphovascular invasion possibly providing a much sought-after biomarker. |
| 200 | 15:21
|
Noninvasive MRI mapping of malignant infiltration into lymph nodes |
1Champalimaud Foundation, Lisbon, Portugal, 2Centre for Medical Image Computing, UCL, London, United Kingdom |
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Mapping malignant infiltration into lymph nodes can have a critical impact on patient decision making. We predicted that multigradient echo (MGE) experiments could reflect cellularity and cell-size changes due to underlying susceptibility distributions. Lymph nodes extracted from rectal cancer patients exhibited the predicted non-monotonic and non-mono-exponential MGE signal decay, which provided insights into the underlying microstructure. A simple model distinguished benign from malignant nodal tissue and the differences were at least partially explained by differences in cellularity and cell size. These results can impact lymph node staging accuracy, as already corroborated by our pilot results in-vivo, upon rectal cancer staging, at 1.5T. |
| 201
|
15:33
|
Androgen Independence Leads to Altered Metabolism in Prostate Cancer Cell and Murine Models |
1Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States |
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This study demonstrated significant increases in flux through glycolysis, oxidative metabolism, and glutaminolysis associated with androgen independence using patient-derived cell lines and a treatment-driven murine model. This data supports using a combination of hyperpolarized [1-13C]pyruvate, [2-13C]pyruvate and [5-13C]glutamine to noninvasively discriminate between androgen-dependent and androgen-independent prostate cancer in future patient studies using hyperpolarized 13C MRI. |
| 202
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13:45
|
Neural activity temporal pattern dictates the long-range brain-wide propagation pathways: An optogenetic fMRI study |
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China, 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China |
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The current overarching challenge in neuroscience is to establish an integrated understanding of the brain networks, particularly the spatiotemporal patterns of neural activities that give rise to functions and behavior. fMRI provides the most versatile neuroimaging platform for mapping large-scale activities in vivo. However, on its own, many important details of the underlying network activities remain unresolved. Here, we employed fMRI in combination with pulsed optogenetic stimulation paradigms to probe the spatiotemporal dynamics and functions of the well-defined topographically-organized somatosensory thalamo-cortical network. We reveal unique long-range propagation pathways that are dictated by distinct neural activity temporal patterns initiated from the thalamus. |
| 203
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13:57
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Spanning spatiotemporal scales with simultaneous mesoscopic calcium imaging and functional MRI |
1Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States, 2Department of Neurobiology, Yale University, New Haven, CT, United States, 3Department of Biomedical Engineering, Yale University, New Haven, CT, United States, 4Department of Neuroscience, Yale University, New Haven, CT, United States, 5Kavli Institute for Neuroscience, Yale University, New Haven, CT, United States, 6Program in Cellular Neuroscience, Yale University, New Haven, CT, United States, 7Neurodegeneration and Repair, Yale University, New Haven, CT, United States, 8Department of Statistics and Data Science, Yale University, New Haven, CT, United States, 9The Child Study Center, Yale University, New Haven, CT, United States, 10Department of Ophthalmology and Visual Science, Yale University, New Haven, CT, United States, 11Department of Neurosurgery, Yale University, New Haven, CT, United States, 12Interdepartmental Neuroscience Program, Yale University, New Haven, CT, United States |
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Neuroscience interrogates brain function across multiple spatiotemporal scales. Yet, most research is confined to one spatiotemporal milieu limiting translation of knowledge across scales. Here we span spatiotemporal scales having built a custom apparatus and analytical framework for simultaneous wide field mesoscopic Ca2+ imaging of the entire cortex and fMRI at 11.7T in mice. We describe the new hardware/software, and present three findings: there is correspondence between spontaneous fluctuations in the magnitude of Ca2+ and fMRI evoked responses, Ca2+ and fMRI connectivity metrics are stable throughout an imaging session, and there is correspondence between Ca2+ and fMRI spontaneous activity patterns. |
| 204 | 14:09
|
Multimodal awake mouse imaging: from two-photon microscopy to BOLD-fMRI |
1Physique, génie physique et optique, Université Laval, Québec, QC, Canada, 2University of California San Diego, La Jolla, CA, United States, 3Boston University, Boston, MA, United States, 4Martinos Center for Biomedical Imaging, MGH, Harvard Medical School, Charlestown, MA, United States, 5University of Texas at Austin, Austin, TX, United States |
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Functional Magnetic Resonance Imaging (fMRI) in awake behaving mice is well positioned to bridge the detailed cellular-level view of brain activity, which has become available due to recent advances in microscopic optical imaging and genetics, to the macroscopic scale of human noninvasive observables. Here, we demonstrate Blood Oxygen Level Dependent (BOLD) fMRI in awake mice implanted with chronic transparent cranial ''windows'', compatible with two-photon microscopy, optical imaging, and optogenetic light stimulation. We thus provide a proof of feasibility for multimodal imaging approaches in awake mice, which in the future can be extended to behavioral studies and biomedical applications. |
| 205 | 14:21
|
Ultra high field BOLD measurements combined with simultaneous determination of blood oxygenation and blood volume by optical imaging |
1Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany, 2Biomedical Magnetic Resonance, University of Tübingen, Tübingen, Germany |
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To disentangle the different parameters contributing to the BOLD effect, a combined setup for intrinsic optical imaging and ultra high field fMRI in rats was designed, using a magnetic field compatible, high sensitivity camera and professional optical components. By illumination of the brain surface with light in four different wavelengths, oxygenation and CBV was observed concurrently with fMRI during forepaw stimulation. Simultaneous measurement of those parameters can help to better understand the BOLD effect and to add additional value to both optical imaging and fMRI experiments. |
| 206
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14:33
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Simultaneous fMRE and fMRI measures the viscoelastic and BOLD responses of the human brain to functional activation in the visual cortex |
1Bioengineering, Stanford University, Stanford, CA, United States, 2Radiology, Mayo Clinic, Rochester, MN, United States, 3Radiology, Stanford University, Stanford, CA, United States |
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Here, we demonstrate a novel multi-modal method to simultaneously acquire robust fMRE and fMRI activation maps. A block paradigm of 24s ON (flashing checkerboard at 10Hz) and 24s OFF (fixation cross) was used and images were acquired with a single-shot spin-echo EPI MRE sequence. Our results show that tissue stiffness within the visual cortex increases 6-12% with visual stimuli. Furthermore, the fMRE and fMRI activation maps agree and overlap spatially within the visual cortex, providing convincing evidence that fMRE is possible in the cortex. |
| 207
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14:45
|
Functional Magnetic Resonance Electrical Impedance Tomography of Aplysia abdominal ganglion |
1Arizona State University, Tempe, AZ, United States |
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Functional Magnetic resonance electrical impedance tomography ( |
| 208 | 14:57
|
Baseline Striatal Dopamine Binding Potential Predicts Functional Connectivity to Ventral Tegmental Area in Control but not in MDD: A Simultaneous [11C] Raclopride PET-fMRI Study |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, China, 2Radiological Sciences Laboratory, Department of Radiology, Stanford University, Palo Alto, CA, United States, 3Harvard-MIT Health Sciences and Technology, MIT, Boston, MA, United States, 4A. A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, United States, 5Center for Social and Affective Neuroscience, Linköping University, Linköping, Sweden, 6Department of Radiology, Harvard Medical School, Boston, MA, United States, 7Department of Psychology, Stanford University, Palo Alto, CA, United States, 8Applied Science Lab, GE Healthcare, Menlo Park, CA, United States |
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Our previous work has indicated a significant connection between dopamine release/binding and fMRI activation during reward processing in healthy controls (CTL), but not in major depressive disorder (MDD). It motivates us to explore whether there is a similar disrupting effect in the coupling of resting-state fMRI and baseline dopamine binding potential in MDD. By conducting a simultaneous [11C] Raclopride PET and fMRI study, we obtained significant correlations between striatal dopamine binding potential and VTA-striatum functional connectivity in CTL, but not in MDD, indicating that the decoupling of dopaminergic system and striatum may play a vital role in the pathophysiology of MDD. |
| 209 | 15:09
|
Spatial-temporal dynamics of the visual cortex stiffness driven by a flashing checkerboard stimulus |
1School of Biomedical Engineering and Imaging Sciences, King’s College London, London, United Kingdom, 2Siemens Healthcare Limited, Frimley, United Kingdom, 3Department of Radiology, Brigham and Women’s Hospital, Boston, MA, United States, 4King's College London, London, United Kingdom |
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In this |
| 210 | 15:21
|
Simultaneous Measurement of functional MRI and MRS by Fast Non-water Suppressed Keyhole MR Spectroscopy Imaging |
1Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States, 2School of Health Sciences, Purdue University, West Lafayette, IN, United States, 3Department of Psychiatry, McGill University, Montreal, QC, Canada, 4Centre d'Imagerie Cérébrale, Douglas Mental Health University Institute, Montreal, QC, Canada, 5Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, United Kingdom, 6Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States |
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The non-water suppressed magnetic resonance spectroscopic imaging (MRSI) sequence with concentric k-space trajectory was proposed to measure functional MRI and MRSI signals simultaneously. A right-hand finger-tapping task was performed at 3T MRI scanner to test the simultaneous hemodynamic and neurochemical measurements at human primary motor cortex. The results showed a significant overlap between T2* and metabolite (glutamate) changes. |
| 211 | 15:33
|
Imaging the Influence of Central Amygdala Neuronal Circuits on Nociception: a Combined Approach of Optogenetics and fMRI |
1Institute of Pharmacology, University of Erlangen-Nuremberg, Erlangen, Germany, 2Research Institute of Molecular Pathology, Vienna Biocenter, Vienna, Austria |
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Optogenetics has proven to be a highly useful tool to delineate the function of distinct proteins. Here, this approach was combined with fMRI to activate in-vivo selectively two interacting, but supposedly opposing, neuronal circuits of the central lateral amygdala (CEl). A classical fMRI paradigm was chosen to study the influence of the activation of either PKCδ- or somatostatin-expressing neurons on central pain processing, and to identify involved brain networks or areas. PKCδ was found to act preferentially anti-nociceptive by controlling via thalamus higher-order brain regions. Somatostatin on the other hand was shown to interact very closely with brainstem regions, controlling in a “bottom-up”-fashion thalamus, limbic system and cortex. |
| 212 | 13:45
|
Design of a volume MRI coil by metalyzing 3D printing substrates by electroless and/or electroplating processes |
1Univ. Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS, Lyon, France, 2Univ. Claude Bernard Lyon 1 (UCBL) Laboratoire AMPERE UMR 5005 CNRS, INSA, ECL, UCBL Campus LyonTech - La Doua, Lyon, France |
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Manufacturing compact, miniature devices required for small samples imaging is still challenging. Here we investigate the feasibility of metalyzing 3D printing subtrates to develop a volume coil dedicated to both small in-vitro / ex-vivo samples and in vivo mouse brain imaging. In order to validate the use of metalized 3D printed process to build MRI coil we build one reference Helmholtz coil made with copper tape wrapped around the coil mount and one with the same geometry using this new technology. First demonstration on bench and in imaging that copper metallization technology can be performed to build volume coil. |
| 213
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13:57
|
Nonlinearity and thermal effects in gradient chains: a cascade analysis based on current and field sensing |
1Information Technology and Electrical Engineering, ETH Zurich, Zurich, Switzerland |
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In MRI, many gradient field imperfections are linear and time-invariant to some extend and can be well modelled by gradient impulse response functions. However, time invariance is violated by thermal effects and linearity e.g. by the gradient amplifier. To isolate sources of model violations we split the gradient chain into a cascade, consisting of eddy current compensation, amplifier and coil. Coil and amplifier responses are disentangled by extending the field measurement by current monitoring. Linearity and time-invariance violations are analyzed by performing heating experiments and varying test pulses. We show that current monitoring enables independent treatment of nonlinear distortion and thermal effects and that gradient response nonlinearities can be resolved directly. |
| 214 | 14:09
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Initial imaging experience with a head gradient (MAGNUS) at 3.0T operating at 200 mT/m and 500 T/m/s |
1GE Global Research, Niskayuna, NY, United States, 2GE Healthcare, Florence, SC, United States, 3Walter Reed National Military Medical Center, Bethesda, MD, United States, 4Uniformed Services University of the Health Sciences, Bethesda, MD, United States, 5Ft. Belvoir Community Hospital, Ft. Belvoir, VA, United States |
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Healthy volunteer subjects were safely imaged in a 3.0 T MRI system with an ultra-high performance head-gradient coil. The MAGNUS coil operates at 200 mT/m and 500 T/m/s, simultaneously on all 3-axes, and has a patient (head) bore diameter of 37-cm. Substantial reduction in pulse sequence TE, TR, and echo-planar imaging echo spacing was achieved with observable improvement in image quality. The design enabled the achievement of higher peripheral nerve stimulation thresholds compared to that for whole-body gradient coils. |
| 215 | 14:21
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A target-field shimming approach for improving the encoding performance of a lightweight Halbach magnet for portable brain MRI |
1Massachusetts Institute of Technology, Cambridge, MA, United States, 2Athinoula A Martinos Center for Biomedical Imaging, Charleston, MA, United States, 3Harvard Medical School, Boston, MA, United States |
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Portable brain MRI scanners have the potential to increase the reach of diagnostic imaging but require relaxing constraints such as magnet homogeneity and gradient linearity or even elimination of gradient switching via a rotating magnet with built-in encoding fields. Nonetheless, the encoding matrix must retain good conditioning and excessive signal bandwidth must be controlled. To address this, we developed and validated a permanent magnet shimming method for a lightweight Halbach-style brain imaging magnet and designed and constructed a pair of compact, head-only phase encoding gradients. We demonstrate these improvements in spatial encoding with head-sized phantom and in vivo brain images. |
| 216
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14:33
|
FAMASITO - FASTMAP Shim Tool Towards User-Friendly Single-Step B0 Homogenization |
1Biomedical Engineering, Columbia University, New York, NY, United States, 2Radiology, Columbia University, New York, NY, United States |
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Fast, automatic shimming by mapping along projections (FASTMAP) is an elegant analytical method developed to quantify 3-dimensional first and second order spherical harmonic B0 shapes along six 1-dimensional column projections. The straightforward application of this theoretical concept to B0 shimming, however, neglects crucial aspects of sequence implementation and shim hardware, commonly necessitating multi-step iterative adjustments. Considering experimental imperfections of the employed B0 mapping and shim coil hardware, we demonstrate optimal single-step adjustment of first and second order terms (with potential <3% refinement of linear terms) in the anterior cingulate cortex, one of the most difficult-to-shim areas in the human brain. |
| 217
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14:45
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Dynamic Optimization of Gradient Field Performance Using a Z-Gradient Array |
1National Magnetic Resonance Research Center (UMRAM), Bilkent University, ANKARA, Turkey, 2Electrical and Electronic Engineering, Bilkent University, ANKARA, Turkey |
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Performance parameters of gradient coils such as size of the linearity volume, linearity error, inductance, power dissipation, gradient strength per unit current are determined at the design stage. On the contrary, array of gradient coils driven by independent amplifiers can enable optimization of this parameters. Therefore, optimal gradient performance can be realized depending on the sequence requirements and target volumes. Nine channel z-gradient array is used to optimize various performance parameters and to analyze the tradeoffs between them. Linear gradient profile generated by Z-gradient array hardware is used as readout gradient to demonstrate the feasibility of the hardware. |
| 218
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14:57
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A 16-Channel RF Receive Array with Integrated B0-shim Capability for Anesthetized Monkey Whole Brain Imaging at 7T |
1Interdisciplinary Institute of Neuroscience and Technology, Qiushi Academy for Advanced Studies, College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, China, 2Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 3MR Collaboration Northeast Asia, Siemens Healthcare, Hangzhou, China, 4Harvard Medical School, Boston, MA, United States, 5Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States |
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To mitigate signal dropout in EPI images due to local B0 inhomogeneities inevitably caused by craniotomies and chamber implantations needed for multimodal studies, we designed a custom 16-channel tight-fit receive array, with each receive element integrated with DC pathway for multi-coil B0 shimming. The feasibility of constructing high-density receive array (5cm diameter loop elements) integrated with B0-Shim has been demonstrated. With DC-enabled higher-order local B0 shimming, obvious improvement in recovering local signal drop out and image distortion around brain surgery region, implying its promising application in high-resolution multi-modal monkey neuroimaging. |
| 219 | 15:09
|
Dynamic Multi-Coil Technique (DYNAMITE) MRI on Human Brain |
1Departments of Biomedical Engineering and Radiology, Columbia University, New York, NY, United States, 2Department of Radiology, Center for Magnetic Resonance Research (CMRR), University of Minnesota, Minneapolis, MN, United States, 3Department of Radiology and Biomedical Imaging, Magnetic Resonance Resesarch Center (MRRC), Yale University, New Haven, CT, United States |
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To date, spatial encoding for human MRI is based on linear X, Y and Z field gradients generated by dedicated X, Y and Z gradient coils. We recently introduced the Dynamic Multi-Coil Technique (DYNAMITE) for B0 magnetic field modeling and demonstrated DYNAMITE MRI in a miniaturized setup. In this study we report the first realization of multi-slice DYNAMITE MRI of the in vivo human brain in which all gradient fields are purely DYNAMITE-based. The obtained image fidelity is comparable to MRI with conventional gradient coils, paving the way for full-fledged human DYNAMITE MRI systems. |
| 220 | 15:21
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Integrated AC/DC coil and dipole Tx array for 7T MRI of the spinal cord |
1NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada, 2Electrical Engineering, Ecole Polytechnique de Montreal, Montreal, QC, Canada, 3École Normale Supérieure de Lyon, Lyon, France, 4Centre for Functional and Metabolic Mapping, The University of Western Ontario, London, ON, Canada, 5Department of Medical Biophysics, The University of Western Ontario, London, ON, Canada, 6Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 7Harvard Medical School, Boston, MA, United States, 8Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, United States, 9Functional Neuroimaging Unit, CRIUGM, University of Montreal, Montreal, QC, Canada |
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Imaging the spinal cord is a never-ending challenge, especially when venturing to ultra-high fields. We propose a novel coil design for spinal cord 7T MRI, which combines state-of-the-art transmit and receive technologies. The transmit coil is a 3-dipole array, allowing homogeneous B1 field with parallel excitation. The receive part consists of a 15-channel AC/DC coil that can achieve both high sensitivity and local B0 shimming, including real-time shimming to compensate for respiratory-induced field variations. The design can achieve 32% reduction of static field inhomogeneities and 27% reduction in temporal field variance, opening the door to exciting EPI and spectroscopy applications. |
| 221 | 15:33
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B-0 shimming of the liver using a local array of shim coils in the presence of respiratory motion at 7T |
1Center for Image Sciences, UMC Utrecht, Utrecht, Netherlands, 2MR Shim GmbH, Reutlingen, Germany |
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Inhomogeneity of the magnetic field (B0) in the human body, for instance caused by physiological motion (e.g. breathing), can lead to artifacts. Static second order magnetic field shimming even in the absence of breathing cannot provide a uniform magnetic field in large organs such as the liver, particularly at ultra-high field throughout the breathing cycle. We show that in conjunction with static second order shimming, local arrays of shim coils can substantially improve the magnetic field uniformity in the liver at different breathing states. |
13:45
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Quantification in Fetal & Placental MRI: Clinical Motivation | |
1Boston Children's Hospital |
14:09
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Quantification in fetal & Placental MRI: Towards Clinical Applications | |
1SPMIC, University of Nottingham, Nottingham, United Kingdom |
14:33
|
Non-Human Primate Models of Pregnancy in Placental & Fetal MRI: Opportunities & Challenges | |
1Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States |
14:57
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Automating Motion Compensation in 3T Fetal Brain Imaging: Localize, Align & Reconstruct | |
1King's College London, London, United Kingdom |
15:21
|
Motion Correction in Fetal Cardiovascular MRI | |
1University of Toronto / Hospital for Sick Children |
13:45
|
Introduction to the Perfusion Open-Source Initiative | |
1Brigham Women's Hospital, Boston, MA, United States |
14:00
|
Building Software for Reproducible Research: Lessons from the BART Project | |
1University Medical Center Göttingen, Germany |
14:20
|
Welcome to the Jungle: Open-Source Software for DCE & DSC | |
14:30
|
Standardized Open-Source Image Analysis: Can We Avoid Confusion but Focus on Perfusion? | |
1Amsterdam University Medical Center, Amsterdam, Netherlands |
14:45
|
Best Practices in DRO Development | |
14:50
|
Digital Reference Objects for DCE-MRI: Sources & Directions | |
14:55
|
An Anthropomorphic Digital Breast Phantom for Simulation & Analysis of MRI Techniques: Implementation for dynamic contrast-enhanced MRI | |
15:00
|
A Population-Based Digital Reference Object (DRO) for Optimizing Dynamic Susceptibility Contrast (DSC) MRI Methods for clinical trials | |
1imaging research, Barrow Neurological Institute, Phoenix, AZ, United States |
15:10
|
DICOM Parametric Maps: A Common Language for Perfusion Software | |
15:30
|
Break & Meet The Teachers |
16:00
|
Hepatologist's Perspective | |
1Duke University Medical Center, Durham, NC, United States |
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Hepatocellular carcinoma (HCC) is a leading cause of cancer mortality worldwide. The key to preventing mortality is to diagnose HCC at an early stage when curative therapies can be offered. Candidacy for hepatic resection or liver transplantation is an early decision. Embolization and ablation procedures are important therapeutic modalities. Patients at high risk for HCC are recommended to participate in surveillance programs. Effective imaging is critical to patients with chronic liver disease given their risk of HCC. Imaging allows early identification and diagnosis with ongoing monitoring capabilities, and patients are given the best option for pursuit of cure from HCC. |
16:30
|
LI-RADS | |
1University of California, San Diego, La Jolla, CA, United States |
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Review worldwide approaches to HCC diagnosis, highlighting similarities and differences in algorithms. Provide an overview of updates to LI-RADS/AASLD, updates to literature, and highlight future directions based on current gaps in knowledge. |
16:55
|
Self Assessment Module (SAM) |
17:00
|
European Guidelines | |
1University of Brescia, Italy |
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Hepatocellular carcinoma surveillance aims to reduce disease-related mortality. High risk patients who were enrolled into a surveillance programme were diagnosed at an earlier stage, received potential curative therapies more frequently, and had better overall survival than did unenrolled patients. |
17:30
|
Asian Guidelines | |
1Kobe University Graduate School of Medicine, Kobe, Japan |
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Diagnostic imaging systems have critical role in the surveillance and diagnose hepatocellular carcinoma (HCC) in early stages, resulting in improvement of the prognosis of patients with HCC. Several scientific organizations have proposed imaging-based diagnostic systems of HCC, and they vary between geographic areas caused by different target populations, resources, and treatment practices. I will review the current imaging-based diagnostic systems especially in Asian, and present its' characteristics with some case presentations. |
18:00
|
Adjournment |
16:00
|
Imaging Biomechanics of Whole Joints | |
1Orthopaedics and Centre for Hip Health and Mobility, University of British Columbia, Canada |
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The purpose of this presentation is to explain why studying whole joint biomechanics is important, outline the benefits and limitations of studying whole joint biomechanics using MRI, and highlight some new MR approaches that have potential for substantial improvements in studying joint biomechanics. |
16:30
|
Prospective Motion Correction During Loading | |
1Dept. of Radiology, Medical Physics, Medical Center - University of Freiburg, Freiburg, Germany |
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Knee MRI with in situ loading is strongly hampered by subject motion. However, the resulting artifacts can be efficiently suppressed by prospective motion correction. The functional principle of prospective motion correction based on optical tracking is explained and its use for knee MRI with in situ loading is demonstrated. Challenges, limitations and pitfalls of the technique are addressed. Results of anatomical and relaxometric cartilage MRI with prospective motion correction are presented. Non-rigid body motion and tracking marker fixation are the main limitations for most orthopedic applications. The ease of implementation and the correction efficacy of prospective motion correction are sequence-dependent. |
17:00
|
Dynamic MRI of Joints: Technical Factors and Clinical Applications | |
1Radiology, Stanford University, CA, United States |
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while static MRI is widely used clinically for the assessment of several joints, it often fails to provide information on their biomechanical and functional status. On the other hand, dynamic MRI allows to gather information on the normal and impaired musculoskeletal function during motion but is technically more challenging. This presentation will cover some of the technical factors needed to perform and analyze a dynamic MRI experiment of the joints, and will highlight some clinical and research applications where dynamic MRI can add useful information to conventional static imaging. |
17:30
|
Clinical Application: Loaded Imaging of the Spine & Peripheral Joints | |
1Radiology, Stanford, Stanford, CA, United States |
18:00
|
Adjournment |
16:00
|
Spin Gymnastics | |
1University of Wisconsin - Madison, United States |
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This educational lecture will provide a general overview of the basic physics of MRI. A broad range of topics will be covered, including magnetization and signal generation, relaxation of magnetization, the spin echo phenomenon, spatial encoding of signal, and a very brief introduction to the concept of k-space. Several of the topics will be introduced in this lecture and will be further elucidated by other presenters in this course. |
17:30
|
Image Quality | |
1United States |
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In this educational talk we discuss how MRI acquisition parameters affect aspects of image quality using the concept of k-space. |
18:00
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Adjournment |
| 222 | Pitch: 16:00 Poster: 17:00 Plasma 1
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A GRANDIOSE sequence to time-lock BOLD and diffusion-weighted fMRI contrasts in humans using ultra-strong gradients and spirals |
1CUBRIC, School of Psychology, Cardiff University, Cardiff, United Kingdom |
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Diffusion-weighted fMRI (dfMRI) has been suggested to provide more direct and specific correlates to neuronal activation than BOLD fMRI. However, its underpinnings are debated. A sequence that captures BOLD and dfMRI contrasts simultaneously can play a vital role in elucidating the dfMRI contrast mechanisms. Hence, we developed a sequence that leverages the ultra-strong gradients for diffusion-weighting and spiral-in and spiral-out trajectories to acquire BOLD and dfMRI contrasts near-simultaneously. We demonstrate its functionality using visual stimulation in humans. This novel sequence enables a direct comparison between BOLD and dfMRI contrasts and offers new opportunities to improve our understanding of these contrasts. |
| 223
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Is spherical diffusion encoding rotation invariant? An investigation of diffusion time-dependence in the healthy brain |
1Radiology, Brigham and Women's Hospital, Boston, MA, United States, 2Harvard Medical School, Boston, MA, United States, 3Random Walk Imaging AB, Lund, Sweden, 4Clinical Sciences Lund, Lund University, Lund, Sweden, 55. Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Copenhagen, Denmark, 6Physical Chemistry, Lund University, Lund, Sweden |
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Recent advances in diffusion weighted MRI have reignited interest in spherical (or isotropic) diffusion encoding. For such encoding to reach high efficiency (minimal echo time), the gradient waveforms have irregular shapes, by design. As such, they lack a well-defined diffusion time and can even be spectrally anisotropic. Most analysis methods based on such encoding assume that diffusion is multi-Gaussian, i.e., that the diffusion is not time-dependent. Since this is a central assumption, we investigate if spherical diffusion encoding is indeed rotation invariant, or if the diffusion time anisotropy has a discernible effect on the diffusion weighted signal in healthy brain. |
| 224 | Pitch: 16:00 Poster: 17:00 Plasma 3
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Application of an Extended Stretched-Exponential Model for Morphometric Analysis of Accelerated Diffusion-weighted 129Xe MRI of the Rat Lung |
1Robarts Research Institute, London, ON, Canada, 2Lawson Imaging, Lawson Health Research Institute, London, ON, Canada, 3Translational Medicine Program, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, ON, Canada, 4Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada, 5Department of Medical Biophysics, Western University, London, ON, Canada, 6Division of Respirology, Department of Medicine, Western University, London, ON, Canada |
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Hyperpolarized 129Xe pulmonary MRI is poised for clinical translation due in part to the clinical-relevance of 129Xe MRI biomarkers of lung disease. A rapid multi-b diffusion-weighted 129Xe MRI requires for clinical morphometry due to the challenges in acquiring a fully-sampled dataset during the relatively short 10-16sec breath-holds. Therefore, in this proof-of-concept evaluation, our objective was to measure morphometry estimates in a small group of control-rats as well as rats with early stage radiation-induced-lung-injury, and compare the stretched-exponential-model based morphometry estimates for three different cases: 1) fully-sampled k-space 2) 85% retrospectively under-sampled k-space, (acceleration factor (AF)=7), and 3) 90% retrospectively under-sampled (AF=10) k-space. |
| 225 | Pitch: 16:00 Poster: 17:00 Plasma 4
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SPatiotemporal ENcoding (SPEN) at ultra-high fields: Applications to high resolution (<100 µm isotropic) in vivo mouse brain DTI |
1Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel, 2Champalimaud Centre for the Unknown, Lisbon, Portugal |
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SPEN can be a valuable alternative to Spin Echo EPI, especially at very high fields where sensitivity is maximized but magnetic field susceptibility artifacts become important. This work presents a new Paravision® 6 software package capable of acquiring and processing SPEN data, incorporating single/multishot acquisitions, motion correction, image zooming and multiple contrast possibilities such as CEST, diffusion or multi-echo acquisition. The power of this method is exemplified with in vivo 2D and 3D diffusion tensor imaging (DTI) studies on whole and zoomed mouse brain regions, acquired at 15.2T utilizing a cryoprobe and reaching isotropic resolution of 75 µm. |
| 226
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Storing phase information in the longitudinal direction: Experimental verification of double diffusion encoding with stimulated echoes applied to closed pores |
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Faculty of Physics and Astronomy, Heidelberg University, Heidelberg, Germany, 3Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany |
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When applying double diffusion encoding (DDE) to arbitrarily shaped closed pores, non-vanishing imaginary parts in the diffusion signal arise, which allow determining the average shape of the pores in the considered volume element. Key limitations in such experiments are the available gradient strength and reaching the diffusion long-time limit restricted by T2 decay. When incorporating stimulated echoes into DDE-sequences, the slower T1 relaxation can be exploited to reach the long-time limit in larger pores demanding lower gradient strengths. We present experimental verification that phase information can be stored in longitudinal magnetization direction thus preserving complex signals under application of stimulated echoes. |
| 227
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Diffusion acquisition methods for unfixed ex vivo neonatal brain scan at 7T: sequence optimisation and preliminary experiments |
1Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, United Kingdom, 2Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom, 3Sir Peter Mansfield Imaging Centre, School of Medicine, University of Nottingham, Nottingham, United Kingdom, 4Centre for the Developing Brain, King's College London, London, United Kingdom, 5Biomedical Engineering Department, King's College London, London, United Kingdom |
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In this work we present preliminary investigations into the use of diffusion-weighted steady state free procession (DW-SSFP) sequences and conventional diffusion-weighted spin-echo (DW-SE) sequences for unfixed neonate brains. We conduct an exploratory experiment to demonstrate the feasibility of existing dMRI methods on an unfixed porcine brain. We then propose a framework to match DW-SE and DW-SSFP contrast in a way that predicts optimal performance of each, in order to compare between methods. |
| 228
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Towards robust free-breathing cardiac DTI |
1MRC/UCT Medical Imaging Research Unit, University of Cape Town, Cape Town, South Africa, 2Cape Universities Body Imaging Centre (CUBIC-UCT), University of Cape Town, Cape Town, South Africa, 3Oxford Centre for Clinical Magnetic Resonance Research (OCMR), University of Oxford, Oxford, United Kingdom, 4Department of Medicine, University of Cape Town, Cape Town, South Africa, 5Hatter Institute for Cardiovascular Research in Africa, University of Cape Town, Cape Town, South Africa |
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A prospective respiratory motion correction control system, capable of performing of slice tracking, was implemented in a spin echo diffusion weighted sequence to perform free-breathing acquisitions. The performance of the motion correction control system was compared against common respiratory motion compensation techniques, namely breath-holds, respiratory gating, and standard slice tracking. The values of all the free-breathing techniques varied from the breath-hold data, however, the motion correction control system produced very consistent results. The slice tracking methods were able to significantly reduce the acquisition time (by 50%), compared to the respiratory gating technique. |
| 229 | Pitch: 16:00 Poster: 17:00 Plasma 8
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Model based joint B0 and image estimation framework for dynamic field mapping and signal pile-up correction in prostate diffusion MRI |
1University College London, London, United Kingdom, 2Canon Medical Research USA, Cleveland, OH, United States |
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Prostate diffusion MRI is recognized as a potential biomarker for tumour detection but currently it is unusable in some patients due to significant distortions. We proposed a novel model based joint image and B0 reconstruction framework that can correct these distortions by using data acquired from opposite phase encoding gradient directions. Using sampling time shift between the two acquisitions, the proposed method is robust against any dynamic changes in the off resonance effects in the prostate-rectal air region. |
| 230
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Self-calibrated and Collaborative Propeller-EPI Reconstruction (SCOPER) for High-Quality Diffusion-Tensor Imaging |
1Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong, China, 2Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, 3The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China, 4Philips Healthcare, Hong Kong, China |
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Propeller-EPI is a self-navigated multi-shot technique for high-resolution diffusion-tensor imaging. However, corrections for 2D Nyquist ghost and distortion for each blade data are necessary to obtain high-quality image. In this study, we aim to develop a self-calibrated and collaborative Propeller-EPI reconstruction (SCOPER) framework that can 1) allows the estimation of phase errors and off-resonance map from the blade data, and 2) collaboratively reconstruct fully-corrected Propeller-EPI image from all blade data and the thereof. Our results demonstrated that SCOPER shows improved SNR performance, compared with conventional Propeller-EPI reconstruction pipelines. |
| 231
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Simultaneous Reconstruction of Multiple b-Values DWI using a Joint Convolutional Neural Network |
1Institute for Medical Imaging Technology (IMIT), School of Biomedical Engineering, Shanghai Jiao Tong university, Shanghai, China, 2Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States |
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This study presented a joint convolutional neural network (CNN) architecture for the reconstruction of multiple b-values diffusion-weighted (DW) images simultaneously. The proposed joint-net is able to extract high-level anatomical correlations among multi-contrast images and correct misalignment between images by adding a spatial transformation layer. Experimental results show that the proposed algorithm outperforms single image reconstruction network and compressed sensing algorithm with improved image quality. The training process of the joint-net is much more efficient compared to individual training for each b-value image. Besides, combination of data consistency and the joint-net enables precise characterization of brain tumor in a patient study. |
| 232
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Improved gSlider Reconstruction for Isotropic High-Resolution DTI Using A Model-Based Method and Virtual Coil Concept |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, 2Department of Radiology, Stanford University, Stanford, CA, United States, 3A. A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, United States, 4Department of Electrical Engineering and Computer Science, MIT, Cambridge, MA, United States |
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Recently, generalized SLIce Dithered Enhanced Resolution (gSlider) has been proposed as a new acquisition strategy for isotropic high-resolution DTI. In this study, to further boost the SNR performance and reconstruction accuracy, the model-based DTI reconstruction method was merged into the gSlider reconstruction procedure. Moreover, virtual coil (VC) concept was also integrated into the proposed method to further improve the SNR of gSlider reconstruction. Compared with conventional GRAPPA, the superiority of the model-based method has been demonstrated by in vivo results, especially when in combination with the virtual coil concept. |
| 233
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SMS-MUSSELS: A Navigator-free Reconstruction for Slice-accelerated Multi-shot Diffusion Imaging |
1University of Iowa, Iowa City, IA, United States, 2GE Healthcare, Milwaukee, WI, United States, 3Stanford University, Stanford, CA, United States |
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Multi-shot diffusion-weighted ( |
| 234 | Pitch: 16:00 Poster: 17:00 Plasma 13
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A nonlinear model for DTI reconstruction with locally low-rank regularization |
1Department of Electrical Engineering, Stanford University, Stanford, CA, United States, 2Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States, 3Department of Radiology, Stanford University, Stanford, CA, United States, 4Department of Bioengineering, Stanford University, Stanford, CA, United States |
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We developed a nonlinear model with simultaneous phase and magnitude updates for iterative multi-shot DWI reconstruction. In addition, locally low-rank regularization along the diffusion encoding direction was included in the proposed model to utilize angular correlation for DTI reconstruction. In-vivo high-resolution and high b-value images have been acquired to validate the proposed method and the proposed method significantly reduces image noise. |
| 235 | Pitch: 16:00 Poster: 17:00 Plasma 14
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ZEBRA – from rich-multi-dimensional data to anatomical profiles |
1Biomedical Engineering Department, School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 2Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 3University College London, London, United Kingdom |
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An efficient joint multi-parametric diffusion-relaxometry MRI acquisition, ZEBRA, is presented. Improvements to optimize the joint sampling in several dimensions include logarithmic TI sampling, superblock strategies and globally and locally optimized gradient schemes. These are introduced together with a proposed whole-brain protocol (resolution 2.5mm isotropic). The data is analysed by an assumption free clustering step – designed to extract tissue information and anatomical profiles directly from the signal. Depiction of several clusters – including the deep grey matter and cerebellar substructures - illustrate the richness of the obtained data. |
| 236 | Pitch: 16:00 Poster: 17:00 Plasma 15
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In-vivo diffusion-fMRI using Incomplete Initial Nutation Diffusion Imaging (INDI) |
1Champalimaud Research, Champalimaud Centre for the Unkown, Lisbon, Portugal, 2Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, Portugal |
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Diffusion functional-MRI (dfMRI) is thought to capture microstructural changes associated with neural activity. The water apparent diffusion coefficient decrease observed upon neuronal activity is hypothesized to be cell-swelling dependent. Yet, one of the confounding factors for dfMRI is that zero and nonzero b-values need to be acquired to deliver accurate changes in diffusivity and those images are typically separated by at least one repetition time. Incomplete initial Nutation Diffusion Imaging (INDI) was proposed as a method to acquire two images with different diffusion-weighting with separation of <50ms. Here, we performed INDI-fMRI experiments to report mean diffusivity changes using forepaw-stimulated rats. |
| 237 | Pitch: 16:00 Poster: 17:00 Plasma 16
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Robustness of PSIR segmentation and R1 mapping at 7T: a travelling head study |
1Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom, 2Nuffield Department of Clinical Neurosciences, University of Oxford, Wellcome Centre for Integrative Neuroimaging (FMRIB), Oxford, United Kingdom, 3School of Psychology, Cardiff University, Cardiff University Brain Research Imaging Centre, Cardiff, United Kingdom, 4Department of Clinical Neurosciences, University of Cambridge, Wolfson Brain Imaging Centre, Cambridge, United Kingdom, 5University of Glasgow, Imaging Centre of Excellence, Glasgow, United Kingdom |
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Ultra-high magnetic field (7T) MRI scanners can provide high spatial resolution images and excellent contrast for classifying brain tissue, but robustness of tissue segmentation and R1 quantification across sites is key for the implementation of multi-site studies. Here, we present a subset of the main UK7T travelling-head study, focusing on harmonized T1-weighted images (0.7mm3 isotropic resolution) acquired on six subjects across three 7T sites, with five repeats at one site. The aim of this study is to assess the harmonisation and robustness of the MP2RAGE sequence and PSIR reconstruction across sites, by focusing on segmentation reproducibility and T1 estimation. |
| 238 | Pitch: 16:00 Poster: 17:00 Plasma 17
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Separation of Cardiac- and Respiratory-driven CSF Motions under Free Breathing based on Realtime Phase Contrast Imaging and S-Transform |
1Department of Human and Information Science, School of Into Science and Technology, Tokai University, Hiratsuka, Japan, 2Center for Frontier Medical Engieering, Chiba University, Chiba, Japan, 3Course of Electrical and Electronic Engineering, Graduate School of Engineering, Tokai University, Hiratsuka, Japan, 4BioSim Research Center, BioView Inc., Tokyo, Japan, 5Department of Radioligy, Tokai University Hospital, Isehara, Japan, 6Department of Neurosurgery, Tokai University School of Medicine, Isehara, Japan |
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To separately visualize respiratory- and cardiac-driven motions of intracranial cerebrospinal fluid (CSF) under free breathing, CSF velocity distribution in 6 healthy volunteers and 3 hydrocephalus patients were acquired with asynchronous real time phase contrast (PC). Spectrograms of CSF velocity waveform as well as ECG and respiratory signals were obtained by Stockwell Transform (ST), in which the length of a Gaussian window length was adaptively changed according to the time-varying frequency of the signals. Comparison with the conventional short-term Fourier transform (STFT) with fixed length window revealed that separation of respiratory and cardiac components of CSF motion was possible with ST. |
| 239
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CVR-MRICloud: an automated online tool for the processing of cerebrovascular reactivity (CVR) MRI data |
1Department of Radiology, Johns Hopkins School of Medicine, Baltimore, MD, United States, 2AnatomyWorks LLC, Baltimore, MD, United States, 3Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States, 4Kennedy Krieger Institute, Baltimore, MD, United States |
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Cerebrovascular reactivity (CVR) has recently become a focus for many labs. However, CVR calculation has always required at least some degree of manual intervention. Therefore, our lab has developed CVR-MRICloud, a free, online, fully automated CVR processing pipeline. Our pipeline returns CVR maps, relative bolus arrival time maps, and region-of-interest CVR values. The maps are given in their original space as well as standardized MNI space. The pipeline has been shown to procure results corresponding to accepted CVR processing techniques that rely on manual intervention. This pipeline has potential to streamline other researchers’ acquisition of CVR values in subjects. |
| 240 | Pitch: 16:00 Poster: 17:00 Plasma 19
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Comparing neural networks for synthesizing FLAIR images from T1WI and T2WI |
1Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Japan |
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| 241 | Pitch: 16:00 Poster: 17:00 Plasma 20
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Performance comparison of compressed sensing algorithms for accelerating T1ρ mapping of Human Brain |
1Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, United States |
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3D-T1ρ mapping sequences are useful MRI methods in various neuropathologies but its data acquisition requires long scan times. We compared the performance of 5 compressive sensing (CS) algorithms with acceleration factors (AF) up to 10. We evaluated image quality and T1ρ estimation errors as a function of AF. Six healthy volunteers were recruited and they underwent T1ρ imaging of the whole brain with full Cartesian acquisition. Assessment of image reconstruction and T1ρ estimation errors in this study show that the CS method using spatial and temporal finite differences as a regularization function performs the best for accelerating T1ρ quantification in the brain. |
| 242 | Pitch: 16:00 Poster: 17:00 Plasma 21
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Enhancement and Evaluation of the White Matter Connectome of the IIT Human Brain Atlas |
1Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, United States |
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In the IIT Human Brain Atlas |
| 243 | Pitch: 16:00 Poster: 17:00 Plasma 22
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Single-shot Diffusion-weighted Spiral Imaging in the Brain on a Clinical Scanner |
1Tomographic Imaging Systems, Philips Research, Hamburg, Germany, 2Radiology, LUMC, Leiden, Netherlands, 3MRI, Philips Healthcare, Best, Netherlands |
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Single-shot diffusion-weighted imaging is predominantly performed with echo planar imaging today. Spiral imaging allows shorter echo times and thus promises higher signal-to-noise ratio, but is sensitive to various system imperfections. While previous work resorted to using a field camera for this reason, this work demonstrates the feasibility of single-shot diffusion-weighted spiral imaging in the brain on a clinical scanner without extra hardware for field monitoring. Good image quality was generally achieved in volunteers for different diffusion gradient directions up to high b-values using the demand trajectory for gridding, parallel imaging for acceleration, and static main field inhomogeneity mapping for deblurring. |
| 244 | Pitch: 16:00 Poster: 17:00 Plasma 23
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The developing Human Connectome Project (dHCP): fetal acquisition protocol |
1Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 2Biomedical Engineering Department, King's College London, London, United Kingdom, 3FMRIB, Oxford University, Oxford, United Kingdom |
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The developing Human Connectome Project seeks to map connectivity in the human brain based on structural, functional and diffusion MRI data acquired from over 1000 subjects (neonatal and fetal). A dedicated acquisition protocol has been developed to efficiently image fetal brain in utero. We describe here the methods and parameters being used alongside initial pre-processing steps. The acquisition protocol has been tuned to complement the neonatal data already collected while adapting to the difficult challenges of imaging the fetal brain in utero. It has been deployed to image over 145 fetuses to date with a success rate of ~90%. |
| 245
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Inversion Recovery Zero Echo Time (IR-ZTE) Imaging for Direct Myelin Detection in Human Brain |
1Department of Radiology, University of California San Diego, San Diego, CA, United States, 2GE Healthcare, San Diego, CA, United States, 3Radiology Service, VA San Diego Healthcare System, San Diego, CA, United States |
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In MRI, direct myelin imaging is challenging due to the short T2* decay (less than 0.5ms) and very low proton density. In the literature, it has been reported that ultrashort echo time (UTE) imaging can directly capture the fast decaying myelin signal. To further enhance the dynamic range, adiabatic inversion recovery (IR) preparation can be utilized so that the white matter signal can be suppressed. Moreover, dual echo UTE imaging scheme can suppress the remaining gray matter signal. In this study, we explore the feasibility of IR prepared zero echo time (IR-ZTE) imaging for direct myelin imaging in the human brain. |
| 246 | Pitch: 16:00 Poster: 17:00 Plasma 25
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Planar rosette spectroscopic imaging at 7T |
1University of Pittsburgh, Pittsburgh, PA, United States, 2UPMC, Pittsburgh, PA, United States |
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To make spectroscopic imaging clinically feasible, rapid and robust acquisitions with high SNR are necessary. We develop and apply rosette spectroscopic imaging at 7T using a 8x2 transceiver array and high degree B0 shimming to acquire rapid (<3min) whole plane brain studies at 0.7cc to 0.3cc resolution. To achieve high spectral bandwidth with moderate gradient demands, two temporal interleaves are used. We demonstrate the performance of this acquisition in controls and tumor patients, with use of regression statistics for determination of abnormality. |
| 247
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Whole brain sub-mm resolution T2* weighted anatomy imaging in less than 2 minutes |
1Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 2Department of Radiotherapy, University Medical Center Utrecht, Utrecht, Netherlands, 3Department of Neuroscience, University of Turin, Turin, Italy, 4Philips Healthcare, Best, Netherlands |
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T2* weighted imaging can be used to study both normal and pathological tissue. These images are commonly obtained using traditional gradient echo sequences which can lead to long scan times that are problematic particularly in a clinical setting. 3D EPI offers a faster alternative with scan times on the order of few minutes. Here, the scan time of T2* weighted 3D EPI scans is further reduced with a shot selective 2D CAIPI acquisition pattern. Whole brain T2* weighted anatomical scans with a resolution of 0.5 mm isotropic were acquired in 1:27 minutes. This holds promising perspectives for future applications in routine examinations. |
| 248
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Reduced Regional Cerebral Venous Oxygen Saturation is a Risk Factor for Cognitive Impairment in Hemodialysis Patients: A Susceptibility-weighted Image Mapping Study |
1Department of Radiology, Tianjin First Central Hospital, Tianjin, China, 2Deparment of Hemodialysis, Tianjin First Central Hospital, Tianjin, China, 3MR Collaboration, Siemens Healthcare Ltd., Beijing, China, 4Department of Radiology, Wayne State University, Detroit, MI, United States |
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The purpose of this study was to noninvasively evaluate the changes of regional cerebral venous oxygen saturation (rSvO2) in hemodialysis patients using quantitative susceptibility-weighted image mapping (SWIM) and then to investigate the relationship between rSvO2, clinical risk factors, and neuropsychological testing results. The results suggest that cerebral rSvO2 is reduced in hemodialysis patients and that this reduction may correlate with neurocognitive dysfunction. Hematocrit, iron, glucose, and pre- and post-dialysis DBP were independent risk factors for reduced cerebral rSvO2. |
| 249
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The UK7T Network’s Harmonized Neuroimaging Protocols |
1Wellcome Centre for Integrative Neuroimaging, FMRIB, NDCN, University of Oxford, Oxford, United Kingdom, 2Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom, 3Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Cardiff, United Kingdom, 4Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom, 5Imaging Centre of Excellence, University of Glasgow, Glasgow, United Kingdom |
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The UK7T Network is a consortium of 7-tesla-MRI capable sites in the United Kingdom, operating with three different scanner models, manufactured by two MR vendors. The Network has established a harmonized set of anatomical and functional MRI protocols for standardized neuroimaging across currently available human 7T scanners.
Here we make these harmonized protocols available to the community, along with example data, and describe the need for manual calibration to achieve harmonization across sites. |
| 250 | Pitch: 16:00 Poster: 17:00 Plasma 29
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High-resolution MR imaging of human brain with multi-echo integrated SSFP |
1State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China, 2University of Chinese Academy of Sciences, Beijing, China, 3CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Beijing, China, 4Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen, China, 5Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, United States, 6Beijing Institute for Brain Disorders, Beijing, China |
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Balanced SSFP (bSSFP) has been used in structural and functional MRI, but always suffered from banding artifacts. While phase cycling was widely used to reduce banding artifact, it would take more scan time. Recently, integrated SSFP (iSSFP) was introduced to acquire banding-free images in shorter scan time than phased-cycled bSSFP. In this work, multi-echo iSSFP was further developed to improve SNR and acquire ultrahigh-resolution images with moderate scan time at 7T. Phantom and in vivo experiments demonstrated that the combined image produced by weighted averaging of multi-echo iSSFP showed obvious SNR and contrast improvement and inherited the characteristics of bSSFP. |
| 251 | Pitch: 16:00 Poster: 17:00 Plasma 30
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Quantitative Susceptibility Mapping: In Vivo Biomarkers for Cerebral Cavernous Malformations Related Epilepsy |
1Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China, 2China National Clinical Research Center for Neurological Diseases, Beijing, China, 3Department of Neurosurgery, Peking University International Hospital, Beijing, China, 4Department of Neuroradiology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China, 5GE Healthcare, China, Beijing, China |
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Hemosiderin deposits surrounding the cerebral cavernous malformations (CCMs) had been proposed to be associated with the pathogenesis of CCM-related epilepsy (CRE). An increased perilesional and extralesional iron deposition were found in CCMs with epilepsy through susceptibility maps of quantitative susceptibility mapping (QSM). To investigate novel biomarkers for the in vivo and longitudinal evaluation of CCM lesions with epilepsy, this study was to explore the iron quantity in CCMs patients with CRE using quantitative susceptibility mapping. |
| 252 | Pitch: 16:00 Poster: 17:00 Plasma 31
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Probing Cerebral Lactate Compartmentalization with Hyperpolarized Diffusion Weighted 13C MRI |
1UCSF, San Francisco, CA, United States |
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Hyperpolarized 13C MRI has been used to non-invasively measure metabolism in real-time. However, perfusion and transporter expression can impact the compartmentalization of metabolites. In this work, we investigated the feasibility of diffusion weighted imaging of lactate generated from HP [1-13C]pyruvate in the human brain to assess lactate efflux and compartmentalization in a healthy volunteer. Whole brain lactate ADC values were 0.37ⅹ10-3 mm2/s, 0.29ⅹ10-3 mm2/s, and 0.41ⅹ10-3 mm2/s when diffusion gradients were applied in the X, Y, and Z direction, respectively, demonstrating the feasibility of diffusion weighted HP 13C MRI in a clinical setting. |
| 253 | Pitch: 16:00 Poster: 17:00 Plasma 32
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Imaging a hallmark of cancer: hyperpolarized [U-2H, U-13C]-glucose and hyperpolarized [1-13C]-dehydroascorbic acid can monitor TERT expression in gliomas |
1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, 2Neurological Surgery, University of California San Francisco, San Francisco, CA, United States |
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Expression of telomerase reverse transcriptase (TERT) is a fundamental hallmark of cancer. Identification of imaging biomarkers of TERT expression will facilitate non-invasive assessment of tumor burden and response to therapy. Our studies in glioma indicate that TERT expression leads to increased redox capacity characterized by elevated 1H-MRS-detectable glutathione and NADPH. Concomitantly, TERT increases 13C-MRS-detectable flux of glucose through the pentose phosphate pathway, which provides NADPH. Importantly, hyperpolarized [U-2H, U-13C]-glucose and hyperpolarized [1-13C]-dehydroascorbic acid can image these alterations in glucose and redox metabolism. Our study identifies potential non-invasive translational metabolic imaging probes of TERT expression in glioma and possibly other cancers. |
| 254
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Initial experience of applying bolus tracking and real-time B0/B1 calibration for human hyperpolarized 13C imaging |
1University of California at San Francisco, San Francisco, CA, United States, 2University of California at Berkeley, berkeley, CA, United States |
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A new hyperpolarized 13C MRI approach with bolus tracking and real-time B0/B1 calibration was developed and tested in 4 human HP 13C MRI studies of brain, prostate, kidney and pancreas metabolism. The use of this framework demonstrated improved accuracy and robustness for human hyperpolarized 13C imaging. |
| 255
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Hyperpolarized C-13 bSSFP Imaging of the Human Brain |
1Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, United States, 2Harvard Medical School, Boston, MA, United States, 3Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, 4GE Healthcare, Dallas, TX, United States |
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Current early phase clinical trials of hyperpolarized C-13 imaging of the brain, prostate, and liver have demonstrated the exceptional ability to rapidly visualize metabolism of pyruvate at high spatiotemporal resolutions. Prior human studies have used MRSI, EPSI, EPI, and spiral MRI and MRSI. In this study, we investigated for the first time the bSSFP sequence with its high SNR efficiency for human hyperpolarized C-13 imaging of pyruvate and lactate. This research showed the ability to acquire dynamic 1-1.5cm isotropic bSSFP images of the human brain in a clinical setting. |
| 256 | Pitch: 16:00 Poster: 17:00 Plasma 35
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Imaging the circumferential hyperpolarized 13C-bicarbonate distribution in the normal heart |
1University of Toronto, Toronto, ON, Canada, 2GE Healthcare, Toronto, ON, Canada, 3Medical Biophysics, University of Toronto, Toronto, ON, Canada, 4Physical Sciences Platform, Sunnybrook Research Institute, Toronto, ON, Canada |
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A typical observation in hyperpolarized 13C cardiac imaging is that the bicarbonate images are not circumferential, near the apex, even in healthy subjects, which precludes interrogation of metabolism in the posterior myocardium. A common explanation for the signal drop-off is anterior receive coil sensitivity. In this abstract, we demonstrate that this is not necessarily the case. A significant source of reduced signal results from B0 inhomogeneity in the posterior wall. Shortened readout durations which achieve higher kmax are shown to enable high resolution imaging of the circumferential bicarbonate distribution in pigs. |
| 257 | Pitch: 16:00 Poster: 17:00 Plasma 36
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Hyperpolarized [1-13C]pyruvate MRS in a large animal model of partial renal obstruction supports clinical use in patients |
1MR Research Centre, Aarhus University, Aarhus N, Denmark, 2Department of Cardiology, Aarhus University Hospital, Skejby, Denmark, 3GE Healthcare, Munich, Germany |
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Hyperpolarized [1-13C]pyruvate was used in this study to explorer the capability of detecting ischemic injury in the kidneys and to present the heterogeneity from the different kidney compartments. This was done using Michaelis–Menten kinetics by obtaining data in |
| 258 | Pitch: 16:00 Poster: 17:00 Plasma 37
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Imaging metabolic heterogeneity in breast cancer using hyperpolarized 13C-MRSI |
1Department of Radiology, University of Cambridge, Cambridge, United Kingdom, 2CRUK Cambridge Institute, Cambridge, United Kingdom, 3Cambridge Breast Unit, Addenbrooke's Hospital, Cambridge University Hospital NHS Foundation Trust, NIHR Cambridge Biomedical Research Centre, Cambridge, United Kingdom, 4Department of Radiology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom, 5Rapid Biomedical GmbH, Rimpar, Germany, 6Department of Oncology, University of Cambridge, Cambridge, United Kingdom, 7Department of Radiology, Addenbrooke’s Hospital, Cambridge University Hospital NHS Foundation Trust and NIHR, Cambridge, United Kingdom, 8Cambridge Breast Unit, Addenbrooke’s Hospital, Cambridge University Hospital NHS Foundation Trust and NIHR, Cambridge, United Kingdom |
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13C magnetic resonance spectroscopic imaging (13C-MRSI) is a promising technique for elucidating metabolic heterogeneity in breast cancer. We used 13C-MRSI to evaluate the extent of glycolysis in different histologic and molecular breast cancer subtypes and correlated these findings with the expression of a key transmembrane transporter (MCT1) and glycolytic enzyme (LDHA). In addition to a strong correlation between glycolysis and tumor volume, there was higher expression of MCT1 and LDHA as well as CAIX, a hypoxia marker, in the more glycolytic tumors. This is the first study in humans to demonstrate the relationship between intertumoral heterogeneity on gene expression analysis and 13C-MRSI. |
| 259 | Pitch: 16:00 Poster: 17:00 Plasma 38
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Kinetic Modeling of Hyperpolarized [1-13C]Lactate Metabolism in a Mouse Model of Ischemic Stroke |
1Geneva School of Health Sciences, University of Applied Sciences and Arts Western Switzerland (HES-SO), Geneva, Switzerland, 2Laboratory of Functional and Metabolic Imaging, École polytechnique fédérale de Lausanne (EPFL), Lausanne, Switzerland, 3Department of Clinical Neurosciences, Centre hospitalier universitaire Vaudois (CHUV), Lausanne, Switzerland, 4Centre d'Imagerie Biomédicale (CIBM), École polytechnique fédérale de Lausanne (EPFL), Lausanne, Switzerland, 5Department of Radiology, University of Geneva (UNIGE), Geneva, Switzerland, 6Department of Radiology, University of Lausanne (UNIL), Lausanne, Switzerland, 7Image Guided Intervention Laboratory, University of Geneva (UNIGE), Geneva, Switzerland |
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Stroke is the second cause of death and third leading cause of disability worldwide. Lactate injection was found to provide neuroprotection in preclinical models of ischemic stroke. Alteration of the metabolism induced by ischemia can be measured in real time using magnetic resonance with hyperpolarized 13C labeled probes. This study aims at investigating the feasibility of quantifying changes in the kinetics of hyperpolarized [1-13C]lactate metabolism following ischemia in a mouse model of stroke in order to assess the potential of hyperpolarized lactate as a theranostic agent for stroke. |
| 260 | Pitch: 16:00 Poster: 17:00 Plasma 39
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Assessment of intracellular lactate relaxation, production and efflux rates in cells using hyperpolarized 13C MR |
1University of California, Berkeley, Berkeley, CA, United States, 2Department of Radiology, University of California, San Francisco, San Francisco, CA, United States |
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Enzymatic conversions can now be measured with hyperpolarized 13C MR on a sub-minute time scale. Using this technology we have shown that renal cell carcinoma cells of varying aggressiveness in 3D culture in bioreactors (5mm NMR tube) can monitor both lactate production and its efflux in real time. Using this platform, we have robustly characterized certain parameters that are difficult to measure in vivo, such as intracellular longitudinal relaxation time and kinetic transport rate. Further validation of these measures were obtained by fitting the same model to data from cells treated with transporter inhibitor. |
| 261 | Pitch: 16:00 Poster: 17:00 Plasma 40
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Fluorine-19 MR at 21.1 Tesla for Enhanced Detection of Brain Inflammation |
1Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany, 2The National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, United States, 3MRI TOOLs GmbH, Berlin, Germany |
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Fluorine-19 (19F) MR methods are invaluable for several applications including detection of brain inflammation but suffer from inherently low signal-to noise ratio (SNR). A magnetic field increase from 9.4 to 21.1 Tesla was studied as strategy for increasing signal sensitivity. As a result of an SNR increase, inflammation regions undetected at 9.4T were revealed at 21.1T. Although the SNR gain at 21.1T does not reach that achieved with a cryogenic quadrature RF surface probe (19F-CRP) at 9.4T, increased sensitivity was observed throughout the whole field of view at 21.1T, from ventral to dorsal head regions. |
| 262 | Pitch: 16:00 Poster: 17:00 Plasma 41
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Fluorine MRI-Visible Mixed-Alginate Gradient Fluorocapsules for Image-Guided Diabetes Treatment |
1Radiology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2Pathology and Medical Biology, University of Groningen, Groningen, Netherlands, 3Oncology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 4Biomedical Engineering, The Johns Hopkins University, Baltimore, MD, United States, 5Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, MD, United States |
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A promising treatment of auto-immune juvenile diabetes is transplantation of beta islet cells. Islets can be encapsulated inside semi-permeable microcapsules to protect them against the patients’ immune system. Low islet survival and the lack of means to monitor the implants are major issues. We employed mixed-alginate gradient (MAG) microcapsules that better support human islet viability compared to currently used microcapsules. By labeling the capsules with clinically used agent CS-1000, we created MAG fluorocapsules which appeared as hot spots in mice on 19F MRI. MAG fluorocapsules offer a drug-free means to treat diabetic patients long-term while enabling imaging of transplanted islets. |
| 263
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Pitch: 16:00 Poster: 17:00 Plasma 42
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Efficient Dictionary-based Attenuation Correction for combined PET-MR systems |
1Department of Physics, University of Pisa, Pisa, Italy, 2IMAGO7 Foundation, Pisa, Italy, 3IRCCS Stella Maris, Pisa, Italy |
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In many diagnostic applications, a correct photon attenuation correction is crucial for quantifying the uptake of a PET tracer. While in PET/CT scanners attenuation map is readily estimated from CT Hounsfield units, in combined PET/MRI scanners it must be obtained by processing of high resolution images. This map must then be co-registered to low resolution PET map, wasting acquisition time. Here, we propose an efficient approach based on a fast transient-state acquisition and a three-component signal model: this allow to obtain tissue fraction maps, which can be used to estimate attenuation map, directly at PET resolution. |
| 264 | Pitch: 16:00 Poster: 17:00 Plasma 43
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An MR based PET attenuation correction using a deep learning approach and evaluation in prostate cancer patients |
1Monash Biomedical Imaging, Monash University, Clayton, Australia, 2Department of Biophysics, Faculty of Mathematics and Natural Sciences, University of Rzeszow, Rzeszow, Poland, 3Monash Institute of Cognitive and Clinical Neurosciences and School of Psychological Sciences, Monash University, Clayton, Australia, 4Department of Electrical and Computer Systems Engineering, Monash University, Clayton, Australia, 5Monash Imaging, Monash Health, Clayton, Australia, 6Department of Surgery, Monash University, Melbourne, Australia, 7Department of Computer Science and Engineering, Indian Institute of Technology, Bombay, India |
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Accurate Magnetic Resonance (MR) imaging based attenuation correction is crucial for quantitative Positron Emission Tomography (PET) in simultaneous MR/PET imaging. However, due to a lack of robust MR bone imaging methods, MR based attenuation correction remains a critical issue in MR/PET image reconstruction. In this work, we developed and evaluated a deep learning (DL) based MR based attenuation correction method for improved MR/PET quantification accuracy in prostatic cancer imaging. |
| 265 | Pitch: 16:00 Poster: 17:00 Plasma 44
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Impact of attenuation correction on image-derived input function and cerebral blood flow quantification with simultaneous [15O]-water PET/MRI |
1Oslo University Hospital, Oslo, Norway, 2Radiology, Stanford Unversity, Stanford, CA, United States, 3GE Global Research, Bangalore, India, 4Neurosurgery, Tokyo Medical and Dental University, Tokyo, Japan |
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This study evaluated the impact of attenuation correction (AC) on image-derived input functions (IDIF) and kinetic modeling of cerebral blood flow (CBF) parameters for simultaneous [15O]-water PET/MRI in the brain. Atlas-based AC led to 4.3% underestimation of the IDIF peak and 8-18% overestimation of absolute CBF in different brain perfusion states. On the other hand, zero echo time (ZTE)-based AC provided reproducible quantification of absolute CBF, comparable to the deep learning AC reference that was trained on real CT images. Attenuation correction is an important consideration for IDIF calculation and parametric mapping with PET/MRI; and ZTE-based and deep learning-based AC provide suitable quantitative accuracy for [15O]-water studies. |
| 266 | Pitch: 16:00 Poster: 17:00 Plasma 45
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Spatial profiling of endogenous cellular iron MRI contrast by machine vision classifies macrophage infiltration in breast cancer models of metabolic- and immune-therapy |
1Memorial Sloan Kettering Cancer Center, New York, NY, United States, 2Radiology, Stony Brook Medicine, Stony Brook, NY, United States |
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Tumor macrophage response to therapy is conventionally detected with iron nanoparticle-enhanced MRI. However, endogenous cellular iron detection methods exist that can bypass caveats intrinsic to contrast agent use. We demonstrate that contrast-agent free multi-gradient echo R2* relaxometry iron MRI and machine vision analysis approaches can map tumor macrophage iron deposits and detect cellular response to metabolic and immunotherapy in preclinical models of breast cancer. Feasibility of endogenous macrophage imaging is shown, and the value of the cellular MRI biomarker is demonstrated as a function of treatment and tumor model. |
| 267 | 16:00
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Auxiliary PTx system for active control of induced RF currents in conductive guidewires |
1School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom |
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The risk of RF-induced currents makes use of electrically conductive guidewires for cardiac catheterization procedures potentially unsafe for MRI. By using a parallel transmit coil array (PTx) system it is possible to generate RF field modes that can be utilized for safe imaging, and also guidewire visualization. As the induced RF currents can change with the guidewire position and operator handling, the control modes become a moving target. In this work we present an actively controlled PTx system that enables safe operation during a procedure in which electrical conditions are changing, and demonstrate this experimentally. |
| 268 | 16:12
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RF transparent ultrafast gradient insert |
1Radiology, UMC Utrecht, Utrecht, Netherlands, 2MRCoils, Zaltbommel, Netherlands, 3Donders institute for Brain Cognition and Behaviour, Radboud University, Nijmegen, Netherlands, 4Gorter center, Leiden UMC, Leiden, Netherlands, 5Futura Composites, Heerhugowaard, Netherlands, 6Spinoza Center for Neuroimaging, Amsterdam, Netherlands |
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Ultrafast gradient insert coils can boost EPI performance when designed as an independent 4th gradient chain. However, at high operating frequencies, substantial eddy currents will be generated in the shields of RF coils. Here we show that RF shields can be removed without compromising MRI performance yet enabling two orders of magnitude increased gradient efficiency at high frequency. |
| 269
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16:24
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Portable, single-sided magnetic resonance sensor for hydration status assessment via multicomponent T2 relaxometry |
1Electrical Engineering & Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States, 2David H. Koch Institute For Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, United States, 3Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States |
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Undiagnosed dehydration compromises health outcomes across many populations including the elderly, infants, soldiers and athletes. Here we introduce a miniature (~1000 cm3), portable (~4 kg), single-sided magnetic resonance (MR) sensor capable of identifying and quantifying fluid loss induced by dehydration. Multicomponent T2 relaxometry of skeletal muscle tissue enables the measurement of distinct fluid compartments. We first quantify fluid loss induced by dehydration with multicomponent T2 relaxometry using a standard MRI. We then extend these findings and demonstrate a portable, low-field MR sensor exhibits comparable performance via a similar measurement while offering significantly reduced sensor mass, measurement time, and system complexity. |
| 270
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16:36
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MRI Powered and Triggered Current Stimulator for Concurrent Stimulation and MRI |
1Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States, 2MR-LINK LLC, West Lafayette, IN, United States, 3Electrical and Computer Engineering, Purdue University, West Lafayette, IN, United States |
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The integration of stimulation, recording and high-field MRI has significant potential to evaluate different organs (brain, heart, gut etc.). However, externally powered devices consisting of cables and connectors for powering and synchronization may perturb the magnetic field within the MRI system and create additional safety concerns at high-fields. Here we present an MRI powered and triggered system, namely X-ON, to deliver electrical stimulation during MRI operation. The MR-compatible system can harvest wireless energy from varying gradient fields and provide programmable current stimulation in synchronization with MRI or fMRI acquisition. |
| 271
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16:48
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High Resolution TRASE by Rapid Echo Encoding with Twisted Solenoid RF Phase Gradient Coils |
1Department of Onoclogy, University of Alberta, Edmonton, AB, Canada, 2Department of Biomedical Engineering, University of Saskatchewan, Saskatoon, SK, Canada |
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TRASE is an MRI k-space encoding method that uses radio-frequency transmit phase gradient fields to achieve millimeter-level spatial resolution. To avoid resolution loss, the total echo train duration should be less than 1.2 times T2. However, previously demonstrated TRASE experiments have been limited by a large echo spacing (~1100 us). Here we present the use of the twisted solenoid to achieve short echo spacing of ~370 us, while remaining within SAR limits. This rapid echo encoding will enable in vivo imaging of short T2 tissues (e.g. ~50ms T2 for muscle at 0.2T) with resolution of 1.2 mm per pixel. |
| 272
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17:00
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The design of a homogenous large-bore Halbach array for low field MRI |
1C.J. Gorter Center for High Field MRI, Radiology, Leiden University Medical Center, Leiden, Netherlands, 2Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany |
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The homogeneity of cylindrical Halbach arrays for low-field MRI is compromised by the finite length and discretisation into individual magnets. In this work we design and construct a large-bore Halbach array intended for imaging hydrocephalus in young children. The magnet is constructed using 23 double-layer Halbach rings with layer radii optimised for homogeneity. Simulated magnetic field strength and homogeneity over a 20cm spherical volume are 50.64mT and 433ppm, respectively. The homogeneity of the realised Halbach array is slightly degraded compared to simulations, but is sufficiently high to allow the use of conventional spatial encoding methods on such a system. |
| 273 | 17:12
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Wireless coil as a portable and practical alternative to a dedicated transceive coil for extremities MRI at 1.5T |
1Department of Nanophotonics and Metamaterials, ITMO University, Saint Petersburg, Russian Federation |
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We show for the first time that a metamaterial inspired, volumetric wireless coil demonstrates similar performance as the same size, cable-connected volume transceiver coil for extremities MRI at 1.5T. Numerical analysis and in vivo human wrist imaging with the wireless coil showed proper quality images with no |
| 274
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17:24
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MRI with Sub-Millisecond Temporal Resolution: An Example Employing Spatially Resolved Eddy Current Characterization |
1Center for MR Research, University of Illinois at Chicago, Chicago, IL, United States, 2Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, United States, 3Department of Radiology and Neurosurgery, University of Illinois at Chicago, Chicago, IL, United States |
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Increasing the temporal resolution has been a major motivation for MRI technical development. Despite considerable progress, the presently achievable temporal resolution of MRI is limited to tens of milliseconds. We report a novel MRI technique, which we call Sub-Millisecond Imaging of cycLic Event (SMILE), that is capable of capturing periodic processes with sub-millisecond resolution. This technique is demonstrated by employing an example of characterization of eddy currents with short time constants. |
| 275 | 17:36
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Equivalent-Charge-Based Optimization of Spokes-and-Hub Magnets for Hand-Held and Classroom MR Imaging |
1Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States, 2Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 3Harvard Medical School, Boston, MA, United States, 4Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, United States |
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Differentiating the potential from end-cap equivalent charges is so efficient at computing fields from bar magnets, that in less than minute, a laptop running MATLAB can computationally-optimize field uniformity in hundred-bar wagon-wheel (or spokes-and-hub) magnets. And optimized spokes-and-hub magnets have several advantages for hand-held and classroom low-field single-slice MR imaging (50-200 mT). Their frame is open, and they are easily assembled and scaled. We demonstrate several such magnets, from finger to wrist to infant size, and match magnetic field measurements to quadrature-based equivalent-charge simulation. We also demonstrate generating spin echoes using a spokes-and-hub magnet in a 200 mT tabletop imager. |
| 276
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17:48
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A Fast and Easy-to-Use Tool for designing High-Permittivity Pads for 3T Body and 7T Neuroimaging Applications |
1Circuits and Systems Group, Delft University of Technology, Delft, Netherlands, 2C.J. Gorter Center for High-Field MRI, Leiden University Medical Center, Leiden, Netherlands |
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High-permittivity pads have proved effective for addressing B1+ inhomogeneities for neuroimaging at 7T and body imaging at 3T. In contrast with the ease of constructing these pads, obtaining an appropriate design involves sophisticated and time-consuming electromagnetic field simulations, meaning that in many applications this technique is not fully exploited. We have therefore developed an easy-to-use software tool which can be run on a standard desktop PC to design dielectric pads for 3T body and 7T neuroimaging applications. |
| 277
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16:00
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Quantification of Benign and Malignant Breast Tumor Cellularity |
1Radiology, Washington University School of Medicine, Saint Louis, MO, United States, 2Radiology, Changhai Hospital, Shanghai, China, 3Medical Scientist Training Program, The University of Alabama at Birmingham, Birmingham, AL, United States, 4Medicine, University of Missouri – Kansas City, Kansas City, MO, United States, 5Radiology, Guangzhou First People’s Hospital, Guangzhou, China, 6Radiology, The First Affiliated Hospital of Nanchang University, Nanchang, China |
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Recent consensus suggested that breast MRI lacks the needed sensitivity or specificity to detect breast cancer. Breast cancer over-diagnosis may result in over-treatments. We recently modified diffusion basis spectrum imaging (DBSI) to accurately localize breast cancer lesion and quantify cancer cellularity. Results revealed that modified-DBSI afforded greater diagnostic sensitivity and specificity than ADC in distinguishing between tumor and benign tissues. |
| 278
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16:12
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Combination of MRI quantitative measures improves prediction of residual disease following neoadjuvant chemotherapy (NAC) for breast cancer in the I-SPY 2 TRIAL |
1Radiology & Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, 2Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, United States, 3Surgery, University of California San Francisco, San Francisco, CA, United States, 4Quantum Leap Healthcare Collaborative, San Francisco, CA, United States |
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This abstract presents the work of combining different MR measures to predict primary tumor residual after patients with breast cancer went through neoadjuvant chemotherapy. Three types of MR measures are investigated in this study: longest diameter, functional tumor volume, and apparent diffusion coefficient. Results showed that when all three types of MR measures are combined in the logistic regression model, it yielded the highest AUC compared to the model with only one of the MR measures. Results also suggested that measures taken at various treatment time points, not just pre-surgery, should be included in the prediction of the residual disease. |
| 279 | 16:24
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Improved lesion conspicuity and confidence level through suppressed background parenchymal enhancement in ultrafast breast dynamic contrast enhanced MRI |
1Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan, 2Siemens Healthcare GmbH. , Erlangen, Germany, 3Breast surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan |
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Ultrafast dynamic contrast enhanced (UF-DCE) MRI is known for its reduced background parenchymal enhancement (BPE), but the evidence is limited. We evaluated BPE, lesion conspicuity and confidence level of UF-DCE MRI compared with those of conventional DCE (C-DCE) MRI. BPE was reduced, and lesion conspicuity and confidence level were improved on UF-DCE MRI compared to C-DCE MRI, indicating another advantage of UF-DCE MRI when applied to younger women and for high-risk screening. |
| 280 | 16:36
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Co-registration of Breast Diffusion MR Images Across Multiple Time Points in a Longitudinal Study to Evaluate the Response to Neoadjuvant Chemotherapy |
1Center for MR Research, University of Illinois at Chicago, Chicago, IL, United States, 2Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, IL, United States, 3Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, United States, 4Department of Diagnostic Radiology, National Cancer Center and National Clinical Research Center for Cancer, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China, 5Departments of Radiology and Neurosurgery, University of Illinois at Chicago, Chicago, IL, United States |
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Breast cancer is one of the most common cancers among women. Recently, several diffusion models have been proposed to characterize breast cancer. To extend these models for the assessment or prediction of treatment response of breast cancer, image co-registration throughout the time course of treatment is a significant challenge, particularly considering the vulnerability to deformation of the breast tissue. In this study, we demonstrate a 3D non-rigid co-registration method, and apply it to diffusion weighted (DW) images acquired in a longitudinal study during neoadjuvant chemotherapy. |
| 281 | 16:48
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Time-Varying Diffusion Patterns in Breast Cancer Linked to Prognostic Factors |
1Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan, 2Siemens Healthcare K.K., Tokyo, Japan, 3Siemens Healthcare GmbH, Erlangen, Germany, 4Breast Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan |
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We investigated the utility of diffusion time-dependence of ADC measurements for the differentiation of prognostic biomarkers in human breast tumors using OGSE and PGSE sequences. Malignant tumors had significantly lower ADC values with longer diffusion times. ADC change significantly correlated with Ki-67 expression. Significant association was found between ADC value (at the effective diffusion time of 5.1ms) and PgR expression. These associations indicate the potential of the diffusion-time-dependent ADC values as a tool to differentiate these prognostic biomarkers and highlight tumor heterogeneity without the need of contrast agents. |
| 282 | 17:00
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Breast lesion classification accuracy using intravoxel incoherent motion diffusion modelling is improved by incorporating all parameters and informative Bayesian priors |
1Institute for Circulation and Medical Imaging, Norwegian University of Science and Technology (NTNU), Trondheim, Norway, 2Department of Radiology and Nuclear Medicine, St Olavs Hospital, Trondheim, Norway, 3Department of Physics, Norwegian University of Science and Technology (NTNU), Trondheim, Norway, 4Department of Radiology and Nuclear Medicine, St Olavs University Hospital, Trondheim, Norway |
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Strategies for intravoxel incoherent motion (IVIM) diffusion imaging acquisition and analysis are often framed in terms of curve-matching, whereas for breast lesions, classification accuracy against histopathologic assessment is a true metric of functional imaging performance. In this study, we show that IVIM diffusion modelling is best able to discriminate breast lesions (23 benign, 29 malignant) when using all parameters, and when derived from Bayesian methods employing either Gaussian shrinkage or local homogeneity priors, with ROC AUC values increasing from 0.83 (D, conventional least-squares) to 0.92 (D+f+D*, shrinkage prior). |
| 283 | 17:12
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Pre-surgical evaluation of residual cancer by breast MRI after neoadjuvant systemic treatment: DWI-based algorism |
1Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University graduate school of medicine, Kyoto, Japan, 2Kobe City Medical Center General Hospital, Kobe, Japan, 3Department of Pathology, Kyoto University Hospital, Kyoto, Japan, 4Department of Breast Surgery, Kyoto University Hospital, Kyoto, Japan |
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We aimed to re-evaluate DWI of pre-surgical MRI as a clue to diagnose pCR or non-pCR. DCE-MRI including kinetic information were also evaluated for comparison. DWI-based evaluation of residual disease in pre-surgical MRI demonstrate excellent diagnostic performance. On the other hand, residual disease is difficult to evaluate based on kinetic information. DWI-based evaluation of residual disease is a useful approach in pre-surgical evaluation of breast cancer following neoadjuvant systemic treatment. |
| 284 | 17:24
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Independent Validation of U-Net Based Breast and Fibroglandular Tissue Segmentation Method on MRI Datasets Acquired Using Different Scanners |
1Department of Radiological Sciences, University of California, Irvine, CA, United States, 2Department of Radiology, E-Da Hospital and I-Shou University, Kaohsiung, Taiwan, 3Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea, Democratic People's Republic of, 4Department of Medical Imaging, Taichung Tzu-Chi Hospital, Taichung, Taiwan |
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Segmentation of breast and fibroglandular tissue (FGT) using the U-net architecture was implemented using training MRI from 286 patients, and the developed model was tested in independent validation datasets from 28 healthy women acquired using 4 different MR scanners. The dice similarity coefficient was 0.86 for breast, 0.83 for FGT; and the accuracy was 0.94 for breast and 0.93 for FGT. The results on MRI acquired using different MR scanners were similar. U-net provides a fully automatic, efficient, segmentation method in large MRI datasets for evaluating its role on breast cancer risk assessment and hormonal therapy response prediction. |
| 285 | 17:36
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Can Machine-Learning-based Radiomics of Whole Tumor on MR Multiparametric Maps Predict the Ki-67 index of Breast Cancer? |
1Radiology, Fudan University Shanghai Cancer Center, Shanghai, China, 2Radiology, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China, 3MR Application Development, Siemens Shenzhen Magnetic Resonance, Shenzhen, China, Shenzhen, China, 4MR Application Predevelopment, Siemens Healthcare, Erlangen, Germany |
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There has recently been increased interest in quantitative MR parameters for assessing tumor proliferation. A total of 134 consecutive patients with pathologically-proven invasive ductal carcinoma were retrospectively evaluated. We extracted the whole-tumor histogram and textural features from an ADC map and DCE-MRI semi-quantitative maps. The LASSO for feature selection and the KNN algorithm for classification were performed. Classifications performed between Ki-67-positive and Ki-67-negative groups resulted in an accuracy of 75.4% using three texture features, whereas classification with only the entropy of ADC yielded an accuracy of 74.6%. |
| 286 | 17:48
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Convolutional neural network uses pre-chemotherapy breast MRI data to predict which tumors will exhibit a pathologic complete response post-chemotherapy |
1Weill Cornell Medicine, New York, NY, United States, 2Memorial Sloan Kettering Cancer Center, New York, NY, United States |
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In this study, we evaluate the performance of a convolutional neural network (CNN) to predict pathologic complete response based on pre-treatment breast MRI images. We achieved moderate accuracy in this initial feasibility study. Future work with larger patient datasets will improve CNN performance. |
| 287 | 16:00
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Arterial Spin Labeling Underestimates CBF in Regions with Fast Arrival Times: a Simultaneous [15O] PET/MRI Study with Acetazolamide Challenge |
1Radiology, Stanford University, Stanford, CA, United States, 2Neurosurgery, Tokyo Medial and Dental University, Tokyo, Japan, 3Center for Stroke Research Berlin (CSB), Charité - Universitätsmedizin Berlin, Berlin, Germany, 4Bioengineering, University of California Riverside, Riverside, CA, United States, 5Global Applied Science Lab, GE Healthcare, Menlo Park, CA, United States, 6Neurosurgery, Stanford University, Stanford, CA, United States |
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In this study, we investigated the effects of arterial transit time (ATT) reduction and the quantitative accuracy of standard and multi-delay arterial spin labeling (ASL) MRI on healthy controls and Moyamoya patients using acetazolamide (ACZ) by the voxel-wise parametric testing. Administration of ACZ shortened ATT and extended the region where cerebral blood flow (CBF) was underestimated by standard ASL and by multi-delay ASL compared to simultaneous [15O]-water PET reference. Consideration of short ATT is critical for accurate ASL measurements of CBF in the deep gray matter and for quantification of cerebrovascular reactivity after a vasodilation challenge that decreases ATT. |
| 288 | 16:12
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ASL signal model for simultaneously measuring CBF and CBV based on ASL imaging for characterizing hemodynamic perfusion state in normal subjects and patients with moyamoya disease. |
1Radiology, University of Fukui, Fukui, Japan, 2Neurosurgery, University of Fukui, Fukui, Japan, 3Radiological center, University of Fukui Hospital, Fukui, Japan, 4Division of Health Sciences, Graduate school of Medical Sciences, Kanazawa University, Kanazawa, Japan, 5MR application and Workflow, GE Healthcare JAPAN, HIno, Japan, 6Department of Medical Imaging, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan, 7Department of Radiology, University of Fukui, Fukui, Japan, 8GE Healthcare JAPAN, Hino, Japan |
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Not only cerebral blood flow (CBF) but also cerebral blood volume (CBV) plays an important role for the maintenance of cerebral blood perfusion. We hypothesized that the ASL signal difference caused by vessel suppression (VS) scheme should be dependent on arterial CBV fraction of total ASL signal. In this study, we introduced modified two-compartments model based on ASL signal with and without VS, so that we can calculate arterial volume fraction of total ASL signal. The objective of this study is to demonstrate the feasibility of arterial CBV map as well as CBF based on ASL imaging. |
| 289 | 16:24
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The Quantification of Feuromxytol Uptake on the Post Enhance in Intracranial Atherosclerotic Plaque by using a 3D high resolution Black Blood(BB) Multiple Echo(ME) T2* Imaging Technique |
1UCAIR, Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, United States, 2Siemens Healthcare, Salt Lake City, UT, United States, 3Department of Surgery, University of Utah, Salt Lake City, UT, United States, 4Department of Veterans Affairs, VASLCHCS, Salt Lake City, UT, United States, 5Department of Neurology, University of Utah, Salt Lake City, UT, United States |
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Post-gadoliniun enhancement(PGE) in ICAD may be related to endothelial dysfunction or breakdown or secondary to plaque inflammation. Delayed ferumoxytol imaging allows intravascular clearance with retention in the macrophages present in vulnerable atherosclerotic plaque. A 3D BB ME T2* Imaging technique allows the quantitative ferumoxytol imaging on delayed scans by measuring T2* in intracranial atherosclerotic plaque. We performed 3D BB T2* sequences on ten patients with ICAD and measured T2* changes between baseline and 72 hour after ferumoxytol injection. The iron nanoparticle uptake in symptomatic ICAD presented in this work may provide important mechanistic implications for the pathophysiology of PGE. |
| 290 | 16:36
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High Risk Characteristics of Cervicocranial Artery Dissection Associated with Ischemic Stroke: A Head and Neck Combined Vessel Wall MR Study |
1Xuanwu Hospital Capital Medical University, Beijing, China |
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The aim of this study was to investigate high risk characteristics of dissected artery using VWMRI. A total of 114 Patients with CeAD were prospectively recruited and 139 dissected vessels were analyzed. Dissected arteries in the stroke group showed a significantly higher prevalence of irregular surface, intraluminal thrombus and severe stenosis (>70%) compared with that of the non-stroke group. Logistic regression analysis showed that the presence of irregular surface and intraluminal thrombus were independently associated with ischemic stroke in CeAD. Our results provide insights into the vascular pathophysiology of symptomatic CeAD and may reveal important predictor of stroke in CeAD. |
| 291
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16:48
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Cerebral hypometabolism measured with intravascular T2-prepared tissue relaxation with inversion recovery (T2-TRIR) and pCASL in adults with sickle cell disease |
1Department of Radiology & Nuclear Medicine, Amsterdam UMC, Amsterdam, Netherlands, 2C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands, 3Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Copenhagen, Denmark, 4Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Dresden, Germany, 5Department of Cardiology and Radiology, Children’s Hospital of Los Angeles, Los Angeles, CA, United States, 6Department of Biomedical Engineering & Physics, Amsterdam UMC, Amsterdam, Netherlands, 7Department of Hematology, Amsterdam UMC, Amsterdam, Netherlands |
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Cerebral metabolic rate of oxygen (CMRO2) quantifies the amount of oxygen consumed by the brain, and relies on continuous delivery of nutrients and oxygen via cerebral blood flow (CBF). In sickle cell disease (SCD), CBF is elevated to compensate for chronic anaemia. This study investigates CMRO2 in adults with SCD using T2-prepared tissue relaxation with inversion recovery (T2-TRIR). CBF increased after acetazolamide-induced vasodilation in both groups but CMRO2 reduced even further in SCD patients while it remained stable in controls. Our results suggest that cerebral shunting is exacerbated by high flow conditions. |
| 292 | 17:00
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Mean Transit Time and Capillary Transit Time Heterogeneity at the Basal Ganglia of Patients with Huntington’s Disease |
1Massachusetts General Hospital, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States, 2Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States, 3Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States |
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We identified abnormally long mean transit time (MTT) and large capillary transit time heterogeneity (CTH) in the basal ganglia of ten individuals with Huntington’s disease (HD) as compared to ten healthy control subjects. Since iron is elevated in the putamen and globus pallidus in HD [1], which can lead to an underestimation of relative cerebral blood flow (CBF) and cerebral blood volume (CBV), excessively prolonged MTT and CTH, which are ratios of CBV and CBF, could be utilized as relatively intact parameters for the estimation of perfusion deficits or breakdown in blood-brain barrier. |
| 293
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17:12
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White matter microstructural alterations in chronic, episodic, and aura migraine |
1Radiology, Center for Biomedical Imaging, New York University School of Medicine, New York, NY, United States, 2Neurology, Beth Israel Deaconess Medical Center, Brookline, MA, United States, 3Neurology, New York University School of Medicine, New York, NY, United States |
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Migraine is associated with increased risk for stroke and white matter abnormalities, though the exact nervous tissue pathology remains poorly understood. This study used diffusion kurtosis imaging, a clinically feasible extension of diffusion tensor imaging, to compare white matter microstructural changes in migraineurs to healthy controls, and between their different subtypes: chronic, episodic, with and without aura. Using a voxel-wise statistical approach, we found that axial and radial kurtosis were significantly altered depending on migraine subtype. While radial kurtosis is significantly reduced in all migraine patients compared to controls, axial kurtosis is increased in episodic migraines with and without aura, suggesting different underlying pathology. |
| 294
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17:24
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Evolution of cerebral hemodynamics and metabolism across the early lifespan in patients with sickle cell disease |
1Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States, 2Pediatric Neurology, Vanderbilt University Medical Center, Nashville, TN, United States |
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Sickle cell disease (SCD) is an inherited hemolytic anemia with altered hemodynamics and increased stroke risk. However, lifetime trends in SCD cerebral hemodynamics and metabolism are poorly understood. We used non-invasive functional measures of cerebral blood flow (CBF) from arterial spin labeling, and oxygen extraction fraction (OEF) from T2-Relaxation-Under-Spin-Tagging MRI, to quantify hemo-metabolic patterns in controls (n=64) and SCD patients (n=125) across the early lifespan (6-40 years). CBF decreases with age in healthy controls (-3.2 mL/100g/min per decade) but increases in patients (5.2 mL/100g/min per decade). OEF was elevated in SCD, showing a similar slope with age as controls. |
| 295
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17:36
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Differences in temporal cerebrovascular reactivity responses between patients with atherosclerotic and non-atherosclerotic intracranial disease: implications for optimal hypercapnic reactivity experiments |
1Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States, 2Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN, United States |
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Intracranial stenosis may be due to atherosclerotic or idiopathic non-atherosclerotic mechanisms, and each condition may incur different consequences on cerebral hemodynamics. The purpose of this study was to use a time regression analysis approach applied to hypercapnic BOLD fMRI data to evaluate how cerebrovascular reactivity (CVR) timing and maximum CVR may differ between patient groups and with vasculopathy extent. Time-to-maximum CVR may be lengthened in territories supplied by stenotic vessels in both patient groups; however, maximum CVR may be reduced on average only in patients with non-atherosclerotic disease, potentially indicating that arteriolar smooth muscle and/or endothelial function may differ substantially between conditions. |
| 296 | 17:48
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In-vivo validation of T2- and susceptibility-based SvO2 measurements with jugular vein catheterization under hypoxia and hypercapnia |
1Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States, 2Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, CA, United States, 3Division of Cardiology, Children’s Hospital Los Angeles, Los angeles, CA, United States |
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This study aimed to validate T2- and susceptibility-based cerebral venous oxygen saturation (SvO2) measurements with the clinical standard, jugular vein catheterization. T2-relaxation-under-tagging (TRUST) and susceptibility-based oximetry (SBO) were performed on two healthy subjects with jugular catheterization and eleven subjects without catheterization under baseline, hypoxia and hypercapnia. TRUST tightly agreed with the jugular reference under hypercapnia but significantly underestimated SvO2 under baseline and hypoxia. Bias between SBO and the reference was independent on the physiological state. A proportional bias was observed comparing TRUST and SBO. The results suggested caution for inter-subject comparison of absolute SvO2 measurements using either TRUST or SBO. |
| 297 | 16:00
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Investigating tissue microstructure using NODDI and histology: A chronic injury study on ex vivo macaque spinal cords |
1Radiology, University of British Columbia, Vancouver, BC, Canada, 2UBC MRI Research Centre, Vancouver, BC, Canada, 3International Collaboration on Repair Discoveries, Vancouver, BC, Canada, 4Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China |
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In this study we sought to understand whether Neurite Orientation Dispersion and Density Imaging (NODDI) could accurately delineate the extent of microstructure damage in an ex-vivo macaque spinal cord. We used histology as a gold standard for delineating the margin between damaged and undamaged tissue. Qualitative analysis exposed disagreements between NODDI maps and histology in areas of damage. This suggests that NODDI may not be appropriate for this model of chronic spinal cord injury. |
| 298
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16:12
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Finger-Tapping Task fMRI in the Human Cervical Spinal Cord at 7T |
1Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 2Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 3Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 4Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom, 5Institute of Psychology, Chinese Academy of Sciences, Beijing, China |
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Functional MRI of the spinal cord is challenging due to its small size and deep anatomical location. Increasing field strength enhances BOLD signal and improves SNR, but B0 distortions produced by the lungs and vertebral column are amplified, presenting additional challenges in protocol optimization. Barry et al. have successfully performed resting-state fMRI at 7T; here, we present observations of robust, well-localized motor task activation in the human cervical spinal cord at 7T. We assessed single-shot and multi-shot EPI at two different resolutions. Multi-shot EPI achieved finer resolution and less spatial distortion in this preliminary 7T spinal cord task fMRI study. |
| 299
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16:24
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Advanced Magnetic Resonance techniques in Post-Mortem Human Spinal Cord Injury: Correlations with Histopathology |
1International Collaboration on Repair Discoveries, Vancouver, BC, Canada, 2Radiology, University of British Columbia, Vancouver, BC, Canada, 3Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada, 4UBC MRI Research Centre, Vancouver, BC, Canada, 5Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada, 6Vancouver Spine Surgery Institute, Vancouver, BC, Canada, 7Vancouver General Hospital, Vancouver, BC, Canada, 8Medicine, University of British Columbia, Vancouver, BC, Canada |
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Spinal cord injury prognosis assessments rely on subjective clinical evaluations and often poorly predict outcome; quantitative imaging biomarkers for spinal cord injury evaluation would aid clinical decision making. Our study applied two advanced MRI techniques to the imaging of post-mortem human spinal cord injury samples. We compared in-homogeneous magnetisation transfer and NODDI metric maps with six histological stains to relate the MR image contrast to biological correlates. We found a correlation trend between ihMT signal with strong T1D-filtering and Luxol Fast Blue optical density (myelin phospholipid stain) in white and grey matter. |
| 300 | 16:36
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Cervical Spine inhomogeneous Magnetization Transfer (ihMT) Imaging Using ECG-Triggered 3D Rapid Acquisition Gradient-Echo (ihMT-RAGE) |
1Siemens Healthcare SAS, Saint-Denis, France, 2Aix-Marseille Univ, CNRS, CRMBM, Marseille, France, 3APHM, Hôpital Universitaire Timone, CEMEREM, Marseille, France, 4Radiology, Division of MR research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States |
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Inhomogeneous magnetization transfer (ihMT) is a promising MRI modality that provides high sensitivity and specificity to myelinated tissue. Demyelinating pathologies in the central nervous system could then be addressed by this technique. The goal of this work is to demonstrate that the combination of ihMT preparation with Rapid Acquisition Gradient Echo (ihMT-RAGE), as recently proposed for the brain, can be adapted to an ECG-triggered 3D exploration of the cervical spinal cord within a clinically-compatible scan time. The in-vivo ihMT results from healthy cervical spinal cord demonstrate the great potential of the ihMT-RAGE technique for future investigations of degenerative spinal cord pathologies. |
| 301 | 16:48
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Intra-Voxel Incoherent Motion at 7T to quantify human spinal cord microperfusion: pitfalls and promises |
1Faculty of Medicine, Aix-Marseille Univ, CNRS, CRMBM, Marseille, France, 2APHM, Hopital Universitaire Timone, CEMEREM, Marseille, France, 3Faculty of Medicine, Aix-Marseille Univ, IFSTTAR, LBA, Marseille, France, 4iLab-Spine International Associated Laboratory, France-Canada, Marseille-Montreal, France, 5Siemens Healthcare GmbH, Erlangen, Germany, 6Siemens Healthcare SAS, Saint-Denis, France |
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Spinal cord microperfusion assessment in human is challenging but would greatly help characterize tissue integrity and surgery decision-making. Intra-Voxel Incoherent Motion (IVIM) microperfusion measurement is promising but remains highly Signal-to-Noise ratio (SNR) demanding. Monte-Carlo simulations show that IVIM two-step segmented fitting approach is less accurate than directly fitting the bi-exponential representation to all b-values. Simulations also help quantify required SNR and estimation errors to measure IVIM parameters in the context of low perfusion. Exploiting 7T SNR gain, large number of repetitions and group average, IVIM was able to unveil the gray matter higher microperfusion-related pattern, compared to white matter, in agreement with brain studies. |
| 302 | 17:00
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Cervical spinal cord diffusion MRI and intraspinal space restriction at the occipito-cervical junction in mucopolysacharidoses patients |
1Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States, 2Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 3Department of Neurology, Palacky University, Olomouc, Czech Republic, 4Department of Biomedical Engineering, University Hospital Olomouc, Olomouc, Czech Republic, 5Department of Medicine III, Clinical Division of Endocrinology and Metabolism, Medical University of Vienna, Vienna, Austria, 6Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada |
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The overall goal of this project is to establish novel MRI parameters for reliable detection of cervical spinal cord (CSC) microstructural abnormalities in patients with Mucopolysaccharidosis (MPS) that develop prior to the clinical manifestation of spinal cord damage. Quantitative analysis of diffusion MRI (dMRI) may characterize microstructural alterations of CSC with high sensitivity. In this study measures of CSC microstructure were determined by dMRI using a protocol based on the RESOLVE (REadout Segmentation Of Long Variable Echo trains) sequence. Derived diffusion metrics were then related to the anatomical measures of the cervical spine in patients with MPS. |
| 303 | 17:12
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A Multi-site/multi-scanner DTI study of the adult spinal cord |
1Thomas Jefferson University, Philadelphia, PA, United States, 2University of Pennsylvania, Philadelphia, PA, United States, 3Johns Hoplkins University, Baltimore, MD, United States |
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This study presents DTI data collected for the complete cervical and thoracic spinal cord in healthy adult subjects as part of a multi-site/multi-scanner study. Thirty adult subjects were imaged with four different scanners including 1.5T and 3T field strengths and variability in DTI metrics was examined. |
| 304 | 17:24
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Column-specific microstructural changes in patients with non-myelopathic degenerative compression of the cervical spinal cord revealed by diffusion MRI |
1Department of Neurology, University Hospital Olomouc, Olomouc, Czech Republic, 2Department of Biomedical Engineering, University Hospital Olomouc, Olomouc, Czech Republic, 3Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States, 4Central European Institute of Technology, Masaryk University, Brno, Czech Republic, 5Department of Neurology, University Hospital Brno, Brno, Czech Republic, 6Department of Medicine III, Clinical Division of Endocrinology and Metabolism, Medical University of Vienna, Vienna, Austria, 7Center for Magnetic Resonance Research, Minneapolis, MN, United States, 8High Field MR Centre, Medical University of Vienna, Vienna, Austria |
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While delineation of microstructural changes in white matter (WM) columns of cervical spinal cord (CSC) in patients with non-myelopathic degenerative CSC compression (NMDCSCC) remains a challenge for most current MRI techniques, High Angular Resolution Diffusion Imaging (HARDI) protocols promise to overcome this issue. Thus, our group utilized novel HARDI-ZOOMit protocol to extract metrics from diffusion tensor and ball-and-stick models in three major CSC columns. HARDI-ZOOMit protocol was able to detect column-specific significant differences between healthy controls and patients with NMDCSCC with more complex abnormalities in ventral CSC columns in C3-C6 levels. |
| 305 | 17:36
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Establishing a Relationship Between Pain and Spinal Cord Demyelination using Magnetization Transfer Imaging and Thermal Sensory Testing |
1Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital, Boston, MA, United States, 2Department of Neurology, Boston Children's Hospital, Boston, MA, United States |
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Myelitis is a demyelinating disorder of the spinal cord . It can occur as an isolated syndrome or in the context of an autoimmune condition such as MS. Pain is a significant problem in myelitis and has a major impact on treatment response and rehabilitation efforts. Magnetization Transfer Imaging has the ability to provide a marker for myelin content. Defining a relationship between pain and demyelination could lead to improved disease outcome. Our results showed significant differences in spinal cord MTR (C1 to T12) and pain (heat/cold stimuli) between patients and controls, and strong correlation between MTR and heat detection thresholds. |
| 306
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17:48
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Construction of a quantifiable rat spinal cord atlas and tract delineation using agglomerative clustering |
1NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada, 2Institute of Biomedical Engineering, University of Montreal, Montreal, QC, Canada, 3UMR 1214 Toulouse Neuroimaging Center, Institut national de la santé et de la recherche médicale, Toulouse, France, 4Montreal Heart Institute, Montreal, QC, Canada, 5Functional Neuroimaging Unit, CRIUGM, Université de Montréal, Montreal, QC, Canada |
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With qMRI becoming the norm in obtaining quantitative values for most MRI studies, there is still a need for its validation as new techniques are constantly being implemented. With this in mind, we propose a matter microstructure atlas of the rat spinal cord based on high-resolution histology. This atlas contains morphometric data such as axon density, axon diameter and g-ratio. Furthermore, a clustering algorithm was implemented to generate white matter tracts delineation based on axon morphometry, possibly leading to an improvement on outdated atlases. The proposed atlas is open access and can be used for quantitative comparisons with qMRI studies. |
| 307 | 16:00
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MANTIS: Model-Augmented Neural neTwork with Incoherent k-space Sampling for accelerated MR parameter mapping |
1Radiology, University of Wisconsin-Madison, Madison, WI, United States, 2Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, United States |
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The purpose of this work was to develop and evaluate a novel deep learning-based reconstruction framework called Model-Augmented Neural neTwork with Incoherent k-space Sampling (MANTIS) for accelerated MR parameter mapping. Our approach combines end-to-end CNN mapping with k-space consistency using the concept of cyclic loss to further enforce data and model fidelity. Incoherent k-space sampling is used to improve reconstruction performance. A physical model is incorporated into the proposed framework, so that the parameter maps can be efficiently estimated directly from undersampled images. The performance of MANTIS was demonstrated for T2 mapping of the knee joint. Our study demonstrated that the proposed MANTIS framework represents a promising approach for efficient MR parameter mapping. MANTIS can potentially be extended to other types of parameter mapping with appropriate models. |
| 308
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16:12
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Three-Dimensional Whole Brain Simultaneous T1, T2, and Apparent Diffusion Coefficient Mapping Using MR Multitasking |
1Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, United States, 2Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 3Cardiovascular Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, United States, 4Siemens Healthcare, Los Angeles, CA, United States |
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Three-dimensional, multi-parametric quantitative mapping of relaxation and diffusion parameters is desirable for many clinical imaging application, including the diagnosis and follow-up assessment of tumors. Traditionally, this is performed by separate scans which are time-consuming. We propose a novel Multitasking framework to achieve 3D whole-brain simultaneous T1/T2/ADC mapping in ~9min. The underlying multidimensional image is modeled as a low-rank tensor, with a time-resolved phase correction technique to compensate for the phase inconsistency induced by pulsatile motion during diffusion preparation. T1/T2/ADC measurements in healthy volunteers agree with reference methods, yielding intraclass correlation coefficients > 0.80 for both gray and white matter. |
| 309
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16:24
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Magnetization transfer (MT) of human brain at 7T in the context of a 3D multi-parameter mapping protocol |
1Clinical Sciences Lund, Medical Radiation Physics, Lund University, Lund, Sweden, 2Philips Danmark A/S, Philips Healthcare, Copenhagen, Denmark, 3National 7T Facility, Lund University, Lund, Sweden, 4Centre for Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden, 5Clinical Sciences Lund, Department of Radiology, Lund University, Lund, Sweden |
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3D multi-gradient echo MRI can be used to estimate T1, T2*, PD and the magnetization transfer (MT), which is increasingly used for multi-parametric mapping (MPM) of human brain. The increased polarization at 7T compared to lower B0 allows for increased spatial resolution or reduced scan times. However, SAR restrictions imposed on the MT pulse and B1 inhomogeneity pose challenges. In this work, we propose a protocol for MPM of human brain at 7T with special attention paid to eliminating bias when mapping MTsat while obtaining submillimeter isotropic spatial resolution in under 12 minutes with acceptable SNR. |
| 310
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16:36
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Echo Planar Time-Resolved Imaging (EPTI) with subspace constraint and optimized k-t trajectory |
1A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 2Electrical Engineering and Computer Science, MIT, Cambridge, MA, United States, 3Harvard-MIT Health Sciences and Technology, MIT, Cambridge, MA, United States |
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Echo planar time-resolved imaging (EPTI) is a multi-contrast quantitative imaging technique, which achieved fast acquisition of distortion- and blurring-free images at multiple echo times (TE). To improve the SNR and accuracy of EPTI at high-accelerations, in this study, we developed a subspace-constrained reconstruction for EPTI and proposed new k-t sampling trajectories to take advantage of this reconstruction. The subspace reconstruction is also augmented with phase-cycling to extract high-resolution phase data, without need of high-resolution B0 calibration scan. Using the proposed approach, whole-brain 1.1mm-isotropic multi-echo images, and T2* and B0 maps are reconstructed from 3D-EPTI data acquired within 50 seconds. |
| 311
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16:48
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Loss Adaptive Dipole Inversion (LADI): A novel data driven approach for quantitative susceptibility mapping |
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Bioengineering, University of Pennsylvania, Philadelphia, PA, United States, 3Biochemistry and Molecular Biophysics, University of Pennsylvania, Philadelphia, PA, United States |
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This abstract presents a novel data driven approach for high quality QSM reconstructions without the use of complex and computationally intensive reconstruction models. The purpose of this approach is to develop a reconstruction technique which does not depend on the use of spatial priors from the magnitude image to remove artifacts and reduce blurring of edges. In our proposed formulation, the data fidelity term is updated based on the deviation of the estimated susceptibility map from the measured local field. With the proposed fidelity-loss adaptive reconstruction formulation, removal of artifacts was achieved without causing smoothing of sharp features. |
| 312
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T2-gSlider: rapid high resolution T2 mapping with generalized SLIce Dithered Enhanced Resolution and model-based reconstruction |
1Center for Brain Imaging Science and Technology, Department of Biomedical Engineering, Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou, China, 2Department of Radiology, Harvard Medical School, Charlestown, MA, United States, 3Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 4Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States, 5Department of Imaging Sciences, University of Rochester, Rochester, NY, United States |
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To obtain rapid high isotropic resolution whole-brain T2 maps, a T2 generalized Slice-dithered enhanced resolution (T2-gSlider) acquisition/reconstruction framework is proposed. An accelerated RF-encoded multi-slab, multi-shot SE-EPI acquisition with variable TEs was developed to obtain high SNR acquisitions with reduced TR. A structured low-rank constraint was applied to reconstruct highly undersampled multi-shot data and achieve robust reconstruction for each slab. A Bloch simulated subspace shuffling model was utilized for T2 quantification and incorporated into gSlider reconstruction to further accelerate the acquisition. The proposed framework is demonstrated to enable whole-brain 1mm isotropic T2 mapping in ~40 seconds. |
| 313 | 17:12
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Towards robust – and accurate – QSM in cortical and sub-cortical regions of the human brain at 9.4T: the influence of masking |
1Biomedical Magnetic Resonance, University Hospital Tübingen, Tübingen, Germany, 2High Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Germany, 3Psychiatry and Psychotherapy, University Hospital Tübingen, Tübingen, Germany, 4Max Planck Institute for Biological Cybernetics, Tübingen, Germany, 5Neurology and Epileptology, Hertie Institute for Clinical Brain Research, Tübingen, Germany, 6Neuropsychology, Hertie Institute for Clinical Brain Research, Tübingen, Germany |
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Quantitative susceptibility mapping (QSM) targets a fundamental MR-parameter but is problematic due to the presence of a strong background and local field variations. These may cause multiple phase wraps which are particularly prominent at high fields and long echo-times. We propose automated tissue masking excluding brain areas with excessive phase wraps and show how this approach can improve the quality of QSM. Performance was evaluated with regard to iron quantification in subcortical and cortical areas, and was compared with R2* maps in the same 21 subjects aged 19-56y and literature values. |
| 314
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17:24
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Model-based reconstruction for simultaneous multi-slice T1 mapping using single-shot inversion-recovery radial FLASH |
1Department of Interventional and Diagnostic Radiology of the University Medical Center Göttingen, Göttingen, Germany |
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Recent advances in real-time MRI and model-based reconstructions have enabled single-slice T1 mapping within a single inversion recovery. To allow fast multi-slice T1 mapping, this work employs radial simultaneous multi-slice (SMS) schemes and develops an SMS model-based reconstruction approach for high-resolution multi-slice T1 mapping based on single-shot inversion recovery FLASH. In comparison to conventional multi-slice approaches, the proposed SMS model-based reconstruction achieves high resolution (0.75 x 0.75 x 5 mm3) T1 maps for three slices of the brain within 4 s with a higher precision and a better preservation of image details. |
| 315
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17:36
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Whole-brain 3D multi-parametric quantitative extraction at 7T using parallel transmission Universal Pulses |
1CEA - Neurospin, Gif-sur-Yvette, France, 2CRMBM/UMR 7339 CNRS, Aix Marseille Université, Marseille, France, 3CENIR, ICM, Paris, France, 4Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, Paris, France, 5Siemens Healthineers, Saint-Denis, France |
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Performing simultaneous quantitative MRI at ultra-high field is challenging, as B0 and B1 heterogeneities, and Specific Absorption Rate increase with field strength. In this work, Quantitative Imaging using Configuration States is successfully applied in vivo at 7T using calibration-free parallel transmission Universal Pulses to retrieve 3D whole-brain M0, flip angle, T1 and T2 maps in a clinically-relevant time. The method relies on the acquisition of multiple contrasts with spoiled SSFP sequence by varying flip angle and radiofrequency spoiling in a limited and optimized number of sets. Quantification of the physical parameters was then performed by fitting acquired data to the Bloch-Torrey equation. |
| 316 | 17:48
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Single Breath-Hold T2 Quantification utilizing a Spiral Multi-Contrast TSE Sequence |
1Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, United States |
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A single breath-hold multi-contrast TSE sequence with spiral k-space sampling is introduced for T2 quantification. Sparsity constraint image reconstruction was applied to reconstruct undersampled datasets acquired under single breath-holding. The feasibility of the proposed sequence and image reconstruction were tested in brain and thoracic imaging for normal volunteers. The proposed method achieved T2 quantification of the thoracic region without clear cardiac motion artifacts. |
| 317
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16:00
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On the linearity of deep neural network trained QSM |
1Department of Electrical and Computer Engineering, Seoul National University, Seoul, Korea, Republic of, 2Department of Radiology, Gachon University, Incheon, Korea, Republic of |
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In this work, the linearity property of a recently proposed neural network-based QSM is explored. The QSMnet, which was trained using healthy volunteers, was quantitatively evaluated for patients with hemorrhage whose susceptibility values were outside of the trained range. The results showed that the QSMnet underestimated the susceptibility in hemorrhage, breaking linearity between true susceptibility and QSMnet-generated susceptibility. To overcome this limitation, we developed a linear scaling method that generalized the network for a wider range of susceptibility. The new network successfully reconstructed the patient data with good linearity results. |
| 318
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16:12
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Separating intra- and extra-axonal susceptibility effects using a Diffusion-Filtered Asymmetric Spin Echo (D-FASE) sequence |
1Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff, UK, Cardiff, United Kingdom, 2School of Psychology, Faculty of Health Sciences, Australian Catholic University, Melbourne, Australia, 3Sir Peter Mansfield Imaging Centre, School of Physiscs and Astronomy, University of Nottingham, Nottingham, UK, Nottingham, United Kingdom |
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The investigation of brain white matter is a key area of application of MRI, with much effort focused on using MR techniques to quantify tissue microstructure. Here, we bring together two complementary approaches that are commonly used to probe tissue microstructure (signal dephasing due to: (i) diffusion and (ii) microscopic susceptibility effects) using a novel Diffusion-Filtered Asymmetric Spin Echo (D-FASE) technique. Using D-FASE we can separately assess the evolution of the intra- and extra-axonal signals under the action of susceptibility effects, revealing differences in the behaviour in fibres that are parallel and perpendicular to B0. |
| 319
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16:24
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VaNDI: Variational Nonlinear Dipole Inversion enables QSM without free parameters |
1Martinos Center for Biomedical Imaging, Charlestown, MA, United States, 2National Nanotechnology Center, Pathum Thani, Thailand, 3Department of Electrical and Computer Engineering, Seoul National University, Seoul, Korea, Democratic People's Republic of |
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We propose Nonlinear Dipole Inversion (NDI) for high-quality Quantitative Susceptibility Mapping (QSM) without additional regularization, while matching the RMSE of state-of-the-art regularized reconstruction techniques. In addition to avoiding over-smoothing these techniques often face, we also obviate the need for parameter selection. NDI is flexible enough to allow for reconstruction from an arbitrary number of head orientations, and outperforms COSMOS using as few as 2-direction data. This is made possible by a nonlinear forward-model that uses the magnitude as an effective prior, for which we derived a simple gradient descent update. We synergistically combine this physics-model with Variational Networks (VN) to leverage the power of deep learning in the VaNDI algorithm. VaNDI adopts this simple gradient descent rule and learns the network parameters during training, hence requires no additional parameter tuning. |
| 320
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U2-Net for DEEPOLE QUASAR–A Physics-Informed Deep Convolutional Neural Network that Disentangles MRI Phase Contrast Mechanisms |
1Department of Computer Science and Automation, Technische Universität Ilmenau, Ilmenau, Germany, 2Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY, United States, 3Clinical and Translational Science Institute, University at Buffalo, Buffalo, NY, United States |
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Magnetic susceptibility is a physical property of tissues that changes with iron level and (de-)myelination. Mapping the susceptibility can help us improve our understanding of the brain and its diseases, such as multiple sclerosis and Alzheimer disease. Quantitative Susceptibility Mapping (QSM) derives the susceptibility using MRI phase data. QUASAR adds a more sophisticated physical model to QSM. Our novel U2-Net for |
| 321 | 16:48
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Deep Learning for solving ill-posed problems in Quantitative Susceptibility Mapping – What can possibly go wrong? |
1Department of Health Science and Technology, Aalborg University, Aalborg, Denmark, 2Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia, 3Healthcare Pty Ltd, Siemens, Brisbane, Australia |
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Quantitative susceptibility mapping (QSM) aims to solve an ill-posed field-to-source inversion to extract magnetic susceptibility of tissue. QSM algorithms based on deep convolutional neural networks have shown to produce artefact-free susceptibility maps. However, clinical scans often have a large variability, and it is unclear how a deep learning-based QSM algorithm is affected by discrepancies between the training data and clinical scans. Here we investigated the effects of different B0 orientations and noise levels of the tissue phase on the final quantitative susceptibility maps. |
| 322
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17:00
|
One-Dimensional k-Space Metrics on Cone Surfaces for Quantitative Susceptibility Mapping |
1Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany, 2Philips Research, Hamburg, Germany, 3Department of Electrical Engineering and Computer Sciences, & Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States |
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An important question in QSM is how to compare different QSM reconstructions. We propose new metrics to compare susceptibility maps on cone surfaces in the Fourier domain following the intrinsic geometry of the dipole kernel. This physically motivated approach augments the idea of previously proposed error spectrum plots in MRI image reconstruction to specifically suit the QSM dipole inversion. The novel metrics complement previous metrics used in the 2016 QSM reconstruction challenge. |
| 323 | 17:12
|
Free lunch may not exist, but free contrast does: Calculation of Susceptibility weighted Imaging contrast from data obtained for MR Elastography |
1Philips Healthcare, Bengaluru, India, 2Indian Institute of Technology, Madras, India |
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In typical phase contrast based MR imaging studies like MR Elastography, the phase of interest is extracted from the data and is used in downstream processing to calculate the relevant clinical parameters of interest. While the background phase is typically discarded, we explored the feasibility of obtaining other relevant contrast like SWI contrast from this background phase. This indeed provides useful independent information and we provide evidence on a phantom and in-vivo human experiments. For example, SWI contrast obtained from MRE data of the brain improves the visualization of diamagnetic choroid plexus and paramagnetic internal cerebral veins. |
| 324
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17:24
|
Artifact free direct conductivity reconstruction method using the Dual Loop and artificial neural network with one current injection in MREIT. |
1School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, United States |
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Most the image reconstruction algorithms in magnetic resonance electrical impedance tomography (MREIT) and diffusion tensor magnetic resonance electrical impedance tomography (DT-MREIT) require at least two independent current patterns to uniquely reconstruct conductivity distributions. However, in transcranial electrical current stimulation (tES) or deep brain stimulation (DBS) only one current injection data is available. We applied Kirchhoff’s voltage law (KVL) in a mimetic discretized network, additional current data obtained from a computational model, and a radial basis function artificial neural network (RBF-ANN) approach, to demonstrate that it is possible to reconstruct the conductivity images using a single experimental current administration. |
| 325
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17:36
|
Concurrent mapping of electric currents and neurophysiological changes during Transcranial Direct Current Stimulation (tDCS) |
1USC Stevens Neuroimaging and Informatics Institute, Los Angeles, CA, United States, 2UCLA Neurology, Los Angeles, CA, United States |
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Transcranial Direct Current Stimulation(tDCS) is a non-invasive neuromodulation technique that uses milliampere currents (applied at the scalp) to modulate cortical excitability. Although tDCS has been shown to improve clinical symptoms in depression, stroke rehabilitation and pain, the exact mechanism of tDCS is not yet fully understood. To help advance the study of tDCS mechanisms, we developed a novel technique that, for the first time, enables concurrent mapping of (i) the applied electric current and (ii) the neurophysiological changes induced in-vivo. In this work, we demonstrate the feasibility as well as reliability of this novel technique through phantom and in-vivo experiments. |
| 326
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17:48
|
Deep Learning based MR Electrical Properties Tomography |
1University Medical Center Utrecht, Utrecht, Netherlands, 2Utrecht University, Utrecht, Netherlands |
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The inability of Magnetic Resonance Electrical Properties Tomography to accurately reconstruct tissue electrical properties severely limits its clinical use, e.g. as a biomarker in oncology. We demonstrate that the electrical properties reconstruction problem can be casted as a supervised deep learning task. Deep learning based electrical properties reconstructions for simulations and MR measurements (3 Tesla) on phantoms and human brains demonstrate great improvement in the quality of reconstructed electrical properties maps. This could be major step forward to turn electrical properties tomography into a reliable biomarker where pathological conditions can be revealed and characterized by abnormalities in tissue electrical properties. |
16:00
|
Myocardial Arterial Spin Labeling (ASL) Perfusion Imaging | |
1Electrical Engineering, University of Southern California, Los Angeles, CA, United States |
16:24
|
T1 Relaxometry: Stress T1-Mapping for the Detection of Cardiac Ischemia | |
16:48
|
T2 Relaxometry: Cardiac BOLD MRI & Stress MRI With CO2 Ventilation | |
17:12
|
Coronary Endothelial Function (CEF) Assessment with MRI | |
17:36
|
Future Horizons in Non-Contrast Functional CMR | |
1ETHZ, Zurich, Switzerland |
16:00
|
Imaging How Early Life Stress Alters Brain Activity in the Adult & Its Response to Fear & Evolution | |
16:15
|
Imaging Cerebral Interstitial Flow by MRI in Rodent Brains: Effect of Evolving Cerebral Amyloid Angi | |
1Yale University, New Haven, United States |
16:30
|
Imaging Cerebral Interstitial Flow by MRI in Rodent Brains: Effect of Evolving Cerebral Amyloid Angi | |
16:45
|
Multimodal Integrative Imaging of Amyloid Lesions: Gadolinium Staining of Amyloid Plaques & 3D Histo | |
17:00
|
Neurovascular Phenotyping: The Next Frontier | |
1Radiology, Johns Hopkins University School of Medicine, MD, United States |
17:15
|
Awake Rat Brain Imaging with a Focus on Forebrain Connectomics: Optogenetics & MRI | |
17:30
|
Biological Basis of Structural Covariance in the Mouse | |
| 7:00 | Concepts of Connectivity |
| Mara Cercignani |
| 7:30 | Diffusion MRI-Based Connectomics Study in Neurodegenerative Diseases |
| Koji Kamagata |
| 8:00 | Adjournment |
| 7:00 | Clinical Polarizer, Sterilization & Clinical Coils |
| Daniel Vigneron |
| 7:20 | Applications in Clinical Cancer Research |
| Ferdia Gallagher |
| 7:40 | Applications in Clinical Cardiovascular Research |
| Damian Tyler |
| 8:00 | Adjournment |
| 7:00 | Exogenous & Endogenous Contrasts |
| Kannie WY Chan |
| 7:30 | Molecular & Cellular Probes |
| Peter Caravan |
| 8:00 | Adjournment |
| 7:00 | Incoherent vs. Coherent Motion |
| Andreas Wetscherek |
| 7:30 | Sequences & Analysis |
| Magalie Viallon |
| 8:00 | Adjournment |
| 7:00 | MRI in Living Donor Assessment |
| Kartik Jhaveri |
| 7:30 | MRI for Post-Liver Transplant Assessment |
| Alessandro Furlan |
| 8:00 | Adjournment |
| 7:00 | Rapid Imaging: The Fast & the Furious: Research Perspective |
| Li Feng |
| 7:30 | Rapid Imaging: The Fast & the Furious - Clinical Perspective |
| Jan Fritz |
| 8:00 | Adjournment |
| 7:00 | New Developments in Sequences for Cardiovascular MR |
| Behzad Sharif |
| 7:30 | New Developments in Motion Correction for Cardiovascular MR |
| Mehdi Hedjazi |
| 8:00 | Adjournment |
| 327 | Pitch: 8:15 Poster: 9:15 Plasma 1
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Targeting brain and cognitive aging with multi-modal imaging and connectome topography profiling |
1Multimodal Imaging and Connectome Laboratory, Montreal Neurological Institute, Montreal, QC, Canada, 2Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute, Montreal, QC, Canada, 3Brain and Cognition Laboratory, Montreal Neurological Institute, Montreal, QC, Canada |
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We present an approach to represent and analyze age-related differences in cortical morphology and Aβ uptake based on connectome topography. Studying healthy individuals, we observed age-related reductions in neocortical thickness and atrophy across posterior hippocampal subfields. Additionally, we observed an interplay between aging effects and functional topography in both neocortical and hippocampal regions, with age-related thinning stronger towards unimodal regions and Aβ deposition increasing towards transmodal regions. Similarly, an inverted pattern of volume loss and Aβ deposition was observed along the hippocampal long-axis. Finally, imaging markers were found to predict cognitive performance in a topography-specific manner. |
| 328 | Pitch: 8:15 Poster: 9:15 Plasma 2
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Age-related whole-brain structural changes in relation to cardiovascular risks |
1Department of Radiology, Beijing Hospital, National Center of Gerontology, Beijing, China, 2ImageTech Laboratory, Simon Fraser University, Surrey, BC, Canada, 3Department of Diagnostic Imaging, Tianjin Medical University General Hospital, Tianjin, China, 4Health Sciences and Innovation, Surrey Memorial Hospital, Fraser Health Authority, Surrey, BC, Canada |
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We investigated the relationship between structural brain health with age and cardiovascular risks across the adult life course. A score of the Brain Atrophy and Lesion Index (BALI), which assesses and integrates multiple changes commonly seen on MRI in the aging brain, was generated for each subject from evaluation of T2-weighted MRI. Our data showed that the accumulation of MRI detectable deficits in the brain became evident even in younger adults. Cardiovascular risks strongly affected the whole-brain structural health, in addition to the effect of age. |
| 329 | Pitch: 8:15 Poster: 9:15 Plasma 3
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Differential developmental trajectory of magnetic susceptibility in healthy rhesus macaque brain |
1Kungming istitute of zoology, Chinese Academy of Sciences, Kunming, China, 2Shanghai United Imaging Healthcare, Shanghai, China, 3UIH American Inc., Houston, Armenia, 4Shanghai Research Center for Brain Science and Brain-Inspired Intelligence, Shanghai, China |
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Myelination and iron deposition in the deep brain nuclei evolve both spatially and temporally. In this study, we quantitatively evaluated the change of iron content along with age in primate brains using quantitative susceptibility mapping (QSM). All the brain images were acquired from 23 healthy rhesus macaque monkeys (23+/-7.85 y, ranged 2 ~ 29 y) with a 3D five-echo GRE sequence. After analyzing susceptibility maps and R2* maps of the ROIs (including putamen, globus pallidus, caudate nucleus, thalamus, dentate nucleus, red nucleus, substantia nigra), susceptibility in most of the ROIs correlated with the growth of age significantly. |
| 330
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Age-related microstructural and physiological changes in normal brain assessed via anomalous diffusion derived γ, DTI, DKI and NODDI metrics |
1SAIMLAL, Sapienza University of Rome, Rome, Italy, 2Institute for Complex Systems, CNR, Rome, Italy, 3Department of Computer Science & Centre for Medical Image Computing, University College London, London, United Kingdom, 4Laboratory for Structural, Physiologic and Functional Imaging, Perelman School of Medicine University of Pennsylvania, Philadelphia, PA, United States, 5ImpAct Team, Neuroscience Research Center, Lyon, France, 6Neuroimaging Laboratory, Santa Lucia Foundation, Rome, Italy |
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In this study we used γ-metrics, derived from anomalous diffusion signal representation, as well as DTI, NODDI, DKI derived parameters to assess physiological (i.e. the iron content) and microstructural (myelin damage, axonal disintegration, neuron cell loss) modifications in cerebral WM and scGM of middle- and older-aged subjects. We found that γ-metrics are remarkably sensitive and provide complementary information compared to DTI-metrics, MK and NODDI to detect modifications in frontal WM, where substantial changes are expected with aging. Also, the combined use of these techniques may unravel different patterns of modifications of the ageing brain. |
| 331 | Pitch: 8:15 Poster: 9:15 Plasma 5
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Characteristic Normal Ageing Patterns of White Matter Tracts in 610 Cambridge Centre for Ageing and Neuroscience (Cam-CAN) Healthy Participants |
1Institute of Medical Device and Imaging, National Taiwan University College of Medicine, Taipei, Taiwan, 2AcroViz Technology, Inc., Taipei, Taiwan, 3Molecular Imaging Center, National Taiwan University, Taipei, Taiwan |
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Previous studies did not clearly characterize normal ageing patterns of white matter tracts across lifespan. Here, we performed tract-specific automatic analysis over the whole brain to measure the diffusion indices on 610 healthy participants recruited from Cam-CAN. We used quadratic or linear models to plot the curves of diffusion indices against age, and calculated the average values and slopes of the curves in 10 subsystems classified from 76 major tracts. Our study characterized different ageing patterns corresponding to different subsystems. |
| 332 | Pitch: 8:15 Poster: 9:15 Plasma 6
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Age-Related Microstructural Alterations in Human Corpus Callosum Measured by High-Gradient Diffusion MRI |
1Radiology, Massachusetts General Hospital, Charlestown, MA, United States, 2Harvard Medical School, Boston, MA, United States, 3Neurology, Massachusetts General Hospital, Charlestown, MA, United States, 4Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States |
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Cerebral white matter exhibits degenerative changes during normal aging. Noninvasive approaches to measure these microstructural alterations would be invaluable for understanding the substrate and regional variability of age-related white matter degenerations. Recent advances in diffusion MRI have leveraged high gradient strengths to increase sensitivity toward axonal size and density in living human brains. Here, we examined the relationship between age and microstructural properties measured using high-gradient diffusion MRI. We observed an increase in apparent axon diameter and decrease in density with advancing age in the corpus callosum, with changes most pronounced in the genu and relatively absent in the splenium. |
| 333 | Pitch: 8:15 Poster: 9:15 Plasma 7
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The link between vascular stiffness and resting-state fMRI measures in healthy aging |
1Rotman Research Institute, Toronto, ON, Canada, 2Physiology, University of Toronto, Toronto, ON, Canada, 3Institute of Medical Science, University of Toronto, Toronto, ON, Canada, 4SickKids Hospital, Toronto, ON, Canada, 5Sunnybrook Research Institute, Toronto, ON, Canada, 6Bloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital, Toronto, ON, Canada |
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Arterial pulse-wave velocity (PWV) is an established measure of vascular stiffness which is an important risk factor in cardiovascular disease and brain dysfunction. It remains unclear, however, whether PWV variations across age is associated with changes in resting-state fMRI (rs-fMRI) measures, as the fMRI signal is a heavily vascular signal. In this study, we show that PWV has a significant impact on rs-fMRI signal fluctuation amplitude and functional connectivity. Moreover, PWV effects are distinct from those of age, and may not have neuronal underpinnings. |
| 334
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Pitch: 8:15 Poster: 9:15 Plasma 8
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Evaluation of standardized as well as study-specific and age-specific structural T1-weighted brain templates for use in studies on older adults |
1Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, United States, 2Rush Alzheimer’s Disease Center, Rush University, Chicago, IL, United States |
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Atlas-based MRI investigations on older adults often utilize young adult standardized templates, such as those of the ICBM. Additionally, a thorough, quantitative assessment of how available standardized, study-specific and age-specific structural templates perform in studies on older adults has not yet been conducted. Here, a new standardized T1-weighted template was developed specifically for studies on older adults, and was compared to 25 other standardized, study-specific, and age-specific templates, in terms of image quality and inter-subject spatial normalization accuracy. |
| 335 | Pitch: 8:15 Poster: 9:15 Plasma 9
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Arterial stiffness and white matter integrity in the elderly: a diffusion tensor and magnetization transfer imaging study |
1Neurosciences, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada, 2NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montréal, Montréal, QC, Canada, 3Unité de Neuroimagerie Fonctionnelle (UNF), Centre de recherche de l’Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montréal, QC, Canada, 4Department of biomedical Sciences, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada, 5Montreal Heart Institute, Montréal, QC, Canada, 6Department of Psychology, Faculty of Arts and Sciences, Université de Montréal, Montréal, QC, Canada, 7Department of biomedical Sciences, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada, 8Institut de Recherches Cliniques de Montréal, Université de Montréal, Montréal, QC, Canada, 9Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada |
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Arterial stiffness is a common condition arising with aging and is associated with an elevated risk for white matter structural abnormalities in the brain. The goal of this study is to combine white matter sensitive techniques (DTI, MTsat) to better understand the impact of arterial stiffness on the white matter microstructure and cognitive health in healthy elderly. Results suggest that arterial stiffness is associated with axon degeneration rather than demyelination. Findings from this study also show that improved executive function performance correlates with white matter metrics. Controlling arterial stiffness might play a role in maintaining the health of white matter axons in the aging brain and thus prevent or slow cognitive decline. |
| 336 | Pitch: 8:15 Poster: 9:15 Plasma 10
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Hippocampal NAA/mIns ratio and spatial working memory across the lifespan |
1Danish Research Center for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Copenhagen, Denmark, 2Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark, 3Department of Neurology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark, 4Center for Magnetic Resonance, Department of Electrical Engineering, Technical University of Denmark, Lyngby, Denmark |
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The NAA/mIns ratio has been proposed as a marker of unhealthy ageing. We found that the NAA/mIns ratio is decreased in the hippocampus for middle-aged and old individuals compared to young individuals. For old individuals, declining NAA/mIns ratios are correlated with poorer performance on a spatial working memory task but this relationship is not found in middle-aged and young individuals. Our results suggest that the NAA/mIns ratio decrease in the hippocampus is observable before the negative functional effects. |
| 337 | Pitch: 8:15 Poster: 9:15 Plasma 11
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Characterization of perivascular space morphology in healthy volunteers between 21 and 55 years old |
1Department of Radiology and BRIC, Univeristy of North Carolina at Chapel Hill, Chapel Hill, NC, United States, 2BRIC, Univeristy of North Carolina at Chapel Hill, Chapel Hill, NC, United States |
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Perivascular spaces (PVS) are an integral part of the brain’s glymphatic system. Although enlarged PVSs are often observed in older population and patient with neurological diseases, normal PVS morphological features in healthy subjects and their age dependences remain poorly understood. We studied the age-dependence of PVS morphology in healthy volunteers aged 21 – 55. The number and diameters of PVSs were positively correlated with age but exhibited large inter-subject variations. We also found clear spatial heterogeneity in the density of visible PVSs. Further studies are needed to realize the utility of PVS as a potential biomarker for aging and neurological diseases. |
| 338 | Pitch: 8:15 Poster: 9:15 Plasma 12
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Behavioral Correlates to Laminar Thickness Within the Cortex |
1Radiology and Radiological Science, allen.t.newton@vumc.org, Nashville, TN, United States, 2Monroe Carell Jr. Children's Hospital at Vanderbilt, Nashville, TN, United States, 3Psychology, Vanderbilt University, Nashville, TN, United States |
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Cortical thickness changes have been shown to be correlated with a wide variety of behavioral measures. Until recently, methods to probe the laminar changes underlying these large scale cortical changes in vivo have not been available. Here, we present methods to measure laminar thickness within the cortex, and show that sufficient precision exists to observe behavioral correlates within individual layers. Furthermore, our data are consistent with the hypothesis that behavior learned early in life has different laminar thickness correlates than does behavior learned later in life. |
| 339 | Pitch: 8:15 Poster: 9:15 Plasma 13
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Reduced functional connectivity of resting state networks in the healthy brain is associated with R2*changes consistent with myelin breakdown |
1Invicro, London, United Kingdom, 2High Field MR Centre, Medical University of Vienna, Vienna, Austria, 3AGE Research Unit, Imperial College London, London, United Kingdom |
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Functional connectivity of select resting state networks has been shown to diminish with age. Reported observations of reductions in visual and salience network strength appear to be supported by findings of vulnerability of the associated parietal, occipital, and frontal lobes to structural changes in the healthy brain.
We present data suggesting that measures of R2* in parietal and frontal lobar regions are correlated to visual and salience network connectivity in healthy individuals. These observations may indicate that early breakdown in myelin, associated with R2* shortening in white matter, may be responsible for age related decline in these resting state networks. |
| 340 | Pitch: 8:15 Poster: 9:15 Plasma 14
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Age-specific Quantitative Brain Atlas Modelling Brain Shape and T1 Changes |
1Advanced Clinical Imaging Technology, Siemens Healthcare AG, Lausanne, Switzerland, 2Department of Radiology, University Hospital (CHUV), Lausanne, Switzerland, 3LTS5, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 4Department of Neuroradiology, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany |
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In order to facilitate the use of quantitative mapping approaches in clinical routine, atlases with normative quantitative values are required for comparison on a single-subject basis. To improve such comparison, we propose here to not only model the age-related change in T1, but also the change in brain shape. The method is demonstrated on a dataset of 196 quantitative T1 maps, yielding a brain model with shape and T1 information over the potential lifespan of a patient to assess. |
| 341 | Pitch: 8:15 Poster: 9:15 Plasma 15
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The Relationship between Glutamate and BOLD signal changes During Face-Name Paired-Associates Encoding and Retrieval Memory Task in Healthy Adults concerning age, performance level and genetic risk-A combined 1H-MRS and fMRI study |
1Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong, Hong Kong, 2State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, Hong Kong, 3Department of Educational Psychology, Chinese University of Hong Kong, Hong Kong, Hong Kong, 4Department of Social Work and Administration, The University of Hong Kong, Hong Kong, Hong Kong, 5Philips Healthcare, Hong Kong, Hong Kong, 6Alzheimer's Disease Research Network, The University of Hong Kong, Hong Kong, Hong Kong |
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Glutamate is hypothesized to be the neurotransmitter in mediating BOLD fMRI. In this study, fMRI technique was combined with Magnetic Resonance Spectroscopy(MRS) to investigate the relationship between glutamate and the BOLD signal changes during face-name memory task. Three different task-based fMRI face name memory experiments were performed respectively focusing on age difference, performance level and genetic risk. [Glx]abs in left hippocampus of elderly(Experiment1), high-performance(Experiment2) and low genetic risk(Experiment3) showed high correlation with BOLD signal changes in activated regions. On the whole, glutamate appears to be excitatory and lead to compensatory excitations. |
| 342 | Pitch: 8:15 Poster: 9:15 Plasma 16
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Mapping axonal conduction velocities from in vivo MRI data |
1CUBRIC, Cardiff University, Cardiff, United Kingdom |
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The ability to infer axonal conduction velocities (CV) non-invasively from in vivo neuroimaging is of huge biological importance. Having previously shown that accurate CV estimates are feasible with MRI-measurable parameters, we show here the sensitivity of MRI-derived CV estimates to modelling errors and acquisition noise. We show that for the parameters typically seen in white matter axons, there is less than 5% error in CV estimates. Application to a human diffusion/relaxometry dataset generates CV estimates in corpus callosum that are close to those observed in electrophysiology literature. This illustrates further the feasibility of estimating CV from in vivo microstructural MRI. |
| 343 | Pitch: 8:15 Poster: 9:15 Plasma 17
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Evaluating microstructure of the corticospinal tract in normal pressure hydrocephalus with diffusion MRI using oscillating gradient spin-echo |
1Radiology, Juntendo University School of Medicine, Tokyo, Japan, 2Radiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan, 3Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, Japan, 4Neurosurgery, Juntendo University School of Medicine, Tokyo, Japan, 5Neurosurgery, Juntendo Tokyo Koto Geriatric Medical Center, Tokyo, Japan, 6Siemens Healthcare K.K., Tokyo, Japan |
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We evaluated the corticospinal tract (CST) of normal pressure hydrocephalus (NPH) patients using the oscillating gradient spin-echo (OGSE) method. Diffusion time can be reduced greatly with OGSE and properties of the microstructure can be evaluated in more detail by collecting data using multiple diffusion times. The diffusivity of the CST increased and the diffusion time dependence was small in NPH patients compared with healthy controls. It is possible to estimate the structural change of CST in NPH by using multiple diffusion times with OGSE. |
| 344
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Investigation of the dependence of free water and pseudo-diffusion MRI estimates on the cardiac cycle |
1Image Sciences Institute, UMC Utrecht, Utrecht, Netherlands, 2C. J. Gorter Center for High Field MRI, Leiden University Medical Center, Leiden, Netherlands, 3Department of Radiology, UMC Utrecht, Utrecht, Netherlands |
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With diffusion MRI (dMRI) data at multiple diffusion weightings it is possible to quantify the relative fractions of multiple water pools. In this work, we investigated changes in free water diffusion and micro- and macro-vascular pseudo-diffusion during the cardiac cycle. Further, we propose a data driven method to bin the dMRI signals according to the cardiac phase. dMRI at 4 diffusion weightings was acquired 80 times with short repetition time. A multi-exponential fit of the binned data showed increases of free water in white matter and periventricular areas, and opposite increases/decreases for micro- and macro-vascular pseudo-diffusion in grey matter, respectively. |
| 345
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Distortion-free diffusion-weighted imaging of the eyeballs and the optic nerves using PSF-EPI |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, 2Philips Healthcare, Beijing, China |
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Distortion-free diffusion-weighted imaging can provide high fidelity information for the diagnosis of ophthalmological diseases. Traditional echo-planar imaging technique suffers from geometric distortion in the skull base. This study applies a point spread function encoded technique in eyeball imaging. This technique can generate distortion-free DWI of the eyeballs and the optic nerves with high efficiency. Its resistance to geometric distortion and ability to generate accurate ADCs were validated on phantom and healthy subjects. This technique has the potential in providing accurate information for diagnosis and characterizing diseases that are difficult to distinguish by traditional imaging methods. |
| 346 | Pitch: 8:15 Poster: 9:15 Plasma 20
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Defining subnetworks by rich-club architecture in 16p11.2 deletion syndrome reveals differential structural white-matter alterations |
1Fetal Neonatal Neuroimaging and Developmental Science Center, Division of Newborn Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States |
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16p22.1 deletion syndrome has been implicated in disorders such as autism and is associated with developmental deficits, including delay in language acquisition. Widespread DTI white-matter alterations have been identified in patients but the structural organisation using network theory has yet to be investigated. Using rich-club nodes to stratify the connectome into rich-club, feeder and seeder subnetworks, we compute graph topological measures in children with 16p11.2 deletion. While rich-club regions were similar to those in Controls, differential alterations in connectivity and topology suggest a reorganisation of subnetworks in patients with the feeder subnetwork possibly compensating for deficits in the rich-club. |
| 347 | Pitch: 8:15 Poster: 9:15 Plasma 21
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Topological reorganizations of the white matter structural networks in early blind adolescents |
1Department of Radiology, Shenzhen Mental Health Center, Shenzhen Kangning Hospital, Shenzhen, China, 2Department of Mechanical Engineering, Sungkyunkwan University, Suwon, Korea, Republic of, 3GE Healthcare, MR Research China, Beijing, China, 4Medical Imaging Center, the First Affiliated Hospital of Jinan University, Guangzhou, China |
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Previous neuroimaging studies have revealed functional neuroplasticity after visual deprivation. However, the structural reorganization of the brain induced by visual deprivation is rarely reported, and the mechanism of structural neuroplasticity remains unclear. This study is one of the first attempts to investigate structural neuroplasticity in the white matter networks at both the global and the local node levels using the Diffusion Tensor Imaging data and the graph theory analysis method. The results demostrate disrupted brain structure and reorganized brain structural networks in early blind adolecents, which provide evidence of structural neuroplasticity induced by visual deprevation. |
| 348 | Pitch: 8:15 Poster: 9:15 Plasma 22
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Using microstructure informed tractography to reduce discrepancy in the density of structural connectomes. An application to Multiple Sclerosis. |
1Department of Computer Science, University of Verona, Verona, Italy, 2DINOGMI, University of Genoa/IRCCS AOU San Martino-IST, Genoa, Italy, 3Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, United States |
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Graph theory is a valuable framework to study brain connectivity and has been widely applied to investigate pathological conditions such as Multiple Sclerosis (MS). However, differences in topology between groups of subjects could be affected by discrepancy in density. Here we propose to use microstructure informed tractography to directly account for such density differences and provide a fair comparison between MS patients and healthy subjects. Our results show the capability of the proposed method to control for density and support the appropriateness of global efficiency and clustering coefficient for the characterization of comprehensive functions such as cognition in MS. |
| 349 | Pitch: 8:15 Poster: 9:15 Plasma 23
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Gyri and sulci microstructural differences in the sheep brain during cortical folding assessed by diffusion MRI. |
1Service développement et croissance, Université de Genève, Genève, Switzerland, 2Laboratoire d'imagerie fonctionnelle et métabolique, Ecole polytechnique fédérale de Lausanne, Lausanne, Switzerland, 3The Ritchie Centre, Hudson Institute of Medical Research, Monash University, Clayton, Australia, 4School of Health and Biomedical Sciences, RMIT University, Bundoora, Australia |
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Despite a large number of studies assessing cerebral development, some of the events underlying folding of the cerebral cortex remain unclear, especially those concerning micro-architectural differences between outward (gyri) and inward (sulci) folds. The aim of this work was twofold: 1) depict cortical microstructure differences between gyri and sulci and 2) assess the potential of NODDI in the understanding of cortical folding. Gyri and sulci present different maturation timelines leading to microstructural differences. Diffusion imaging is a powerful tool to probe accurately these differences. These results are of high interest for the understanding of cortical folding process. |
| 350
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Cholesteatomas Detection using PSF-encoded EPI DWI |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, 2Philips Healthcare, Beijing, China, 3Department of Otorhinolaryngology, Peking Union Medical College Hospital, Beijing, China |
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DWI has proved to be valuable in detection of cholesteatoma, but there still remain challenges. Susceptibility artifacts and geometric distortions in single-shot EPI DWI affect the identification of subtle nidus. TSE-based DWI can reduce susceptibility-induced artifacts, but the disadvantages are SNR degradation and T2-blurring. In this work, point-spread-function (PSF) encoded EPI DWI was employed to overcome the aforementioned limitations for cholesteatomas detection. This technique has the capability to acquire high-quality, distortion- and blurring-free diffusion images with more accurate lesion boundary. |
| 351 | Pitch: 8:15 Poster: 9:15 Plasma 25
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Diffusion Time Dependence in the Evaluation of Choroid Plexus Cysts |
1Department of Radiology, Graduate School of Medicine, Juntendo University, Tokyo, Japan, 2Department of Radiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan, 3Siemens Healthcare Japan KK, Tokyo, Japan, 4Siemens Healthcare GmbH, Erlangen, Germany |
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To obtain information regarding the internal structure of choroid plexus cysts (CPCs) that appear hyperintense on DWI, we investigated the ADC values acquired with a shorter diffusion time using an oscillating gradient spin-echo (OGSE). The ADC values for twenty-seven patients with CPCs were measured with effective diffusion time (Δeff) of 6.5 and 35.2 ms. The ADC values of CPCs were significantly higher at the Δeff of 6.5 ms than with Δeff of 35.2 ms. The dependence of ADC values on the diffusion time in CPCs suggested spatially restricted diffusion. |
| 352
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Fast High-Resolution Diffusion Tensor Imaging of the Cervical Spinal Cord Using Point-Spread-Function Encoded EPI (PSF-EPI) |
1Department of Biomedical Engineering, Center for Biomedical Imaging Research, Beijing, China, 2Philips Healthcare, Beijing, China, 3Beijing Chao Yang Hospital, Beijing, China, 4Beijing ChaoYang Hospital, Beijing, China |
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Diffusion tensor imaging (DTI) of spinal cord holds great promise to aid diagnosis of spine-related diseases. However, it is greatly limited in clinics by the physiological motion induced artifacts and susceptibility inhomogeneity induced distortions. To reduce distortions in DTI, various multi-shot EPI (MS-EPI) methods have been proposed. However, the acquisition time is prolonged due to multiple shots. In this study, we achieved cervical spine DTI using only 6 shots based on a distortion- and blurring- free MS-EPI technique, Point-Spread-Function Encoded EPI (PSF-EPI). The acquisition time is within 5 minutes. The efficacy of PSF-EPI is demonstrated on healthy volunteers and patients. |
| 353
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Pitch: 8:15 Poster: 9:15 Plasma 27
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Diffusion Tensor Imaging Tractography for Diagnosing Traumatic Brachial Plexus Root Avulsions: A Proof-of-Concept Study |
1Leeds Institute of Medical Research, University of Leeds, Leeds, United Kingdom, 2Department of Plastic and Recosntructive Surgery, Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom, 3Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom, 4Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, United Kingdom, 5Advanced Imaging Centre, University of Leeds, Leeds, United Kingdom, 6Leeds Musculoskeletal Biomedical Research Unit, University of Leeds, Leeds, United Kingdom |
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Due to limitations in the accuracy of clinical MRI, adults with traumatic brachial plexus injuries (BPI) undergo major exploratory surgery to define their injury. Early exploration and reconstruction restores limb function and improves quality of life. Diffusion tensor imaging (DTI) tractography offers the potential to replace exploratory surgery by assessing the continuity of the roots of the brachial plexus. Twenty healthy adults were used for sequence development on a 3 Tesla system and the protocol validated on 12 patients with known patterns of BPI. DTI reliably reconstructs the normal and injured brachial plexus with high fidelity and superior diagnostic accuracy. |
| 354 | Pitch: 8:15 Poster: 9:15 Plasma 28
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Diffusion kurtosis imaging in quantitative diagnosis of nonalcoholic fatty liver disease: a rabbit model study |
1Department of radiology, Clinical Medical School of Yangzhou University, Northern Jiangsu People’s Hospital, Yangzhou, China, 2XiangYa school of medicine, Central South University, Changsha, China, 3GE Healthcare，MR Research China, beijing, China |
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We aimed to investigate if diffusion kurtosis imaging (DKI) can be applied to assess nonalcoholic fatty liver disease (NAFLD) by providing fractional anisotropy (FA), mean diffusion (MD) and mean kurtosis (MK). We used DKI derived parameters to analyze NAFLD in a rabbit model and compared them with the apparent-diffusion-coefficient (ADC) from a mono-exponential diffusion-weighted imaging model. While FA showed comparable results with the severity of NAFLD group, MD and MK indicated more robust performance in the diagnosis of nonalcoholic steatohepatitis (NASH) compared with ADC. We therefore demonstrated that DKI had potential in stratifying NAFLD and early diagnosis of NASH. |
| 355 | Pitch: 8:15 Poster: 9:15 Plasma 29
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Can preoperative Diffusion-weighted MR predict the Microvascular invasion of hepatocellular carcinoma? A deep learning evaluation |
1School of Medical Information Engineering, Guangzhou University of Chinese Medicine, Guangzhou, China |
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Microvascular invasion (MVI) of hepatocellualr carcinoma(HCC) is regarded as the most important factor associated with the success of curative resection and the outcome after liver transplation. As the MVI prediction can only be ultimately determined by the histopathological features of the tumor cells, numerous works have attempted to predict the MVI of HCC based on noninvasively preoperative images. Diffusion-weighted MR has also shown to be effective for MVI prediction based on signal intensities of lesions and the apparent diffusion coefficient (ADC). In this work, the emerging deep learning technique is used for MVI prediction of HCC based on DWI. |
| 356 | Pitch: 8:15 Poster: 9:15 Plasma 30
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Exploring the Application of an Multi-Advanced-Diffusion-Model-Based Radiomics Method in Grading of Intestinal Fibrosis of Crohn's Disease |
1The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China, 2The First Affiliated Hospital of Sun Yat-Sen University, guangzhou, China, 3MR Scientific Marketing, Siemens Healthcare, guangzhou, China, 4Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, shanghai, China |
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In the present study, we investigated a multiple diffusion-model-based radiomics model in grading of bowel fibrosis of Crohn's disease (CD) patients. We used histogram features derived from parameters of DWI, IVIM and DKI models and chose SVM as the classifier to construct a prediction model. The results showed that the most accurate prediction was achieved by incorporating the following 6 features into a nomogram, including the DKI-related histogram parameters (mean D, mean K, 10th percentiles of K) and IVIM-related parameters (mean D0-2000, mean D*0-2000, 90th percentiles of f), with AUC and accuracy reached 0.835 and 0.833, respectively. |
| 357
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Pitch: 8:15 Poster: 9:15 Plasma 31
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The Predominant Role of the Vagus Nerve in Gastric Electrical Stimulation Evoked Gut-Brain Axis |
1Biomedical Engineering, Purdue University, West Lafayette, IN, United States, 2Electrical and Computer Engineering, Purdue University, West Lafayette, IN, United States, 3Psychological Science, Purdue University, West Lafayette, IN, United States |
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The gut-brain axis serves the bidirectional communication between the enteric nervous system and the central nervous system and links the gastrointestinal function with cognitive and emotional centers of the brain. Three different pathways have been identified to be responsible for the gut-brain axis, including the chemical modulation, the spinal nerve, and the vagus nerve. However, the functional role of each pathway is unclear and still under investigation. Using functional magnetic resonance imaging (fMRI), we report that gastric electrical stimulation (GES) can modulate the gut-brain axis and evokes fMRI activity in multiple brain regions including both cognitive and sensory systems. Most of the GES evoked brain regions are attributable to the vagal function, suggesting a central role of the vagus nerve in the gut-brain axis, especially in modulating the cognitive and emotional centers. |
| 358
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Pitch: 8:15 Poster: 9:15 Plasma 32
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In-Vivo Current Mapping in Transcranial Direct Current Stimulation (tDCS) – A Concurrent tDCS-MRCDI Study |
1Stanford Law School, Palo Alto, CA, United States, 2Biophysics, Stanford, Palo Alto, CA, United States, 3Radiology, Stanford University, Stanford, CA, United States |
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Transcranial direct current stimulation (tDCS) is gaining momentum both in the research community and in the general public as an attractive tool for neuromodulation. However, the mechanism of tDCS in the brain is not fully understood. In this study, we conducted a concurrent tDCS–magnetic resonance current density imaging (MRCDI) experiment to measure the primary direction and magnitude of current in a human brain undergoing direct current stimulation. Our results show that current flow deviates significantly from its desired distribution based on human head models and that the current mostly flows through the white matter and cerebrospinal fluid. |
| 359 | Pitch: 8:15 Poster: 9:15 Plasma 33
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Reconstructing multi-dimensional face attributes from fMRI signals |
1Beijing Advanced Innovation Center for Big Data and Brain Computing (BDBC), Beihang University, Beijing, China, 2School of Computer Science and Engineering, Beihang University, Beijing, China, 3State Key Laboratory of Virtual Reality Technology and Systems School of Computer Science and Engineering, Beihang University, Beijing, China |
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We develop a new framework that can reconstruct the perceived faces from functional MRI signals. Inspired by the psychological evidences that face processing is transmitted along two distinct neuroanatomical visual pathways in human brain, our framework can efficiently extract the multidimensional information of facial expression and facial identity information from functional MRI signals for precise face image reconstruction. |
| 360 | Pitch: 8:15 Poster: 9:15 Plasma 34
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Attention modulation of layer-specific signals in human visual cortex |
1State Key Lab of Brain and Cognitive Science,Institute of Biophysics,Chinese Academy of Sciences, Beijing, China, 2University of Chinese Academy of Sciences, Beijing, China, 3The Innovation Center of Excellence on Brain Science, Chinese Academy of Sciences, Beijing, China, 4Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen, China, 5Department of Neurology, University of California Los Angeles, Los Angeles, CA, United States, 6Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, United States |
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Attention mechanisms at different cortical layers of the human visual cortex remain poorly understood. Here we investigated the attention modulation of layer-specific activities in the human visual cortex, using submillimeter-resolution BOLD fMRI at 7 Tesla. Results showed that compared to the middle-layer activities, attention increased signals in the superficial and deep layers of V1, and in the superficial layers of V2 and V3. Contrast modulation was strongest in the middle layer of V1, consistent with the feedforward input from the LGN. These findings suggest that top-down spatial attention mainly modulates output signals in the superficial layers of human visual cortex. |
| 361 | Pitch: 8:15 Poster: 9:15 Plasma 35
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Assessing somatotopic and mototopic organisation in Focal Hand Dystonia using high-resolution 7T fMRI |
1Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom, 2School of Psychology, University of Nottingham, Nottingham, United Kingdom, 3Department of Neurology, Nottingham University Hospitals Trust, University of Nottingham, Nottingham, United Kingdom |
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7T fMRI provides a non-invasive method to study somatotopy and mototopy. Here, healthy controls (HCs) and Focal Hand Dystonia (FHD) patients 4-weeks post-Botox injection undergo behavioural and fMRI assessment. Behavioural measures include temporal discrimination, amplitude thresholding and spatial acuity assessment. fMRI includes a somatosensory travelling wave and event-related paradigm, and mototopy travelling wave paradigm. In FHD patients, amplitude threshold, temporal discrimination threshold and spatial acuity was increased compared to HCs. Maps of somatotopy and mototopy are shown for FHD patients and HCs along with digit separation. FHD patients will be rescanned 3 months post-Botox to determine whether changes are evident. |
| 362 | Pitch: 8:15 Poster: 9:15 Plasma 36
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Characteristics of mouse BOLD fMRI responding to visual stimulation |
1Department of Biomedical Engineering, Sungkyunkwan University, Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, Korea, Republic of |
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While the most common BOLD fMRI studies in mice have focused on evoking BOLD response in the somatosensory system, the functional response characteristic of mouse visual system is not well explored. Here, we investigated BOLD fMRI in mice with visual stimuli varying flash frequency in the range of 1 to 10Hz and pulse width from 1 to 50ms under ketamine/xylazine anesthesia at 9.4T. |
| 363 | Pitch: 8:15 Poster: 9:15 Plasma 37
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Looping Star silent fMRI: a platform for improving studies of auditory processing |
1Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom, 2ASL Europe, General Electric Healthcare, Munich, Germany |
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Conventional functional magnetic resonance imaging (fMRI) produces acoustic noise levels comparable to a running chainsaw. This presents numerous challenges for functional data interpretation, providing a substantial confound for auditory processing. Recently, a novel imaging technique known as “Looping Star” has been developed, which reduces this acoustic noise to the amplitude of normal conversation. We applied this acquisition technique with an auditory paradigm for the first time, comparing it with conventional fMRI. We established that it displays good functional sensitivity in spite of reduced signal-to-fluctuation-noise, alongside functional localisation free from inflow effects. This technique could revolutionise future investigations of acoustic processing. |
| 364 | Pitch: 8:15 Poster: 9:15 Plasma 38
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Reconstruction of highly-accelerated multi-echo fMRI using parametric POCS based multiplexed sensitivity-encoding (POCSMUSE) |
1The University of Hong Kong, Hong Kong, Hong Kong, 2National Central University, Taiwan, Taiwan, 3Philips Healthcare, HKSAR, China, Hong Kong, Hong Kong |
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Multi-echo fMRI is an emerging technique that can improve the fidelity and interpretability of fMRI, such as differentiating BOLD and non-BOLD signals. In multi-echo fMRI acquisition, high acceleration factor for parallel imaging (i.e., R = 3) was used to achieve reasonable TE interval and maintain the same resolution as single-echo acquisition. The accelerated multi-echo data are reconstructed using SENSE, which may suffer from undesired noise amplification. In this study, we proposed a multi-echo multi-segment EPI (MEMS-EPI) technique to acquire multi-echo fMRI with high acceleration factor, and then used parametric POCSMUSE algorithm to reconstruct the data. |
| 365 | Pitch: 8:15 Poster: 9:15 Plasma 39
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Improving k-t PERRI: a low-rank data-driven fMRI k-t acceleration method |
1Wellcome Centre for Integrative Neuroscience, FMRIB Centre, University of Oxford, Oxford, United Kingdom, 2Wellcome Centre for Human Neuroimaging, UCL Institute of Neurology, London, United Kingdom |
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FMRI data quality requires both good image fidelity (conferring spatial specificity), and high temporal resolution (conferring statistical robustness). We present an image reconstruction algorithm that aims to achieve both aims through a spatio-temporal (k-t) image reconstruction. Our approach utilises low-rank reconstruction algorithms and 3D golden angle k-space sampling. Using golden-angle sampling, we demonstrate that data-driven spatial and temporal priors can be incorporated into reconstruction. We demonstrate improvement over previously-proposed methods (k-t FASTER and k-t PSF) that correspond to special cases of our prior-based reconstruction. These results have great potential to improve on time-independent reconstructions currently in use. |
| 366 | Pitch: 8:15 Poster: 9:15 Plasma 40
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Measuring layer-dependent CBV fMRI in the visual system |
1NIH, Bethesda, MD, United States, 2IBS Center, Sungkyunkwan, Korea, Republic of, 3MBIC, Maastricht University, Maastricht, Netherlands, 4MGH, Boston, MA, United States |
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With recent developments of ultra-high field MRI and high-resolution CBV-sensitive VASO sequences, it became possible to measure activity changes across cortical depths in brain areas of large cortical thicknesses (4mm in M1). Applications of layer-dependent CBV-fMRI in the visual cortex, however, have been complicated by long arterial-arrival-times, coverage requirements, and lower cortical thickness (1.9mm). Here, we developed new sequence setups for layer-dependent acquisition of CBV changes during tasks and resting-state. We find that the proposed large-coverage VASO protocols with 0.8mm (iso) resolutions can pinpoint feedforward and feedback input into V1 from LGN and V5 during tasks and resting-state. |
| 367 | Pitch: 8:15 Poster: 9:15 Plasma 41
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Dual-echo simultaneous multi-slice spiral acquisition for simultaneous CBF and BOLD fMRI at 7T |
1Maastricht University, Maastricht, Netherlands |
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Dual-echo acquisition with arterial spin labelling (ASL) allows for simultaneous measurements of CBF and BOLD signal changes which are helpful to understand the cerebral haemodynamics in health and disease. At ultra-high field (≥7T), however, this becomes impractical with established EPI based techniques since the readout duration precludes the use of appropriate echo times at commonly desired spatial resolutions. Single-shot spiral imaging presents a promising alternative: it allows the CBF signal to be acquired at very short TE while providing a flexible choice of TE for the second BOLD echo. In this work we show a dual-echo simultaneous multi-slice spiral out-in sequence for the acquisition of CBF and BOLD signals. |
| 368 | Pitch: 8:15 Poster: 9:15 Plasma 42
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Comparison of SMS-EPI versus 3D-EPI in an fMRI localizer study at HCP-style resolution and TR, using parallel transmission Universal Pulses at 7T |
1Neurospin, CEA, Université Paris-Saclay, Gif-sur-Yvette, France, 2Siemens Healthineers, Saint-Denis, France, 3Neurospin, CEA, Université Paris-Saclay, INSERM, Gif-sur-Yvette, France, 4German Center for neurodegenerative diseases (DZNE), Bonn, Germany, 5Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands, 6Collège de France, Paris, France |
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Simultaneous-Multi-Slice (SMS) and 3D-EPI sequences with parallel-transmit B1 homogenization by means of calibration-free Universal Pulses were evaluated at 7T and at HCP-style resolution and repetition time (1.6mm iso, TR=1120ms). Comparison was based on sensitivity and specificity of activation detection in a multi-modal functional localizer task paradigm. When including nuisance regressors in the analysis, the SMS-EPI shows superior sensitivity but lower specificity than the 3D-EPI, with overall comparable performance when weighting the two metrics equally, but with significantly smaller SAR demands and sound pressure levels for the 3D-EPI. |
| 369 | Pitch: 8:15 Poster: 9:15 Plasma 43
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BOLD temporal SNR bias and variance across the HCP population as a function of cortical B0-orientation and orientation variability |
1Athinoula A. Martinos Center for Biomedical Imaging, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, United States, 2Massachusetts Institute of Technology, Division of Health Sciences and Technology, Cambridge, MA, United States |
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BOLD fMRI signals vary with the orientation of the cortex to the B0-field as extravascular susceptibility effects vary with the orientation of the cortical pial vasculature. This creates regional tSNR biases with cortical folding. Certain cortical folds are more homogenous across the population than others and orientation variability across subjects should introduce tSNR variability at the group-level. Here, we use HCP 3T rs-fMRI data to show that B0-orientation contributes to within-subject tSNR bias and orientation variability contributes to tSNR variance across subjects. We found that functional connectivity networks with more perpendicular orientation exhibit higher tSNR and networks with high orientation consistency have lower tSNR variability. |
| 370 | Pitch: 8:15 Poster: 9:15 Plasma 44
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Evaluation of Sparse Sampling Approaches for 3D Functional MRI |
1University of Michigan, Ann Arbor, MI, United States |
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This work evaluates the performance of a novel sampling pattern compared to common undersampling techniques with the ultimate goal of obtaining high spatiotemporal resolution 3D fMRI via sparse sampling and model-based reconstruction. We examine a novel 3D Cartesian sampling pattern with random phase encodings in ky-kz rotated by the golden angle, resulting in a variable density sampling of k-space, with dense sampling of the high-signal energy k-space center. The functional activation and noise amplification (g-factor) results of this sampling technique are compared to those of standard sampling regimes. |
| 371 | Pitch: 8:15 Poster: 9:15 Plasma 45
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Microstrip Array Insert for Head Coils: Towards Layer fMRI at High Fields |
1Department of Radiology, Medical Physics, Medical Center ‐ University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany, 2German Cancer Consortium Partner Site Freiburg, German Cancer Research Center (DKFZ), Heidelberg, Germany |
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Rx coils for high field strengths are mostly based on loop coil design and cover relatively large FOVs, limiting the achievable voxel size due to the SNR and acquisition time constraints. Microstrip coils have limited sensitivity profile along the B1 direction, thus are useful for resolving cortical activity. In this study, we introduce flexible microstrip array insert coils (MSAi) that are compatible with existing volume coils. We demonstrate measurement of BOLD and highly confined activity wide spread in calcarine sulcus and motor cortex using MSAi at 3 T |
8:15
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MRS of Lipids & Fatty Acids: Metabolism, Composition & Quantification | |
1Translational Biomarkers, Merck & Co., Inc., West Point, PA, United States |
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Lipids are a large class of biomolecules naturally occurring in different forms throughout the body. As many lipid species tend to exist in high concentrations, they are an abundant source of MR-observable nuclei. This presentation will review the measurements of lipids that have been made successfully with MRS-based approaches and highlight the important findings from MRS studies of lipids. Specifically, focus will be on the following areas: (1) Introduction to characteristics of lipids, (2) Detection and quantification of lipid levels with 1H MRS, (3) Assessment of lipid composition with 1H MRS and 13C MRS too, (4) Measurement of the kinetics of lipid metabolism with 13C MRS. |
| 372
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8:45
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Fat-fraction provides classification and treatment response assessment of metastatic lymph nodes for patients with radio-recurrent prostate cancer |
1Centre for medical imaging, University College London, London, United Kingdom, 2Dept of Radiology, University College London Hospital(UCLH), London, United Kingdom, 3Department of Radiology & Nuclear Medicine, St Bartholomew’s Hospital, London, United Kingdom, 4Institute of Nuclear Medicine (INM), University College London Hospital (UCLH), London, United Kingdom, 5Department of Oncology, University College London Hospital (UCLH), London, United Kingdom, 6epartment of Surgery & Cancer, Faculty of Medicine, Imperial College London, London, United Kingdom |
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Lesion size threshold is the most common imaging feature used to assess response to therapy. Size as an imaging feature has its limitations. Quantitative imaging biomarkers (QIBs) could identify subtle microstructural changes prior to morphological changes. In this study, we explored the use of novel whole-body MRI (WB-MRI) QIBs for nodal disease characterisation and treatment response monitoring in radio-recurrent prostate cancer (rPC). We showed signal fat fraction could discriminate between positive and negative nodes and that it can be used for response monitoring. |
9:05
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MRS of Lipids & Fatty Acids: Relevance in Cancer | |
1University of Pennsylvania, United States |
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TARGET AUDIENCE – Imaging scientists interested in MR spectroscopy or imaging of lipidsand fatty acids. Scientists and clinicians interested in the interpretation or MR spectra of lipidsand fatty acids, and their relation to lipid biology. |
| 373
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9:35
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Measuring large lipid droplet sizes by probing restricted lipid diffusion effects with Diffusion-Weighted Magnetic Resonance Spectroscopy at 3 T |
1Department of Diagnostic and Interventional Radiology, Technical University Munich, Munich, Germany, 2Else Kröner Fresenius Center for Nutritional Medicine, Technical University Munich, Munich, Germany, 3Chair for Food and Bioprocess Engineering, Technical University Munich, Freising, Germany, 4Clinic of Orthopaedic Surgery, Technical University Munich, Munich, Germany, 55 Department of Computer Science, Technical University Munich, Munich, Germany |
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Despite its strong relevance in metabolism, non-invasive measurement of adipocyte size remains an unmet need. High b-value DW-MRS has been previously applied to probe diffusion restriction effects of intramyocellular lipids or brown adipocytes using preclinical systems with strong gradient systems. However, probing diffusion restriction in large lipid droplets on a clinical system remains a major challenge. The present work proposes a methodology to probe lipid droplet sizes with high b-value long diffusion time DW-MRS. The method was examined with simulations, validated in phantoms and tested to estimate bone marrow adipocyte size in the tibia of healthy subjects. |
| 374 | 9:55
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Musculoskeletal Lipid Compartments Separation and Quantification by High-Resolution Metabolite Cycling Magnetic Resonance Spectroscopic Imaging at 3 T |
1School of Health Sciences, Purdue University, West Lafayette, IN, United States, 2Department of Radiology, University of California Los Angeles, Los Angeles, CA, United States, 3Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States, 4Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States |
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A fast and high-resolution density-weighted concentric ring trajectory metabolite cycling MRSI sequence was implemented to generate simultaneous lipid- and water-only spectra within a short scan time (~3 min) at 3T, and compared to Dixon MRI. LCModel was used to fit the peaks of intramyocellular and extramyocellular lipids that were used to generate separate high-resolution maps for each of these lipid compartments. In addition, the proposed MRSI sequence showed higher sensitivity by sampling lipids at areas that Dixon failed to detect any lipid signal. |
10:15
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Adjournment |
8:15
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Overview of Image Analysis for Prostate MRI | |
1Department of Radiology and Nuclear Medicine, St. Olavs hospital, Trondheim University Hospital, Trondheim, Norway |
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Prostate cancer is one of the most frequently diagnosed cancers worldwide and multiparametric MRI is an important part of the diagnostic work-up of prostate cancer patients. Suggestions for standardization of acquisition and interpretation of the images are provided in the PI-RADS v. 2 system, which is increasingly used in clinical practice. New approaches for image analysis, where quantitative features are extracted from the images, allow for the quantitative and multidimensional nature of image data to be exploited. Various machine learning approaches has been used in a wide range of applications within evaluation of prostate mpMRI. |
| 375
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8:45
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Noninvasive Prostate Cancer Grading Using Diffusion MR Structural Fingerprints |
1Radiology, Washington University School of Medicine, Saint Louis, MO, United States, 2Radiology, Changhai Hospital, Shanghai, China, 3Medical Scientist Training Program, The University of Alabama at Birmingham, Birmingham, AL, United States, 4Medicine, University of Missouri – Kansas City, Kansas City, MO, United States, 5Radiology, Guangzhou First People's Hospital, Guangzhou, China, 6Radiology, The First Affiliated Hospital of Nanchang University, Nanchang, China |
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Prostate cancer (PCa) is second most common cause of cancer death among American men. Curently clinicians rely on needle biopsies for PCa grading, although biopsy Gleason scores often differ from those of pathological analyses. We demonstrated modified-DBSI captured and quantified heterogeneous diffusion fingerprints reflecting prostatic histopathology, capable of noninvasively grading PCa with high accuracy. The diagnostic power of modified-DBSI could prevent low-grade cancer patients from undergoing unnecessary and costly invasive procedures, offering patients more reliable assessments on cancer progression during active surveillance, and helping patients and clinicians to determine the most appropriate treatment options. |
| 376 | 8:57
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Peri-tumoral radiomics on 3T MRI discriminative of D’Amico prostate cancer risk categories show association with epithelium, lumen and stromal densities on whole mount pathology |
1Case Western Reserve University, Cleveland, OH, United States, 2Self-employed, Lleida, Spain, 3University of Turku, Turku, Finland, 4Turku University Hospital, Turku, Finland, 5Icahn School of Medicine at Mount Sinai, New York, NY, United States |
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There is currently increasing interest in looking at role of radiomic features within the peri-tumoral region for disease characterization. In this work, we explore association of peri-tumoral radiomic features of prostate extracted from mpMRI with D’Amico risk. Additionally, we explore morphologic basis of these peri-tumoral features by analyzing the region on whole mount pathology. We observed greater epithelial content in high-risk compared to low, intermediate-risk lesions and vice versa with stroma. This heterogeneity within the peri-tumoral region may be captured by radiomic features that suggest peri-tumoral region of prostate may contain important information associated with risk of prostate cancer progression. |
9:09
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Advances in Image Acquisition | |
1UCSF, San Francisco, California, United States |
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Existing prostate cancer imaging and processing techniques are constantly improving, while new ones are being developed. This talk will focus on the potential benefits of four techniques: hybrid multidimensional MR imaging, luminal water imaging, multi-shot diffusion-weighted imaging, and restriction spectrum imaging. |
| 377 | 9:39
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Prospects of a Dedicated Nonlinear Gradient for Prostate DWI |
1Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States |
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DWI is a crucial contrast for prostate cancer, not only for detection but also biopsy guidance and monitoring. Unfortunately, DWI of prostate is plagued by very low SNR, caused by the long TEs needed to encode diffusion with standard imaging gradients. Here we show that by abandoning typical requirements of an imaging gradient, especially nonlinearity, very strong diffusion weighting can be locally achieved using a single standard amplifier, greatly improving DWI image quality. Experiments verify the feasibility of DWI with nonlinear gradients. Though prostate is an ideal first target, this approach could find application in many other organs. |
| 378 | 9:51
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Evaluation of Prostate Cancer Detection using Modified MR Dispersion Imaging |
1Radiological Sciences, University of California, Los Angeles, Los Angeles, CA, United States |
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A modified version of MR dispersion imaging, mMRDI, is introduced to achieve an effective estimation of intravascular dispersion parameter while maintaining low computational complexity. A total of 53 patients who underwent 3T mp-MRI exams prior to |
| 379 | 10:03
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Evaluation of an eight element AIR coil array for MRI in the prostate |
1Department of Radiology, Mayo Clinic, Rochester, MN, United States |
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Obtaining sufficient SNR in MRI of the prostate can be problematic without the use of an endorectal coil (ERC). We have constructed a lightweight, highly flexible receive-only surface coil array consisting of 8 recently developed AIR coil elements (GE Healthcare, Waukesha, WI, USA). This work compares the AIR coil array to commercial arrays commonly used for prostate imaging with and without the inclusion of an ERC. Initial phantom results show that the AIR coil array has approximately 2.5-3× higher SNR than the GE 32 channel anterior body/GEM posterior array when no ERC is used and approaches ERC SNR performance. |
10:33
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Adjournment |
| 380 | 8:15
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The Role of Diffusion Tensor Imaging in the Characterisation of Paediatric Brain Tumours - a Multi-Centre Study |
1Institute of Cancer and Genomic sciences, The University of Birmingham, Birmingham, United Kingdom, 2Birmingham Children's Hospital, Birmingham, United Kingdom, 3School of Life and Health sciences, Aston University, Birmingham, United Kingdom, 4Department of Radiology, Alder Hey Children's NHS Foundation Trust, Liverpool, United Kingdom, 5Institute of Digital Healthcare, WMG, University of Warwick, Coventry, United Kingdom, 6Institute of Child Health, Great Ormond Street Hospital, London, United Kingdom, 7Paediatric Oncology Department, Great North Children’s Hospital, Newcastle upon Tyne, United Kingdom, 8Neuroradiology Department, Newcastle upon Tyne Hospitals, Newcastle upon Tyne, United Kingdom, 9The Children‘s Brain Tumour Research Centre, University of Nottingham, Nottingham, United Kingdom |
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CNS tumours are the most common solid tumour in paediatrics and the most common cause of childhood cancer deaths. The diagnostic role of Diffusion Tensor Imaging (DTI) in patients with either medulloblastoma (MB), pilocytic astrocytoma (PA) or ependymoma (EP) was investigated. Fractional anisotropy (FA) and mean diffusivity (MD) means were found to be significantly different between tumour groups, as determined by one-way ANOVA (p=0.0002 and <0.0001). MD distributions enabled classification of tumour type, using linear discriminant analysis (LDA), with an average accuracy of 80%. DTI metrics were shown to provide an insight into the structure of paediatrics CNS tumours with LDA classification using MD demonstrating improved accuracy over FA. |
| 381 | 8:27
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New insights into the development of white matter microstructure across childhood and adolescence from ultra-strong gradients |
1Developmental Imaging, Murdoch Children's Research Institute, Parkville, Australia, 2Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, United Kingdom, 3Department of Paediatrics, University of Melbourne, Parkville, Australia, 4School of Psychology, Australian Catholic University, Melbourne, Australia |
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Recent advancements in diffusion-weighted imaging analysis techniques, such as fixel-based analysis (FBA), have improved our understanding of fibre-specific patterns of white matter development over childhood. Here, we investigate differential patterns of fibre properties with age and sex, using multiple b-value sampling schemes. The body of the corpus callosum and cingulum undergo significant development over the ages of 8-18, and FBA was robust to these patterns across sampling schemes. However, apparent fibre density (AFD) may be overestimated in clinical sampling schemes for older children, suggesting that higher b-values may improve AFD estimation in emerging complex fibre configurations developing with age. |
| 382 | 8:39
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White matter fibrography of the extremely preterm brain: longitudinal connectome changes from childhood to adolescence. |
1Boston University, Boston, MA, United States, 2Boston University Medical Center, Boston, MA, United States, 3University of North Carolina at Chapel Hill Medical Center, Chapel Hill, NC, United States |
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Purpose: To study comparatively and longitudinally the connectome changes from childhood (age 10 years) to adolescence (age 15 years) using white matter fibrography (WMF). Methods: WMF was used to generate the connectomes of 9 extremely preterm born individuals using MRIs obtained at ages 10 and 15 years. Results: The most noticeable connectome change was a marked increase in the fiber density accompanied by fiber thinning. Conclusion: As anticipated, WMF connectomics of the extremely preterm brain demonstrate clearly observable WM architectural changes from 10 to 15 years of age from sparse fiber-thick to dense fiber-thin. |
| 383 | 8:51
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Evaluation of multi-shell diffusion MRI acquisition strategy on quantitative analysis of multi-compartment models |
1Yerkes Imaging Center, Emory University, ATLANTA, GA, United States |
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Multi-shell diffusion MRI (dMRI) allows for analyzing the water diffusion signal using multi-compartment diffusion models, providing more specific characterization of tissue microstructure in grey matter and white matter than standard diffusion tensor imaging (DTI). However, the traditional multi-shell dMRI data acquisition usually demands high gradient strength and long scanning duration and its application is hindered for subjects like fetuses and infants in which fast imaging and reduced gradient strength is required. In the present study, the quantification analysis of NODDI and DBSI was evaluated using different hybrid diffusion imaging (HYDI) acquisition strategy for fast imaging on a clinical 3T setting. The results demonstrated that the data acquisition time for multi-shell dMRI can be reduced dramatically using HYDI gradient encoding strategy, while the quality of derived NODDI, DBSI, and DTI indices is generally maintained, suggesting quantitative analysis of multi-compartment models are applicable for developmental study of whole brain fetuses and infants by using multi-shell dMRI with HYDI encoding scheme.
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| 384
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9:03
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Electrocorticography-combined diffusion tract quantification model to improve benefit-risk assessment in pediatric epilepsy surgery |
1Pediatrics and Translational Imaging Laboratory, Wayne State University School of Medicine, Detroit, MI, United States, 2Translational Neuroscience Program, Wayne State University School of Medicine, Detroit, MI, United States, 3Pediatrics, Neurology and Translational Imaging Laboratory, Wayne State University School of Medicine, Detroit, MI, United States, 4Pediatrics and Neurology, Wayne State University School of Medicine, Detroit, MI, United States |
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The present study proposes a novel diffusion weighted imaging (DWI) tract classification methodology which integrates DWI-maximum a posteriori probability (DWI-MAP) analysis with Kalman filter in order to predict an optimal margin of cortical resection balancing postoperative benefit (seizure freedom) and risk (motor deficit in face, hand and leg) in pediatric epilepsy surgery. The predicted margins provided high Fisher’s exact test probability, 0.92 (0.94) of successful avoidance of motor deficits with (or without) seizure freedom. This finding demonstrates the translational value of a DWI tract classification approach in quantitative benefit-risk assessment to achieve ultimate goal of pediatric epilepsy surgery. |
| 385 | 9:15
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Early identification of neonatal mild hypoxic-ischemic encephalopathy by Amide Proton Transfer magnetic resonance imaging: A Pilot Study |
1Medical Image Center, Nanfang Hospital, Southern Medical University, Guangzhou, China, 2Philips Healthcare, Guangzhou, China |
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Neonatal hypoxic-ischemic encephalopathy (HIE) is a major complication of perinatal asphyxia, with high morbidity and morbidity. APT imaging is a potential technique for detecting in vivo characterization of the internal environment during hypoxic-ischemic brain injury. We investigated the feasibility of APT in differentiating neonatal mild HIE from normal age-matched infants, and to explore the changes in the internal environment in neonatal mild HIE. The results indicate that APT imaging for neonatal mild HIE is a useful and feasible technique with diagnostic capability. |
| 386 | 9:27
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Long half-life of propylene glycol in neonatal brain: an MRS study |
1Radiology and Nuclear Medicine, Amsterdam UMC, Location VUMC, Amsterdam, Netherlands, 2Pediatrics / Neonatology, Amsterdam UMC, Location VUMC, Amsterdam, Netherlands, 3Child Neurology, Amsterdam UMC, Location VUMC, Amsterdam, Netherlands, 4Pharmacy, Erasmus MC - Sophia Children's Hospital, Rotterdam, Netherlands |
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Neonatal convulsions are preferably treated with intravenous phenobarbital that contains propylene glycol (PG) as solvent. Very high concentrations of brain PG have been observed with quantitative MRS, especially when low-concentrated phenobarbital medication was used. PG can have serious adverse effects, and the half-life is longer in neonates than in adults. Based on given medication and the interval until MRS examination we estimated a PG half-life in neonatal brain that is at least 30 hours and maybe up to 43 hours. This shows that extremely high and potentially toxic PG concentrations will persist longer than expected in the neonatal brain. |
| 387 | 9:39
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A MR-based nomogram for predicting cerebral palsy in periventricular leukomalacia children before 2 years old |
1The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China, 2The First Affiliated Hospital of Henan University of traditional Chinese Medicine, Zhengzhou, China, 3Xi’an Children Hospital, Xi'an, China, 4GE Healthcare, Bei Jing, China |
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Early identification of cerebral palsy (CP) in children with periventricular leukomalacia (PVL) is crucial for prescribing the indispensable treatment and rehabilitation. In this study, we visually assessed PVL-associated MR signs, i.e. T2/T2 Flair hyperintense in the centrum ovale, posterior limb of internal capsule, pedunculus cerebri and thalamus, and found they were independent predictors of CP. Based on these signs, a MR-based nomogram for predicting CP in PVL children aged less than 2 yr was developed. Results indicated that the area under receiver operating characteristic curve, sensitivity and specificity for this nomogram were 0.921, 91.2% and 83.3%, respectively. These suggested the potential role of our MR nomogram in predicting the CP outcome of PVL children before 2 years old. |
| 388 | 9:51
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Silent MR Can Improve the Success Rate of Infant Examination: The Application Value of an MRI Acoustic Reduction Technique in Infants |
1Subei Peoples Hospital of Jiangsu Province, Jiang Su Yang Zhou, China, 2Subei Peoples Hospital of Jiangsu Province, YangZhou, China, 3GE Healthcare, MR Research, Beijing, China |
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Although the data for the objective image quality of silent MR do not correspond with the subjective image quality scores, these data can greatly improve the success rate of the examination, reduce acoustic noise, improve patient comfort, and allow for higher overall diagnostic usefulness when compared with those of conventional MR. In summary, silent MR is more suitable for the infant brain than conventional MR. |
| 389 | 10:03
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A 24-channel head and spine array for 3T pediatric MRI under 3-year-old |
1Lauterbur Imaging Research Center,Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China, 2Shenzhen Key Laboratory for MRI, Shenzhen, China, 3Shanghai United Imaging, Shanghai, China, 4Department of Radiology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China, 5Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, 6UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, CA, United States |
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Pediatric MRI is an important tool for clinical diagnosis and research. It demands high spatial resolution and short scan time to increase success rates. To obtain high resolution images within resonable scan time, a dedicated 24-channel head and spine coil array was designed and fabricated for patient under 3-year-old in this work. Compared to a commercial 24-channel head and neck adult coil, the proposed coil offers higher resolution, image quality and shorter scan time in patient studies. |
| 390 | 8:15
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To discriminate glioblastoma from solitary brain metastasis with inflow-based vascular-space-occupancy (iVASO): comparison with dynamic susceptibility contrast MR imaging |
1Department of Medical Imaging, Nanfang hospital, Southern Medical University, Guangzhou, China, 2School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China, 3Division of CT & MR, Radiology Department, First Affiliated Hospital of Gannan Medical University, Ganzhou, China, 4Philips Healthcare, Guangzhou, China, 5Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 6Neurosection, Division of MRI Research, Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 7Division of Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Johns Hopkins Hospital, Baltimore, MD, United States, 8Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, United States |
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Accurate differentiation between GBM and SBM is of vital importance clinically. DSC-MRI cannot differentiate them accurately using measures derived from tumoral regions. Moreover, DSC-MRI requires gadolinium contrast agent administration. Inflow-based vascular-space-occupancy (iVASO) is a novel perfusion technique without the need for exogenous contrast agents. In this study, the capability of iVASO in differentiating GBM and SBM was investigated and compared with that of DSC-MRI. The results showed that iVASO-based measures within tumoral regions could differentiate them accurately. This suggests that iVASO may be used as an alternative for perfusion study on brain tumor. |
| 391
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8:27
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MRI-based Oxygen Extraction Fraction and Cerebral Metabolic Rate of Oxygen Mapping in High-Grade Glioma Using a Combined Quantitative Susceptibility Mapping and Quantitative Blood Oxygenation Level-Dependent Approach |
1Computer Assisted Clincial Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany, 2Department of Biomedical Engineering, Cornell University, Ithaca, NY, United States, 3Department of Radiology, Weill Cornell Medical College, New York, NY, United States, 4Department of Radiology, Tongji Hospital, Wuhan, China |
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MRI-based oxygenation mapping would be beneficial for treatment planning of high-grade gliomas. We used dynamic contrast-enhanced imaging and a combined quantitative susceptibility mapping and blood oxygenation level-dependent approach to quantify the oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2) in 6 patients with glioblastoma multiforme and 2 with anaplastic astrocytoma. Robust reconstruction of physiologically meaningful uniform OEF maps in healthy tissue was achieved and OEF was significantly lower in the tumor compared to the contralateral side. Blood flow was significantly higher in the tumor only for glioblastoma multiforme. CMRO2 showed no significant differences. |
| 392 | 8:39
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Investigating the Influence of DSC-MRI Acquisition Methods on the Clinical Application of Percentage Signal Recovery in Brain Tumors |
1Division of Neuroimaging Research, Barrow Neurological Institute, Phoenix, AZ, United States, 2Alpert Medical School Brown University, Providence, RI, United States, 3Department of Diagnostic Imaging, Rhode Island Hospital, Providence, RI, United States |
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Percentage signal recovery (PSR) derived from DSC-MRI has been shown to exhibit unique properties between enhancing malignant lesions, due to T1 and T2* contrast agent leakage effects. |
| 393
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8:51
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Synthesizing rCBV maps from DCE-MRI of brain tumors using conditional adversarial networks |
1Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, TX, United States, 2Diagnostic Radiology, University of Texas MD Anderson Cancer Center, Houston, TX, United States |
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In this work we investigate conditional adversarial networks for synthesizing relative cerebral blood volume (rCBV) maps from dynamic contrast enhanced (DCE)-MRI. A network based on the pix2pix framework is trained to map DCE-MRI to rCBV maps using rCBV maps generated from dynamic susceptibility contrast (DSC)-MRI in the same patient cohort. The results demonstrate the feasibility of synthesizing realistic rCBV maps from DCE images, potentially improving MR perfusion imaging of the brain using a single contrast injection. |
| 394 | 9:03
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Evaluation of Single Bolus, Multi-Echo Dynamic Susceptibility Contrast Protocols in Brain Tumor Patients |
1Neuroimaging Research, Barrow Neurological Institute, Phoenix, AZ, United States, 2Radiology, Barrow Neurological Institute, Phoenix, AZ, United States, 3Department of Radiology, Mayo Clinic Arizona, Phoenix, AZ, United States |
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Relative cerebral blood volume (rCBV) obtained from dynamic susceptibility contrast (DSC) MRI is adversely impacted by contrast agent leakage in brain tumors. Using a digital reference object, we previously demonstrated that multi-echo DSC-MRI protocols provide advantages in terms of contrast agent dosing, pulse sequence flexibility, and rCBV accuracy. The purpose of this study is to assess the in-vivo performance of multi-echo acquisitions in patients with brain tumors. Multi-echo rCBV obtained without a preload is compared to the standard single-echo rCBV obtained with preload. In addition, two contrast agent doses and two flip angles are compared for the multi-echo acquisition. |
| 395 | 9:15
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Evaluation of Fractional Tumor Burden (FTB) fidelity using a no-preload, low-flip angle dynamic susceptibility contrast MRI acquisition scheme |
1Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States, 2Radiology, Mayo Clinic Arizona, Phoenix, AZ, United States, 3Diagnostic Imaging, Rhode Island Hospital, Providence, RI, United States, 4Imaging Research, Barrow Neurological Institute, Phoenix, AZ, United States, 5Neurology, Medical College of Wisconsin, Milwaukee, WI, United States, 6Radiology, Medical College of Wisconsin, Milwaukee, WI, United States |
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This study examines the fidelity of a no pre-load, low flip-angle (LFA) dynamic susceptibility contrast MRI acquisition approach in the calculation of Fractional Tumor Burden (FTB) maps, which have shown promise as a predictive biomarker in glioblastoma patients. The LFA approach was recently identified as providing similar accuracy to the standard mid-range flip-angle approach with preload. FTB was found to have robust quantitative and spatial agreement between LFA and MFA approaches. The results of this study bode well for increased adoption of FTB as a biomarker amenable to both the standard and newer LFA approach. |
| 396 | 9:27
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Detection of fluid/solid tissue behavior of neurotumors by magnetic resonance elastography |
1Charité - Universitätsmedizin Berlin, Berlin, Germany, 2University Leipzig, Leipzig, Germany, 3University Hospital Leipzig, Leipzig, Germany, 4Neuroradiology Center, Erfurt, Germany, 5Radiology, Charité-Universitätsmedizin Berlin, Berlin, Germany |
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It is known that glioblastoma (GB) display high heterogeneity and porosity (higher water content) than meningioma (MEN) suggesting a higher fluidity of GB than MEN. However, we will demonstrate by MR elastography (MRE) in patients and phantoms that the concept of fluidity cannot be naively transferred to brain tumors. Instead, the macroscopic viscosity-fluidity behavior of GB and MEN can be understood MRE of materials that comprise various amounts of water including materials with fibrillary architecture such as tofu. Similar to tofu, viscosity and fluidity in GB and MEN seem to reduce with increasing water content, indicating an ‘anomalous’ viscosity-fluidity behavior. |
| 397 | 9:39
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T1, T2 relaxometry for tissue cell density quantification in glioma imaging: Exploration study via 11C-methionine PET and its validation via stereotactic tissue sampling |
1Neurosurgery, Osaka International Cancer Institute, Osaka, Japan, 2Canon Medical Systems Corporation, Tochigi, Japan, 3Diagnostic and Interventional Radiology, Osaka International Cancer Institute, Osaka, Japan, 4Institute for Clinical Research, Osaka National Hospital, Osaka, Japan, 5Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, Suita, Japan, 6Diagnostic Pathology and Cytology, Osaka International Cancer Institute, Osaka, Japan, 7Neurosurgery, Osaka University Graduate School of Medicine, Suita, Japan |
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In this study, the authors attempted to use T1, T2 relaxometry for predicting tumor cell density within the brain in glioma patients. The study was conducted in two stages, first as an exploratory study comparing T1, T2 relaxometry and 11C-methinonie PET images, and second as a validation study using intraoperative stereo-tactically obtained tissues. The authors were able to identify a range of T1 and T2 relaxation time indicative of high cell density, which finding was confirmed by stereotactic tissue sampling. This technique was further able to create predictive tumor cell density map by T1, T2 relaxometry alone. |
| 398
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9:51
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Differentiation of IDH1 mutant and wild-type gliomas based on metabolic signatures obtained from pH- and oxygen-sensitive molecular MRI |
1Brain Tumor Imaging Laboratory (BTIL), Center of Computer Vision and Imaging Biomarker, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 2Department of Bioengineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, Los Angeles, CA, United States, 3Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 4Department of Neurosurgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 5UCLA Brain Research Institute (BRI), David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 6Brain Tissue Translational Resource (BTTR), David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 7Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 8Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 9Physics and Biology in Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 10Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States |
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In the current study, we have demonstrated that pH- and oxygen-sensitive amine CEST-SAGE-EPI (chemical exchange saturation transfer spin-and-gradient-echo echoplanar imaging) is a clinically feasible, powerful imaging technique for distinguishing between IDH1-mutant and wild-type gliomas. Results suggest that IDH1 mutation is associated with lower MTRasym at 3.0ppm and lower R2’, implying lower acidity and vascular hypoxia. We hypothesize that 2-HG produced by IDH1-mutant activates PHD and the degradation of HIF1α, subsequently preventing a metabolic shift from oxidative phosphorylation to glycolysis. This is supported by our histological findings of loss of correlation between levels of hypoxia and HIF1α tissue expression in IDH1 mutants. |
| 399
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10:03
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Quantitative intra-tumoral-susceptibility-signal (ITSS) vasculature volume (IVV) using QSM vs R2* approach for Glioma Grading |
1Center for Biomedical Engineering, Indian Institute of Technology, Delhi, NEW DELHI, India, 2Philips Health Systems, Philips India Limited, Gurugram, India, 3Health Systems, Philips India Limited, Philips Innovation Campus, Bangalore, India, 4Department of Radiology, Fortis Memorial Research Institute, Gurugram, India, 5Department of Biomedical Engineering, All India Institute of Medical Science, New Delhi, India |
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Susceptibility-weighted imaging (SWI) improves the diagnostic accuracy by detecting intra-tumoral-susceptibility-signal-intensities (ITSS). Existing semi-quantitative methods are observer-dependent which manually counts intra-tumoral-susceptibility-signal-intensities (ITSS); a combination of haemorrhage and vasculature. |
| 400 | 8:15
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Free Breathing Isotropic Cardiac Diffusion Tensor MRI of the Left Ventricle Using M2-gSlider: Unfolding the Fiber Architecture of the Human Heart |
1Department of Medicine, Harvard Medical School, Charlestown, MA, United States, 2Cardiovascular Research Center, Massachusetts General Hospital, Charlestown, MA, United States, 3Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 4Department of Radiology, Harvard Medical School, Charlestown, MA, United States, 5Cardiovascular Institute, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, United States, 6Department of Computer Science, University of São Paulo, São Paulo, Brazil |
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Free breathing isotropic cardiac diffusion tensor MRI (DT-MRI) of the entire left ventricle was achieved by combining two recently-developed technologies: second moment (M2) motion compensated spin echo encoding and generalized slice dithered enhanced resolution (gSlider). M2-gSlider can address cardiac motion-induced signal loss under free breathing and can achieve isotropic spatial resolution of 2.5 mm. With spatial resolution three times that of conventional cardiac DT-MRI, the precision of tractography-based indices can be improved. Furthermore, isotropic acquisition eases the interpretation of myocardial fiber architecture including in an “unfolded” representation, depicting both circumferential and longitudinal microstructure in a planar format. |
| 401
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8:27
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Fast and Accurate Free-Breathing Whole-Heart 3D T2 Mapping |
1School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 2MR Research Collaborations, Siemens Healthcare Limited, Frimley, United Kingdom |
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T2 mapping is a promising quantitative imaging technique for the detection of myocardial edema. Conventionally, T2 mapping is performed using T2-prepared single-shot 2D acquisitions, acquiring multiple slices in several breath-holds. While showing high accuracy and reproducibility, breath-holding limits achievable spatial resolution and heart coverage and can be challenging in very sick patients. Here we propose a free-breathing whole-heart 3D T2 mapping technique with high isotropic spatial resolution in a clinically feasible scan time. This is achieved by combining an accelerated T2-prepared acquisition with patch-based reconstruction and dictionary-based signal matching. Feasibility of the proposed method was investigated in a standardized T1/T2 phantom and healthy subjects. |
| 402 | 8:39
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Motion-corrected 3D high-resolution fat-water imaging of the heart |
1Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany, 2Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, Padua, Italy, 3Charité Medical Faculty University Medicine, Berlin, Germany, 4Working Group on Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center (ECRC), DZHK partner site Berlin, Berlin, Germany, 5Department of Cardiology and Nephrology, HELIOS Klinikum Berlin Buch, Berlin, Germany |
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Fat infiltration in the myocardium is of great clinical interest as potential predictor of poor prognosis in patients with either ischemic or non-ischemic cardiac diseases. Commonly, 2D chemical shift encoded MR methods are used to obtain fat-water separated images. Nevertheless, fat infiltrations are often small and hence could be missed due to poor slice resolution. Here we propose a free-breathing 3D whole-heart fat-water imaging approach with an isotropic resolution of 1.5mm3, which uses respiratory motion correction and retrospective cardiac gating. The approach was evaluated in five patients demonstrating accurate visualisation of the heart and small fat infiltrations in the myocardium. |
| 403 | 8:51
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Fast T1, T2 evaluation with machine learning for quantitative cardiac MRI |
1College of Control Science and Engineering, Zhejiang University, Hangzhou, China, 2Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States |
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Quantitative T1/T2 mapping provides important cardiovascular prognostic value. Conventional dictionary-matching based methods are time consuming for cardiac T1/T2 mapping as the dictionary need to be generated on-line. In this work, we propose to use machine learning algorithms for faster T1/T2 prediction. Bloch equation simulation was used to generate training data. The XGBoost and DNN models were evaluated and compared based on simulation, phantom and in vivo studies. Results demonstrated that using the machine learning approach can generate cardiac T1 and T2 maps much faster while generating similar T1 and T2 values compared to the conventional dictionary-matching approach. |
| 404 | 9:03
|
Diffusion tensor cardiovascular magnetic resonance in a Langendorff perfused beating porcine heart |
1Cardiovascular Magnetic Resonance Unit, The Royal Brompton Hospital and Imperial College London, London, United Kingdom, 2Department of Perfusion, The Royal Brompton Hospital, London, United Kingdom, 3Translational Biomedical Research Centre, University of Bristol, Bristol, United Kingdom, 4National Heart and Lung Institute, Imperial College London, London, United Kingdom, 5Magdi Yacoub Institute, Imperial College London, London, United Kingdom, 6Aeronautics, Imperial College London, London, United Kingdom |
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We have developed an MRI compatible Langendorff perfused beating isolated porcine heart model. Hearts are harvested and transported to a remote imaging centre, avoiding the need for onsite pre-clinical facilities. The model allows comparison of beating and arrested data in equivalent cardiac states. We performed cine imaging, parametric mapping and diffusion tensor cardiovascular magnetic resonance in the beating and arrested hearts. After MRI, co-localised 3D histology is performed. |
| 405 | 9:15
|
Combined Cardiac CINE and T1, T2, and M0 Mapping with MR Fingerprinting |
1Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 2Radiology, University Hospitals, Cleveland, OH, United States |
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A method is introduced for combined cardiac CINE and T1, T2, and M0 quantification using MR Fingerprinting throughout the cardiac cycle. Data are acquired continuously using an MRF acquisition and binned by cardiac phase using an external ECG. Undersampled MRF images from all TRs are non-rigidly registered to a consistent cardiac phase before pattern matching in order to generate CINE T1, T2, and M0 maps. CINE-MRF has a breathhold duration (10s) and temporal resolution (25 cardiac phases) similar to conventional CINE scans, while providing both relaxation time measurements and functional information. |
| 406
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9:27
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Magnetic susceptibility and T2* of myocardial reperfusion injury at 3 and 7 T |
1Bioengineering, University of Pennsylvania, Philadelphia, PA, United States, 2Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States, 3Physics and Astronomy, Wheaton College, Norton, MA, United States, 4Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States, 5Surgery, Columbia University, New York City, NY, United States, 6Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States |
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Intramyocardial hemorrhage is a frequent complication of acute myocardial infarction (MI) after reperfusion therapy. This study investigated the relationship between T2* and susceptibility and how they are affected by magnetic field strength. We compare cardiac quantitative susceptibility mapping (QSM) and T2* at 3 and 7 T and demonstrate improved detection of hemorrhage and infarct regions at 7 T in a large animal model correlating with infarct pathophysiology. |
| 407 | 9:39
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Hyperpolarised 13C MR Spectroscopy Demonstrates Impaired PDH flux In the Diabetic Human Heart, Correlating with Impaired Energetics, Relaxation and Increased Myocardial Lipid Content: A Multi–Nuclear Spectroscopy Study. |
1Oxford Centre for Magnetic Resonance Research, Oxford, United Kingdom, 2Department of Physiology, Anatomy and Genetics., University of Oxford, Oxford, United Kingdom, 3School of Life Sciences, Coventry University, Coventry, United Kingdom, 4Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada |
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Hyperpolarised 13C MRS offers unparalleled opportunities for studying in-vivo, real time metabolism. In our current study we demonstrate how the technique easily demonstrates early pathological changes in PDH flux in the diabetic heart, and is complementary to other spectroscopic and imaging techniques, in defining the metabolic and structural changes characterising the disease. |
| 408
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9:51
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Cardiac dark-blood T2 mapping increases effective myocardial thickness by 35-75% for T2 evaluation in healthy subjects and patients |
1Yale University, New Haven, CT, United States |
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Cardiac dark-blood T2 mapping is an emerging technique to measure myocardial T2 with simultaneous suppression of blood pool and pericardial fat. In this work, we compared dark-blood T2 mapping with conventional bright-blood T2 mapping in terms of accuracy, precision, and effective myocardial thickness, in 8 healthy subjects and 7 patients. We found similar accuracy and precision between the two T2 mapping methods, but a largely improved effective myocardial thickness with dark-blood T2 mapping, due to reduced partial-voluming. The increased thickness may improve the accuracy of T2 in thin-walled structures for clinical evaluation. |
| 409
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10:03
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Free-running 3D Whole Heart Myocardial T1 Mapping with High Isotropic Spatial Resolution |
1School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 2Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, China |
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Myocardial T1 mapping provides quantitative tissue characterization for the assessment of various cardiomyopathies. However, currently available myocardial T1 mapping techniques still have several limitations such as insufficient coverage, low spatial resolution, and the need of acquiring the data under multiple breath-holds. To overcome these problems, here we propose a free-running (free-breathing, no ECG gating) 3D whole heart T1 mapping technique with high isotropic spatial resolution. This approach allows for myocardial T1 mapping at arbitrary cardiac phases, enabling high-resolution dynamic T1 maps. The feasibility of the proposed sequence was validated against conventional methods in phantom and five healthy subjects. |
| 410
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8:15
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In Vivo Diffusion MRI Evaluation of Human Patellar Tendon Microstructure and Microcirculation |
1Biomedical Engineering, Stony Brook University, Stony Brook, NY, United States, 2Radiology, Stony Brook University, Stony Brook, NY, United States, 3Orthopaedics, Stony Brook University, Stony Brook, NY, United States |
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The patellar tendon (PT) is essential for knee extension and patellar tendinopathy causes persistent knee pain in ~14% of recreational athletes. Microstructure and microcirculation play a critical role in the progression of tendinopathy and can be non-invasively assessed by DTI and IVIM MRI, respectively. In this study, the novel ste-RS-EPI diffusion MRI protocol originally developed for Achilles tendon imaging was applied to image healthy PT. For the first time, DTI and IVIM images were acquired of PT for microstructure and microcirculation evaluation. |
| 411 | 8:27
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Advantages of tractography for the evaluation of intramuscular variances in human thigh muscles |
1Neurology, BG-University Hospital Bergmannsheil, Bochum, Germany, 2Radiology, University Medical Center Utrecht, Utrecht, Netherlands |
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Muscle diffusion tensor imaging can indirectly provide information about muscular microstructure and architecture, which plays an increasing role in the evaluation of neuromuscular disease progression and treatment monitoring. The separation of different muscles is essential to evaluate intermuscular differences and variances. Here we have compared three methods to assess diffusion metrics of thigh muscles and showed, that tractography shows less variance in diffusion metrics than parameter maps. For the observed parameters FA, MD, RD and λ1 we found significant main effects of muscle, when using tractography, which was not found with manual annotation using ROI assessment of the parameter maps. |
| 412
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8:39
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Quantitative multi-parametric MRI reveals micro-structural changes in upper-leg muscles after running a marathon |
1Department of Biomedical Engineering and Physics, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands, 2Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands, 3Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 4Radboud Institute for Health Sciences, Department of Physiology, Radboud University Medical Center, Nijmegen, Netherlands |
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Quantitative MR techniques have shown promise for detection of muscle micro trauma. Muscle injury and recovery involve many pathophysiological processes including, inflammation, regeneration and fibrosis, therefore multi-parametric approaches are critically needed. This study used a multi-parametric quantitative approach to assess micro structural changes in the upper leg muscles after running a marathon on an individual muscle basis as well as on a localized level. Our results indicate that diffusion indices are highly sensitive to detect micro-structural changes on a localized and whole volume basis and that this approach could prove valuable for improved outcome prediction and risk-assessment of sports-related-injuries. |
| 413
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8:51
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Phosphocreatine recovery in the human tibialis anterior after dynamic exercise shows a proximo-distal gradient, which is not explained by acetylcarnitine differences. |
1Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, Netherlands |
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The phosphocreatine (PCr) recovery rate of the tibialis anterior muscle after isometric exercise shows a strong gradient along the length of the muscle. In this study we demonstrate that this also holds for dynamic exercise of the TA. To further examine if mitochondrial metabolism is involved we determined acetylcarnitine (AC) levels along the length of the TA, but no differences were detected. Together with previous correlations found for blood oxygenation by NIRS experiments and perfusion by IVIM we conclude that muscle perfusion and oxygenation are main components determining the PCr recovery gradient in the TA. |
| 414
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9:03
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Simultaneous Measurement of Perfusion and T2* in Calf Muscle at 7T with Dynamic Exercise using Radial Acquisition. |
1Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, United States, 2School of Kinesiology, Auburn University, Auburn, AL, United States, 3Department of Physical Therapy, University of Alabama at Birmingham, Birmingham, AL, United States |
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Impairments in oxygen delivery and consumption can lead to reduced muscle endurance and physical disability. Perfusion, a measure of microvascular blood flow, provides information on nutrient delivery. T2* provides information about relative tissue oxygenation. Changes in these parameters following stress, such as exercise, can yield important information about imbalance between delivery and consumption. In this study we implemented golden angle radial MRI acquisition technique to simultaneously quantify muscle perfusion and T2* at 7T, and demonstrate assessment of spatial and temporal changes in these parameters within calf muscles during recovery from plantar flexion exercise. |
| 415 | 9:15
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Mapping of Muscle Strain Rate at Varying Force Levels of Isometric Contraction, with Compressed-Sensing Velocity-Encoded Phase-Contrast MR Imaging. |
1Radiology, UC San Diego, San Diego, CA, United States, 2Physics, UC San Diego, San Diego, CA, United States, 3Physics, San Diego State University, San Diego, CA, United States |
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Strain rate (SR) tensor mapping can be conveniently computed from velocity encoded phase contrast (VE-PC) imaging. The study of the variation of strain rate indices with force output (% Maximum Voluntary Contraction (MVC)) can provide additional information similar to stress-strain relationships measured at the whole muscle level. However, such studies have been limited by the long VE-PC sequence time precluding its use at high MVCs. We have developed a compressed sensing VE-PCI technique to enable acquisitions across a range of MVCs. Successful SR mapping for 30-70%MVC on six subjects is reported here. |
| 416 | 9:27
|
Quantitative MR Relaxation Imaging of Cartilage Compositional Response to Exercise |
1Department of Radiology, University of Cambridge, Cambridge, United Kingdom, 2Independent Clinical Imaging Consultant, Munich, Germany, 3Experimental Medicine Imaging, GlaxoSmithKline, London, United Kingdom |
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We introduce a method for imaging changes in healthy knee cartilage composition after joint loading with exercise that could be extended for use in subjects with joint disease. Six healthy participants were imaged before and at multiple time-points after a mild joint loading exercise. Our study demonstrates that quantitative MR mapping of T1ρ and T2 relaxation times of femorotibial cartilage is repeatable and able to demonstrate changes in cartilage composition in response to short-term joint loading exercise. Imaging cartilage compositional recovery after joint loading may present a new way of detecting early alterations in cartilage homeostasis associated with osteoarthritis. |
| 417 | 9:39
|
Quantification of patellofemoral cartilage deformation and contact area changes in response to static loading via high-resolution MRI with prospective motion correction |
1Dept. of Radiology, Medical Physics, Medical Center - University of Freiburg, Freiburg, Germany, 2Department of Informatics, Medical Image Computing Group, University of Bremen, Bremen, Germany, 3Institute for Medical Image Computing, Fraunhofer MEVIS Bremen, Bremen, Germany, 4Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 5Department of Orthopedic and Trauma Surgery, Medical Center – University of Freiburg, Freiburg, Germany |
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Patellofemoral cartilage deformation and contact area changes in response to in situ loading were measured with high-resolution MRI. In situ loading was realized with a pneumatic loading device and motion artifacts were corrected with prospective motion correction based on optical tracking of the knee cap. Semi-automatic cartilage segmentation based on deep learning proved essential for robust quantification of the load-induced changes. Cartilage thickness and contact area showed significant and weight-dependent changes in response to loading. The patellofemoral deformation and contact mechanism under loading might be used for investigation of the knee biomechanics and as a biomarker of early-stage cartilage degeneration. |
| 418
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9:51
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Detecting articular cartilage and meniscus deformations under mechanical load using magnetization transfer ultrashort echo time (MT-UTE) modeling: ex vivo study |
1Radiology, University of california, San Diego, San Diego, CA, United States, 2Radiology Service, VA San Diego Healthcare System, San Diego, CA, United States |
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Ultrashort echo time (UTE) MRI can be used for quantitative assessment of compressive tissues in knee joint such as articular cartilage (AC) and meniscus. In osteoarthritis, the mechanical properties of AC and menisci are altered prior to gross morphological changes. In this study, magnetization transfer UTE imaging (UTE-MT) with two-pool modelling was used to detect deformation levels of AC and meniscus under load. Compression resulted in significant increases of macromolecular fraction (MMF) in AC and menisci of young, but not elderly donors. Our results indicate that biomechanical changes vary with age and can be detected with UTE-MT MRI. |
| 419 | 10:03
|
Magic-Angle Effect on In Vivo T2 Mapping of Cartilage |
1Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland, 2Medical Research Center, University of Oulu and Oulu University Hospital, Oulu, Finland, 3Department of Applied Physics, University of Eastern Finland, Kuopio, Finland, 4Center for Magnetic Resonance Research, Minneapolis, MN, United States, 5Department of Radiology, University of Minnesota, Minneapolis, MN, United States, 6Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland, 7Department of Applied Physics, University of Eastern Finland, Oulu, Finland |
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| 420 | 8:15
|
Biophysically motivated efficient estimation of spatially isotropic component from a single, standard gradient recalled echo measurement |
1Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, 2Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, 3Department of Education and Psychology - Neurocomputation and Neuroimaging Unit, Freie Universität Berlin, Berlin, Germany, 4Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany, 5Wellcome Centre for Human Neuroimaging, UCL Institute of Neurology, London, United Kingdom |
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Gradient recalled echo-based $$$R_{2}^{*}$$$ measurements are sensitive to the degree of myelination of white matter fibres and their local orientation inside the magnetic field of the MR scanner. This orientation dependence has been observed experimentally and could be explained biophysically by anisotropic susceptibility of the myelin sheaths. In case of single, quantitative $$$R_{2}^{*}$$$ measurements the orientation dependence represents a potential confounder, since the observed $$$R_{2}^{*}$$$ would be biased by the sample’s orientation inside the scanner. Here, we propose an efficient method for separating $$$R_{2}^{*}$$$ into orientation dependent and independent components based on a biophysically motivated higher order $$$R_{2}^{*}$$$ decay model. |
| 421
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8:27
|
Brain tissue multi-compartment relaxometry - An improved method for in vivo myelin water imaging |
1Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, Netherlands |
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In this study, we propose an extension to GRE based myelin water fraction techniques based on 3-comparment models. The new model includes T1 and chemical exchange effects between a free water pool and a myelin water pool and can be fitted to a variable flip angle acquisition strategy. Furthermore, we demonstrate that it can both correct the T1 dependency in MWF, make the fitting procedure less ill-posed and more SNR efficient, resulting in robust estimation across subjects. |
| 422 | 8:39
|
Noise sensitivity study of model-free rPCA in Myelin Water Fraction Mapping using multi-echo GRE |
1Department of Electrical and Electronic Engineering, Yonsei University, seoul, Korea, Republic of, 2Department of Radiology, Konkuk University Medical Center, Konkuk University School of Medicine, seoul, Korea, Republic of, 3Department of Radiology, Gangnam Severance Hospital, Yonsei University College of Medicine, seoul, Korea, Republic of |
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Recently, a robust principle component analysis (rPCA) method was implemented to myelin water fraction (MWF) mapping using mGRE data. Based on the intrinsic nature of T2* relaxation, hankelization and non-negative matrix factorization was implemented to enhance low rankness of each rank-1 component. In this study, the noise sensitivity of model-free rPCA was investigated. According to simulation and in vivo analysis, model-free rPCA technique is more robust at noise and other physiological artifacts than model-based fitting technique. |
| 423 | 8:51
|
Inherent bias in multi-component DESPOT myelin water fraction estimation. |
1Biomedical Engineering Department, School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 2Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 3Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom |
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mcDESPOT is a quantitative relaxometry technique that enables estimation of myelin water fraction (MWF) in a clinically feasible acquisition time with high signal-to-noise ratio efficiency. Many studies show in-vivo MWF maps with realistic grey matter-white matter contrast, which conflicts with statistical analyses suggesting that parameter estimation should be inaccurate and imprecise. We show that the parameters (including MWF) and their corresponding variance are indeed ill-conditioned, but their estimation is strongly influenced by the typically used fitting approach (stochastic region contraction). We also demonstrate that this degeneracy arises primarily from intercompartmental exchange. |
| 424 | 9:03
|
Multivariate template creation of a myelin water brain atlas with GRASE and mcDESPOT |
1Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada, 2International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada, 3Institute of Psychiatry, Psychology & Neuroscience, King's College, London, United Kingdom, 4Radiology, University of British Columbia, Vancouver, BC, Canada, 5Medicine, University of British Columbia, Vancouver, BC, Canada, 6Chemical and Biological Engineering, University of British Columbia, Vancouver, BC, Canada, 7Pediatrics, University of British Columbia, Vancouver, BC, Canada |
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Myelin water imaging (MWI) techniques provide metrics with high specificity to myelin content, and benefit greatly from an efficient, standardized method for data interpretation. In this study, high performance diffeomorphic normalisations are used to create a myelin water atlas; statistics related to MWI metrics at each point in a template space. Multivariate template creation methods were used to simultaneously leverage anatomical features from two popular MWI techniques (GRASE and mcDESPOT). The resulting multivariate myelin water atlas can be used in future studies with either technique and provides insight into their differences. |
| 425 | 9:15
|
Real-time processing of myelin water imaging using artificial neural network |
1Department of Electrical and Computer Engineering, Seoul National University, Seoul, Korea, Republic of |
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In this study, a real-time processing method for GRASE myelin water imaging is proposed by using an artificial neural network. Two different networks, one pairing multi-echo measurement with myelin water fraction and the other pairing multi-echo measurement with T2 distribution, were developed. Both networks took <1.5 sec for the whole brain processing (FOV = 240×180×112 mm3 and matrix = 160×120×28) with less than 5% error in white matter. |
| 426 | 9:27
|
The influence of temperature on two ex vivo myelin specific imaging protocols: Inhomogeneous Magnetization Transfer and Myelin Water Imaging |
1UBC MRI Research Centre, Vancouver, BC, Canada, 2International Collaboration on Repair Discoveries (ICORD), Vancouver, BC, Canada, 3Physics & Astronomy, University of British Columbia, Vancouver, BC, Canada, 4Department of Radiology, University of British Columbia, Vancouver, BC, Canada, 5MR Clinical Science, Philips Healthcare Canada, Markam, ON, Canada, 6Department of Pathology & Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada |
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The impact of temperature on inhomogeneous magnetization transfer (ihMT) measurements in formalin-fixed human brain was studied. White matter (WM) ihMT signal increased with temperature when a T1D-filter was applied, supporting the hypothesis that components with long T1D (>1ms) are more sensitive to temperature variations. Grey matter ihMT did not vary with temperature. This suggests a difference in T1D values between WM and GM, and confirms that several T1D components contribute to myelin ihMT. Myelin water fraction values decreased with increasing temperature, possibly due to faster exchange between water compartments. Temperature is an important factor to consider in order to characterize the microstructure. |
| 427 | 9:39
|
Steady-state imaging with “inhomogeneous” MT contrast |
1Biomedical Engineering Department, School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 2Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom |
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A matrix-based framework for modelling of inhomogeneous MT effects was developed for steady-state gradient echo sequences. This was applied to sequences using multi-band pulses that are designed to create some off-resonance saturation simultaneously with excitation of free water. Simulations and phantom results show that ihMT contrast can be achieved in this way, and in-vivo results show the expected strong white-matter contrast. |
| 428 | 9:51
|
Toward quantitative inhomogeneous magnetization transfer (qihMT) using a general Matrix Exponential Model |
1Aix Marseille Univ, CNRS, CRMBM UMR 7339, Marseille, France, 2Department of Radiology, Division of MR Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States, Boston, MA, United States |
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Inhomogeneous magnetization transfer is becoming an important tool in the detection of demyelinating pathologies, as well as in the understanding of the molecular mechanisms engaged in demyelinating/remyelinating processes. Although ihMT ratio delivers a reproducible index sensitive to the dipolar order underpinning the ihMT effect, advanced approaches analogous to quantitative MT could allow estimation of quantitative parameters directly related to the underlying biophysical model of myelin. This study proposes a general framework based on the Matrix Exponential Model allowing fast fitting of ihMT data. Demonstration of qihMT is performed ex-vivo on rat spinal cord specimen and in-vivo on mouse brain. |
| 429
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10:03
|
Fast Bound Pool Fraction mapping via steady-state MT saturation using single-shot EPI |
1Queen Square MS Centre, Department of Neuroinflammation, UCL Queen Square Institute of Neurology, Faculty of Brain Sciences, UCL, London, United Kingdom, 2Philips UK, Guilford, United Kingdom, 3Centre for Medical Imaging Computing, Department of Computer Science, UCL, London, United Kingdom, 4Centre for Medical Imaging Computing, Department of Medical Physics and Biomedical Engineering, UCL, London, United Kingdom, 5Universitat Oberta de Catalunya, Barcelona, Spain, 6Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy |
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The bound pool fraction (BPF) is a quantitative parameter that reflects macromolecular tissue fraction, and has shown sensitivity to myelin content in human white matter. BPF mapping is still largely unexploited for characterizing white matter disease in vivo due to the long MRI protocols needed for its accurate and precise computation. In this work, we develop a new method that allows fast unbiased BPF estimation, suitable for clinical applications. |
| 430
|
8:15
|
Toward Human Head Imaging at 10.5T Using an Eight-Channel Transmit/Receive Array of Bumped Fractionated Dipoles |
1Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey, 2National Magnetic Resonance Research Center (UMRAM), Ankara, Turkey, 3Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, United States, 4Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States |
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| 431
|
8:27
|
Design and implementation of a combined sodium-loop proton-dipole transceiver array for body imaging at 10.5 Tesla |
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 2Restorative Therapies Group, Medtronic, Minneapolis, MN, United States |
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A multinuclear combined sodium-proton transceiver array consisting of 8 proton-dipoles and 8 sodium-loops for imaging the body at 10.5T was designed and implemented. Performance of the array was compared against 3 other designs using numerical simulations with the goal of achieving multinuclear imaging capabilities while minimizing the losses typically associated with such dual-tuned coils. The first 10.5T sodium images were obtained inside a saline-filled torso-size phantom with the implemented coil. |
| 432
|
8:39
|
Split-Ring-Resonator shield improves SAR efficiency and homogeneity of birdcage antenna. |
1Center of Image Sciences, University Medical Center Utrecht, Utrecht, Netherlands, 2ITMO University, St. Petersburg, Russian Federation, 3Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands |
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A Split-Ring-Shield is a metamaterial structure that operates as a magnetic shield and thereby increases the penetration of the B1-field of a dipole antenna into a phantom. However, due to increased sample resistance it cannot be used effectively with a conventional birdcage. As a solution, a multi-transmit birdcage coil is presented, which can be used with the SRS. Simulations indicate a 10% increase in SAR-efficiency compared to a conventional birdcage. This setup was constructed and preliminary images were obtained. |
| 433 | 8:51
|
Double-Tuned 31P/1H Human Head Array with High Performance at Both Frequencies for Chemical Shift Spectroscopic Imaging (CSI) at 9.4T. |
1High-Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Germany |
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SNR enhancement at ultra-high field (UHF, >7T) is very critical for X-nuclei imaging. X-nuclei CSI of a human brain is potentially valuable for diagnostics of many diseases. CSI benefits from a whole-brain coverage and a high transmit performance not only at X- but also at 1H-frequency. It is rather difficult to optimize the DT-array at both frequencies at the same time. Therefore, often the performance of the X-nuclei portion of the RF array coil is optimized while the 1H-array performance is compromised. In this work, we developed a novel DT-array, which provides good performance at both 31P and 1H frequencies. |
| 434 | 9:03
|
A Robust Cryogenic RF Coil (88K) for In-vivo Hyperpolarized 13C MRI of Rats |
1Department of Electrical Engineering, Technical University of Denmark (DTU), Kgs. Lyngby, Denmark, 2MR Research Centre, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark |
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We report the performance of a cryogenic RF receive-only coil for 13C imaging of small animals. It is experimentally demonstrated 2-fold SNR improvement in comparison to a room temperature coil in immediate vicinity of the sample. The self-developed cryostat employed for coil cooling shows thermal stability within 5 h of use for 6 L of LN2, which can be extended up to 12 h if more LN2 is added. The Q88K/Q290K ratio of the unloaded coil is 550/285. |
| 435
|
9:15
|
Dielectric resonator for targeted breast MRI at 3T |
1Department of Nanophotonics and Metamaterials, ITMO University, Saint Petersburg, Russian Federation, 2Department of Radiology, Vreden Russian Institute of Traumatology and Orthopedics, Saint Petersburg, Russian Federation, 3Giricond Research Institute, Ceramics Co., Ltd., Saint Petersburg, Russian Federation, 4Department of Radiology, Leiden University Medical Center, Leiden, Netherlands |
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A novel concept for targeted MRI that can be directly integrated into an existing clinical system is proposed and demonstrated for 3T breast imaging. A practical demonstration of the concept features a dielectric resonator, based on a composite material with a very high permittivity that is electromagnetically coupled to the birdcage body coil. In vivo breast imaging with the proposed resonator showed 70% higher signal-to-noise ratio and reduced motion |
| 436
|
9:27
|
Compact Self Grounded Bow Tie Antenna Resonator for Cardiac MRI at 7.0 Tesla |
1Berlin Ultrahigh Field Facility, Max-Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany, 2MRI.TOOLS GmbH, Berlin, Germany, 3Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany, 4Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max-Delbrück Center for Molecular Medicine, Berlin, Germany |
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A compact dielectric resonator antenna array was developed for cardiovascular MRI at 7.0T MRI. The antenna building block is based on the concept of a self-grounded bow-tie (SGBT) antenna placed inside a resonator cavity filled with deuterium oxide. This approach ensures light-weight design and affords high-density RF arrays, which constitutes a major advantage over current state-of-the-art electric dipole configurations. The proposed high-density SGBT transceiver array provides ample parallel imaging and real time imaging capabilities. It contributes to the technological basis for the future clinical assessment of parallel transmit techniques designed for ultrahigh field cardiac MR. |
| 437 | 9:39
|
Over-overlapped Loop Arrays |
1College of nuclear equipment and nuclear engineering, Yantai University, Yantai, China, 2Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, 3Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States, 4Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States |
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Loops are usually overlapped by approximately 10% in |
| 438
|
9:51
|
An eight-channel array coil for zero echo time imaging |
1ETH Zurich and University of Zurich, Zürich, Switzerland |
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With dedicated short-T2 techniques such as zero echo time (ZTE) imaging not only rapidly decaying signal from the sample but also from the RF coil (plastic housing, glue, solder flux etc.) is detected. To enable experimental examination of parallel imaging opportunities, a 1H-reduced eight channel array was designed. ZTE images of short-T2* rubber samples and PETRA images of human head could be acquired. |
| 439 | 10:03
|
Development of a Local Pituitary Coil for Assessment of Pituitary Microadenomas |
1Radiological Sciences, University of California, Los Angeles, Los Angeles, CA, United States, 2Electrical Engineering, University of California, Los Angeles, Los Angeles, CA, United States, 3Radiology and Imaging sciences, University of Utah, Salt Lake City, UT, United States, 4Neurosurgery, University of California, Los Angeles, Los Angeles, CA, United States, 5California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, United States |
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Pituitary microadenomas are difficult to detect due to their small size, and the surgeon is sometimes forced to |
| 440
|
8:15
|
Dynamic speech imaging at 0.55T using single shot spirals for 11ms temporal resolution |
1National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States |
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Pushing the spatiotemporal resolution using spiral acquisition has been an active area of research in dynamic speech imaging. However application of long readout spirals at high field have been limited by off-resonance blurring around the mouth and airway. Low field MRI offers an advantage to speech imaging, due to reduced local susceptibility gradients. Here, we demonstrate reconstructions of single shot spiral (up to 9.4 ms readouts) without accruing any blurring artifacts resulting in high temporal resolution (11 ms) dynamic speech imaging. |
| 441 | 8:27
|
Improved spiral dynamic MRI of vocal tract shaping at 3 Tesla using dynamic off resonance artifact correction |
1Biomedical Engineering, University of Iowa, Iowa city, IA, United States, 2Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, CA, United States, 3Department of Radiology, University of Iowa, Iowa city, IA, United States |
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Spiral trajectories have been valuable in several dynamic speech production MRI studies due to its robust motion encoding, and time acquisition efficiency. However they are challenged by off-resonance artifacts at high field strengths and use of long readouts. In this work, we demonstrate correction of off-resonance induced blurring and signal losses on 3T spiral dynamic speech MRI data. The approach estimates the dynamic field map directly from the single TE data and compensates for this during a multi-frequency interpolation reconstruction. Effectiveness in improving sharpness of various articulator boundaries for long readout sequences (> 2ms) are demonstrated. |
| 442 | 8:39
|
Echo Planar Imaging of the Human Brain with 100 mT/m Gradients |
1Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland |
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First results obtained with Echo Planar Imaging using a gradient insert producing 100 mT/m with 1200 T/m/s slew rate are reported. High-resolution single-shot images of human head with a very low level of distortion and blur were obtained without the need of high parallel acceleration. However, at these extreme gradient strengths, high-order fields produced by eddy-currents require special measures to avoid spatially modulated “Nyquist ghosts”. Our strategy consisted of multi-position monitoring of eddy-current fields, fitting these results with 5th-order spherical harmonics, and including this model in the signal encoding matrix inverted during reconstruction. |
| 443
|
8:51
|
Temperature-dependent Gradient System Transfer Function (GSTF) |
1Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Würzburg, Germany, 2X-Ray & Molecular Imaging Lab, Technical University Amberg-Weiden, Weiden, Germany, 3Siemens Healthcare GmbH, Erlangen, Germany |
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The gradient system transfer function (GSTF) characterizes the frequency transfer behavior of a dynamic gradient system and can for example be used to correct non-Cartesian k-space trajectories. This work analyzes the impact of the gradient coil temperatures on the GSTF by applying gradients with high amplitudes at extensive duty cycles. The obtained results show that heating changes the transfer characteristics of the system. Based on these findings, we developed a model to predict the self- and B0-terms of the GSTF in dependency of the temperature. |
| 444
|
9:03
|
Fast 4D model based eddy current characterization for shim pre-emphasis calibrations |
1Institute of Neuroscience and Medicine 4, INM-4, Forschungszentrum Jülich, Jülich, Germany, 2Institute of Neuroscience and Medicine 11, INM-11, JARA, Forschungszentrum Jülich, Jülich, Germany, 3JARA - BRAIN - Translational Medicine, Aachen, Germany, 4Department of Neurology, RWTH Aachen University, Aachen, Germany |
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Eddy current characterizations are needed for pre-emphasis implementations in dynamic shimming applications. However, since a high spatio-temporal sampling of the eddy current fields is required, this a challenging task. Image-based approaches are well-suited for this purpose, but require substantial acquisition times. This work presents a 2D image-based sampling scheme, which is fast compared to existing 3D techniques and still provides sufficient information for an unambiguous pre-emphasis parameter reconstruction. Moreover, a model-based fit is proposed, which jointly applies the spatial and temporal eddy current model to the acquired data. It is shown, that this approach is well-suited for reducing fitting noise. |
| 445
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9:15
|
Simple Auto-Calibrated Gradient Delay Estimation From Few Spokes Using Radial Intersections (RING) for Interactive Real-time MRI |
1Institut für Diagnostische und Interventionelle Radiologie, University Medical Center Göttingen, Göttingen, Germany, 2Partner site Göttingen, German Centre for Cardiovascular Research (DZHK), Göttingen, Germany |
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Radial k-space trajectories are popular for fast imaging but come at the expense of a high sensitivity to system imperfections such as eddy currents and gradient delays. Current gradient delay compensation strategies often demand calibration scans or many spokes for auto-calibration and can be computationally demanding. Here, we use the novel RING approach to estimate the gradient delays for each frame of a real-time cardiac MRI measurement to reliably remove streaking artifacts, even if the slice position is changed interactively. |
| 446
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9:27
|
Correction of physiological field fluctuations in high- and low-resolution 3D-EPI acquisitions at 7 Tesla |
1German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany, 2Department of Physics and Astronomy, University of Bonn, Bonn, Germany |
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Segmented gradient-echo 3D-EPI images suffer from physiologically induced field fluctuations due to long echo times and k-space data acquisition across multiple shots. In this work, the effect of 0th-order B0 correction on high-resolution and low-resolution 3D-EPI acquisitions is investigated by means of a 16-channel NMR field probe system. A clear improvement in image quality and |
| 447
|
9:39
|
Dwell Time Compensation of the Gradient System Transfer Function (GSTF): Field Camera versus Phantom-based Measurement |
1Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Würzburg, Germany, 2Cardiovascular Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States |
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As a linear and time-invariant (LTI) system, the dynamic gradient system can be described by the gradient system transfer function (GSTF). GSTF can be determined by special measurement equipment such as field cameras. Alternatively, phantom-based approaches were introduced as for GSTF determination without additional hardware needed. This study compares the field camera-based measurement to the phantom-based measurement and introduces a dwell time compensation. The GSTFs are applied for trajectory correction using a 3D wave-CAIPI imaging sequence. |
| 448
|
9:51
|
Silent Magnetization Prepared B1-map Acquisition - SIMBA |
1Neuroimaging, King's College London, London, United Kingdom, 2General Electric Healthcare, London, United Kingdom, 3ASL Europe, General Electric Healthcare, Munich, Germany |
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Characterization of the B1-transmit field (B1+) is important for many quantitative imaging techniques. Here, we present a novel, silent, B1+-mapping technique using a magnetization prepared zero-echo time 3D radial sequence. The proposed technique, named SIMBA, is shown to correspond very well to a standard 2D B1+-mapping technique (Bloch-Siegert). The efficacy of the technique is shown by correction of quantitative T1-maps obtained using the variable flip angle method. |
| 449 | 10:03
|
Geometric Coil Mixing (GCM) to Dampen Confounding Signals in MRI Reconstruction |
1Department of Radiology, A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 2Harvard Medical School, Boston, MA, United States, 3Department of Physics and Astronomy, Heidelberg University, Heidelberg, Germany, 4Siemens Healthcare GmbH, Erlangen, Germany, 5Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen, China, 6Fetal-Neonatal Neuroimaging & Developmental Science Center, Boston Children's Hospital, Boston, MA, United States, 7Division of Neuroradiology, Department of Radiology, Massachusetts General Hospital, Boston, MA, United States, 8Harvard-MIT Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States |
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We introduce an artifact reduction technique that exploits the spatial locality afforded by multi-channel receiver array coils. Specifically, we create an optimal coil mixing with the purpose of dampening confounding signals prior to parallel imaging (PI) reconstruction. We demonstrate the mitigation of artifacts caused by PI model inaccuracies for Wave-CAIPI imaging in neurological and MSK applications. In addition, we illustrate the potential of this technique for minimizing the effects of non-rigid maternal and fetal motion during fetal brain imaging. This computationally efficient approach should allow for direct application of model based reconstruction/motion correction methods in difficult imaging scenarios. |
8:15
|
Motion-Resolved Continuous MRI | |
1Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, United States |
8:45
|
Simultaneous Flow & Motion Imaging in Cardiovascular MRI | |
1Radiology, Stanford University, Stanford, CA, United States |
9:15
|
Spin More Out of Spins in Extra Dimensions: Time-Resolved MR Spectroscopic Imaging | |
1University of Illinois at Urbana-Champaign, United States |
9:45
|
Dynamic Quantitative Multiparametric Mapping | |
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States |
8:15
|
Introduction | |
1Memorial Sloan-Kettering Cancer Center |
8:30
|
Lessons Learned from Early Adoption of Low-Field Integrates MR Guided Radiotherapy System: The UCLA Experience | |
9:05
|
MRI-guided Radiotherapy: the Need for Speed in Data Acquisition, Reconstruction & Processing | |
9:40
|
4D MRI & Synthetic CT in the Context of MR-Guided Radiotherapy | |
1The Institute of Cancer Research, United Kingdom |
| 10:30 | Translational Research for MR Application of Nanotechnology: Beyond Imaging |
1Radiology, Seoul National University Hospital, Korea, Republic of |
| 11:00 | Machine Learning in Medical Imaging |
1KAIST, Korea, Republic of |
| 11:20 | Machine Learning in Clinical Practice |
| 11:40 | How Machine Learning can Supercharge Scientific Discovery |
1Electrical & Computer Engineering, McGill University, Montreal, QC, Canada |
13:30
|
Overview of Motion Correction with External Sensors | |
1University Medical Centre Freiburg, Germany |
14:00
|
Qualitative Motion Sensors & Gating | |
1University of Oxford, United Kingdom |
14:30
|
Optical Tracking Systems for Neuroimaging | |
1Otto-von-Guericke-University Magdeburg, Germany |
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Head and brain motion is usually described as rigid with 6 degrees of freedom (translation and rotation). Optical tracking systems use cameras for pose tracking inside the MRI system to determine the 6 motion parameters with relatively high update rate. Optical motion tracking approaches include multiple cameras-based stereoscopic reconstruction of few markers incl. infrared tracking with cameras outside or inside the magnet bore. Alternatively, single camera approaches using encoded checkerboard markers moiré phase tracking (MPT) markers has been presented. Structured light is another alternative. These methods are now being commercialized. |
15:00
|
Abdominal Motion Detection | |
1Radiology, Brigham and Women's Hospital, Harvard Medical School, MA, United States |
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Sensors are everywhere, for example there are hundreds of them on a car, and they represent a natural future direction for MRI. Scanners of the future may incorporate suites of sensors gathering information about patient and hardware, providing a diverse and eclectic collection of information to be fed into convolutional neural networks for interpretation, for enhanced/improved imaging results. Work on ultrasound-based sensors will be described here in some detail; these sensors accompany patients into the MRI bore, providing streams of high-temporal resolution information about internal motion that can be utilized as part of the image reconstruction process. |
15:30
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Adjournment |
13:30
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Introduction to MRI System Imperfections | |
1A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States |
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This talk will familiarize MRI engineers and clinicians with some of the principal limitations on MRI scanner hardware performance, along with methods for characterizing and mitigating these imperfections. We will also discuss issues arising from the interaction of the scanner's static and radiofrequency fields with the human body. |
14:00
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Software for Simulating MRI Systems | |
1German Center for Neurodegenerative Diseases, Bonn, Germany |
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The presentation will introduce computer simulations of classical MR physics, incorporating state-of-the-art MRI scanner hardware and some of their often-inevitable imperfections. |
14:30
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Field Probes for Characterizing & Calibrating MRI Systems | |
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 2Skope MRT, Zurich, Switzerland |
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Driving MR image acquisitions requires a level of accuracy of the dynamics of the magnetic fields that is almost impossible to achieve by design. Induced eddy currents, lead inductances, amplifier delays and other effects have hence to be corrected by feed-back, pre-distortion and post-correction schemes. All these approaches however are based on accurate characterizations of the field evolution in the scanner. In this talk, characterization methods based on field probes will be discussed along with the application of the obtained data for system calibration. |
15:00
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Robotic Field Scanner | |
1Physikalisch Technische Bundesanstalt (PTB), Berlin, Germany |
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In our efforts to strengthen open source science, open source medical technology and collaboratively building an affordable open source MRI scanner, we have realized the necessity to also construct affordable and customizable open source scientific measurement equipment. Here the developments and applications of COSI Measure, a robotic field scanner with submillimeter fidelity are presented. The documentation and design files of COSI Measure are freely available and licensed under the open source hardware license CERN OHL v1.2 (www.opensourceimaging.org/cosi-measure). |
15:30
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Adjournment |
| 450
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Pitch: 13:30 Poster: 14:30 Plasma 1
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Longitudinal Study of Aortic Stiffness and Flow Reversal in Patients with Cryptogenic Stroke |
1Radiology, Northwestern University, Chicago, IL, United States, 2Neurology, Northwestern University, Chicago, IL, United States, 3Radiology, Mayo Clinic, Rochester, MN, United States |
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Atherosclerotic plaque in the descending aorta has emerged as a potential etiology of embolic stroke due to diastolic flow reversal in this region. This study seeks to investigate 1) whether aortic stiffness assessed by pulse wave velocity (PWV) may be related to flow reversal and 2) the effects of medical therapy on PWV and flow reversal. Twenty cryptogenic stroke patients were included in this 4D flow MRI study. We found relationships between age, PWV and flow reversal. No systematic change in PWV or flow reversal was detected for patients taking medications with potential de-stiffening effects. |
| 451 | Pitch: 13:30 Poster: 14:30 Plasma 2
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Enhanced non-invasive pressure drop and flow inefficiencies quantification via 4D-flow MRI |
1School of Biomedical Engineering & Imaging Sciences, Kings College London, London, United Kingdom, 2Division of Cardiovascular Medicine, Radcliffe Department of Medicine, Oxford, United Kingdom |
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The pressure drop caused by convective effects is the standard clinic method for diagnosis of aortic stenosis using simplified Bernoulli. However simplified Bernoulli results in a reported overestimation that can be resolved with 4D-flow MRI and Simplified Advective Work-energy relative pressure (SAW). This work further refines SAW formulation and proposes an enhanced analysis of the positive and negative components of flow profile. Whereas forward SAW pressure drop correlates better with mean SB (R2=0.951) than full velocity profile by SAW (R2=0.901), backward SAW is totally independent of SB (R2=0.490), which makes the flow efficiency a potential predictive value for disease progression. |
| 452 | Pitch: 13:30 Poster: 14:30 Plasma 3
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MRI flow and volume quantification with internal validation and correlation to Fick and thermodilution catheterization derived values in pulmonary hypertension |
1Radiology, Geneva University Hospital, Medicine Faculty of the University of Geneva, Geneva, Switzerland, 2Cardiology, Geneva University Hospital, Geneva, Switzerland, 3Pulmonary Medicine, Geneva University Hospital, Geneva, Switzerland, 4Pediatric Cardiology, Geneva University Hospital, Geneva, Switzerland |
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Cardiac output (CO) determination is mandatory for the diagnosis work-up of pulmonary hypertension (PH). It is classically obtained by invasive methods such as indirect Fick (Qfick) and thermodilution (Qthermo) performed during right heart catheterisation (RHC). However, non-contrast, non-invasive and reliable methods may be preferred for clinical routine and post-treatment monitoring of patients. This study compared QFlow derived parameters (stroke volumes and cardiac index/ pulmonary and aortic flow) measured non-invasively in PH patients for internal validation of MRI and for comparison to RHC. |
| 453 | Pitch: 13:30 Poster: 14:30 Plasma 4
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Reynolds Stress Tensor Quantification using a Flow-MRF Approach |
1German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany |
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This work demonstrates the feasibility to quantify simultaneously the Reynolds stress tensor and velocities using a Flow-MRF based approach in conditions of turbulent flow. This is achieved by measuring spatially undersampled time-series with pseudo-randomly varying velocity encoding moments, based on the MR Fingerprinting framework. |
| 454 | Pitch: 13:30 Poster: 14:30 Plasma 5
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3D MR Velocimetry of Very Slow Flows |
1National Institute of Health, Bethesda, MD, United States, 2University of Florida, Gainesville, FL, United States, 3The Ohio State University, Columbus, OH, United States |
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Methods are needed to non-invasively measure in vivo very slow flows, which govern many important physiological processes like brain glymphatic flow. In this study, a new stimulated echo-based phase contrast MRI sequence, robust to phase errors induced by gradient hardware, is used to measure 3D flows as slow as 1 μm/s. The method was validated using a controlled pipe flow experiment. In the absence of induced flow, the method revealed unusual natural convection flows in a water filled tube placed in a wide-bore magnet. The method may be applied to measure important slow flows in vivo. |
| 455 | Pitch: 13:30 Poster: 14:30 Plasma 6
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4D-Flow MRI and robust local Pulse Wave Velocity allow the detection of alterations in human aortas |
1Biomedical Imaging Center, Pontificia Universidad Catolica de Chile, Santiago, Chile, 2Millennium Nucleus for Cardiovascular Magnetic Resonance, Santiago, Chile, 3Electrical Engineering, Pontificia Universidad Catolica de Chile, Santiago, Chile, 4Heart Institute, Cincinnati Children's Hospital, Cincinnati, OH, United States, 5Pediatrics, UT Southwestern, Dallas, TX, United States, 6Imaging and Biomedical Engineering, Kings College of London, London, United Kingdom, 7Radiology, Pontificia Universidad Catolica de Chile, Santiago, Chile, 8Institute for Biological and Medical Engineering, Pontificia Universidad Catolica de Chile, Santiago, Chile |
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An improved version of continuous pulse-wave velocity estimation uses 4D-Flow data with time-delay recovered from a faster formulation using FFT. The novelty also relies upon neglecting regressive time-delay zones, yielding stable and reliable results. Numerical simulations are shown to assess the method. We also present its application in patients with Familial Hypercholesterolemia and Fontan. Consistently with previous findings, adult controls have stiffer aortic walls compared to young controls. Also, Fontan patients appear with stiffer aortic arch than other subjects. More interestingly, all subjects show a softening in the aortic arch respect to the rest of the vessel. |
| 456 | Pitch: 13:30 Poster: 14:30 Plasma 7
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Dilated Pulmonary Arteries and Wall Shear Stress in Patients with Repaired Tetralogy of Fallot. |
1National Tsing Hua University, Hsinchu, Taiwan, 2Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, 3National Yang-Ming University, Taipei, Taiwan, 4National Taiwan University Hospital, Taipei, Taiwan |
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We aimed to investigate the impact of pulmonary area on wall shear stress (WSS) and oscillatory shear index (OSI) to explore the altered vascular characteristics in patients repaired tetralogy of Fallot (rTOF). rTOF patients with pulmonary dilatation presented decreased axial WSS and increased axial OSI. The correlations between pulmonary area and axial WSS and OSI were missing in rTOF patients, depicting the abnormal endothelial regulation function in response to axial WSS and OSI. In conclusion, the correlation analyses between pulmonary area, axial WSS and OSI might provide helpful information in investigating the altered vascular characteristics in patients with rTOF. |
| 457 | Pitch: 13:30 Poster: 14:30 Plasma 8
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Accelerated whole-chest 4D flow imaging without navigator echo |
1Medical College of Wisconsin, Milwaukee, WI, United States, 2University of Michigan, Ann Arbor, MI, United States |
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4D flow MRI allows for thorough evaluation of hemodynamic patterns. Nevertheless, 4D flow imaging is very time consuming from both image acquisition and reconstruction perspectives. In this study, we provide preliminary data about accelerated sub-10-minutes whole-chest 4D flow imaging without navigator echo, based on recent acquisition and reconstruction technical developments, and compare the results to conventional 2D PC imaging across large arteries and atrioventricular valves. Measurements from accelerated 4D flow were in good agreement with conventional 2D PC imaging. The accelerated 4D flow technique would improve MRI cost effectiveness, lead to increased clinical adoption, and provide more patient comfort. |
| 458
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Pitch: 13:30 Poster: 14:30 Plasma 9
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Dual-echo 2D Image Navigators for Respiratory Motion-Corrected Whole-Heart Water/Fat CMRA |
1School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 2MR Research Collaborations, Siemens Healthcare GmbH, Frimley, United Kingdom |
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Whole-heart water/fat coronary MR angiography (CMRA) is a promising technique for improved visualisation of the cardiac anatomy and epicardial and pericardial fat. However, respiratory motion remains a challenge for its integration into clinical routine. Here we propose a respiratory motion-corrected whole-heart water/fat CMRA approach based on dual-echo 2D image navigators (iNAVs) and a combined 2D translational and 3D non-rigid motion corrected reconstruction scheme. Results from healthy subjects indicate that out-of-phase iNAVs produce accurate respiratory translational motion estimation, and that motion-corrected water/fat CMRA images are comparable to reference diaphragmatic-gated images, but are acquired in a significantly shorter scan time. |
| 459
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Pitch: 13:30 Poster: 14:30 Plasma 10
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Fat-free free-running coronary MRA at 1.5T using LIBRE water excitation pulses |
1Department of Radiology, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, 2Advanced Clinical Imaging Technology, Siemens Healthcare AG, Lausanne, Switzerland, 3LTS5, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland, 4Center for Biomedical Imaging (CIBM), Lausanne, Switzerland |
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Previously published work in fully self-gated free-breathing 3D radial coronary MRA at 1.5T with cardiac-and-respiratory-motion-resolved reconstruction (Free-running framework) suffered from the disadvantage of requiring interrupted bSSFP with ramp-up and fat saturation pre-pulses. Using numerical simulations, in vitro and in vivo scans, we successfully tested the hypothesis that LIBRE, a new water excitation technique, obviates the need for such pre-pulses, improves time efficiency when compared to earlier approaches, and provides both superior fat saturation and vessel delineation relative to more conventional water excitation. |
| 460 | Pitch: 13:30 Poster: 14:30 Plasma 11
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XD-ORCCA for BOOST: accelerated motion-compensated simultaneous bright- and black-blood 3D whole-heart coronary MRI |
1School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 2MR Research Collaborations, Siemens Healthcare Limited, Frimley, United Kingdom |
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Recently, a novel free-breathing 3D whole-heart sequence, called T2-prepared BOOST, was proposed for non-contrast enhanced bright-blood and black-blood coronary MR imaging, for simultaneous coronary lumen and coronary thrombus/ intraplaque hemorrhage visualization. However, high-resolution fully-sampled BOOST acquisitions require long scan times of ~20min. Here, we propose to use a modified version of XD-ORCCA, a highly efficient respiratory-resolved motion-corrected framework, to accelerate BOOST acquisitions. XD-ORCCA exploits the sparsity in a motion-corrected domain to acquire high-quality respiratory-resolved bright- and black-blood BOOST images in ~6min. Hence, high-resolution free-breathing BOOST imaging is achieved within clinically feasible acquisition times. |
| 461
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Pitch: 13:30 Poster: 14:30 Plasma 12
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Natively Fat-Suppressed Fast Interrupted Steady State (FISS) for 5D Whole Heart Imaging at 1.5 and 3T |
1Radiology, UNIL-CHUV, Lausanne, Switzerland, 2Advanced Clinical Imaging Technology, Siemens Healthcare AG, Lausanne, Switzerland, 3Center for Biomedical Imaging, Lausanne, Switzerland, 4Department of Radiology, NorthShore University HealthSystem, Evanston, IL, United States, 5The University of Chicago Pritzker School of Medicine, Chicago, IL, United States, 6Northwestern University Feinberg School of Medicine, Chicago, IL, United States |
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Fast interrupted steady state (FISS) sequences provide bSSFP signal contrast and concomitant fat signal suppression. In this work, 3D radial FISS was implemented as part of a respiratory self-gated free-breathing cardiac and respiratory motion-resolved 5D imaging framework. Its capabilities for fat suppression were tested and characterized at both 1.5 and 3T. Combined with a XD-GRASP reconstruction, FISS offers a versatile alternative for motion-resolved fat suppressed high-resolution whole-heart anatomical and functional cine imaging with a scan time as low as 8 minutes. |
| 462
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Pitch: 13:30 Poster: 14:30 Plasma 13
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Efficient T2 Mapping of the Carotid Artery using a 3D Stack-of-Stars Variable Flip Angle TSE Pulse Sequence |
1Medical Imaging, University of Arizona, Tucson, AZ, United States, 2Biomedical Engineering, University of Arizona, Tucson, AZ, United States, 3Electrical and Computer Engineering, University of Arizona, Tucson, AZ, United States, 4Surgery, University of Arizona, Tucson, AZ, United States |
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We present a radial stack-of-stars TSE pulse sequence with an efficient radial view ordering and optimized refocusing flip angles for 3D T2 mapping of the carotid artery. The technique provides excellent anatomical coverage within clinically acceptable times. The short acquisition time makes the technique less susceptible to motion. Performance of the technique is evaluated using phantoms and in vivo experiments. |
| 463
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Pitch: 13:30 Poster: 14:30 Plasma 14
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Quantitative Measurements of Carotid Atherosclerotic Plaque Compositions using in vivo T1 Mapping: Validation by Histology |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing, China, 2Beijing Tiantan Hospital, Capital Medical University, Beijing, China, 3China National Clinical Research Center for Neurological Diseases, Beijing, China, 4School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 5Department of Neurosurgery, Peking University Third Hospital, Beijing, China, 6Department of Radiology, Peking University Third Hospital, Beijing, China |
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Plaque compositional features are effective indicators for vulnerability and associated with ischemic stroke risk. Multicontrast vessel wall imaging has been utilized to characterize plaque compositions but this technique is time consuming and dependent on reviewer’s experience. Therefore, it is important to characterize plaque compositions with time-efficient imaging approach. This study sought to determine T1 values of carotid plaque components determined by quantitative imaging validated by histology. We found that the T1 values of intraplaque hemorrhage, necrotic core, and loose matrix were distinguishable. Our findings suggest that carotid plaque components might be distinguishable and automatically segmented on quantitative MR imaging. |
| 464 | Pitch: 13:30 Poster: 14:30 Plasma 15
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Dynamic Evaluation of Flow in the Lower Extremity Peripheral Arteries using Cine Fast Interrupted Steady-State in Combination with Arterial Spin Labeling. |
1Radiology, McGaw Medical Center of Northwestern University, Chicago, IL, United States, 2Radiology, NorthShore University HealthSystem, Evanston, IL, United States, 3Radiology, University of Chicago Pritzker School of Medicine, Chicago, IL, United States, 4Vascular Surgery, NorthShore University HealthSystem, Evanston, IL, United States, 5Feinberg School of Medicine of Northwestern University, Chicago, IL, United States |
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For non-invasive evaluation of peripheral artery disease in the lower extremities prior to revascularization, physicians rely on contrast-enhanced CT angiography and magnetic resonance angiography which generate static images in the arterial phase and do not reveal blood flow. We adapted a prototype non-contrast MRA technique, cine fast interrupted steady-state in combination with arterial spin labeling (cine FISS ASL), to facilitate dynamic visual and quantitative flow evaluation of the lower extremity peripheral arteries. In-plane flow patterns were well visualized and there was very strong positive correlation between peak flow velocities measured by cine FISS ASL and 2D phase contrast MRA. |
| 465
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Pitch: 13:30 Poster: 14:30 Plasma 16
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Reconstruction of multi-shot diffusion-weighted MRI using unrolled network with U-nets as priors |
1Department of Electrical Engineering, Stanford University, Stanford, CA, United States, 2Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States, 3ByteDance AI Lab, Beijing, China, 4Department of Applied Physics, Stanford University, Stanford, CA, United States, 5Department of Radiology, Stanford University, Stanford, CA, United States, 6Department of Bioengineering, Stanford University, Stanford, CA, United States |
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In this work, we demonstrated the feasibility of using deep neural networks for rapid multi-shot DWI reconstruction. An unrolled network with six U-nets, which operated in frequency and image domains alternatively, was shown to have the capability to remove aliasing artifacts from shot-to-shot phase |
| 466 | Pitch: 13:30 Poster: 14:30 Plasma 17
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Generation of globally consistent non-confidential MRI data using deep generative adversarial networks |
1Institute of Signal Processing and System Theory, University of Stuttgart, Stuttgart, Germany, 2Radiology Department, University Hospital Tübingen, Tübingen, Germany |
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The lack of easily accessible open-source medical datasets is one of the biggest limiting factors to advance the development of deep models for any medical task. In this work, we utilize |
| 467 | Pitch: 13:30 Poster: 14:30 Plasma 18
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Fast Acquisition and Low-delay Reconstruction of Stack-of-stars Trajectory Using Temporal Multiresolution Images and a Convolutional Neural Network |
1Advanced Technology Research Department, Research and Development Center, Canon Medical Systems Corporation, Yokohama, Japan, 2Software Technologies Group, MRI Systems Development Department, MRI Systems Division, Canon Medical Systems Corporation, Yokohama, Japan |
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For fast data acquisition and low-delay reconstruction in applications using stack-of-stars trajectory, the authors propose a new reconstruction method using a CNN with temporal multiresolution inputs. Conventionally, stack-of-stars images reconstructed from a few spokes contain streaking artifacts. By utilizing view sharing technique for suppressing the artifacts, reconstructed images are often blurred. For low-delay reconstruction, it is not straightforward to use well-studied methods based on compressed sensing with temporal priors. The proposed method aims to adjust spatio-temporal resolution to a suitable one. Experimental results show that the proposed method could reconstruct highly under-sampled radial dynamic images with reduced artifacts. |
| 468 | Pitch: 13:30 Poster: 14:30 Plasma 19
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Integrating Imaging Prior Knowledge in Deep Convolutional Network - A Novel Approach of Cranial Pseudo-CT Generation |
1Medical Physics and Research, Hong Kong Sanatorium & Hospital, Hong Kong, Hong Kong, Hong Kong, 2Department of Diagnostic & Interventional Radiology, Hong Kong Sanatorium & Hospital, Hong Kong, Hong Kong, Hong Kong |
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A deep convolutional network for cranial pseudo-CT generation was developed with the consideration of prior knowledge involved in radiotherapetic imaging workflow. This prior knowledge has been scarcely studied along with deep learning. It could greatly reduce the complexity of image data handled by the network. Examined on 14 sets of DIXON-MR and CT images, the proposed model achieved low generalization gap and offered accurate results regardless of the amount of training data. It achieved an average of 89.77±29.32HU mean-absolute-difference in two-fold cross-validation. It is experimentally shown that the proposed method is well-suited for generating clinical pseudo-CT for radiotherapeutic applications. |
| 469 | Pitch: 13:30 Poster: 14:30 Plasma 20
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Exploring Complex-Valued Neural Networks with Trainable Activation Functions for Magnetic Resonance Imaging |
1Digital Technology and Innovation, Siemens Healthineers, Princeton, NJ, United States, 2EPITA, Le Kremlin-Bicêtre, France, 3Magnetic Resonance, Siemens Healthcare GmbH, Erlangen, Germany |
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MR signals by nature are complex valued. However, most of the current deep neural networks for MR are derived from applications dealing with real-valued images. Recent studies proposed an adaptation of neural networks to the complex domain to learn a better representation of the signal. In this study, multiple CVNN with trainable complex-valued activation functions are proposed and validated on MR fingerprinting regression problem. 2D activation functions with trainable parameters have been demonstrated here to suit the CVNN well and provide significant improvement over the non-trainable versions. |
| 470 | Pitch: 13:30 Poster: 14:30 Plasma 21
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Learning Perceptual Neural Proximals for Robust MRI Recovery |
1Electrical Engineering, Stanford University, Stanford, CA, United States, 2Statistics, Stanford University, Stanford, CA, United States, 3Radiology, Stanford University, Stanford, CA, United States |
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This abstract proposes a framework for robust reconstruction of MR images from highly undersampled measurements. Inspired by proximal gradient descent (PGD) iterations a recurrent neural network is trained to learn a high diagnostic proximal using Wasserstein GANs. For a Knee dataset, the proximal modeled with only two residual blocks shared across 5 iterations not only trains fast but also reveals fine diagnostic details with limited training data. All in all, this study suggests that sharing the proximal weights across iterations regularizes the reconstruction and improves the generalization. |
| 471 | Pitch: 13:30 Poster: 14:30 Plasma 22
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Application of a k-Space Interpolating Artificial Neural Network to In-Plane Accelerated Simultaneous Multislice Imaging for Motion Monitoring |
1Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, United States, 2Radiology, Medical College of Wisconsin, Milwaukee, WI, United States |
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A scan-specific deep learning approach to Cartesian k-space interpolation was extended to in-plane accelerated simultaneous multislice imaging. This method yields images more accurate and less noisy reconstructions than conventional SMS parallel imaging algorithms, particularly as acceleration factors approach the number of receive coils. Furthermore, the models trained in one particular motion state are applicable to test data from a different motion state. This suggests that this method will be useful for cine imaging. |
| 472 | Pitch: 13:30 Poster: 14:30 Plasma 23
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Deep learning without ground truth: an unsupervised method for MR image denoising and super-resolution |
1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States |
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Deep learning has shown great success in MR image segmentation, enhancement and reconstruction. However, most methods, if not all, rely on a pair of the input image and the ground-truth image to train the network for a given task. In practice, it is often hard to get the corresponding ground-truth MR images due to limitations in data acquisition. In this study, we aim to use the convolutional neural network (CNN) structure itself as a constraint without using ground-truth images in an optimization task and to evaluate its performance in MR image denoising and super-resolution applications. |
| 473 | Pitch: 13:30 Poster: 14:30 Plasma 24
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Using deep reinforcement learning to actively, adaptively and autonomously control a simulated MRI scanner |
1Centre for Advanced Biomedical Imaging, University College London, London, United Kingdom |
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In deep reinforcement learning (DRL), software agents based on deep neural networks are used to explore environments in order to maximise a reward (e.g. score in a video game). Here, DRL was used to control a virtual MRI scanner and actively interpret acquired data. An environment was constructed in which correctly determining the shape of a phantom was rewarded with a high score, and penalised by increasing acquisition time. Following training, the algorithm had learnt to acquire sparse images, assigning TE, TR and flip angles that enabled it to act as an edge detector and deduce shape with 99.8% accuracy. |
| 474 | Pitch: 13:30 Poster: 14:30 Plasma 25
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Leveraging conditional GANs with adaptive loss balancing for MRI sparse reconstruction. |
1GE Global Research, Herzliya, Israel, 2GE Global Research, Niskayuna, NY, United States, 3GE Healthcare, Menlo Park, CA, United States, 4GE Healthcare, Waukesha, WI, United States |
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We propose a Conditional Wasserstein Generative Adversarial Network (cWGAN), trained with a novel Adaptive Loss Balancing (ALB) technique that stabilizes the training and minimizes the presence of artifacts, while maintaining a high-quality reconstruction with more natural appearance (compared to non-GAN techniques). Multi-channel 2D brain data with fourfold undersampling were used as inputs, and the corresponding fully-sampled reconstructed images as references for training. The algorithm produced higher-quality images than state-of-the-art deep learning-based models in terms of perceptual quality and realistic appearance. |
| 475 | Pitch: 13:30 Poster: 14:30 Plasma 26
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Reconstructing Lesions not seen during training using a Recurrent Inference Machine |
1Delft University of Technology, Delft, Netherlands, 2Radiotherapy, Netherlands Cancer Institute, Amsterdam, Netherlands, 3Spinoza Centre for Neuroimaging, Amsterdam, Netherlands, 4Anatomy and Neurosciences, VU University Medical Center, Amsterdam, Netherlands, 5Radiology, Academic Medical Center, Amsterdam, Netherlands, 6Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, Netherlands |
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Deep learning can accelerate MRI beyond what is currently possible. Broad clinical application requires generalizability to multiple contrasts, acceleration levels and pathologies. Here we explore how a Recurrent Inference Machine trained on healthy volunteer T1-weighted brain images performs in such a situation, by reconstructing FLAIR images with white matter lesions, in simulation and prospectively undersampled patient data. Lesion contrast is maintained up to 6x acceleration and higher than in compressed sensing (CS) reconstruction, and all lesions are retained compared to CS. |
| 476 | Pitch: 13:30 Poster: 14:30 Plasma 27
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Multi-Shot Diffusion MRI using Deep MUSSELS |
1University of Iowa, Iowa City, IA, United States |
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This work proposes a deep-learning based computationally efficient method to reduce phase errors in multi-shot diffusion-weighted images. Recently, we introduced a navigator-free method to reduce these errors using structured low-rank matrix completion based approach termed as MUSSELS. This approach produces state-of-the-art results but is computationally expensive and requires a matrix lifting to estimate filter bank for each direction and slice, independently. We propose a generic deep-learning based approach to estimate phase errors for an unseen dataset by pre-learning the denoiser from exemplary data. The resulting model-based deep learning architecture reduces the computation time by a factor of around 450 with comparable reconstruction quality. |
| 477 | Pitch: 13:30 Poster: 14:30 Plasma 28
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AUTOmated pulse SEQuence generation (AUTOSEQ) for MR spatial encoding in unknown inhomogeneous B0 fields |
1Radiology, MGH Martinos Center for Biomedical Imaging, Charlestown, MA, United States, 2Radiology, Harvard Medical School, Boston, MA, United States, 3Physics, Harvard University, Cambridge, MA, United States, 4Biostatistics, Harvard University, CAMBRIDGE, MA, United States |
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The equations of motion that govern nuclear magnetic resonance lead to an incredible variety of MRI contrast mechanisms and spatial encoding schemes to be accessed via the application of cleverly constructed sequences of applied magnetic fields. However, the full potential of the Bloch equations has been difficult to exploit due to their non-intuitive, nonlinear dynamics which can devolve into chaotic behaviors and otherwise have intractable, non-analytical solutions1. Our previous work4 introduced a model-free reinforcement learning approach to pulse sequence generation, with an AI agent that explores an unknown MR imaging environment with pulse sequence “actions,” and constructs a model through corresponding RF receive-signal “rewards.” In this work, we demonstrate the same AI agent learning to generate optimal RF waveforms to perform slice selection in unknown inhomogeneous B0 settings. |
| 478 | Pitch: 13:30 Poster: 14:30 Plasma 29
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A Variational Neural Network for Accelerating Free-breathing Whole-Heart Coronary MR Angiography |
1School of Biomedical Engineering & Imaging Sciences, King's College London, London, United Kingdom |
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3D whole-heart coronary MR angiography (CMRA) has shown great potential to visualize the coronary arteries. However, scan times remain lengthy as a large amount of data needs to be acquired to obtain high-resolution images. Several undersampled compressed-sensing (CS) reconstruction approaches have been applied to accelerate CMRA. However, CS-based techniques suffer from residual aliasing artifacts, high-dependency on regularization parameters and long reconstruction times. We propose a Variational Neural Network for fast reconstruction of undersampled motion-compensated 3D cardiac MRI, which combined with 100% respiratory efficiency, enables the acquisition of high-quality isotropic CMRA images in ~2-4 minutes, and their reconstruction in ~20 seconds. |
| 479 | Pitch: 13:30 Poster: 14:30 Plasma 30
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NoiseFlow: Deep Learning using Noise-Driven Training |
1Radiology, Stanford University, Stanford, CA, United States, 2Electrical Engineering, Stanford University, Stanford, CA, United States |
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Deep learning provides a powerful data-driven solution to a wide range of imaging tasks, from data acquisition to image interpretation. To train these deep and highly nonlinear models, a well labeled and very large dataset is typically required. However, data with accurate labels are difficult, sometimes impossible, and expensive to collect. Without enough data, the learned model will be highly biased and unable to generalize. In the worst case, the application of the deep model may result in misdiagnosis and improper patient management. Thus, we propose NoiseFlow, a solution to reduce the dependency of deep learning solutions on real data through noise-driven training. |
| 480 | Pitch: 13:30 Poster: 14:30 Plasma 31
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First assessment of cardiac energy metabolism in the lateral and inferior segments of the left ventricle in vivo at 7T |
1OCMR, RDM Cardiovascular Medicine, University of Oxford, Oxford, United Kingdom, 2Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia, 3High-Field MR Centre, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria, 4The Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom |
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Using a novel whole-body transmit coil with an integrated 30-element receive array, powered by a 35kW RF power amplifier, we show the feasibility of whole-heart cardiac 31P-MRS at 7T. PSF simulations were performed to directly compare the new coil to a published protocol using a 16-element surface coil. The whole-body coil delivers analysable spectra from all left ventricular segments in the hearts of 3 volunteers, whereas the 16-element surface coil allowed probing energetics only in the proximal half of the left ventricle. This coil will enable new studies of focal disease and improve the SNR for regionally homogenous disease investigations. |
| 481
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Pitch: 13:30 Poster: 14:30 Plasma 32
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Dynamic 31P MRS of Skeletal Muscle with a 1 Telsa Extremity Scanner |
1Electrical & Computer Engineering, Texas A&M University, College Station, TX, United States, 2Biomedical Engineering, Texas A&M University, College Station, TX, United States, 3Electronic Systems Engineering Technology, Texas A&M University, College Station, TX, United States, 4Department of Health & Kinesiology, Texas A&M University, College Station, TX, United States, 5Center for Translational Research on Aging and Longevity, Texas A&M University, College Station, TX, United States |
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The potential of using low-field MRI scanners as a platform to enable low-cost 31P studies outside of the conventional hospital environment was examined. All experiments were conducted on an ONI 1T scanner with a custom broadband multichannel receiver. A transmit-only birdcage and receive-only four-element array were designed and built to enhance the SNR and improve linewidth. Preliminary phantom and in vivo results show the proposed design improved the linewidth from 0.71 ppm to 0.33 ppm, SNR was increased by approximately 2 times, and inorganic phosphate and phosphocreatine exchange were observed during the volunteer’s exercise. |
| 482 | Pitch: 13:30 Poster: 14:30 Plasma 33
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Human Brain 31P NMR Spectra at 7T: UDP-Glucose Assignment Revisited |
1Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States, 2Department of Radiology, UT Southwestern Medical Center, Dallas, TX, United States, 3Department of Chemistry, University of Texas at Dallas, Richardson, TX, United States, 4VA North Texas Health Care System, Dallas, TX, United States |
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In a typical human brain 31P NMR spectrum, a small peak is often present at ~-9.7 ppm, near the α-ATP and NAD+/NADH signals. This 31P resonance, accounting for ~1/30th of the brain α-ATP signal, has been considered to be a doublet and assigned to UDPG. Here we present strong evidence to show that the -9.7 ppm signal is in fact a finely structured quartet. This finding has direct impact on current 31P NMR method for evaluation of brain redox, which requires UDPG correction. It may also have implication on our interpretation of brain energy metabolism based on 31P NMR data. |
| 483 | Pitch: 13:30 Poster: 14:30 Plasma 34
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Activity of the Pentose Phosphate Pathway Is Increased in Hepatoma Using a Novel Tracer, [2,3-13C2]glucose |
1Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States, 2Radiology and Internal Medicine, UT Southwestern Medical Center, Dallas, TX, United States |
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The pentose phosphate pathway (PPP) was investigated in a rat model of hepatoma and results were compared to normal liver and other tissues. A novel and specific tracer of the PPP, [2,3-13C2]glucose, is introduced. The resulting isotopomers are informative because [1,2-13C2]lactate arises only from glycolysis and [2,3-13C2]lactate arises only from the PPP. The PPP was more active in the fed vs. fasted state in most tissues. These results correlated with mRNA expression of key enzymes in the PPP, and flux through both the PPP and glycolysis was substantially increased in hepatoma compared to healthy liver. |
| 484 | Pitch: 13:30 Poster: 14:30 Plasma 35
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Phosphorous and Proton MR Spectroscopy Study of Creatine Transporter Deficiency |
1National Institutes of Health, Bethesda, MD, United States, 2Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States |
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The X- linked Creatine Transporter Deficiency (CTD) is one of three types of the cerebral creatine deficiency disorders. It is caused by mutations in the X-linked gene SLC6A8. We report the first combined 31P and 1H MRS study of CTD patients. Relative concentrations of key metabolites were quantitatively analyzed. The PCr/total-phosphate and total-Cr/NAA ratios were found to be markedly reduced in CTD patients. By combining the proton and 31P data we found that the relative reduction in PCr in CTD patients is much less than that of total Cr. |
| 485 | Pitch: 13:30 Poster: 14:30 Plasma 36
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Volumetric mapping of intra- and extracellular pH in glioma patients using 31P MRSI at 7 Tesla |
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany |
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In vivo phosphorus magnetic resonance spectroscopic imaging (31P MRSI) enables the non-invasive mapping of absolute intra- and extracellular pH values of the human brain. However, achieving reasonable spatial resolution for studies of brain tumor patients is challenging due to low phosphate concentrations. In this study we demonstrate that 31P MRSI at 7 Tesla enables volumetric mapping of intra- and extracellular pH for studies of brain tumor patients. Volumetric pH maps with actual voxel size of 8 ml can be obtained within 30 minutes acquisition duration, and may provide novel insight into the pathophysiology of brain tumors. |
| 486
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Pitch: 13:30 Poster: 14:30 Plasma 37
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Full coverage 31P MRSI of the liver with a body coil at 7T |
1Radiology, University Medical Center Utrecht, Utrecht, Netherlands |
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We demonstrate increased 31P metabolite sensitivity by acquiring 31P signals over a large volume in the liver of a volunteer using a 31P whole body birdcage coil at 7T and minimize spatial reach of muscle signal leakage plus investigate frequency alignment due to B0 homogeneities. Sufficient SNR could be obtained in weighted average spectrum of all liver voxels and of four local liver voxels. Correcting B0 inhomogeneities by aligning resulted in a two-fold and 30% increase compared to non-aligned for the liver voxel average and the local voxel average respectively. The full setup allowed for full liver coverage and minimized muscle signal leakage. |
| 487
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Pitch: 13:30 Poster: 14:30 Plasma 38
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Quantitative 23Na MRI of the human liver at 7 Tesla |
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Faculty of Physics and Astronomy, University of Heidelberg, Heidelberg, Germany, 3Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany, 4Institute of Medical Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany, 5Faculty of Medicine, University of Heidelberg, Heidelberg, Germany |
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Sodium (23Na) MRI has been proposed as a potential imaging modality for the characterization of hepatic tumors and for monitoring therapy response. Up to now, only one study has been performed on implanted hepatocellular carcinomas in rats. In the present work, in-vivo 23Na MRI of the healthy human liver is performed and to the best of our knowledge, the hepatic tissue sodium concentration is estimated for the first time. For quantitative 23Na MRI correction methods were applied such as self-gating and B1+ correction. The mean sodium concentration for three volunteers was estimated to be (27±5) mM in the liver. |
| 488
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Pitch: 13:30 Poster: 14:30 Plasma 39
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Simultaneous proton MR fingerprinting and sodium imaging |
1Center for Advanced Imaging Innovation and Research, Department of Radiology, New York University School of Medicine, New York, NY, United States, 2Sackler Institute of Graduate Biomedical Sciences, NYU Langone Health, New York, NY, United States |
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Sodium MRI can provide unique metabolic information to study the human body and its afflictions. However, the low intrinsic signal to noise ratio of sodium MRI limits the resolution of the sodium images to 3-5 mm isotropic and necessitates long acquisition times (~10-20 min). The necessity to perform 1H and 23Na acquisitions sequentially also prolongs the total scan time and limits applications of combined proton-sodium imaging. In this work, we demonstrate a technique to simultaneously acquire sodium images and multi-parametric proton maps in one single scan. |
| 489
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Pitch: 13:30 Poster: 14:30 Plasma 40
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Longitudinal structural change in skeletal muscle tissue of Duchenne muscular dystrophy patients based on 1H- and 23Na-MRI |
1Institute of Radiology, University Hospital Erlangen, FAU, Erlangen, Germany, 2NMR laboratory, Institute of Myology, Paris, France, 3NMR laboratory, CEA/DRF/IBFJ/MIRCen, Paris, France, 4Department of Pediatrics, Division Neuropediatrics, FAU, Erlangen, Germany |
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Duchenne muscular dystrophy (DMD) is a hereditary neuromuscular disease leading to progressive muscle wasting. Here, young DMD boys were examined twice within six months with a MRI protocol that included commonly used biomarkers such as fat fraction derived from the Dixon method and water T2 as well as 23Na MRI indices. Sodium anomalies were commonly observed and developed even in absence of fatty degenerative changes and water T2 increases over the observational period. Although limited in the small number of subjects, the data supports that 23Na could be used to characterize early dystrophic muscle alteration in a longitudinal fashion. |
| 490
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Pitch: 13:30 Poster: 14:30 Plasma 41
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bSSFP vs SSFP acquisitions of 7Li MRI at 7T: Comparison of sensitivity and quantification accuracy |
1CEA, NeuroSpin, Gif-sur-Yvette, France, 2Siemens Healthineers, Erlangen, Germany, 3Hôpital Fernand Widal, Paris, France, 4Hôpital Albert-Chenevier, Créteil, France, 5Neurology, RWTH Aachen University Hospital, Aachen, Germany, 6INSERM UMRS-1144, Hôpital Fernand Widal, Paris, France |
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3D 7Li SSFP and balanced SSFP approaches have been compared by acquiring both datasets from seven euthymic bipolar disorder (BD) patients at 7T. Quantification was performed using the phantom replacement approach accounting for global T1 and T2 relaxation effects. With both methods, heterogeneous brain Li distributions were observed with marked differences in the eyes notably. However, strong correlations between averaged apparent lithium concentrations could be established across all BD patients. While the bSSFP approach is a viable and practical option for 7Li MRI, a more realistic quantification pipeline should be considered in the future. |
| 491 | Pitch: 13:30 Poster: 14:30 Plasma 42
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Glycogen detection in human brain via natural abundance 13C MRS at 7T |
1Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States, 2Radiology, UT Southwestern Medical Center, Dallas, TX, United States, 3Philips Healthcare, Gainesville, FL, United States, 4Pediatrics, UT Southwestern Medical Center, Dallas, TX, United States, 5Chemistry, University of Texas at Dallas, Dallas, TX, United States, 6Internal Medicine, UT Southwestern Medical Center, Dallas, TX, United States |
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Large quantities of abnormally-branched brain glycogen are hypothesized to be accumulating in disorders such as Lafora disease and Adult Polyglucosan Body Disease (APBD). However, non-invasive tools for brain glycogen detection in vivo are lacking. In this work we have used natural abundance 13C MRS at 7T with NOE, to detect glycogen in both normal and APBD brain. Qualitative comparison of the respective glycogen C1 signals in these two cases indicates no dramatic increase of the detectable glycogen concentration in APBD. To our knowledge this is the first human cerebral glycogen detection via natural abundance 13C MRS. |
| 492 | Pitch: 13:30 Poster: 14:30 Plasma 43
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On the magnetic field dependence of deuterium metabolic imaging (DMI) |
1Yale University, New Haven, CT, United States, 2University Medical Center Utrecht, Utrecht, Netherlands |
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Deuterium metabolic imaging (DMI) is a novel, MR-based method to spatially map metabolism. DMI has been shown to provide robust and sensitive maps of cerebral glucose metabolism in healthy volunteers and patients with brain tumors. Here the magnetic field dependence of DMI in terms of sensitivity and resolution is investigated. Using RF coils sized for animal and human studies on magnetic fields ranging from 4T to 11.7T, a supralinear magnetic field dependence of the DMI sensitivity is established. The increased sensitivity of DMI at 7T compared to 4T allows the acquisition of human brain DMI at a 1 mL spatial resolution. |
| 493 | Pitch: 13:30 Poster: 14:30 Plasma 44
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Deuterated water labeling followed by deuterium MRI for visualization of tumors in vivo |
1Experimental Transplantation and Immunology Branch (ETIB), National Cancer Institute (NCI), National Institutes of Health (NIH), Bethesda, MD, United States, 2Radiation Biology Branch, NCI, NIH, Bethesda, MD, United States, 3Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke (NINDS), NIH, Bethesda, MD, United States, 4ETIB, NCI, NIH, Bethesda, MD, United States, 5Radiation Biology Branch (RBB), NCI, NIH, Bethesda, MD, United States, 6Urologic Oncology Branch, NCI, NIH, Bethesda, MD, United States, 7RBB, NCI, NIH, Bethesda, MD, United States |
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In vivo DNA labeling with deuterated water (2H2O) has been used for cell kinetics research and more recently to image rapidly proliferating immune cells in the context of graft-versus-host disease. Using a custom dual-resonance coil (1H-2H) we demonstrate that this approach can be applied to the in vivo detection of tumors via MRI in a xenograft tumor mouse model. Therefore, this novel imaging technique could serve as a sensitive, safe, and non-radioactive method of tumor detection with significant impact on the field of oncology. |
| 494
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Pitch: 13:30 Poster: 14:30 Plasma 45
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Evaluation of trifluoroacetic acid as a theranostic fluorine-19 MRI agent for chemical ablation of solid tissue. |
1Department of Imaging Physics, The UT MD Anderson Cancer Center, Houston, TX, United States, 2Department of Interventional Radiology, The UT MD Anderson Cancer Center, Houston, TX, United States, 3Department of Veterinary Medicine & Surgery, The UT MD Anderson Cancer Center, Houston, TX, United States |
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Chemical ablation therapies are an established treatment for hepatocellular carcinoma, but accurate mapping and monitoring of the ablative agent’s distribution is critical to improving outcomes. We evaluated the theranostic application of trifluoroacetic acid (TFA) as an ablative agent. Fluorine-19 MRI was optimized to image the agent with excellent sensitivity and cine 19F-MRI was developed to demonstrate the feasibility of real-time injection monitoring. Ablation of ex vivo liver tissue demonstrated TFA to be both effective and imageable, even at low concentrations. We conclude that TFA is a promising theranostic agent for ablation of solid tissue. |
13:30
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Imaging Fat in Muscle | |
1Department of Diagnostic and Interventional Radiology, Technical University of Munich, Germany |
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The present educational lecture will provide an overview of the technical aspects of measuring skeletal muscle fat fraction and will discuss recent applications of measuring muscle fat fraction in neuromuscular disorders, orthopedics, metabolic diseases and aging. |
14:00
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Quantitative MRI of Muscle | |
1Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands, 2Translational and Molecular Imaging Institute, Mount Sinai School of Medicine, New York, NY, United States |
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In this educational I will introduce the use of quantitative MRI to study muscle injury and disease and discuss various applications. |
| 495 | 14:30
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Quantification of water T1 and fat fraction in inclusion body myositis using MR fingerprinting with water and fat separation (MRF-WF) |
1NMR Laboratory, Institute of Myology, NIC, Paris, France, 2NMR Laboratory, CEA, DRF, IBFJ, MIRCen, Paris, France |
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We evaluated the accuracy of MR fingerprinting with water and fat separation (MRF-WF) in 22 patients with inclusion body myositis and investigated the potential of water T1 for monitoring disease activity in this inflammatory myopathy characterized by a combination of inflammatory and myodegenerative features. FF and B1 values derived from MRF-WF were highly correlated to reference values and we observed a significant relationship between water T1 and water T2 in the patients. MRF-WF may represent a competitor to the multi-component fitting of MSME data, or to the IDEAL-CPMG method to simultaneously extract biomarkers of disease progression and activity in neuromuscular diseases. |
| 496
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14:42
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Accurate and Fast Reconstruction of Magnetic Resonance Fingerprinting for Water-Fat Separation in Neuromuscular Diseases |
1Institute for Surgical Technology and Biomechanics, University of Bern, Bern, Switzerland, 2NMR Laboratory, Institute of Myology, Paris, France, 3NMR Laboratory, CEA, DRF, IBFJ, MIRCen, Paris, France, 4Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland, 5Support Center for Advanced Neuroimaging (SCAN), Institute for Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland |
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The MR fingerprinting sequence MRF-WF is tailored for water and fat separation imaging for neuromuscular diseases (NMDs). Currently, the adoption of MRF-WF in the clinics is hindered by the long MR map reconstruction time of four hours per image slice. We propose a spatiotemporal convolutional neural network (CNN) to reconstruct the MR maps. We show that our CNN is robust to a highly heterogeneous dataset including patients with various NMDs. The method might be a possible solution for |
| 497
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14:54
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Behavioural intervention in myotonic dystrophy type 1 assessed by longitudinal MRI of skeletal muscles |
1Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, Netherlands, 2Neurology, Radboud university medical center, Nijmegen, Netherlands, 3Neuromuscular Reference Center, Henri Mondor university Hospital, Paris, France, 4Radiology, Henri Mondor university Hospital, Paris, France |
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A behavioural intervention, directed to increase physical activity, had a beneficial effect on lower extremity muscle function in patients with myotonic dystrophy type 1 (DM1). Here, we evaluated potential causes of the effect of this intervention with quantitative MRI in the 20 lower extremity muscles of 27 DM1 patients. We showed that it leads to a ~4% average increase in muscle mass, especially in healthy appearing muscle. Fat infiltration was not decelerated. Therefore, we conclude that some muscles in DM1 patients are trainable, preferably early on in the course of the disease. |
| 498
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15:06
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Effects of Tetrahydrobiopterin on Limb Blood Flow and Muscle Metabolism in Patients with COPD |
1Kinesiology, University of Massachusetts Amherst, Amherst, MA, United States, 2Internal Medicine, University of Utah, Salt Lake City, UT, United States, 3Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, United States, 4Centre de Resonance Magnetique Biologique et Medicale, Marseille, France, 5Radiology and Imaging Services, University of Utah, Salt Lake City, UT, United States |
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Exercise intolerance is an important predictor of mortality in patients with COPD, and evidence shows reduced nitric oxide (NO) bioavailability is a contributing factor. Thus, restoration of NO using BH4, a cofactor involved in NO production, is a novel therapy for improving oxygenation and metabolism in these patients. Patients with COPD performed dynamic plantar flexion exercise with 31P-MRS and vascular Doppler ultrasound assessments following supplementation of BH4. Limb blood flow during exercise was unchanged, however, exercise-induced changes in metabolic measurements were improved with BH4 supplementation. Therefore, BH4 supplementation in patients with COPD appears a promising therapy to improve muscle metabolism. |
| 499
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15:18
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Increased fatty infiltration of individual extraocular muscles in myasthenia gravis and graves’ orbitopathy |
1Neurology and Radiology, CJ Gorter center for high field MRI, Leiden University Medical Center, Leiden, Netherlands, 2Ophthalmology and radiology, CJ Gorter center for high field MRI, Leiden University Medical Center, Leiden, Netherlands, 3Ophthalmology, Leiden University Medical Center, Leiden, Netherlands, 4Neurology, Leiden University Medical Center, Leiden, Netherlands, 5Radiology, CJ Gorter center for high field MRI, Leiden University Medical Center, Leiden, Netherlands |
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We explored the feasibility of 7 Tesla quantitative MRI for quantifying fat fraction and muscle volume of individual extraocular muscles in myasthenia gravis (MG) and Graves’ orbitopathy (GO) patients and healthy controls. The Dixon scans show a high reproducibility for individual extraocular muscles. The fat fractions are higher in MG and GO patients than in healthy controls. Quantitative MRI of individual extraocular muscles may provide a first step to understand the pathophysiology and pattern of muscle involvement of the eyes in MG and GO patients. |
15:30
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Adjournment |
| 500 | 13:30
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Dextran-based CEST MRI for detecting extradomain-B fibronectin in pancreatic cancer |
1Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, United States, 2Department of Radiology, Johns Hopkins University, Baltimore, MD, United States, 3Department of Oncology, Johns Hopkins University, Baltimore, MD, United States, 4F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institue, Baltimore, MD, United States |
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A dextran-peptide conjugate was developed for MR molecular imaging of pancreatic ductal adenocarcinoma (PDAC) through its overexpressed microenvironment biomarker, extradomain-B fibronectin (EDB-FN). Dextrans can be directly detected by chemical exchange saturation transfer (CEST) MRI without the need for radionuclide- or metallic labeling. In addition, large molecular weight dextran, dextran 10 (MW~ 10 kD), provides an approximately fifty times higher sensitivity per molecule than a single glucose unit. The potential of this highly biocompatible diamagnetic probe is demonstrated in a murine syngeneic allograft PDAC tumor model. |
| 501 | 13:42
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Multi-Parametric MRI assessment of pulsed focused ultrasound treated pancreas tumor |
1Department of Radiology, University of Washington, Seattle, WA, United States, 2Applied Physics Laboratory, University of Washington, Seattle, WA, United States, 3Division of Gastroentrology, University of Washington, Seattle, WA, United States, 4Department of Medicine, Stanford, Stanford, CA, United States |
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Pancreatic ductal adenocarcinoma (PDA) is characterized by excessive levels of hyaluronan and collagen, resulting in a dense fibroinflammatory stroma that inhibits penetration of chemotherapeutic drugs into the tumor. Pulsed focused ultrasound (pFUS) treatment has shown promising results in disrupting the dense stroma and reducing the interstitial fluid pressure of PDA. The purpose of this study is to noninvasively assess response to pFUS treatments using quantitative MRI and to correlate the MRI results with histopathology data. |
| 502
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13:54
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Dynamic Oxygen-Enhanced MRI (dOE-MRI) with group ICA detects increased oxygenation in murine tumours treated with VEGF-ablation therapy |
1Physics & Astronomy, University of British Columbia, Vancouver, BC, Canada, 2Oncology, BC Cancer Research Centre, Vancouver, BC, Canada, 3UBC MRI Research Centre, Vancouver, BC, Canada, 4BC Cancer Research Centre, Vancouver, BC, Canada, 5University of British Columbia, Vancouver, BC, Canada |
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Tumours treated with VEGF ablation sustain changes to their vasculature, which can result in tissue oxygenation changes. This work uses dynamic oxygen enhanced MRI (dOE-MRI) to assess oxygenation of murine SCCVII tumours treated with B20-4.1.1 (murine anti-VEGF antibody) relative to controls. T1-weighted parameter maps and a modified ICA quantitative analysis technique, groupICA, describe an increase in B20-treated tumour oxygenation. |
| 503 | 14:06
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Dynamic OE-MRI Mapping of Lung Parenchymal Radiotherapy Effects in Non-Small Cell Lung Cancer Patients |
1Quantitative Biomedical Imaging Laboratory, University of Manchester, Manchester, United Kingdom, 2Division of Cancer Sciences, University of Manchester, Manchester, United Kingdom, 3The Christie NHS Foundation Trust, Manchester, United Kingdom, 4Division of Neuroscience and Experimental Psychology, University of Manchester, Manchester, United Kingdom, 5Bioxydyn Limited, Manchester, United Kingdom |
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Radiation induced lung disease (RILD) can occur following thoracic irradiation, chemotherapy and immunotherapy in lung cancer patients, manifesting as inflammation, radiation pneumonitis or fibrosis. Oxygen Enhanced (OE)-MRI provides spatial information on oxygen delivery to lung tissue. Five non-small cell lung cancer patients underwent OE-MRI pre and post radiotherapy. Statistically significant changes were measured between pre and post radiotherapy scans in both the contralateral and ipsilateral lungs. These findings indicate that OE-MRI can assess changes in lung function following radiotherapy, with potential application for personalised therapy and reduction of toxicity. |
| 504 | 14:18
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Prediction of Breast Cancer Response to Neoadjuvant Chemotherapy with High b-Value Non-Gaussian Diffusion MRI |
1Center for Magnetic Resonance Research, University of Illinois at Chicago, Chicago, IL, United States, 2Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, United States, 3Department of Radiology, Cancer Hospital, Chinese Academy of Medical Sciences, Beijing, China, 4Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, IL, United States, 5Departments of Radiology and Neurosurgery, University of Illinois at Chicago, Chicago, IL, United States |
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Neoadjuvant chemotherapy has been used to extend surgical options by downstaging tumor in both locally advanced and operable breast cancer. An early imaging assessment of tumor response to neoadjuvant chemotherapy is critical for timely tailoring personalized treatment strategies. In this study, we investigate whether the changes in the parameters derived from a non-Gaussian diffusion model – continuous-time random-walk (CTRW) model – are predictive of pathologic response in women undergoing neoadjuvant chemotherapy. Our results demonstrate the high predictive performance of the combined changes in CTRW parameters from pre-treatment levels as early as the second cycle of chemotherapy. |
| 505
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14:30
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Utilizing deep learning for automatic longitudinal assessment of brain tumor response based on RANO criteria |
1Sagol Brain Institute, Tel Aviv Sourasky Medical Center, Tel - Aviv, Israel, 2The Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Tel - Aviv, Israel, 3Sackler Faculty of Medicine, Tel Aviv University, Tel - Aviv, Israel, 4Sagol School of Neuroscience, Tel Aviv University, Tel - Aviv, Israel, 5Division of Radiology, Tel Aviv Sourasky Medical Center, Tel - Aviv, Israel, 6Neuro-Oncology Service, Tel Aviv Sourasky Medical Center, Tel - Aviv, Israel |
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The aim of this study was to implement a deep-learning approach for automatic therapy response assessment in patients with high-grade-glioma (HGG), based on the response-assessment in neuro-oncology (RANO) criteria. A total of 135 conventional MRI scans from 67 patients were included. A neural network with a U-net architecture was trained for identification and subsegmentation of lesion components. The similarity coefficient score between segmentation results and ground truth was 0.88±0.06. Consistency in therapy response assessment was obtained in the majority of cases. These results demonstrate the potential applicability of the proposed method for automatic therapy response assesment in patients with HGG. |
| 506 | 14:42
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Multiparametric Advanced Fast Imaging (MAFI) to Characterize Tumor Habitat in Orthotopic Mouse Models of Pediatric Brain Tumors |
1Radiology, University of Colorado Denver, Aurora, CO, United States, 2University of Colorado Denver, Aurora, CO, United States, 3Neurooncology, Children's Hospital Colorado, Aurora, CO, United States |
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Brain tumors are the second most common malignancy in childhood (exceeded only by leukemia). Clinically, multiparametric MRI is now considered to be the neuroimaging standard for detecting brain tumors. Pediatric brain tumors have a diverse array of clinical manifestations, cellular and molecular phenotypes, and tumor habitats. There is an unmet need to develop human-faithful pediatric mouse models and fast high-resolution physiological MRI for their detection and characterization. Here, we report on a non-gadolinium, Multiparametric Advanced Fast Imaging (MAFI) approach followed by radiomics analysis to detect, characterize and differentiate three distinct brain tumor subtypes in mouse patient-derived xenograft (PDX) models. |
| 507 | 14:54
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Identification of early stage murine pancreatic tumors by a combinatorial approach employing SPEN DWI, FLAIR T1 and hyperpolarized 13C MRI |
1Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel, 2The Moross Integrated Cancer Research Center, Weizmann Institute of Science, Rehovot, Israel |
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Pancreatic ductal adenocarcinoma has a poor prognosis. This study explored the use of a multimodal screening approach on a preclinical mouse PDAC model that included T1 and T2 mapping, SPatiotemporal ENcoding (SPEN) and EPI-based DWI, and MT methods, and hyperpolarized 13C metabolic MRSI, to follow the progress of the disease from early on. Whereas T2 and MT were of little help, markedly decreased diffusivity, extended T1s and significantly higher metabolic activities could be detected for large and small tumors alike. These approaches could provide a translatable approach to the early noninvasive detection of pancreatic cancer, leading to timely treatment. |
| 508 | 15:06
|
Characterization of metabolic adaptations of patient-derived xenografts to in vitro tissue and cell culture using high-resolution NMR |
1Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States, 2Urology, Stanford University, Stanford, CA, United States |
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In this study we investigated the metabolic changes that occurred when a renal cell carcinoma patient-derived xenograft was propagated in tissue slice culture or primary cell culture at varying pO2 levels to understand the attributes and limitations of each of the model systems for studying the metabolic underpinnings of this pathology using high resolution NMR. This data indicates drastically altered metabolism at varying pO2 and between each model system. |
| 509 | 15:18
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Does ADC better predict tumour cellularity or necrosis? A multi-centre multi-vendor study in twelve rodent tumour models |
1University of Manchester, Manchester, United Kingdom, 2Cancer Research UK Cambridge Institute, Cambridge, United Kingdom, 3AstraZeneca, Cambridge, United Kingdom, 4INSERM Center for Research on Inflammation, Paris, France, 5Imperial College, London, United Kingdom, 6Radboud University Medical Center, Nijmegen, Netherlands, 7European Institute for Molecular Imaging, University of Münster, Münster, Germany, 8TRIC, University Hospital, University of Münster, Münster, Germany, 9STFC, Daresbury, United Kingdom, 10Bioxydyn, Manchester, United Kingdom |
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We studied tumour Apparent Diffusion Coefficient (ADC), necrosis and cellularity in untreated rodent tumours of twelve types from six centres using two different vendors’ equipment. Tumour types included human xenografts (conventional and patient-derived) genetically engineered mouse tumours and syngeneic rat tumours. Across this broad spectrum there was a robust inverse correlation between ADC and cellularity, and a weaker positive correlation between ADC and necrosis. ADC mean and median were the best correlates for cellularity, while ADC standard deviation and kurtosis provided the best correlates for necrosis. This work advances the biological validation of ADC as a biomarker of tumour cellularity. |
| 510
|
13:30
|
Simultaneous linear-combination modeling of MEGA-PRESS sum and difference spectra without soft constraints |
1Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States, 3Institute of Pathophysiology, Medical Faculty, University of Ljubljana, Ljubljana, Slovenia |
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J-difference edited magnetic resonance spectroscopy is widely used to estimate levels of low-concentration metabolites with overlapping signals. Quantification is commonly performed on the difference spectra only, either using single-resonance fitting or linear-combination modeling based on simulated basis functions. Here, simultaneous linear-combination modeling of GABA-edited MEGA-PRESS sum and difference spectra is demonstrated. Simultaneous modeling incorporates all available spectral information, and does not require the definition of soft constraints on the low-concentration metabolite estimates. Across a large dataset, this new approach gave lower coefficients of variation for estimates of GABA, glutamate, and glutamine than modeling of the difference and sum spectra only. |
| 511
|
13:42
|
Robust Correction of Frequency and Phase Errors in Edited MRS Data |
1Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States, 3Douglas Mental Health University Institute and Department of Psychiatry, McGill University, Montreal, QC, Canada, 4Center for Neurodevelopmental and Imaging Research, Kennedy Krieger Institute, Baltimore, MD, United States, 5Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 6Department of Psychiatry and Behavioral Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD, United States |
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MRS data are subject to shot-to-shot frequency and phase errors that often arise from B0 field drift and participant motion. These result in misalignment of individual subspectra, leading to signal loss and—in the case of J-difference editing—subtraction artifacts. Here, we present a frequency-and-phase correction algorithm, built upon the time-domain-based spectral registration method, that is robust against alignment errors resulting from large B0 field drift, substantial head motion and strong lipid contamination. The method has the same strengths as standard spectral registration but outperforms it in challenging cases and is applicable to multiplexed edited MRS data. |
| 512 | 13:54
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Effects of Carrier Frequency Mismatch on Frequency-Selective Spectral Editing |
1National Institute of Mental Health, National Institutes of Health, Bethesda, MD, United States |
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This study investigated the effects of carrier frequency mismatch on spectral editing and its correction by frequency matching of basis functions. Full density matrix computations and Monte Carlo simulations based on MRS data collected from five healthy volunteers at 7 T were used to analyze the effects of carrier frequency mismatch on spectral editing. There were significant errors in metabolite quantification without frequency matching of basis functions when carrier frequency mismatch was generally considered negligible. By matching basis functions with the history of frequency deviation, errors in glutamate, glutamine, g-aminobutyric acid, and glutathione concentrations were significantly reduced. |
| 513 | 14:06
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Prospective motion correction in single voxel spectroscopy at 7T using fat navigators and higher order shimming |
1Philips Healthcare, Copenhagen, Denmark, 2Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark, 3Center for Magnetic Resonance, Department of Electrical Engineering, Technical University of Denmark, Lyngby, Denmark |
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Navigator based motion correction is shown for single voxel spectroscopy at 7T, utilizing fat-selective navigators and static higher order shims, but with linear shims that are switched between 2 sets for the navigator and spectroscopy sub-sequences. |
| 514
|
14:18
|
Longitudinal Relaxation Times of Metabolites in vivo at 9.4 T |
1MRZ, Max Planck Institute for Biological Cybernetics, Tuebingen, Germany, 2IMPRS for Cognitive and Systems Neuroscience, Eberhard-Karls University of Tübingen, Tuebingen, Germany |
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Longitudinal relaxation times for 11 human brain metabolites are reported for GM and WM rich voxels at 9.4T. These values are reported to potentiate the ability to perform absolute quantification at 9.4T in humans with reference to water. A bi-exponential model was used to fit the signal curve from using an inversion recovery metabolite cycling STEAM sequence. Results are further extrapolated to report the T1-relaxation from a theoretically pure WM and GM voxel by means of a linear assumption of the relaxation time and tissue contribution of a voxel. |
| 515 | 14:30
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Towards absolute quantification of brain metabolites using Electronic REference To access In vivo Concentrations (ERETIC) for MR spectroscopic imaging (MRSI) |
1Dept. of Radiology, MGH, A. A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States, 2Harvard Medical School, Boston, MA, United States, 3Mittelhessen University of Applied Science, Giessen, Germany, 4Siemens Healthcare, Erlangen, Germany, 5Siemens Medical Solutions USA, Charlestown, MA, United States |
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Absolute quantification of metabolite concentration from MRSI data requires a reference signal of known concentration. An external synthetic electronic reference signal method (Electronic REference To access In vivo Concentrations – ERETIC) has shown great promise for absolute quantification and calibration. However, ERETIC based absolute quantification is challenging for MR spectroscopic imaging (MRSI) data and here we set on investigating strategies and performance of ERETIC in combination with MRSI and multi-channel receive arrays. |
| 516
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14:42
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Estimation of Brain Tissue Composition and Voxel Location in MR Spectroscopy Using Neural Networks |
1Radiology, Brigham and Women's Hospital, Boston, MA, United States, 2Electrical and Computer Engineering, Boston University, Boston, MA, United States |
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This work presents a machine learning method to estimate the tissue partial volumes of gray matter (GM), white matter (WM) and cerebrospinal fluid (CSF), in a given MR spectroscopy voxel, providing an alternative to the standard time‑intensive MRI segmentation pipeline. The tissue composition was determined |
| 517 | 14:54
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MR SPECTROSCOPY ARTIFACT REMOVAL WITH U-NET CONVOLUTIONAL NEURAL NETWORK |
1CREATIS, CNRS UMR 5220, Lyon, France |
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In in vivo MR spectroscopy, a variety of artifacts may affect spectral quality and are not easy to detect and remove by non-experts. A U-NET architecture is proposed to remove artifacts from MRS spectra with deep learning. The principle is demonstrated on synthetic simulated data mimicking in vivo conditions. |
| 518
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15:06
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Accelerated Spectral Fitting Using Convolutional Neural Networks |
1Radiation Oncology, Emory University, Atlanta, GA, United States, 2Radiology and Imaging Sciences, University of Miami, Miami, FL, United States, 3Biomedical Informatics, Emory University, Atlanta, GA, United States, 4Radiology and Imaging Sciences, Emory University, Atlanta, GA, United States |
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3D whole-brain spectroscopic MRI can measure quantitative metabolite concentrations without any contrast agents and is useful in identifying occult glioblastoma beyond that seen on standard MRI. However, a key hurdle in its widespread adoption is spectral fitting, which can take up to an hour for scan consisting of ~10,000 voxels. In this work, we develop a deep learning architecture for rapid spectral fitting within the context of an a priori spectral model. We demonstrate that this architecture can perform whole-brain spectral fitting in <30 seconds, pushing spectroscopic MRI towards on-board scanner processing to fit in the rapid clinical workflow. |
| 519 | 15:18
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High-Resolution Magnetic Resonance Spectroscopic Imaging quantification by Convolutional Neural Network |
1CIBM - Faculty of medicine, University of Geneva, Geneva, Switzerland |
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High-resolution magnetic resonance spectroscopic imaging quantification at 3T is affected by a poor signal to noise ratio as well as signal contamination from macromolecules and field inhomogeneities. For the metabolite identification problem, the convolutional neural network (CNN) algorithm seems to be a very adapted tool. We demonstrate here the performance our CNN on metabolite concentration estimation compared to the well-used LCModel. Achieving better accuracy on simulated datasets, we obtained also comparable results as LCModel on concentration maps on in-vivo data but with 103 times less computing time. |
| 520
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13:30
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High-resolution multiparametric quantitative MRI of the cervical spinal cord at 7T: preliminary results at the early stage of multiple sclerosis |
1Aix-Marseille Univ, CNRS, CRMBM, Marseille, France, 2APHM, Hôpital Universitaire Timone, CEMEREM, Marseille, France, 3iLab-Spine - Laboratoire international - Imagerie et Biomécanique du rachis, Marseille, France, 4APHM, Hôpital Universitaire Timone, Service de Neurologie, Marseille, France, 5APHM, Hôpital Universitaire Timone, Service de Neuroradiologie, Marseille, France |
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In this exploratory study, a high-resolution multiparametric quantitative MRI protocol including T1 mapping and diffusion tensor imaging was used to explore the cervical spinal cord of multiple sclerosis patients at 7T, in comparison to healthy controls. These patients were also explored at 3T to investigate the potential benefits of 7T MRI in terms of lesion detection and delineation. The obtained preliminary results showed an improved qualitative anatomical depiction when compared to clinical fields and for the first time an in vivo multiparametric quantitative characterization of the pathological cervical spinal cord in multiple sclerosis at ultra-high field. |
| 521 | 13:42
|
Spinal cord atrophy in Neuromyelitis Optica is associated to spinal cord lesions and clinical disability |
1Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 2Department of Neurology, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 3Clinic of Neurology, Faculty of Medicine, University of Belgrade, Belgrade, Yugoslavia |
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Although spinal cord involvement is one of the major magnetic resonance imaging (MRI) and clinical finding in Neuromyelitis Optica (NMO), there is a lack of quantitative studies in this field. This study quantifies and localizes spinal cord atrophy in 40 NMO patients and assesses its relationship with spinal cord lesions and clinical variables. Differently from what happens in multiple sclerosis, NMO cord atrophy seems related to the occurrence of spinal cord lesions and not to a more diffuse damage. Atrophy measures are strongly correlated with global EDSS and its pyramidal and sensitive subscores, suggesting its clinical relevance. |
| 522
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13:54
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An exploratory study to evaluate the potentiality of advanced multi-parametric MRI for longitudinal follow-ups of patients with Neuromyelitis optica spectrum disorder |
1Aix-Marseille Université, CNRS, CRMBM, Marseille, France, 2AP-HM, Hôpital Universitaire Timone, CEMEREM, Marseille, France, 3Department of Neurology, CHU Timone, AP-HM, Marseille, France, 4Department of Neurology, CHU Lyon, Hôpital Pierre Wertheimer, Lyon, France |
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The temporal pattern of spinal cord (SC) tissue changes in Neuromyelitis optica spectrum disorder, a rare neuro-inflammatory condition, was evaluated for the first time using a multi-parametric MR protocol covering the whole cervical SC (high-resolution T2*-weighted anatomical imaging, diffusion tensor imaging (DTI), 3D-MP2RAGE T1-mapping, conventional and inhomogeneous Magnetization Transfer (MT/ihMT) imaging). Results showed substantial pathological variations of all MR metrics at baseline in agreement with the presence of a multi-level inflammatory lesion and a temporal pattern suggesting progressive recovery to control values, with T1 values being the most sensitive to temporal changes and showing residual tissue destructuration following the myelitis. |
| 523 | 14:06
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Reproducibility of Quantitative Cervical Spinal Cord MRI for Multi-center Clinical Trials in Multiple Sclerosis |
1Icahn School of Medicine at Mount Sinai, New York, NY, United States, 2Touro college of osteopathic medicine, New York, NY, United States, 3Washington University in St. Louis, St. Louis, MO, United States |
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Quantitative cervical spinal cord (C-spine) MRI offers promising biomarkers for progressive multiple sclerosis (MS). The intra- and inter-site, short- and long-term reproducibility of these quantitative C-spine MRI measurements is crucial for designing longitudinal or multi-site study. In this two-site pilot study, we evaluated the reproducibility of quantitative C-spine MRI and demonstrate the feasibility of multi-site study with high reproducibility using a harmonized protocol. |
| 524 | 14:18
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Does myelin content heterogeneity in the spinal cord reflect disability in multiple sclerosis? |
1Medicine, University of British Columbia, Vancouver, BC, Canada, 2Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada, 3International Collaboration on Repair Discoveries (ICORD), Vancouver, BC, Canada, 4Radiology, University of British Columbia, Vancouver, BC, Canada, 5Pathology & Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada, 6Biomedical Engineering, University of British Columbia, Vancouver, BC, Canada |
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The spinal cord is inherently more difficult to image than brain resulting in fewer MRI studies in multiple sclerosis (MS) patients. We used GRASE-derived myelin water fraction (MWF) mean (myelin content) and standard deviation (SD; myelin content heterogeneity) to better understand MS cervical spinal cord pathology compared to healthy controls. We found significant differences in cervical spinal cord MWF SD between progressive MS, relapsing-remitting MS and healthy controls. Further, MWF SD was correlated with disability measures in progressive MS. Our findings suggest that MWF SD as a measure of myelin abnormality in cervical cord relates to disability in MS. |
| 525 | 14:30
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Improving longitudinal spinal cord atrophy measurements in multiple sclerosis using the Generalised Boundary Shift Integral |
1Department of Neuroinflammation, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom, 2Department of Neurosciences, Federico II University, Naples, Italy, 3National Institute for Health Research (NIHR), University College London Hospitals (UCLH) Biomedical Research Centre, London, United Kingdom, 4Centre for Medical Image Computing (CMIC), Department of Medical Physics and Bioengineering, University College London, London, United Kingdom, 5Universitat Oberta de Catalunya, Barcelona, Spain, 6Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 7Neurocenter of Southern Switzerland, Ospedale Regionale di Lugano, Lugano, Switzerland, 8Department of Medical, Surgical, Neurologic, Metabolic and Aging Sciences, University of Campania Luigi Vanvitelli, Naples, Italy, 9MRI Research Center SUN-FISM, Institute of Diagnosis and Care (IDC) Hermitage-Capodimonte, Naples, Italy, 10MR Unit and Section of Neuroradiology, Department of Radiology, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain, 11Department of Neurology, Universitätsmedizin Mannheim, University of Heidelberg, Mannheim, Germany, 12Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, United Kingdom, 13St. Josef Hospital, Ruhr University, Bochum, Germany, 14Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, Netherlands |
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Spinal cord atrophy is a clinically-relevant feature of multiple sclerosis (MS), but can be difficult to estimate longitudinally using segmentation-based methods. We applied a fully-automated registration-based technique for spinal cord atrophy measurement (Generalised Boundary Shift Integral-GBSI-) on MS patients (n=282) and controls (n=82), from MAGNIMS and Queen Square cohorts. GBSI provided similar spinal cord atrophy rates, compared with cervical cord cross-sectional area (CSA), but with lower variability and favourable sample size estimates. GBSI performed better than CSA in differentiating cases from controls, and in depicting MS clinical features. GBSI could be used to monitor disease progression and in neuroprotective trials. |
| 526 | 14:42
|
Spine atrophy and sensory-motor disability in African Americans with Multiple Sclerosis |
1Neurology, Department of Neurology, Icahn School of Medicine at Mount Sinai, NEW YORK, NY, United States, 2Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, and Mother-Child health, University of Genoa, Genoa, Italy, 3Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 4Department of Neurology, Columbia University Medical Center, New York, NY, United States, 5Department of Neurology, New York University School of Medicine, New York, NY, United States, 6Department of Neurology, Icahn School of Medicine, New York, NY, United States, 7Department of Neurology, Radiology and Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States |
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African Americans with multiple sclerosis (MS) present a more severe disease course than Caucasians with MS, but the contribution of spinal lesions and cervical spinal cord damage to clinical disability has never been explored. In the present study, we investigated the extent of cervical spinal cord (CSC) damage in AA MS patients compared to age-, sex- and race matched healthy controls. Our study showed that CSC damage in terms of both macroscopic lesions and atrophy significantly impacts motor and sensory performances in AA with MS. |
| 527 | 14:54
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7T MRI Shows Enlarged Anterior Vein in the Spinal Cord of Multiple Sclerosis Patients |
1Vanderbilt University Institute of Imaging Science, Nashville, TN, United States, 2Harpeth Hall High School, Nashville, TN, United States, 3Neuroscience Graduate Program, Vanderbilt University, Nashville, TN, United States, 4Department of Radiology, Monroe Carell Jr Children's Hospital at Vanderbilt, Nashville, TN, United States |
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T2*-weighted Gradient Echo (T2*FFE) were collected at 7-Tesla in patients with relapsing-remitting multiple sclerosis (MS) and healthy controls for a more detailed image of the spinal cord, specifically the vasculature of the spinal cord. Analyzing the anterior vein may provide insight into the connection between the vasculature and lesion presence in the spinal cord of MS patients. Our results demonstrate significantly enlarged anterior veins in MS patients compared to healthy controls. The anterior vein in the spinal cord has not been studied in great detail prior to this study. |
| 528 | 15:06
|
Using Quantitative MT- and CEST-derived Metrics to Evaluate Longitudinal Tissue Changes in the Spinal Cord of Multiple Sclerosis Patients at 3T |
1Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, 2Vanderbilt University Institute of Imaging Science, Nashville, TN, United States, 3Phillips Healthcare, Baltimore, MD, United States, 4University of Oxford, Oxford, United Kingdom, 5Department of Neurology, Vanderbilt University, Nashville, TN, United States, 6Department of Radiology and Radiological Science, Vanderbilt University, Nashville, TN, United States |
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Conventional T1 and T2 weighted MRI are ubiquitously used to diagnose and monitor disease progression in multiple sclerosis, but are only sensitive to later-stage inflammatory lesions and atrophy. Imaging biomarkers sensitive to tissue changes earlier in disease pathology may have significant implications in the diagnosis and prognosis of MS. Quantitative magnetization transfer (qMT) and chemical exchange saturation transfer (CEST) MRI have shown sensitivity to macromolecules and tissue biochemistry, respectively. In this work, we investigate quantitatively derived metrics from qMT and CEST as potential biomarkers for pathological changes which precede lesion formation. |
| 529 | 15:18
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Quantitative MRI with spatiotemporal normalization can detect longitudinal changes in primary lateral sclerosis cervical spinal cord |
1Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada, 2International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada, 3Institute of Psychiatry, Psychology & Neuroscience, King's College, London, United Kingdom, 4Radiology, University of British Columbia, Vancouver, BC, Canada, 5Kinesiology, University of British Columbia, Vancouver, BC, Canada, 6Medicine, University of British Columbia, Vancouver, BC, Canada |
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Analysis of longitudinal quantitative MRI data can be confounded by a variety of factors. We use spatiotemporal normalization and a symmetric diffeomorphic normalization algorithm to compare quantitative MRI metrics in a patient-specific halfway space. Utilizing these methods, myelin water imaging and diffusion tensor imaging were able to detect changes in primary lateral sclerosis (PLS) spinal cord similar to those found in the faster-progressing amyotrophic lateral sclerosis (ALS). Future studies could employ spatiotemporal normalization with more subjects and imaging timepoints to investigate the use of longitudinal MWI and DTI as a biomarker for motor neuron disease progression. |
| 530
|
13:30
|
Resting-State “Physiological” Networks |
1Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, United States, 2Department of Radiology, Harvard Medical School, Boston, MA, United States, 3Biomedical Engineering, Boston University, Boston, MA, United States, 4Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN, United States, 5Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Cambridge, MA, United States |
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In this abstract, we offer a systemic characterization of the spatiotemporal patterns of fMRI signals subsequent to slow fluctuations in respiratory volume and heart rate. We show that these slow physiological dynamics contain structured network patterns that are somewhat consistent across individuals. We also show that global signal regression (GSR) may introduce anti-correlating patterns of the physiological dynamics to the final observations of functional connectivity. |
| 531 | 13:42
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Contribution of sympathetic vasoconstriction to the fMRI global signal during autonomic arousals |
1NINDS, NIH, Bethesda, MD, United States, 2Vanderbilt University, Nashville, TN, United States, 3UC Irvine, Irvine, CA, United States |
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Recent work has suggested that the fMRI global signal (GS) in part may result from activity carried by the extensive sympathetic innervation of the extraparenchymal arteries of the brain. One of the pathways that potentially triggers sympathetic activity is the phenomenon of subcortical (autonomic) arousal, which is closely associated with the K-complex, a signature event observed in scalp EEG. In this work, we analyzed previously acquired data during sleep, and showed a strong association between fMRI GS, K-complexes, and photoplethysmography (PPG) from the finger skin, a proxy for sympathetic activity. Since sympathetic activity may be variable and elicited by a variety of stimuli during both sleep and wake, it likely plays an important, while largely overlooked role in most fMRI experiments. |
| 532
|
13:54
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Pharmacological stimulation of cholinergic activity alters brain-wide spontaneous fMRI network dynamics |
1Neural Computation Laboratory, Istituto Italiano di Tecnologia, Center for Neuroscience and Cognitive Systems @ UNITN, Rovereto, Italy, 2CIMeC, Center for Mind/Brain Sciences, University of Trento, Rovereto, Italy, 3Functional Neuroimaging Laboratory, Istituto Italiano di Tecnologia, Center for Neuroscience and Cognitive Systems @ UNITN, Rovereto, Italy |
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We recently demonstrated that resting-state fMRI (rsfMRI) network dynamics can be mapped with voxel-resolution in the mouse, and that oscillatory state transitions govern rsfMRI network dynamics in the resting mouse brain. Here we show that pharmacological modulation of cholinergic activity strongly affects the spatio-temporal dynamics of rsfMRI state fluctuations, encompassing novel spatial topographies and altered spatio-temporal dynamics. Our results implicate ascending cholinergic activity in the generation of oscillating fMRI states in the resting brain. |
| 533 | 14:06
|
Modulation of resting-state functional MRI signal by astrocyte |
1National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, United States, 2National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan |
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Although resting-state functional MRI (rs-fMRI) is extensively used to study brain circuitry, recent animal studies suggest a non-neuronal origin of the rs-fMRI signal. We hypothesized that astrocytes may play an important role in rs-fMRI signal. We used chemogenetic technology to selectively activate astrocytes (increasing Ca2+ levels) and recorded rs-fMRI signals in lightly anesthetized rats. Chemogenetic activation of astrocytes following 0.1 mg/kg of clozapine injection induced signal intensity changes and reduced functional connectivity. These in vivo results are consistent with previous brain slice studies, confirming a potentially important role of astrocytes in rs-fMRI signals. |
| 534
|
14:18
|
Negative BOLD responses in the rat visual pathway |
1Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown, Lisbon, Portugal |
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Negative BOLD responses (NBRs) in the rat visual cortex (VC) are reported, for the first time, upon high frequency visual stimulation. So far, in rats, only an attenuation of the positive BOLD response (PBR) in VC had been reported with increase of the stimulus frequency up to 10-12Hz1,2. Here, experiments with very high sensitivity thanks to a cryoprobe operating at 9.4T, reveal NBRs in VC and how they are modulated by hyperoxia (already reported for PBRs3,4). Results suggest the possibility that the neurovascular couplings operating under PBRs and NBRs might not be the same. |
| 535 | 14:30
|
Characterization of BOLD hemodynamic response function in subcortical and cortical regions of human brain at 3T and 9.4T |
1Baylor College of Medicine, Houston, TX, United States, 2University of Tuebingen, Tuebingen, Germany, 3Max Planck Institute for Biological Cybernetics, Tubingen, Germany |
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Measurement of blood oxygen level dependent hemodynamic response function (BOLD HRF) can be used to evaluate neurovascular coupling and understand underlying physiology (e.g. oxygen uptake and blood flow). However, there is dearth of understanding subcortical neurovascular coupling, which is critical for brain health. Here, we characterize human subcortical HRFs at both 3T and 9.4T and compare them with HRFs in visual cortex. |
| 536 | 14:42
|
Testing temporal dependence of spatial specificity in BOLD fMRI at 7T: comparing short versus long stimulus duration |
1Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 2Department of Radiology, Harvard Medical School, Charlestown, MA, United States, 3Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States |
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The spatial specificity of the BOLD-fMRI response has previously been shown to vary systematically across cortical depths, with highest specificity found in voxels furthest from the pial surface, while highest sensitivity of the response is found in voxels closest to the pial vessels. Analogous trade-offs between spatial specificity and sensitivity can be appreciated in the temporal evolution of the BOLD-fMRI response. Here we investigate spatial specificity of the response to both short-duration and long-duration stimuli as they evolve in time using high-resolution BOLD-fMRI at 7T, and demonstrate that BOLD-fMRI response exhibits high specificity both at early and late time points. |
| 537
|
14:54
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Prospects for improving neuronal specificity of fMRI with Ferumoxytol: an evaluation of vascular segmentation and cortical depth-dependent analysis |
1Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, MA, United States, 2Department of Radiology, Harvard Medical School, Boston, MA, United States, 3Division of Hematology, Massachusetts General Hospital, Boston, MA, United States, 4Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, MA, United States |
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Ferumoxytol, a superparamagnetic iron oxide nanoparticle, is commonly used as an intravenous treatment for anemia, but has been recently employed as a blood-pool contrast agent for MRI. Here we evaluated Ferumoxytol as a tool to improve the neuronal specificity of fMRI using it for both improved vascular segmentation and for CBV-weighted functional contrast. We employed multi-echo gradient recalled echo (ME-GRE) acquisitions with functional imaging pre and post injection, performed vascular extraction/segmentation, and report apparent quantitative CBV changes surrounding vessels as a function of echo-time. This work demonstrates the possibility of high-resolution CBV mapping, gray- and white-matter angiography, and cortical depth-dependent analyses with this contrast agent. |
| 538 | 15:06
|
Hyperoxia calibrated fMRI for dynamic mapping of CMRO2 responses using MR-based measurements of whole-brain Yv: Comparison to standard calibration models and measurement of CMRO2 response to finger tapping |
1Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Department of Radiology, University of Navarra, Pamplona, Spain, 3Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States |
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The magnitude of neurometabolic responses to stimuli can be quantified using calibrated fMRI. Here we compare existing calibration models to Yv-based calibration. The Yv-based calibration model measures whole-brain venous oxygen saturation in the superior sagittal sinus along with BOLD changes and ASL-measured CBF changes to derive maps of the calibration constant, M, in response to a hyperoxia stimulus. M-maps were compared between the proposed and existing calibration models. Then, relative CMRO2 changes in response to a finger tapping task were computed based on the derived M-maps. A ~19% increase in CMRO2 in the motor cortex was observed. |
| 539 | 15:18
|
Non-contrast assessment of BBB permeability using WEPCAST MRI: validation with contrast-agent based method |
1Department of Radiology, Johns Hopkins University, Baltimore, MD, United States, 2Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States, 3Department of Radiation Oncology, St. Jude Children's Research Hospital, Memphis, TN, United States |
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Water-extraction-with-phase-contrast-arterial-spin-tagging (WEPCAST) MRI was recently proposed for non-contrast assessment of blood-brain barrier (BBB) permeability to water. However, this approach has not been directly compared with contrast-based method. In this study, we used Gd-based MRI method to validate the WEPCAST MRI. Two methods provide consistent results, suggesting that WEPCAST MRI has a potential to become an alternate to clinical contrast-based BBB permeability assessment. |
| 540 | 13:30
|
CEST MRI with distribution-based analysis for assessment of early stage disease activity in a multiple sclerosis mouse model |
1Russell H. Morgan Dept. of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States, 2Dept. of Neurology, Hainan General Hospital, Haikou, China, 3Cellular Imaging Section, Institute for Cell Engineering, Johns Hopkins University, Baltimore, MD, United States, 4Dept. of Information Sciences and Technology, Northwest University, Xi'an, China |
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Imaging biomarkers that can detect pathological alterations earlier in multiple sclerosis (MS) progression may enable earlier intervention and improved therapeutic efficacy of available treatments. Here we assessed disease manifestations at an early stage using CEST MRI in a preclinical MS model with histogram-guided analysis. The analysis method is simple-to-execute and robust for evaluation of diseases with subtle changes that lack a priori knowledge of abnormal regions of interest (ROIs) and have multiple potentially contributing offsets. We demonstrated that CEST Z-spectra signals at 1 and 2 ppm are potential MRI biomarkers for detecting early and subtle pathological changes in EAE mice. |
| 541
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13:42
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Ultrashort echo time magnetization transfer (UTE-MT) imaging in the cuprizone mouse model of multiple sclerosis |
1Physical Therapy and Rehabilitation Science, University of California San Francisco, San Francisco, CA, United States, 2Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, 3Pharmaceutical, Veterinary and Biomedical Sciences, Bio-Imaging Laboratory, Antwerp, Belgium, 4Berkeley and University of California, UC Berkeley-UCSF Graduate Program in Bioengineering, San Francisco, CA, United States |
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We first evaluated the potential of ultrashort echo time magnetization transfer (UTE-MT) and MT imaging to generate high contrast images of the healthy mouse brain. Next, we conducted a longitudinal study to examine the temporal changes of UTE-MT ratio (UTE-MTR) and MTR following cuprizone (CPZ)-mediated demyelination, gliosis, and remyelination. UTE-MTR detected CPZ-induced alterations in white matter, subcortical, and cortical grey matter during demyelination, and persistent tissue microstructure changes in grey matter. Furthermore, UTE-MTR changes correlated significantly with myelin levels. Altogether, we showed that UTE-MT imaging holds great potential to improve characterization of brain lesions in MS at clinical field strength. |
| 542
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13:54
|
Sequential and Deep Multi-Pool CEST MR Fingerprinting in In-Vivo Tumor-Bearing Mice |
1A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, United States, 2Memorial Sloan Kettering Cancer Center, New York, NY, United States, 3Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, United States |
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Magnetic resonance fingerprinting (MRF) was recently suggested for fast and quantitative chemical exchange saturation transfer (CEST) imaging. However, for in-vivo pathologies, multiple tissue parameters will vary simultaneously, thereby reducing the schedule discrimination ability and increasing the reconstruction time. Herein, we propose the sequential utilization of three MRF acquisition schedules and their incorporation in deep-learning reconstruction networks (DRONE). The technique outputs 6 quantitative maps (water, semi-solid, and amide pool properties) with acquisition and reconstruction times of 365s and <200ms, respectively. The method was evaluated in a longitudinal brain-tumor mouse study, yielding comparable parameter values to ground-truth and traditional Z-spectrum evaluations. |
| 543 | 14:06
|
Hemodynamic imaging in brain tumors using dextran1-enhanced CEST MRI |
1Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States, 2Department of Radiology, Johns Hopkins University, Baltimore, MD, United States, 3F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States, 4Department of Oncology, Johns Hopkins University, Baltimore, MD, United States, 5Department of Medical Radiation Physics, Lund University, Lund, Sweden |
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Sugar-based compounds have shown potential as biodegradable contrast agents for cancer detection. Recently, a multi-size dextran MRI approach was developed for detecting permeability-related properties in tumors. Here, we explored a small size dextran, dextran1 (MW~ 1 kD), as a new MRI contrast agent for detecting brain tumor hemodynamic properties including |
| 544 | 14:18
|
Imaging injectable liposomal hydrogels using CEST MRI for applications in the brain |
1City University of Hong Kong, Hong Kong, China, 2Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 3F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, MD, United States |
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Nanocarrier-loaded hydrogel shows good prospects in biomedical application. However, there is lack of noninvasive methods for |
| 545
|
14:30
|
CryptoCEST, a promising tool for differential diagnosis and treatment monitoring of fungal brain lesions |
1Biomedical MRI, KU Leuven, Leuven, Belgium, 2MoSAIC, KU Leuven, Leuven, Belgium, 3Laboratory of Tumor Immunology and Immunotherapy, KU Leuven, Leuven, Belgium, 4Department of Neurosurgery, Erasme Hospital, Brussels, Belgium, 5Laboratory of Clinical Bacteriology and Mycology, KU Leuven, Leuven, Belgium |
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Differential diagnosis of fungal brain infections from other types of lesions is challenging. We assessed the presence of fungal metabolites in Cryptococcus lesions using in vivo MR spectroscopy and CEST. Hereby, we studied the use of trehalose, a disaccharide and fungal biomarker, for endogenous contrast in CEST imaging. Using the novel CryptoCEST technique, we were able to non-invasively differentiate Cryptococcus lesions from glioma. However, no significant effect of antifungal treatment on the CEST contrast was observed. If translated to the clinic, this technique has great potential in assisting in the differential diagnosis and specific spatial localization of cryptococcal brain lesions. |
| 546
|
14:42
|
In vivo MRI of mouse liver glycogen based on the nuclear Overhauser enhancement (NOE) with water (glycoNOE) |
1The Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2F.M. Kirby Research Center for Functional, Brain Imaging Kennedy Krieger Institute, Baltimore, MD, United States |
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Glycogen is abundant in different tissues and plays a central role in glucose homeostasis. We propose a new method for imaging glycogen using the nuclear Overhauser enhancement (NOE) between glycogen and water. We mapped the glycogen NOE signal in the Z-spectral range around -1 ppm from water, both in phantoms and in mouse liver in vivo. For validation, we performed a fasting protocol and glucagon infusions. Glycogen levels were greatly reduced after 24 hours fasting and after the intraperitoneal injection of glucagon (100 ml, 1mg/ml). This glycoNOE MRI has the potential for non-invasive imaging of liver glycogen levels in vivo. |
| 547 | 14:54
|
Detection of abnormal glucose uptake and metabolism in perinatal hypoxia using glucoCEST MRI |
1Howard University, Washington, DC, United States, 2Children's National Medical Center, Washington, DC, United States |
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Perinatal brain injury, such as perinatal hypoxia from chronic lung disease, results in devastating, neurologic impairment. The immediate and long-term effects on brain energy metabolism of glucose – a major source of energy for the brain - are not known. Previous studies have shown that perinatal brain injury from perinatal hypoxia results in long-term decreases in neuronal oxidative metabolism of glucose and decreased synthesis of N-acetylaspartate. In this study, we utilized dynamic glucoCEST enhancement MRI to investigate the pattern of glucose uptake and metabolism between the mice of normoxic and hypoxic treatment. |
| 548 | 15:06
|
Saturation transfer of relayed nuclear Overhauser enhancement: its relationship with the chemical exchange |
1University of Pittsburgh, Pittsburgh, PA, United States, 2Center for Neuroscience Imaging Research, Institute for Basic Science, Suwon, Korea, Republic of, 3Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Suwon, Korea, Republic of |
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In saturation transfer experiments, the Nuclear Overhauser enhancement (NOE) is often detected from mobile macromolecules and is usually assumed through an exchange-relayed pathway. However, the relationship of such relayed-NOE signals with the chemical exchange is still unclear. We reported simulation, phantom and in vivo studies to examine the dependence of |
| 549
|
15:18
|
Quantitative Magnetization Transfer Detects Renal Fibrosis in Swine Kidney with Renal Artery Stenosis |
1Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, United States |
||
Quantitative magnetization transfer (qMT) was used on swine kidneys with renal artery stenosis (RAS). The reproducibility of qMT at 1.5 and 3.0 T was tested in two RAS pigs and its utility in measuring renal fibrosis investigated in seven pigs at 3.0 T by comparing to histology. The Henkelman-Ramani equation was used to derive the bound pool fraction f. Comparable f values were obtained at 1.5 and 3.0 T. Measured f also correlated well with renal fibrosis by histology. In conclusion, qMT is reproducible at different field strengths and can be used to measure renal fibrosis in swine with RAS. |
| 550
|
13:30
|
Gradient Non-Linearity Correction for Spherical Mean Diffusion Imaging |
1Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany |
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Gradient non-linearities are a significant source of errors in MRI systems with strong gradients. In the case of diffusion imaging, they induce spatial deviation of the b-vectors. The spherical mean methods in diffusion relies on the acquisition of spherical b-shell. To recover accurate spherical mean values, it is necessary to undistort the diffusion signal. Therefore, we evaluated three correction methods for gradient non-linearities using the Connectom gradient system as a showcase. We show how a simple heuristic can reduce the spherical mean errors by 20 folds. |
| 551
|
13:42
|
Disentangling diffusion-weighted SSFP: ADC estimates in terms of an effective diffusion time |
1Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom, 2Department of Radiology, University of Chicago, Chicago, IL, United States, 3Clinical Neurology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom, 4Biomedical Image Computing and Analytics, University of Pennsylvania, Philadelphia, PA, United States |
||
Diffusion-weighted SSFP (dwSSFP) is a high-SNR-efficiency diffusion imaging method. Unlike conventional diffusion measurements, the dwSSFP signal reflects a range of diffusion times because the signal is recycled over multiple excitations. This complicates interpretation and leads to an ill-defined b-value. We present a framework to describe dwSSFP-derived ADC estimates in terms of an effective diffusion time. To achieve this, we require dwSSFP measurements at two flip-angles. Experimental results are presented in a whole, postmortem brain at 7T. This enables us to simultaneously addresses flip-angle inhomogeneity at 7T and provide ADC estimates that are more comparable to conventional diffusion MRI. |
| 552 | 13:54
|
Multi-Dimensional Diffusion MRI Sampling Scheme: B-tensor Design and Accurate Signal Reconstruction |
1Research School of Engineering, Australian National University, Canberra, Australia, 2Computer Science department, University of Verona, Verona, Italy, 3Univ Rennes, Inria, CNRS, IRISA, Rennes, France |
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b-tensor encoding enables the separation of isotropic and anisotropic tensors. However, little consideration has been given as to how to design a b-tensor encoding sampling scheme. In this work, we propose the first 4D basis for representing the diffusion signal acquired with b-tensor encoding. We study the properties of the diffusion signal in this basis to give recommendations for optimally sampling the space of axisymmetric b-tensors. We show, using simulations, that the proposed sampling scheme enables accurate reconstruction of the diffusion signal by expansion in this basis using a clinically feasible number of samples. |
| 553 | 14:06
|
Technical validation of b-tensor encoding shows the need for standardized acquisition protocols |
1Dept. of Translational Medicine, Division of Medical Radiation Physics, Lund University, Malmö, Sweden, 2Dept. of Clinical Sciences, Division of Radiology, Lund University, Lund, Sweden, 3Brigham and Women's Hospital, Boston, MA, United States, 4Harvard Medical School, Boston, MA, United States, 5Lund University, Lund, Sweden |
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Tensor-valued diffusion encoding can be used to separate effects of microscopic anisotropy, orientation dispersion, and isotropic kurtosis. The aim of this work was to determine the impact of encoding tensor shapes and sizes (b-values) on the estimated model parameters using in-vivo data and simulated signals from several microdiffusion environments. We found that some signal sampling protocol had a relevant impact on the estimated diffusion parameters and may negatively impact the parameter reproducibility. This demonstrates the need for a standardization of sampling schemes to facilitate study comparisons, data pooling, and meta analysis. |
| 554
|
14:18
|
Learning-Based Jointly-Optimal Design of the Diffusion Encoding Scheme and Orientation Estimation Method for Diffusion MRI |
1University of Southern California, Los Angeles, CA, United States, 2Massachusetts General Hospital, Boston, MA, United States, 3Harvard Medical School, Boston, MA, United States |
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Diffusion MRI is powerful but limited by long scan times. When optimizing diffusion MRI, most previous methods have either optimized the encoding scheme (i.e., q-space samples) or have optimized the parameter estimation method. In this work, we propose and evaluate a novel approach that jointly optimizes both the encoding scheme and the estimation scheme. This is enabled by combining linear estimation theory with machine learning techniques. Our results show the strong potential of our new approach. Perhaps surprisingly and in contrast to conventional wisdom, we observe that a two-shell sampling scheme appears to be preferred for orientation estimation. |
| 555
|
14:30
|
Improved white matter response function estimation for 3-tissue constrained spherical deconvolution |
1The Florey Institute of Neuroscience and Mental Health, Melbourne, Australia, 2The Florey Department of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia |
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Multi-shell multi-tissue constrained spherical deconvolution (MSMT-CSD) and single-shell 3-tissue CSD (SS3T-CSD) decompose the diffusion MRI signal in a white matter (WM) fibre orientation distribution (FOD) and grey matter (GM) and cerebrospinal fluid (CSF) compartments. An unsupervised method was recently proposed to estimate the required WM/GM/CSF response functions. In this work, we improved WM response function estimation by leveraging WM properties across b-values, resulting in better 3-tissue CSD fit to most data. Slightly beyond the scope of this work, we also make an interesting observation in developing Human Connectome Project data. |
| 556 | 14:42
|
Improved precision and accuracy in q-space trajectory imaging by model-based super-resolution reconstruction |
1imec-Vision Lab, Dept. of Physics, University of Antwerp, Antwerp, Belgium, 2Brigham and Women's Hospital, Boston, MA, United States, 3Harvard Medical School, Boston, MA, United States, 4Medical Radiation Physics, Lund University, Lund, Sweden |
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Q-space trajectory imaging (QTI) facilitates tensor-valued diffusion encoding with variable shapes and provides more specific parameters than those available from conventional stick-shaped encoding. However, it generally requires longer echo times than conventional encoding, impacting the spatial resolution, scan time or signal-to-noise ratio. In this work, we propose a super-resolution acquisition and reconstruction approach for QTI that allows high-resolution parameter maps to be estimated from multiple low-resolution images. Using simulations and real data, we show that this does not only improve QTI’s precision, it also significantly improves its accuracy, as it avoids deleterious signal bias caused by the noise floor. |
| 557 | 14:54
|
Non-negative mean apparent propagators using sum-of-squares optimization: MAP+ |
1University of Copenhagen, Copenhagen, Denmark, 2Linköping University, Linköping, Sweden |
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Mean apparent propagator (MAP) MRI provides an efficient representation of the three-dimensional q-space signal that is used to characterize the diffusional characteristics of the tissue. The standard implementation of MAP-MRI imposes soft constraints, leaving the possibility for negative values of the propagator; we observed that such physically unjustifiable reconstructions are widespread throughout the brain. Here, we introduce a new framework based on sum-of-squares optimization that guarantees the non-negativity of the reconstructed propagator, thus yielding improved estimates of the propagator as well as the scalar measures derived from it. |
| 558 | 15:06
|
Water mobility spectral imaging of the spinal cord: parametrization of model-free Laplace MRI |
1National Institutes of Health, Bethesda, MD, United States, 2Center for Neuroscience and Regenerative Medicine, Rockville, MD, United States |
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Diffusion magnetic resonance imaging of biological systems most often results in non-monoexponential signal, due to their complexity and heterogeneity. One approach to interpreting the data without imposing microstructural models is to fit it to a multiexponential function, and to display the coefficients as a distribution of the diffusivities. Here we suggest parameterizing the measured water mobility spectra using a bimodal lognormal function. This approach allows for a compact representation of the spectrum, while also resolving overlapping spectral peaks. We apply the method on a spinal cord sample and use it to generate robust intensity images of slow and fast-diffusion components. |
| 559 | 15:18
|
Generalize diffusion-MRI-based brain age predictive model using transfer learning |
1Institute of Medical Device and Imaging, College of Medicine, National Taiwan University, Taipei, Taiwan, 2AcroViz Technology Inc., Taipei, Taiwan, 3Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei, Taiwan, 4Molecular Imaging Center, National Taiwan University, Taipei, Taiwan |
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Heterogeneity of diffusion MRI data limits the diffusion-MRI-based machine learning model to be generalized to the data acquired at other sites. To generalize the brain age model based on diffusion-MRI-derived features, we used transfer learning techniques to transfer the pre-trained model from the source domain to the target domain with a few tuning data. We found that 75 tuning data with transfer learning framework achieved the acceptable performance, and 150 tuning data achieved the performance comparable to the maximum samples in the target domain. This study provides a practical solution to solve the limitation of diffusion-MRI-based model using transfer learning. |
13:30
|
Imaging the Brain at the Microscopic Scale With Electron Microscopy & Micro CT | |
13:52
|
Imaging the Brain at the Mesoscopic Scale With Ex Vivo Diffusion MRI | |
1Johns Hopkins University, United States |
14:14
|
Bridging Diffusion MRI and Electron Microscopy of the Brain Using Realistic Random Walk Simulations | |
1New York University School of Medicine, United States |
14:36
|
Inferring Brain Tissue Composition & Microstructure via MR Relaxometry | |
1Vanderbilt University, United States |
15:00
|
The IronTract Challenge & Imaging Connectional Anatomy Across Species & Scales | |
15:20
|
Panel Discussion |
13:30
|
Expanding Access to UHF-MR: Major Concerns & Developing Guidelines | |
13:50
|
Safety, Subjective Experience & Acceptance of 7.0 T MRI in a Clinical Environment: The User’s Point | |
14:10
|
Safety Testing of Implants at 7T: Translation of Lower Field Methods | |
1Berlin Ultrahigh Field Facility (B.U.F.F.), Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany |
14:30
|
The Untapped Potential of Parallel Transmit: Managing Electromagnetic Fields | |
1School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom |
14:50
|
Enhanced Applications & Access Through RF Coil Development | |
15:10
|
Initial Experience at 10.5T: The MR Safety Perspective | |
1Radiology, University of Minnesota, Minneapolis, MN, United States |
15:45
|
Biology of the Interactions at the Cartilage-Bone Interface | |
1University of Toronto, Toronto, ON, Canada |
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The Cartilage-Bone interface acts as a viscoelastic material that can actively adapt to mechanical loads on both an instantaneous and long term basis. Loading this structure produces shear stresses on tissue components which, if excessive, lead to injury and its reaction. Reaction to injury has an early phase consisting of edema in subjacent bone marrow and overlying articular cartilage. Reaction to injury may extend as microfractures through the calcified cartilage,subchondral bone and/or trabecular bone. This is followed by repair which has the capacity to functionally regenerate the cartilage and bone tissues. |
16:15
|
Imaging Early: Advanced Imaging of Short T2 Species | |
1University of Eastern Finland, Kuopio, Finland |
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This part of the educational course covers MRI techniques used to image the short/ultra-short T2 spins, abundant for example in the cartilage-bone interface and discuss the potential of the methods in the assessment of the short T2 species. The lectures will cover the main imaging methods, namely the UTE, ZTE, and SWIFT imaging sequences and their applications in the musculoskeletal system, especially in cartilage, bone, and the interface in between. |
16:45
|
Clinical Applications of Imaging Cartilage-Bone Interactions | |
1University of California, San Diego, United States |
||
Cartilage-bone interactions are structurally and functionally complex. Understanding this complexity is crucial with regard to non-invasive diagnosis and characterization of disease, as well as for development of treatment methods. |
17:15
|
Metabolic Changes at the Cartilage-Bone Interface with PET/MR | |
1Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States |
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Osteoarthritis (OA) is a degenerative whole joint disease. Simultaneous PET-MR imaging provides a unique opportunity to study bone-cartilage interactions in joint degeneration, and provides a key to the pathophysiology of OA. |
17:45
|
Adjournment |
15:45
|
Spin Echo Imaging | |
1GE Healthcare, United States |
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The spin echo pulse sequence is one of the most important pulse sequences in MRI. Fast spin echo imaging is routinely used due to its robustness to tissue susceptibility variations and local field inhomogeneities, as well as for its ability to produce excellent T1, T2 and PD contrasts. The aim of this lecture is to describe the basic physical principles governing spin echo imaging and to illustrate how key imaging parameters, such as TE, TR and ETL (echo train length) can be selected to achieve the desired contrast while maximizing image quality and imaging efficiency. |
16:45
|
Gradient Echo Imaging | |
1Institute of Radiology, Friedrich-Alexander University (FAU) Erlangen-Nürnberg, Germany |
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Magnetic resonance imaging (MRI) techniques can usually be classified into spin-echo (SE) and gradient-echo (GRE) pulse sequences. In this presentation, the basic physical principles of GRE imaging, as well as different mechanisms to generate image contrast will be explained. Differences between SE and GRE MRI will be discussed. Additionally, the influence of different pulse sequence parameters (e.g. echo time, repetition time, flip angle; as well as spoiling techniques and preparation pulses) on the image contrast will be covered. Clinical applications of GRE imaging techniques will be shown exemplarily. |
17:45
|
Adjournment |
| 560
|
Pitch: 15:45 Poster: 16:45 Plasma 1
|
Cardiorenal Sodium MRI at 7.0 Tesla Using an 8-Channel 1H/23Na RF Coil Array |
1Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany, 2MRI.TOOLS GmbH, Berlin, Germany, 3Institute of Radiology, University Hospital Erlangen, Erlangen, Germany |
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Cardiorenal syndrome (CRS) describes disorders of the heart and the kidneys in which a dysfunction of one of the organs induces a dysfunction in the other. Sodium MRI at ultrahigh magnetic fields offers an appealing strategy to gain a better functional and metabolic understanding of CRS and detect these diseases earlier. This work describes the design, construction and application of an 8-channel 1H/23Na RF coil tailored for cardiorenal imaging at 7.0 Tesla. |
| 561
|
Pitch: 15:45 Poster: 16:45 Plasma 2
|
Evaluation of a sleeve monopole antenna array, a novel 16-channel radiative antenna array at 10.5T |
1Center for Magnetic Resonance Research, Minneapolis, MN, United States, 2Seoul National University, Seoul, Korea, Republic of, 3AIRS medical, Seoul, Korea, Republic of |
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We designed an elliptical 16-channel transceiver sleeve monopole array for human head imaging at 10.5T and evaluated the performance both in simulation and experiment. The 16-channel sleeve monopole array was compared to 8-channel end-loaded dipole and monopole arrays. Porcine brain images acquired with the sleeve monopole array demonstrate good coverage and performance. |
| 562 | Pitch: 15:45 Poster: 16:45 Plasma 3
|
Evaluation of Short Folded Dipole Antennas as Receive Elements of Ultra-High Field (UHF) Human Head Array. |
1High-Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Germany, 2Department of Nanophotonics and Metamaterials, ITMO University, St. Petersburg, Russian Federation, 3Department for Biomedical Magnetic Resonance, University of Tübingen, Tübingen, Germany |
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Increasing the number of surface loops in a human head receive (Rx)-array improves the peripheral SNR, while the central SNR doesn’t substantially change. Recent work demonstrated that optimal central SNR at UHF requires a contribution of two current patterns associated with a combination of loops and dipoles. A novel array consisting of 8 transceiver surface loops and 8 optimized folded Rx-dipoles was developed and tested. Addition of Rx-dipoles doesn’t substantially alter B1+ field and the maximum local SAR. At the same time the new design improves both central and peripheral SNR as compared to the similar 16-element array with Rx-only vertical loops. |
| 563 | Pitch: 15:45 Poster: 16:45 Plasma 4
|
Preamp decoupling improves SNR and the earth is flat |
1Philips Research, Hamburg, Germany |
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Preamplifier decoupling has been used to isolate elements of receive array coils for decades. For good SNR, decoupling of elements is essential. However, recent research results claim that this just holds for “real” electromagnetic decoupling rather than preamp decoupling as long as the SNR-optimal channel combination is used. We performed experiments on the impact of preamplifier decoupling including also accelerated imaging using SensE. We found no significant difference in SNR between preamplifier decoupled and resonant coil elements. |
| 564
|
Pitch: 15:45 Poster: 16:45 Plasma 5
|
Approaching the ultimate intrinsic coil performance for 7T body imaging with high-density parallel transmit/receive arrays |
1Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands, 2Radiology, WaveTronica B.V., Utrecht, Netherlands, 3Avans Hogeschool Den Bosch, Den Bosch, Netherlands, 4New York University School of Medicine, New York, NY, United States, 5Biomedical Image Processing, Eindhoven University of Technology, Eindhoven, Netherlands |
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In order to calculate |
| 565
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Pitch: 15:45 Poster: 16:45 Plasma 6
|
Flexible multi-turn multi-gap coaxial RF coils (MTMG-CCs): design concept and bench validation |
1IR4M (Imagerie par Résonance Magnétique et Multi-Modalités), UMR 8081, Université Paris-Sud/CNRS, Université Paris-Saclay, Orsay, France, 2Division MR Physics, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria, 3Université de Lorraine, Inserm, IADI, Nancy, France |
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The design of flexible coaxial coils (CCs) based on the single-turn single-gap concept is extended by multiple turns and multiple gaps (MTMG-CCs) to achieve a larger range of coil diameters for a given resonance frequency. An equivalent circuit for MTMG-CCs is presented and the resonance condition is solved numerically for coils with diameters up to 20 cm, 1-3 turns, and 1-3 gaps. For validation of the calculations, 27 coils with 6/9/12 cm diameters, 1-3 turns, and 1-3 gaps were built and characterized on the bench. |
| 566
|
Pitch: 15:45 Poster: 16:45 Plasma 7
|
An 8Tx dipoles/32Rx loop coil array – Evaluation of fMRI performances in auditory cortices at 7T |
1LIFMET, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 2CIBM-AIT, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 3Department of Radiology, Université de Lausanne, Lausanne, Switzerland, 4Department of Radiology, Université de Genève, Genève, Switzerland, 5Department of Biomedical Engineering, King's College London, London, United Kingdom |
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The performances of a 32-channel receive coil array combined with a tight-fitted whole-brain dipole coil array were investigated. Functional MRI data targeting the auditory cortices was acquired. Noise correlation matrices, SNR and g-factor maps were measured. Compared to a commercial 32Rx, the in-house built 8T/32Rx coil array demonstrated higher robustness in the fMRI results. Lower noise correlation coefficients were measured with the in-house built 8Tx/32Rx coil array while the overall experimentally measured SNR and g-factor maps were comparable. |
| 567 | Pitch: 15:45 Poster: 16:45 Plasma 8
|
A System for 16-Channel 13C Magnetic Resonance Spectroscopy Data Acquisition at 7T |
1Electrical and Computer Engineering, Texas A&M University, College Station, TX, United States, 2Biomedical Engineering, Texas A&M University, College Station, TX, United States, 3Advanced Imaging Research Center, UT-Southwestern Medical Center, Dallas, TX, United States, 4Radiology, UT-Southwestern Medical Center, Dallas, TX, United States, 5Philips Medical Systems, Cleveland, OH, United States, 6Internal Medicine, UT-Southwestern Medical Center, Dallas, TX, United States |
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A system has been developed to enable the acqusition of 16-channel 13C data on a Philips Achieva 7T scanner. Radiofrequency mixers are used to convert the transmitted signal to 13C, and the received signal back to 1H to be acquired by the host system's receiver. A 16-element unilateral breast coil has been developed, and data have been acquired that show a substantial SNR improvement from use of the array. |
| 568
|
Pitch: 15:45 Poster: 16:45 Plasma 9
|
Development of 1H/13C RF Head Coil for Hyperpolarized 13C Imaging of Human Brain |
1Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States, 2Clinical MR Solutions, Brookfield, WI, United States, 3Electrical and Computer Engineering, Texas A&M University, College Station, TX, United States, 4Department of Radiology, UT Southwestern Medical Center, Dallas, TX, United States, 5Internal Medicine, UT Southwestern Medical Center, Dallas, TX, United States, 6GE Healthcare, Toronto, ON, Canada, 7Electrical Engineering, UT Dallas, Richardson, TX, United States |
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A customized 1H/13C RF head coil that consists of a 1H quadrature transmit (Tx) and receive (Rx) coil and 13C quadrature transmit and array receive (QTAR) coils was developed. The performance of the new head coil was evaluated using phantoms and compared to the existing 13C-only quadrature Tx/Rx (QTR) head coil. Metabolic imaging of human brain was performed using the 1H/13C head coil, following an injection of hyperpolarized [1-13C]pyruvate. |
| 569 | Pitch: 15:45 Poster: 16:45 Plasma 10
|
Towards whole-cortex enhancement with a uHDC Helmet at 3T |
1Radiology, Pennsylvania State College of Medicine, Hershey, PA, United States, 2HyQ Research Solutions, LLC, State College, PA, United States, 3Engineering Science and Mechanics, Pennsylvania State University, University Park, PA, United States |
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We performed a human brain imaging study using a prototype conformal helmet constructed with ultrahigh dielectric constant (uHDC) materials inserted into a standard 20-Ch head coil at 3T. We characterized the transmit and receive performance of the helmet by comparing to results using the 20-Ch and 64-Ch head coil (n=5 subjects) without the uHDC helmet. The SNR and its spatial distribution within the cerebrum using the 20-Ch Coil with uHDC Helmet is comparable to that of the 64-Ch Coil. Further improvement of the uHDC helmet insert is expected to significantly improve the performance of standard receive arrays for brain imaging. |
| 570 | Pitch: 15:45 Poster: 16:45 Plasma 11
|
Performance of a novel cryogen-free cryostat with an automated temperature control for fine tuning of High Temperature Superconducting RF coils: high-resolution MR imaging at 1.5 T |
1IR4M, UMR8081, Université Paris-Sud/CNRS, Université Paris-Saclay, F-91405 Orsay, France, Orsay, France, 2Irfu, CEA Paris-Saclay, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France, Gif-sur-Yvette, France |
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We present the performance of an MR-compatible cryogenic system dedicated to cool High Temperature Superconducting (HTS) radiofrequency coils for micro-MRI at 1.5 T. A real time control and regulation of the temperature were performed to finely tune the HTS coil to the Larmor resonance frequency with a precision of 1 Hz. Firstly, we demonstrated that this cryostat does not cause any electromagnetic disturbance. Secondly, MR images of a 1 mm-cubic liquid phantom were acquired using the HTS coil as a transceiver with a spatial resolution down to (100 μm)3 under real clinical research experimental conditions. |
| 571 | Pitch: 15:45 Poster: 16:45 Plasma 12
|
Fast and Intuitive RF-Coil Optimization Pipeline Using a Mesh-Structure |
1Center for Biomedical Imaging, Department of Radiology, NYU School of Medicine, New York, NY, United States, 2Center for Advanced Imaging Innovation and Research (CAI2R), NYU School of Medicine, New York, NY, United States |
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At the last years ISMRM we proposed an RF coil optimization pipeline based on a mesh structure consisting of 50-Ohm sources and copper patches. This allowed us to compute the maximal possible SNR of a given mesh as well as the emulation of concrete coil geometries in post-processing. In this work we present an analysis of body imaging at 7T with an appropriately chosen mesh size that can reach the UISNR. Furthermore the optimal current weights are analyzed to create a physically realizable coil that approaches the UISNR. |
| 572 | Pitch: 15:45 Poster: 16:45 Plasma 13
|
An 8-channel transmit 32-channel receive 7T head coil for 1Tx and pTx scanner modes |
1University of Glasgow, Glasgow, United Kingdom, 2Department of Clinical Physics and Bioengineering, NHS Greater Glasgow and Clyde, Glasgow, United Kingdom |
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In this work, a nested array of 8-transmit elements was developed and combined with a 32-channel receive array for imaging the human brain at 7T. This setup can be used in the single channel and parallel transmit mode of the Siemens 7T scanner. The transmit array was designed to make the setup less claustrophobic and provide an open feel, benefitting fMRI and patient studies. The transmit performance of this setup is presented here. |
| 573 | Pitch: 15:45 Poster: 16:45 Plasma 14
|
Fast transmit/receive switch for SWIFT imaging at 7T |
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States |
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Sweep imaging with Fourier transformation (SWIFT) can image extremely short-lived MRI signals such as cortical bone and lung. However, it requires fast transmit/receive (T/R) switching during the gapped RF excitation, which cannot be handled with standard clinical MRI hardware. A fast transmit/receive switch (switching time ≤ 400 ns) is developed for integration into an 8-channel in-bore T/R switch interface. These T/R switches are driven via repurposed Varian PIN drivers which are, in turn, triggered via an optical-to-TTL signal. This hardware enabled the acquisition of SWIFT images of the human head at 7T with an 8-channel transmit/receive degenerate birdcage coil. |
| 574 | Pitch: 15:45 Poster: 16:45 Plasma 15
|
Out-phasing Modulated Current-Mode Class D (CMCD) Amplifier with Improved Dynamic Range |
1Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 2Hyperfine Research, Guilford, CT, United States, 3Radiology, Case Western Reserve University, Cleveland, OH, United States |
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Developments in RF transmit systems have been trending towards increasing independent elements and compact designs. Previous work has shown the capability of enhancement mode Gallium Nitride (eGaN) FETs in high-efficiency switchmode RF amplifier (RFPA) based on envelope elimination and restoration (EER). Switchmode RF amplifiers, however, suffer from nonlinearity and limited dynamic range, leading to errors in excitation profiles. Here we present preliminary results on a new prototype which adds an additional modulation methods using digital controls to increase RFPA dynamic range. |
| 575 | Pitch: 15:45 Poster: 16:45 Plasma 16
|
Respiratory Motion Management in MR-guided Radiotherapy treatment and assessment with IVIM. |
1Radiation Oncology, Virginia Commonwealth University, Richmond, VA, United States, 2C. Kenneth and Dianne Wright Center for Clinical and Translational Research, Virginia Commonwealth University, Richmond, VA, United States, 3Radiation Oncology, Washington University in St. Louis, St. Louis, MO, United States |
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In radiotherapy (RT), respiratory motion induced target displacement can cause the treatment beam to miss the target, irradiating normal tissue instead. This study introduces a novel pressure based motion management system with biofeedback, compatible with MRI, CT, and megavoltage RT. A belt, wrapped around the abdomen, with a pressure sensor provided respiratory traces and guidance to subjects during MR acquisition. Superior-inferior liver dome motion could be reduced from 30.6mm under free breathing to 5.6mm with a small guiding window. This device provides significant motion reduction and a surrogate to internal organ motion for use across the RT treatment process. |
| 576 | Pitch: 15:45 Poster: 16:45 Plasma 17
|
Comparison and Integration of DCE- and IVIM-MRI for Breast Cancer Diagnosis: A Preliminary Study |
1International School of Beaverton, Aloha, OR, United States, 2Oregon Health & Science University, Portland, OR, United States, 3University of Washington, Seattle, WA, United States |
||
The goal is to compare DCE-MRI PK parameters with IVIM-MRI parameters and ADC in breast cancer diagnostic accuracy, and assess if integration of DCE and IVIM markers further improves diagnostic performance. Twenty-two patients with 23 suspicious breast lesions underwent pre-biopsy DCE- and DW-MRI with 12 b values. PK parameters were estimated using the Shutter-Speed model. IVIM parameters and ADC were derived with biexponential and monoexponential modeling of the DW-MRI data, respectively. Both DCE- and IVIM-MRI, with individual or combined markers, outperformed clinical MRI reading in breast cancer diagnosis. The integration of DCE and IVIM markers provided the best diagnostic performance. |
| 577 | Pitch: 15:45 Poster: 16:45 Plasma 18
|
Integration of DCE-MRI and Molecular Markers for Improved Early Prediction of Breast Cancer Response to Neoadjuvant Chemotherapy |
1Oregon Health & Science University, Portland, OR, United States |
||
The goal is to determine if integration of DCE-MRI and molecular markers improves early prediction of breast cancer response to neoadjuvant chemotherapy (NACT). 49 patients undergoing standard of care NACT had DCE-MRI before and after the first NACT cycle, with 12 of them achieving pathologic complete response (pCR) after NACT. Pharmacokinetic (PK) analysis of DCE-MRI data was performed using the shutter-speed model. Changes in PK parameters were superior to changes in tumor size for early prediction of pCR. The improvement in predictive performance by combining DCE and HR, HER2 molecular markers was statistically significant compared to using MRI markers alone. |
| 578 | Pitch: 15:45 Poster: 16:45 Plasma 19
|
Magnetic Resonance SIGnature MAtching (MRSIGMA) for Real-Time Volumetric Motion Tracking |
1Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, United States, 2Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, United States |
||
New MR-Linac systems allow for simultaneous imaging and radiation-treatment, and hold great promise for adaptive radiation-treatment of moving organs. However, even with the latest MRI acquisition and reconstruction technologies, tracking volumetric motion in real-time is still challenging. This work describes a novel technique called MR SIGnature MAtching (MRSIGMA), which consists of (1) offline learning, where 3D motion states and corresponding unique rapid signatures are learned; and (2) online matching, where only rapid signature data are acquired to determine corresponding motion states. Initial implementation using golden-angle radial sampling is shown for liver motion tracking with a latency of < 200ms. |
| 579 | Pitch: 15:45 Poster: 16:45 Plasma 20
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DCE-MRI is more sensitive than IVIM-DWI for assessing therapy induced changes in tumour perfusion in colorectal liver metastases |
1CRUK Cancer Imaging Centre, The Institute of Cancer Research and Royal Marsden NHS Foundation Trust, London, United Kingdom, 2Department of Medicine, GI and Lymphoma Unit, The Royal Marsden NHS Foundation Trust, London and Sutton, United Kingdom |
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This study evaluates response to anti-angiogenic treatment in 25 patients with colorectal liver metastases to determine whether the observed changes on dynamic contrast enhanced (DCE)-MRI are detectable by IVIM-DWI. Significant therapy response measured in this cohort by DCE and confirmed by tumour biopsies was not mirrored by the perfusion related IVIM parameters. No strong correlation was found between DCE and IVIM perfusion parameters. DCE-MRI is more sensitive than IVIM-DWI for assessing therapy induced changes in tumour perfusion in colorectal liver metastases. |
| 580 | Pitch: 15:45 Poster: 16:45 Plasma 21
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Prediction of breast lesion malignancy in high-risk oncogenetic patients with MRI BI-RADS 4 lesion using multiparametric MRI-based radiomic |
1CREATIS CNRS UMR 5220; Inserm U1206; INSA-Lyon; UCBL Lyon 1, Université de Lyon, Villeurbanne, France, 2Department of Radiology, Centre de lutte contre le cancer Léon Berard, Lyon, France |
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In this study a multiparametric MRI-based radiomic method to predict cancer in MRI BI-RADS 4 breast lesions, in high-risk oncogenetic patients is proposed. The results demonstrated that mpMRI-based radiomic can predict all malignant lesions among MRI BI-RADS 4 lesion and reduced the number of unnecessary biopsy by 86% in our population. |
| 581 | Pitch: 15:45 Poster: 16:45 Plasma 22
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Glutamine Metabolism Dysregulated in PDAC induced Cachexia |
1Division of Cancer Imaging Research, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2Department of Medicine - Gastroenterology and Hepatology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 3Department of Oncology-Gastrointestinal Cancer, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 4Department of Pathology-Gastroenterology and Liver Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 5Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 63Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD, United States |
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Glutamine is one of the most abundant circulating amino acids that is critical for many fundamental functions in cancer cells, including synthesis of metabolites that maintain mitochondrial metabolism, protein synthesis, acting as a carbon source or as the primary nitrogen donor for multiple essential biosynthetic pathways, and in the activation of cell signaling. Here we have identified significant differences in glutamine in human plasma from pancreatic cancer patients that were also observed in tumor interstitial fluid from pancreatic cancer xenografts that induced cachexia. These results suggest that agents with glutaminolytic activity may be useful in treating cachexia. |
| 582 | Pitch: 15:45 Poster: 16:45 Plasma 23
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Tomoelastography for the detection and characterization of liver tumors |
1Department of Radiology, Charité-Universitätsmedizin Berlin, Berlin, Germany, 2Institute of Medical Informatics, Charité-Universitätsmedizin Berlin, Berlin, Germany |
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Tomoelastography is a full field-of-view multifrequency MR elastography technique for high-resolution mapping of stiffness and viscosity of in-vivo tissues. We applied tomoelastography to patients with hepatic lesions and analyzed the accuracy of the method for tumor detection (contrast between lesion and liver tissue) and characterization (difference between malignant and benign tumors). Our results show that shear-wave-speed and phase angle of the complex shear modulus have good accuracy for detection (AUC=0.90 and 0.93, respectively) and characterization (AUC=0.92 and 0.88, respectively) of hepatic lesions. Tomoelastography can add important quantitative information about the biophysical constitution of liver tumors. |
| 583
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Pitch: 15:45 Poster: 16:45 Plasma 24
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Whole body 3.0 T MRI in Adult Lymphomas: Assessment of Quantitative Imaging Biomarkers for Nodal Disease Assessment |
1Centre for Medical Imaging, University College London, Lodon, United Kingdom, 2University College London Hospital, London, United Kingdom, 3Univesriy College London Hospital, London, United Kingdom |
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Whole-body MRI (WB-MRI) is being increasingly advocated as an alternative/adjunct imaging platform in range of cancers including lymphomas. In this study we investigated the application of quantitative imaging biomarkers (QIBs) from a multi-parametric WB-MRI protocol for nodal disease assessment in adults’ lymphomas. We have shown that signal fat fraction (sFF) is more accurate for delineation of positive and/or negative disease compared to apparent diffusion coefficient (ADC) and might be a useful addition to widely used ADC quantitation. |
| 584
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Pitch: 15:45 Poster: 16:45 Plasma 25
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T1 mapping of neuroblastoma pathology: insight from a computational pathology study in the Th-MYCN transgenic mouse model |
1Division of Radiotherapy and Imaging, The Institute of Cancer Research, London, Sutton, United Kingdom, 2Division of Molecular Pathology, The Institute of Cancer Research, London, Sutton, United Kingdom, 3Division of Clinical Studies, The Institute of Cancer Research, London, Sutton, United Kingdom |
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A reduction in T1 has been reported as a generic biomarker of successful treatment in the Th-MYCN model of neuroblastoma, a childhood tumor of the developing nervous system. The aim of this study was to decipher the pathological determinant(s) contributing to global and regional variations in native T1 by comparison with R2* maps and registered computed density maps of both segmented cells and classified cells, extracted from whole-slide digital pathology images in tumors arising in the Th-MYCN transgenic model of neuroblastoma. |
| 585 | Pitch: 15:45 Poster: 16:45 Plasma 26
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Magnetic resonance imaging for confirmation of catheter-selective tumor-targeting liposomes distribution |
1Medical College of Wisconsin, Milwaukee, WI, United States, 2Northwestern University, Chicago, IL, United States |
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Hepatocellular carcinoma is the most common form of primary liver cancer, and globally it is the sixth most common cancer. In this study, we use liposomes that can co-encapsulate the therapeutic agent (oxaliplatin or gemcitabine) in addition to iron oxide nanoparticles to enable MRI-monitored local delivery of the therapeutic agent to limit proangiogenic responses in non-resectable liver tumors following transcatheter embolotherapies. The results showed increased R2* values in the tumor regions at one week post-infusion, compared to the surrounding liver parenchyma and to same regions immediately after infusion, which allows for confirmation of procedural success and proper catheter-selective tumor targeting. |
| 586 | Pitch: 15:45 Poster: 16:45 Plasma 27
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High-frequency electrical conductivity imaging of rat brain tumor |
1Centre for Preclinical Imaging, University of Liverpool, Liverpool, United Kingdom, 2Department of Biomedical Engineering, Kyung Hee University, Seoul, Korea, Republic of, 3School of Engineering, Macquarie University, Sydney, Australia |
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Magnetic Resonance Electrical Property Tomography (MREPT) allowed the evaluation of the intra- and extracellular ionic changes in a rat model of brain tumor. A multi-echo T2-weighted pulse sequence was used with 10 echos to map the B1 field and reconstruct the tissue conductivity at 9.4T. Higher conductivity values were measured in the tumors compared to the healthy brain tissue, suggesting an increased ionic content and mobility in the tumor. |
| 587 | Pitch: 15:45 Poster: 16:45 Plasma 28
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Non-Contrast Multiparametric Mapping for Pancreatic Ductal Adenocarcinoma Cancer (PDAC) Tissue Characterization |
1Radiological Department, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China, 2Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 3Cedars-Sinai Medical Center, Los Angeles, CA, United States |
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Pancreatic ductal adenocarcinoma (PDAC) is one of the most-common malignant tumors and has poor outcomes. With increasing size, the mass causes obstruction of the main pancreatic duct which results in chronic pancreatitis of the upstream pancreas (towards the tail). However, the downstream pancreas (towards the head) does not have these changes. In this study, we quantitatively measured multiple MR parameters (T1, T2, and ADC) of PDAC, upstream, and downstream pancreas along with normal pancreas in healthy volunteers and found these values can be used to differentiate these tissue types. The combination of the three parameters improves overall accuracy in differentiating PDAC with upstream pancreas, downstream pancreas, and normal pancreas over single parameter. |
| 588 | Pitch: 15:45 Poster: 16:45 Plasma 29
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Assessment of Tumor Hypoxia response to sorafenib in Rabbit VX2 Liver Tumor xenografts by Tissue Oxygen Level Dependent MR imaging |
1Department of Radiology, Zhujiang Hospital, Southern Medical University, Guangzhou, China, 2MR Clinical Science, Philips Healthcare, Guangzhou, China |
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Developing non-invasive methods that assess drug resistance, which causes tumor hypoxia, is a research hotspot. We applied tissue oxygen level dependent (TOLD) MRI to investigate the changes in tumor oxygen inhalation of rabbit liver VX2 tumor xenografts before and sorafenib treatment. |
| 589 | Pitch: 15:45 Poster: 16:45 Plasma 30
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Improvement and systematic analysis of the selective multiple quantum coherence 1H MRS lactate imaging pulse sequence for application to brain tumor and lymphoma patients |
1Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States, 2Division of Hematology Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States |
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We have tested our revised Sel-MQC-CSI sequence for dependence of Lac/H2O on the B0 and B1 field inhomogeneity. The immunity of the Lac/H2O from our sequence on the above factors was demonstrated. We have improved lipid suppression from previously reported 100-fold to 22,000-fold while not losing the lactate signal. The revised sequence was applied to a glioma patient and a normal volunteer with a lactate phantom seated near the typical lymphoma occurring region of the body. In both human studies, satisfactory performance of the sequence was demonstrated. |
| 590 | Pitch: 15:45 Poster: 16:45 Plasma 31
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Investigating the relation between amide signal and pH in breast cancer using CEST-MRI and 31P MRSI at 7T. |
1Radiology, University Medical Centre Utrecht, Utrecht, Netherlands, 2Oncology, Amsterdam Medical Centre, Amsterdam, Netherlands |
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In this study, we combine CEST-MRI and 31P-MRSI measurements, to better comprehend the underlying mechanisms of the measured changes in APT signal by relating it to the pHi. CEST-MRI and 31P-MRSI were acquired in breast cancer patients receiving neoadjuvant chemotherapy (NAC) treatment before and after the first cycle of NAC at 7T. We found a linear correlation between APT-CEST and pH and a linear correlation between PE/Pi and the pH in the tumor of breast cancer patients before the start of NAC treatment. We hypothesized that an increased pH results in an increased APT signal, yet we found the opposite. As APT mainly depends on mobile amide proton concentration and the exchange rate, this data suggest that the main contributor to the APT signal is the concentration of mobile amide protons. |
| 591 | Pitch: 15:45 Poster: 16:45 Plasma 32
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Preoperative prediction of lymphovascular invasion in invasive breast cancer with DCE-MRI-based radiomics |
1radiology, Jiangmen Central Hospital, Jiangmen, China, 2Automation, Guilin University of Aerospace Technology, Guilin, China, 3Philips Healthcare, Guangzhou, China |
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Preoperative assessment of lymphovascular invasion (LVI) plays an important role in the therapeutic planning for individual breast cancer patient. A few MRI features have been shown to be associated with LVI, but remain controversial. This prospective study explored DCE-MRI-based radiomics for preoperative prediction of LVI in breast cancer. The results suggested that radiomics signature and MRI based axillary lymph node status were significantly correlated with LVI. The combined model, which incorporated the radiomics signature and MRI based axillary lymph node status, could preoperatively predict LVI with acceptable performance in the training and validation cohorts. |
| 592 | Pitch: 15:45 Poster: 16:45 Plasma 33
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Investigation of the use of T1 relaxation time map in synthetic MRI for diagnosis of breast cancer |
1Department of Medical Imaging, Sun Yat-sen University Cancer Center, Guangzhou, China, 2GE Healthcare, MR Research China, Beijing, China |
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It is known that benign and malignant breast cancer feature different T1 relaxation, the use of T1 relaxation in differential diagnosis has been reported. However accurate measurement of T1 relaxation requires knowledge of B1 distribution, which is inhomogeneous in breast. Synthetic MRI offers B1 corrected T1 relaxation time, its use breast cancer diagnosis has not yet been reported. Here, the use of the T1 mapping in synthetic MR in differential diagnosis of benign and malignant cancer is investigated. Our results demonstrated that T1 mapping offered by synthetic MR may be a potential quantitative biomarker for diagnosis of breast cancer. |
| 593 | Pitch: 15:45 Poster: 16:45 Plasma 34
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Breast Pharmacokinetic Mapping using an Abbreviated Dynamic Contrast Enhanced (DCE) MRI Protocol |
1Stanford University, Stanford, CA, United States |
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The morphologic and kinetic information of a breast lesion can be quantified using pharmacokinetic models enabled by DCE MRI, which often has |
| 594 | Pitch: 15:45 Poster: 16:45 Plasma 35
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Automatic Search in Breast MRI Dataset For Detection of Suspicious Lesions Using Mask R-CNN |
1Department of Radiological Sciences, University of California, Irvine, CA, United States, 2Department of Medical Imaging, Taichung Tzu-Chi Hospital, Taichung, Taiwan, 3Department of Radiology, E-Da Hospital and I-Shou University, Kaohsiung, Taiwan |
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A Mask R-CNN algorithm was implemented to search the entire dataset of breast MRI to identify suspicious lesions for further diagnosis. A total of 102 patients with confirmed cancer were analyzed. There were a total of 2,314 positive cases (i.e. imaging slices containing lesion); and 8,512 slices without lesion as negative cases. The search results show 1,943 true positives; 6,149 true negatives; 2,363 false positives; and 371 false negatives, with sensitivity 0.83, specificity 0.72, and the overall detection accuracy 0.75. The Dice Similarity Coefficient of the tumor segmented in the detection box compared to ground truth is 0.84. |
| 595
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Pitch: 15:45 Poster: 16:45 Plasma 36
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Influence of residual fat signal on diffusion kurtosis MRI of suspicious mammography findings |
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 3Institute of Radiology, University Hospital Erlangen, Erlangen, Germany, 4Radiological Practice at the ATOS Clinic Heidelberg, Heidelberg, Germany, 5Radiology Center Mannheim (RZM), Mannheim, Germany |
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One of the factors determining the success of diffusion-weighted imaging of the female breast is complete fat suppression, especially when using high b-values. In this study, modified diffusion kurtosis models accounting for residual fat signal were compared to conventional DWI approaches. The comparison was based on a MR mammography dataset acquired in two study centers. The dataset comprised 198 patients with suspicious lesions detected during X-ray mammography screening. The ROC analysis shows significantly better performance of the modified diffusion kurtosis model in discriminating between malignant and benign lesions. This could improve the diagnostic accuracy regarding ambiguous mammography findings. |
| 596 | Pitch: 15:45 Poster: 16:45 Plasma 37
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Differential Diagnosis of Benign and Malignant Breast Lesions Based on DCE-MRI by Using Radiomics and Deep Learning with Five Different Networks |
1Department of Radiology, The First Affiliate Hospital of Wenzhou Medical University, Wenzhou, China, 2University of California, Irvine, CA, United States, 3Department of Thyroid and Breast Surgery, The First Affiliate Hospital of Wenzhou Medical University, Wenzhou, China |
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A total of 152 patients receiving breast MRI for diagnosis were analyzed, including 93 patients with 103 malignant cancers, and 59 patients with 73 benign lesions. Three DCE parametric maps corresponding to early wash-in, maximum, and wash-out were generated. Radiomics analysis based on texture and intensity histogram, and deep learning using 5 networks, were performed for differential diagnosis. The accuracy of radiomics was 0.80, and the accuracy of deep learning varied in the range of 0.79-0.94 depending on the network. The smallest bounding box containing the tumor with small amount of per-tumor tissue has the highest diagnostic accuracy. |
| 597 | Pitch: 15:45 Poster: 16:45 Plasma 38
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Radiomics Signature on preoperative MR imaging:To predict pathological complete response and disease-free survival in patientes with Triple-negative breast cancer(TNBC) to neoadjuvant chemotherapy (NAC) |
1Shanghai Center for Mathematical Sciences, Shanghai, China, 2Centre for Computational Systems Fudan University, Shanghai, China, 3Fudan University Cancer Hospital, Shanghai, China |
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To investigate whether radiomics based on contrast-enhanced MRI can predict pathological complete response(pCR) and disease-free survival(DFS) of locally advanced TNBC undergoing neoadjuvant chemotherapy(NAC). |
| 598 | Pitch: 15:45 Poster: 16:45 Plasma 39
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Unsupervised Hierarchical Clustering of PET/MRI Radiomics Features Might Be Helpful to Predict Response to Neoadjuvant Chemotherapy of Breast Cancer |
1Medical Physicist and Research Department, Hong Kong Sanatorium and Hospital, Hong Kong, Hong Kong, 2Department of Diagnostic and Interventional Radiology, Hong Kong Sanatorium and Hospital, Hong Kong, Hong Kong |
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| 599 | Pitch: 15:45 Poster: 16:45 Plasma 40
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Patient-specific characterization of breast tumor-associated flow using image-guided computational fluid dynamics |
1Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, United States, 2Institute for Computational and Engineering Sciences, University of Texas at Austin, Austin, TX, United States, 3Department of Radiology, University of Chicago, Chicago, IL, United States, 4Department of Diagnostic Medicine, University of Texas at Austin, Austin, TX, United States, 5Department of Oncology, University of Texas at Austin, Austin, TX, United States |
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Tumor blood supply and interstitial flow play an essential role in tumor growth, invasion, and treatment response. In this contribution, we employ quantitative DCE-MRI and DWI data to constrain a patient-specific, computational fluid dynamics model of blood flow within breast tumors. To the best of our knowledge, this represents the first attempt at employing non-invasive imaging data to enable |
| 600 | Pitch: 15:45 Poster: 16:45 Plasma 41
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Deep learning-based whole breast segmentation to support automated breast density measurements from fat-water decomposition MRI |
1Biomedical Engineering, Stony Brook University, Stony Brook, NY, United States, 2Biomedical Engingeering, Stony Brook University, Stony Brook, NY, United States, 3Medical Imaging, University of Arizona College of Medicine, Tucson, AZ, United States, 4Pathology, Stony Brook Medicine, Stony Brook, NY, United States, 5Hematology & Oncology, Stony Brook Medicine, Stony Brook, NY, United States, 6Radiology, Stony Brook Medicine, Stony Brook, NY, United States, 7Psychiatry, Stony Brook Medicine, Stony Brook, NY, United States |
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Breast density monitoring has become a clinically interesting topic in the past several years. MRI-based methods are attractive because they allow for frequent monitoring without ionizing radiation. Here, we present evidence that a convolutional neural network can replace manual or algorithmic breast segmentation in such pipelines. |
| 601 | Pitch: 15:45 Poster: 16:45 Plasma 42
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Convolutional neural network classification of axillary lymph node metastasis on MRI of breast cancer patients |
1Stony Brook University, Stony Brook, NY, United States, 2Columbia University, New York City, NY, United States |
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The majority of breast cancer metastasis spreads through the axillary lymph nodes. It is challenging to classify whether there is disease or no-disease axillary lymph nodes because they are small and cluster together. We implemented a convolutional-neural network for automatic classification of diseased versus non-diseased axillary lymph nodes by analyzing data from standard clinical breast MRI. Data were assigned randomly to 70/30 as training/validation set. The results showed the remarkable agreement with ground truths, with 86.7% accuracy. This approach may prove useful for automatically detecting lymph nodes metastasis on MRI in clinical settings in breast cancer patients. |
| 602 | Pitch: 15:45 Poster: 16:45 Plasma 43
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Quantitative magnetization transfer imaging of breast cancer: Initial results at 3T |
1Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States, 2Department of Radiology & Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States, 3Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, United States, 4School of Medicine, Vanderbilt University, Nashville, TN, United States, 5Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, TX, United States, 6Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, United States, 7Department of Diagnostic Medicine, The University of Texas at Austin, Austin, TX, United States, 8Department of Oncology, The University of Texas at Austin, Austin, TX, United States |
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Quantitative MT (qMT) techniques provide measurements of the ratio of macromolecular to free water protons, or pool-size-ratio (PSR), which may be useful for detection of changes in macromolecular content of breast tumors early in the course of treatment. Here we report preliminary qMT data acquired as part of an ongoing study employing quantitative MRI to predict the response of breast tumors to neoadjuvant therapy. PSR measurements in tumors were found to be significantly reduced compared to the surrounding fibroglandular tissue in patients diagnosed with invasive breast cancer. |
| 603 | Pitch: 15:45 Poster: 16:45 Plasma 44
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First-in-human: tackling the hypoxic challenge in breast cancer with advanced MRI |
1Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria, 2Department of Neurosurgery, University of Erlangen-Nürnberg, Erlangen, Germany, 3Department of Pathology, Medical University of Vienna, Vienna, Austria, 4Department of Surgery, Medical University of Vienna, Vienna, Austria, 5Department of Internal Medicine, Medical University of Vienna, Vienna, Austria |
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To develop a novel MRI approach for the non-invasive assessment of hypoxia and neovascularization in benign and malignant breast tumors and to provide insights into the intratumoral heterogeneity of breast cancer. 76 patients with a BI-RADS 4/5 lesion underwent 3T MRI of the breast with Vascular Architecture Mapping (and quantitative Blood Oxygenation Level Dependent (qBOLD) imaging. Our approach demonstrated that breast cancer consumes more oxygen and is more hypoxic and neovascularized than benign tumors. This non-invasive approach can be easily integrated in a diagnostic MRI protocol and has the potential to improve tumor characterization and facilitate tailored breast cancer treatment. |
| 604 | Pitch: 15:45 Poster: 16:45 Plasma 45
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Multi-shot DWI with multiplexed sensitivity encoding (MUSE) versus single-shot DWI in the breast |
1Department of Electrical Engineering, Stanford University, Stanford, CA, United States, 2Global MR Application and Workflow, GE Healthcare, Boston, MA, United States, 3Global MR Application and Workflow, GE Healthcare, Menlo Park, CA, United States, 4Department of Radiology, Stanford University, Stanford, CA, United States, 5Department of Bioengineering, Stanford University, Stanford, CA, United States |
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Diffusion-weighted imaging (DWI) has shown strong potential for clinical impact in breast MRI but is limited by low resolution and image distortion. Multi-shot acquisitions can help to address these limitations. Here we assess a multi-shot diffusion acquisition utilizing two different reconstructions in comparison to single-shot DWI in breast cancer patients. The assessment includes quantified perceived resolution and ratings of qualitative image characteristics with respect to the DCE-MRI acquisition. |
15:45
|
Motion of the Heart with the Respiratory & Cardiac Cycles: Conventional Approaches to Motion Correction | |
1NYU School of Medicine, United States |
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Respiratory and cardiac motion can result in degradation of MR images. We review the basic aspects of these motions, and some standard means that can be used to monitor them and control their effects on imaging. |
16:10
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Self Assessment Module (SAM) |
16:15
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Motion of the Heart with the Respiratory & Cardiac Cycles: Advanced Motion Correction Techniques | |
1King's College London |
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MRI acquisition is slow compared to physiological motion, thus the extensive cardiac- and respiratory- induced motion of the heart during the acquisition period can degrade image quality by introducing ghosting and/or blurring like motion artefacts. Several cardiac and respiratory motion compensation techniques have been proposed to overcome this problem. These techniques are based on minimizing, correcting or resolving the motion during the acquisition. This talk will include examples of recently introduced advanced methods to deal with cardiac and respiratory motion, discussing their strengths and limitations. |
| 605
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16:45
|
Imaging Fetal Congenital Heart Disease Using Motion Compensated Cardiovascular Magnetic Resonance Imaging |
1Radiology, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, 2Translational Medicine, The Hospital for Sick Children, Toronto, ON, Canada, 3Medical Biophysics, University of Toronto, Toronto, ON, Canada, 4Pediatric Cardiology, The Hospital for Sick Children, Toronto, ON, Canada, 5Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom, 6Paediatric and Fetal Cardiology, Evelina Children's Hospital, London, United Kingdom, 7Pediatrics and Diagnostic Imaging, University of Toronto, Toronto, ON, Canada |
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In pregnancies where fetal congenital heart disease is suspected during routine obstetric ultrasound, a thorough echocardiographic workup is required to assess the fetal cardiac anatomy and function. MRI has been increasingly proposed as an adjunct diagnostic tool to evaluate the fetus. In this work, we present a newly developed method for reconstructing high-resolution dynamic MR images of the fetal heart, evaluate this modality in the context of visualizing cardiac abnormalities, and compare to echocardiography. We show that MRI of the fetal heart has the potential to compliment echocardiography in the assessment of congenital heart disease. |
| 606
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17:05
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3D Multitasking for Non-ECG, Free-Breathing, Simultaneous Cardiac Motion-Resolved T1 Mapping and Function Evaluation |
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 2Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 3Siemens Healthineers, Los Angeles, CA, United States, 4Department of Bioengineering, UCLA, Los Angeles, CA, United States |
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Myocardial T1 mapping characterizes focal and diffuse fibrosis. We have recently shown cardiac motion-resolved 2D T1 maps with free breathing and without ECG, greatly simplifying workflow. In this study, we extend this approach to 3D and redesign the acquisition to improve spatial resolution and sampling efficiency compared to 2D. We also show the feasibility of assessing function from the same cardiac-resolved 3D Multitasking scan used for T1 mapping. T1 maps were compared to 2D MOLLI and function was compared to a breath-hold cine sequence. |
| 607
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17:25
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Non-contrast enhanced simultaneous bright- and black-blood 3D whole-heart MRI for the assessment of arterial and venous anatomy in patients with congenital heart disease. |
1School of Biomedical Engineering and Imaging Science, King's College London, London, United Kingdom, 2MR Research Collaborations, Siemens Healthcare Limited, Frimely, United Kingdom, 3Hospital Universitario Virgen del Rocio, Seville, Spain |
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Bright- and black-blood MRI sequences provide complementary diagnostic information in patients with congenital heart disease (CHD). Typically, contrast agent administration is needed to depict structures such as the pulmonary veins or regions of disturbed blood flow. However, contrast-enhanced imaging is not ideal for regular screening, while the acquisition of bright- and black-blood sequences in a sequential fashion remains sub-optimal. Here we propose a motion-compensated 3D whole-heart sequence that provides co-registered bright- and black-blood volumes without the need for contrast agent administration. The sequence was tested in patients with CHD and showed high-quality delineation of both arterial and venous structures. |
17:45
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Adjournment |
| 608
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15:45
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Measuring layer-dependent fMRI activity across layers in cognitive brain areas: challenges and capabilities |
1NIH, Bethesda, MD, United States |
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While recent advances in high-resolution fMRI allow for investigating activity across cortical layers, applications beyond the well-studied primary sensory and primary motor areas have been complicated by multiple technical challenges: lack of anatomical landmarks, complicated folding structure, weak signal, restricted task design, etc. The purpose of this study is to develop a scanning/stimulation/analysis setup that allows us to overcome these challenges. Our results suggest that with advanced imaging methodology, corresponding task design, and appropriate analysis strategies it is possible to reliably measure layer-dependent activity differences in cognitive brain areas, such as the dorsolateral prefrontal cortex. |
| 609
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15:57
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Laminar CBF and BOLD fMRI in the human visual cortex using arterial spin labelling at 7T |
1Cognitive Neuroscience, Maastricht University, Maastricht, Netherlands, 2Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Korea, Republic of |
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Laminar fMRI at ultra-high field is typically carried out using the BOLD contrast. Despite its unrivalled sensitivity, the BOLD contrast is limited in its spatial specificity (e.g. due to intracortical ascending and pial veins). Alternatively, the regional change in cerebral blood flow (CBF), is a quantitative measure directly related to neuronal activation. However, CBF fMRI with high spatial resolution is challenging due to the relatively lower SNR. Building on previous work, we demonstrate for the first time, sub-millimetre spatial resolution simultaneous CBF and BOLD acquisition using arterial spin labelling (ASL) for laminar fMRI at 7T. |
| 610 | 16:09
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A Novel Intravascular Contrast for Laminar Functional MRI |
1Section on Functional Imaging Methods, NIMH, Bethesda, MD, United States, 2Functional MRI Core, NIMH, Bethesda, MD, United States |
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In this work, we proposed a novel intravascular contrast for laminar specific fMRI in the human brain at 7T. This technique was shown to be sensitive to both cerebral blood volume (CBV) and flow (CBF) changes. We demonstrate that this new tool, with its highly specified functional layer profile, robust reproducibility and improved sensitivity, allows neuroscientific investigation of information flow across cortical microcircuits. |
| 611
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16:21
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Concurrent intracellular calcium recordings with laminar fMRI mapping |
1Graduate Training Centre of Neuroscience, International Max Planck Research School, University of Tuebingen, Tübingen, Germany, 2Magnetic Resonance Department, Max Planck Institute for Biological Cybernetics, Tübingen, Germany, 3MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, USA., Boston, MA, United States |
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The ultra-high magnetic field strengths of 14.1T allows visualization of laminar-specific neurovascular coupling events with fMRI in living animals. Combining line-scanning fMRI and intracellular calcium signal recording, we present laminar-specific coupling features at high temporal and spatial resolution along the cortical thickness, showing strong Layer 4 fMRI correlation to the calcium signal and largely varied coupling features from adjacent cortices in the anesthetized rats. |
| 612 | 16:33
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Whole brain depth-dependent task based connectivity with laminar fMRI |
1Donders Institute, Nijmegen, Netherlands, 2Department of Psychology, University of Birmingham, Birmingham, United Kingdom, 3Max Planck Institute for Psycholinguistics, Nijmegen, Netherlands, 4Erwin L. Hahn Institute for MRI, Universität Duisburg-Essen, Essen, Germany, 5Faculty of Science and Technology, University of Twente, Twente, Netherlands |
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Laminar resolution, functional magnetic resonance imaging (lfMRI) is a noninvasive technique with the potential to distinguish top-down and bottom-up signal contributions on the basis of depth-dependent interactions with distal regions. Hitherto, lfMRI has not been used to investigate whole-brain distributed networks nor complex cognitive tasks. We show here that lfMRI can reveal whole-brain directed networks during word reading. We identify language critical regions based on their association with the top-down signal stream and herewith establish lfMRI for the non-invasive assessment of directed connectivity. |
| 613 | 16:45
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Increased activity in superficial and deep layers of human S1 for prediction error |
1Okayama University, Okayama, Japan, 2The Japan Society for the Promotion of Science, Tokyo, Japan, 3National Institute of Mental Health, Bethesda, MD, United States |
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Sensory processing in humans is thought to rely on a predictive model of the environment. And these predictions are constantly optimized to minimize future sensory prediction errors. However, the neural microcircuits underlying this prediction error model are still poorly understood. Here, we used an index finger prediction task that consists of sequential finger-stroking in high-resolution (0.71mm) BOLD and VASO fMRI at 7T to investigate how the prediction error activity changes across layers in the human primary somatosensory cortex (S1). We found that prediction error activity is stronger in superficial and deep layers rather than the middle layers of S1. |
| 614
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16:57
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De-noising high-resolution fMRI data using cortical depth-dependent analysis |
1Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, United States, 2Department of Radiology, Harvard Medical School, Boston, MA, United States, 3Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Cambridge, MA, United States, 4Biomedical Engineering, Boston University, Boston, MA, United States |
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In this study, we exploit cortical depth-dependent information to de-noise high-resolution fMRI data. We have proposed a novel de-noising pipeline that can automatically differentiate neural and non-neural fluctuations according to cross-cortical-depth delay patterns. We also show that by excluding voxels intersecting the pial surface can reduce physiological effects and improve neuronal/spatial specificity. |
| 615 | 17:09
|
Robust detection of layer-specific activities in the human LGN |
1State Key Lab of Brain and Cognitive Science,Institute of Biophysics,Chinese Academy of Sciences, Beijing, China, 2Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen, China, 3Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, United States, 4Department of Neurology, University of California Los Angeles, Los Angeles, CA, United States |
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The lateral geniculate nucleus (LGN) of the thalamus is the main relay station of retinal input to the visual cortex. It plays important roles in perception and cognition, and has close relationships with several eye and brain diseases. The current study showed that high resolution BOLD fMRI at 7T can reliably distinguish eye layers as well as magnocellular and parvocellular layer activities of the human LGN. |
| 616 | 17:21
|
Probing spatio-temporal information during attention modulations in humans with sub-second sampling of cortical depth dependent BOLD fMRI signals at 7T |
1CMRR, University of Minnesota, Minneapolis, MN, United States |
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Temporal dynamics of the BOLD signal have been recently exploited with fast TR fMRI. However, the ability to concurrently retain sub-millimeter spatial resolution along with high temporal resolution (e.g. =< ~600 ms TR), with sufficient SNR efficiency, has been elusive. Such a data set could provide unprecedented access to studying the human brain non-invasively. In this work, we push the spatio-temporal limits of 7T fMRI and investigate the possibility of exploiting BOLD temporal dynamics as a function of cortical depth, using spatio-temporal multi-voxel pattern analysis during attention modulations. |
| 617 | 17:33
|
High-resolution fMRI maps of columnar organization in human primary somatosensory cortex |
1Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Okayama, Japan, 2Section on Functional Imaging Methods, National Institute of Mental Health, Bethesda, MD, United States, 3The Japan Society for the Promotion of Science, Tokyo, Japan, 4Functional MRI Core Facility, National Institute of Mental Health, Bethesda, MD, United States |
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More than half a century ago, animal studies revealed that area 3b of the primary somatosensory cortex (S1) receives cutaneous input from slow-adapting (SA) and rapidly adapting (RA) cutaneous receptors in a columnar manner. However, there have been no direct observations of columnar origination in the human SI. Here, for the first time, we investigate the columnar organization in the human S1 by using advanced high-resolution (0.7mm) fMRI at 7T. We find that the human area 3b is columnar organized with alternating SA and RA columnar preferences. We find that SA selective stimulation evokes activity in the middle layers only. |
| 618
|
15:45
|
In vivo MRI detection of β-amyloid pathologies at early and late stages of Alzheimer’s disease |
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, China, 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China, 3Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China, 4F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, MD, United States, 5Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States |
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Early diagnosis of Alzheimer’s disease (AD) is crucial. However, there is a lack of effective diagnostic tools to detect AD at the early stage. Early stage β-amyloid (Aβ) oligomers (AβOs) and |
| 619 | 15:57
|
Predicting Progression from Mild Cognitive Impairment to Alzheimer’s Disease |
1The Mind Research Network, Albuquerque, NM, United States |
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This exploratory analysis tests the suitability of deep residual networks to learn neuroanatomical abnormalities from the structural MRI (sMRI) modality, and utility of dynamic (i.e. time-varying) functional connectivity approaches in delineating discriminative functional MRI (fMRI) features to predict progression of individuals with mild cognitive impairment to Alzheimer’s disease. Results demonstrate better than state-of-the-art prediction performance using the structural MRI modality alone. Multimodal prediction performed significantly better than unimodal sMRI or fMRI predictions, thus corroborating the benefits of predicting in the augmented space. Results also corroborate the diagnostic utility of the sMRI and fMRI features used to make the predictions. |
| 620
|
16:09
|
Cerebrovascular reactivity (CVR) as a potential biomarker in vascular cognitive impairment: relationship with cognition, clinical diagnosis, amyloid and tau proteins. |
1Department of Radiology, Johns Hopkins University, Baltimore, MD, United States, 2Department of Medicine, Johns Hopkins University, Baltimore, MD, United States, 3Department of Psychiatry, Johns Hopkins University, Baltimore, MD, United States, 4Department of Neurology, Johns Hopkins University, Baltimore, MD, United States, 5Department of Oncology, Johns Hopkins University, Baltimore, MD, United States, 6F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States, 7Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, United States |
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Is whole brain cerebrovascular reactivity (CVR) associated with cognitive function in subjects with cognitive impairment and normal cognition? In a cross-sectional study of 72 subjects, whole brain CVR as assessed with the BOLD response to a CO2 breathing challenge, was significantly associated with measures of cognitive function. These relationships remained after adjusting for cerebrospinal fluid biomarkers of Alzheimer’s disease pathology and measures of vascular risk. These findings suggest that whole brain CVR may be useful as a biomarker for assessing altered cognition resulting from vascular dysfunction separate from Alzheimer’s disease. |
| 621
|
16:21
|
Product-Ratios of Metabolite Concentrations as Potential Alzheimer’s Disease Biomarker |
1Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany, 2Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Klinik und Hochschulambulanz für Neurologie, Charité - Universitätsmedizin Berlin, Berlin, Germany, 3Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin, Berlin, Germany, 4Studies on Prevention of Alzheimer's Disease (StOP-AD) Centre, Douglas Mental Health University Institute, Montreal, QC, Canada, 5Department of Psychiatry, McGill University, Montreal, QC, Canada, 6Department of Neurology, University Medicine Greifswald, Greifswald, Germany |
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Previous studies have reported changes in the concentrations of several neurometabolites in Alzheimer’s disease (AD). Nevertheless, group differences of these metabolites between healthy controls, mild cognitively impaired, and AD patients remain small. The transition to ultrahigh fields enables the assessment of further metabolites, and some of them, like GABA and glutamate, have been observed to change in AD. In this study, the combination of several metabolite concentrations associated with AD into a product-ratio to serve as a stronger MRS biomarker for Alzheimer’s than individual concentrations of metabolites, and their relationship with volume of brain structures and memory performance is investigated. |
| 622
|
16:33
|
Intracranial Pulse Wave Velocity in Alzheimer’s Disease using Flow Encode Split and Low Rank Reconstructed 4D Flow MRI |
1Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 2Department of Medicine, University of Wisconsin-Madison, Madison, WI, United States, 3Department of Radiology, University of Wisconsin-Madison, Madison, WI, United States |
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Experimental, clinical and epidemiologic evidence shows vascular factors play a role in Alzheimer’s Disease (AD); however, whether |
| 623
|
16:45
|
Tau Propagation Pattern Is Suggested Through Associations with Structural Tract Alterations: A Data Driven Approach |
1Indiana University, School of Medicine, Indianapolis, IN, United States, 2Department of Epidemiology and Biostatistics, Indiana University, School of Public Health, Bloomington, IN, United States |
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To test the hypothesis that the propagation of tau is facilitated by microstructural alterations in white-matter tracts, we applied a data driven approach to study the “upstream tau – tract alteration – downstream tau” associations throughout the whole brain using tau positron emission tomography (tau-PET) and diffusion MRI (dMRI). The discovered pathways of spread support the characteristic pattern observed in Braak staging. |
| 624 | 16:57
|
Progressive alterations in structural topological properties in T2DM with and without mild cognitive impairment |
1Department of Radiology, Tongji Hospital, Tongji Medical College, HUST, Wuhan, China, 2Department of Neurology, Tongji Hospital, Tongji Medical College, HUST, Wuhan, China, 3GE Healthcare, MR Research China, Beijing, China |
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This study aims to investigate the topological organization in T2DM with and without impairment, and characterize its relationships with clinical measurements. Forty T2DM patients were divided into two sub-groups(impaired and normal cognition), together with ten healthy controls, were imaged at a 3T scanner. We found that the T2DM patients with cognitive impairment had decreased global efficiency, local efficiency, but increased shortest path length than those with normal cognition and healthy controls. Decreased nodal properties were also detected. Decreased clustering coefficients correlated with the neuropsychological assessment and disease duration. The structural topological properties research shows potential feasibility in characterizing intrinsic alterations of diabetic encephalopathy. |
| 625
|
17:09
|
White Matter Damage of Alzheimer’s Disease using Magnetization Transfer Imaging |
1Department of Computer Science, State University of New York at Binghamton, Binghamton, NY, United States, 2Department of Psychology, University of Pittsburgh, Pittsburgh, PA, United States, 33. Department of Psychiatry and Neurology, University of Pittsburgh, Pittsburgh, PA, United States, 4Department of Radiation Oncology, Washington University, Saint Louis, WA, United States |
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The magnetization transfer rate has not been widely used as a biomarker for Alzheimer’s disease (AD). In this study, we measured the magnetization transfer rates in the cardiovascular health study (CHS) cognition study (CHS-CS) cohort at 1.5 T by acquiring T1 maps with and without off-resonance saturation. The magnetization transfer rates were analyzed both cross-sectionally and longitudinally. The longitudinal analysis indicated that damage to white matter regions in the frontal lobe may be associated with AD progression. The study findings demonstrated that the magnetization transfer rate of frontal white matter may be a promising biomarker for |
| 626 | 17:21
|
Dynamic glucoCEST MRI detects regional changes in cerebral glucose uptake in Alzheimer’s disease at 3T |
1Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China, 2F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, MD, United States, 3Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 4Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China |
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Alzheimer’s disease (AD) is affecting over 50 million people globally. Altered glucose uptake is an early hallmark in AD. Here, we apply glucoCEST, in particular, dynamic glucose enhanced (DGE) MRI to study regional glucose uptake in AD at 3T. First, we optimize saturation parameters, and then we apply these parameters to study glucose uptake in AD mice. Moreover, we use a piecewise exponential fitting to extract specific changes related to glucose uptake and utilization. Results showed a global and regional decrease in cerebral glucose uptake in AD mice compared to WT, which could be an effective mean for early diagnosis. |
| 627
|
17:33
|
Magnetic Resonance Elastography of the Hippocampal Subfields in Alzheimer’s Disease |
1University of Edinburgh, Edinburgh, United Kingdom, 2University of Delaware, Newark, DE, United States, 3Dartmouth College, Hanover, NH, United States |
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Magnetic resonance elastography (MRE) of the hippocampus has shown promise as an imaging biomarker for Alzheimer’s disease (AD). In this work, we report that MRE of the hippocampal subfields are consistent with the known cytoarchitecture. We also found softening of the hippocampal subfields in patients with AD compared to healthy controls with a more pronounced reduction in the subiculum and CA1 compared to the global hippocampus. The dentate-gyrus/CA3 was also more viscoelastic in AD (indicating greater elasticity and less viscosity), whereas no viscoelastic effect was detected globally. MRE of the subfields may provide additional information regarding hippocampal integrity in disease. |
| 628 | 15:45
|
The feasibility and clinical value of single-direction diffusion-weighted imaging in the fetal corpus callosum |
1MRI, Shandong Medical Imaging Research Institute, Shandong University, Jinan, China, 2MR Collaboration AP, Siemens Healthcare, MR Collaboration AP, Beijing, China, 3Obstetrics, Jinan Maternity and Child Care Hospital, Jinan, China |
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We investigated the value and feasibility of single-direction diffusion-weighted imaging for the assessment of the fetal corpus callosum in 67 healthy fetuses and 26 fetuses with corpus callosum dysplasia. The results showed that single-direction DWI is significantly superior in optimal visibility and contrast ratio (CR) compared to the conventional HASTE and TrueFISP sequences. This study demonstrated that the application of single-direction DWI is promising in fetal corpus callosum lesions and can be used in routine clinical examination. |
| 629
|
15:57
|
Fetal diffusion MRI acquisition and analysis in the developing Human Connectome Project |
1Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 2Biomedical Engineering Department, School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom |
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Fetal diffusion MRI (dMRI) can offer unique insight in brain development during the period of rapid, formative growth in the third trimester of pregnancy. The developing Human Connectome Project (dHCP) aims to create a comprehensive mapping of brain connectivity development in a large neonatal and fetal imaging cohort. Here, we design a state-of-the-art acquisition and analysis pipeline for fetal dMRI, including closely integrated dynamic distortion correction and slice-to-volume motion correction. We present results in the first 125 fetal dHCP subjects acquired, demonstrating high quality motion and distortion corrected output in the large majority of subjects and across a broad age range. |
| 630 | 16:09
|
In utero exposure to chemotherapy affects cortical neurodevelopment |
1Oncology, KU Leuven, Leuven, Belgium, 2Imaging and Pathology, KU Leuven, Leuven, Belgium, 3Radiology, University Hospitals Leuven, Leuven, Belgium, 4Development and Regeneration, KU Leuven, Leuven, Belgium, 5Gynaecology and Obstetrics, University Hospitals Leuven, Leuven, Belgium, 6Gynaecologic Oncology, Antoni van Leeuwenhoek, Amsterdam, Netherlands, 7Gynaecologic Oncology, Netherlands Cancer Institute, Amsterdam, Netherlands, 8Gynaecologic Oncology, Amsterdam university medical centers, Amsterdam, Netherlands |
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One in every 1000-2000 pregnancies is complicated by maternal cancer, for which chemotherapy is increasingly administered during pregnancy. However, only limited knowledge exists on the long-term impact of in utero exposure to cancer therapy. This study investigated the impact of prenatal exposure to chemotherapy, at the age of nine, on cortical development using surface-based morphometry. We found cortical thickness to be significantly lower in the superior part of the left pre-central sulcus of the prenatal-exposed children, compared to controls, whereas the gyrification index was significantly higher in the left post-central sulcus of this group, possibly impacting attentional development. |
| 631
|
16:21
|
Altered development of structural brain networks in young children with prenatal alcohol exposure |
1Radiology, University of Calgary, Calgary, AB, Canada, 2Department of Paediatrics, University of Calgary, Calgary, AB, Canada |
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Prenatal alcohol exposure (PAE) can result in lifelong cognitive and behavioral deficits. Structural brain abnormalities have been shown in older children, but whether they are apparent in younger children is unclear. We investigated structural brain connectivity in 32 children with PAE aged 2-7 years compared to 95 healthy controls using diffusion tensor imaging. Group differences in structural connectivity and correlations with age were examined within and between eight different brain networks. Children with PAE had lower connectivity within and between several networks, but faster development of connectivity than controls, suggesting delayed development. |
| 632 | 16:33
|
Direct comparison between macromolecular proton fraction and apparent diffusion coefficient as quantitative biomarkers of the human fetal brain maturation |
1Radiology, University of Washington, Seattle, WA, United States, 2Research Institute of Biology and Biophysics, Tomsk State University, Tomsk, Russian Federation, 3Institute “International Tomography Center” of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russian Federation |
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Apparent diffusion coefficient (ADC) is known as a quantitative biomarker of prenatal brain maturation. Fast macromolecular proton fraction (MPF) mapping is an emerging method for quantitative assessment of myelination that was recently adapted to fetal MRI. This study compared spatiotemporal trajectories of MPF and ADC changes in the brain anatomic structures of 42 fetuses in utero. MPF and ADC demonstrated qualitatively similar but quantitatively different spatiotemporal patterns. MPF appeared more sensitive to changes in the brain structures with known prenatal onset of myelination. |
| 633 | 16:45
|
Building 4D neonatal cortical surface atlases using Wasserstein barycenter |
1China Jiliang University, Hangzhou, China, 2University of North Carolina at Chapel Hill, Chapel Hill, NC, United States |
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Spatiotemporal (4D) neonatal cortical surface atlases are important tools for understanding the dynamic early brain development. To better preserve the sharpness and clarity of cortical folding patterns on surface atlases, we propose to compute the Wasserstein barycenter under the Wasserstein distance metric, for the construction of 4D neonatal surface atlases at each week from 39 to 44 postmenstrual weeks, based on a large-scale dataset with 764 neonates. Our atlases show sharper and more geometrically-faithful cortical folding patterns than the atlases built by the state-of-the-art method, thus leading to boosted accuracy for spatial normalization and facilitating early brain development studies. |
| 634 | 16:57
|
T1 and T2 Weighted Image Segmentation from 1.0T Neonatal MRI |
1King's College London, London, United Kingdom, 2Medical Physics and Biomedical Engineering, University College London, London, United Kingdom, 3Shaare Zedek Medical Centre, Jerusalem, Israel, 4Faculty of Medicine, The Hebrew University, Jerusalem, Israel |
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In this work we present joint-image segmentation results from a novel 1.0T neonatal-specific MRI scanner. Data from machines such as this represent a new way to observe the growth and development of the preterm brain and can transfer our understanding of neurodevelopment prematurity. Advanced image analysis techniques are required to understand these developmental processes and we show preliminary results showing that good results can be obtained from these data. |
| 635 | 17:09
|
Cortical thickness is a sensitive biomarker for characterizing the gray matter abnormities in neonates with mild white matter injury |
1Department of Diagnostic Radiology, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China, 2Department of Radiology and BRIC, University of North Carolina at Chapel Hill, North Carolina, NC, United States, 3MR Research China, GE Healthcare, Beijing, China |
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White matter injury is common in neonates. The most common punctate white matter lesions (PWML) can disappear along with time and are easily missed diagnosis, but quantitative measurements may find more subtle alterations. Since DTI is not sensitive to detect the white-matter microstructural changes in mild PWML, alterations in gray-matter (GM) may provide additional knowledge for predicting prognosis. This study aims to quantitatively assess alterations of GM in neonates with mild PWML. Compared with controls, a significant reduction of cortical volume is observed in neonates with mild PWML, and cortical thickness is a sensitive biomarker for characterizing the GM abnormalities. |
| 636 | 17:21
|
Myelin Water Imaging and R2* Mapping in Neonates |
1Pediatrics, UBC, Vancouver, BC, Canada, 2Radiology, Chongqing Medical University, Chongqing, China, 3Pediatrics, UBC, 2221 Wesbrook Mall, BC, Canada |
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Understanding sources of R2* in the brains of infants and adults could lead to novel imaging biomarkers that could inform clinicians and researchers about white matter microstructure, and iron and myelin content. These biomarkers could in turn help determine the health, disease state, or developmental progress of white matter tissue, with many potential benefits to diagnosis, treatment, and therapeutic research. As opposed to adults who show a remarkable fit of R2* against fibre orientation, neonates showed very little dependence on myelin or fibre orientation. |
| 637
|
17:33
|
Rapid Anatomical Imaging of the Neonatal Brain Using T2-Prepared 3D Steady-State Free Precession |
1Division of Diagnostic Imaging and Radiology, Children's National Medical Center, Washington, DC, United States, 2Division of Fetal and Transitional Medicine, Children's National Medical Center, Washington, DC, United States, 3Department of Pediatrics, George Washington University, Washington, DC, United States, 4Department of Radiology, George Washington University, Washington, DC, United States |
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Anatomical imaging of the neonatal brain is typically acquired using T2-weighted imaging based on either 3D fast spin echo (FSE) or 2D single shot FSE (SSFSE). While 3D imaging provides higher signal-to-noise ratio (SNR) and spatial resolution than 2D, its scan time is relatively long.In this study, we developed rapid 3D anatomical imaging for the neonatal brain using 3D steady-state free precession (SSFP) with T2 preparation. Our proposed method demonstrated similar T2 contrast to that of 3D FSE and 2D SSFSE while achieving shorter scan time than 3D FSE and higher through-plane resolution and higher SNR than 2D SSFSE. |
| 638
|
15:45
|
Whole-abdomen Free-breathing Quantitative Dynamic Contrast Enhanced (DCE) MR Imaging of Pancreatic Ductal Adenocarcinoma (PDAC) with Fast T1 Mapping Using Multitasking: A Pilot Study |
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 2Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, United States, 3Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 4Radiologic Department, Chaoyang Hospital, Beijing, China, 5Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA, United States |
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PDAC is the 3rd leading cause of cancer-related death in the US with poor prognoses. Although conventional DCE-MRI techniques have demonstrated high sensitivity and specificity in tumor delineation, the diagnosis and prognosis of PDAC continues to be challenging with currently available imaging tools. In this work, we proposed a novel Multitasking DCE technique enabling free-breathing acquisition, 3D whole-abdomen coverage, high temporal resolution (500 ms), and dynamic T1 mapping to allow for accurate quantification of tissue perfusion and vascular properties of PDAC. The in vivo feasibility of the proposed technique is demonstrated in healthy subjects and patients with PDAC. |
| 639 | 15:57
|
The Stiffness as Obtained by MR Elastography Correlates with the Stroma Proportion and Prognosis of Resectable Pancreatic Adenocarcinoma |
1shengjing hospital of china medical university, shenyang, China |
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One of the defining characteristics of pancreatic adenocarcinoma (PDAC) is abundant desmoplastic stroma. Our study showed that pancreatic stiffness determined by magnetic resonance elastography (MRE) is a promising technique to predict the stroma proportion and shows potentials to predict prognosis of resectable PDAC. |
| 640
|
16:09
|
Precise stiffness-based detection of pancreatic carcinoma by tomoelastography |
1Radiology, Charite - University Hospital Berlin, Berlin, Germany, 2Surgery, Charite - University Hospital Berlin, Berlin, Germany, 3Informatics, Charite - University Hospital Berlin, Berlin, Germany |
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Pancreatic stiffness was investigated using multifrequency MR elastography (MRE) and tomoelastography data processing in healthy controls (CTR) and patients with pancreatic ductal adenocarcinoma (PDAC). In healthy volunteers, tomoelastography was highly reproducible and showed no significant influences of region and age on pancreatic stiffness. Furthermore, we show that PDAC can be detected as stiff masses with full separation of MRE-values between CTR and PDAC. MRE-based tumor volume correlated excellently with CT-volumetry. Tomoelastography is well suited for boundary detection of pancreatic tumors within standardized, quantitative and contrast-agent free imaging examinations. |
| 641 | 16:21
|
Evaluation of the clinical usefulness of 3-dimensional Magnetic Resonance Cholangiopancreatography with compressed sensing in patients with pancreatobiliary disease |
1Magnetic Resonance Imaging, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China, 2MR Collaborations, Siemens Healthcare, Beijing, China, 3Siemens Healthcare Gmbh, Erlangen, Germany, 4Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China |
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This study aimed to compare the acquisition time, image quality, and diagnostic performance of three three-dimensional (3D) magnetic resonance cholangiopancreatography (MRCP) with compressed-sensing (CS) prototype protocols with those of conventional MRCP in a large cohort of patients with suspected pancreaticobiliary disorders, and to explore the effect of the in-plane phase-encoding direction on the image quality of small-field-of-view (FOV) breath-hold (BH) CS-MRCP (sFOV-BH-CS-MRCP). We found that CS-MRCP provides comparable image quality and diagnostic performance with significantly shortened scan time, and sFOV-BH-CS-MRCP should be acquired in the head-feet phase-encoding direction instead of the left-right direction. |
| 642
|
16:33
|
Can two breath-hold 3D-MRCP replace the conventional 3D-MRCP? |
1Department of Radiology, Peking Union Medical College Hospital, Beijing, China, 2Philips Healthcare, Beijing, China, 3Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, United Kingdom |
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This study was to evaluate and compare the image quality and diagnostic performance of three MRCP protocols, including BH-3D-CS-MRCP, Gradient Spin Echo (BH-GraSE-3D-MRCP) and navigator-triggered (NT) MRCP. |
| 643
|
16:45
|
Pancreatic perfusion modulation following glucose stimuli revealed by non-invasive Arterial Spin Labeling (ASL) MRI |
1Division of MRI research, Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boson, MA, United States |
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Being able to non-invasively monitor pancreatic perfusion changes is essential for its clinical translation, but it can also prove useful in the evaluation of endocrine disorders such as diabetes. While some perfusion modification following a glucose challenge was observed with PET, ASL has not yet succeeded. We propose here an investigation of pancreatic perfusion modulation following an oral glucose challenge with background-suppressed pCASL at 3T, highlighting perfusion modulation that could be linked to pancreatic endocrine function. Such paradigm could either serve as a tool for studying endocrine disorders or provide a glucose-enhanced scan that increases SNR for diagnostic purposes. |
| 644 | 16:57
|
Magnetic Resonance Fingerprinting of the Normal Pancreas |
1Radiology, University of Cambridge, Cambridge, United Kingdom, 2Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom, 3Cancer Research UK, Cambridge, United Kingdom, 4IMAGO7 Foundation, Pisa, Italy, 5GE Healthcare, Munich, Germany, 6Radiology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom, 7University of Cambridge, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom |
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MR imaging of the pancreas is challenging due to its retroperitoneal deep-sited location in the abdomen. In addition to its position, the pancreas is subject to breathing motion artifact, which limits the clinical value of pancreatic MRI. Patients with pancreatic cancer are usually very frail, which limits their tolerance to long examinations or breath-hold MRI measurements. MR Fingerprinting (MRF) is an innovative measurement technique that provides qualitative data and quantitative parameter maps from a single acquisition with the potential to reduce exam times. MRF is technically challenging due to limitations in processing capabilities, which we assess in this work. |
| 645 | 17:09
|
Comparison of reduced field-of-view (rFOV) and full FOV (fFOV) diffusion-weighted imaging (DWI) in the assessment of insulioma: image quality and WHO grading |
1Department of Radiology, Peking Union Medical College Hospital, Beijing, China, 2Philips Healthcare, Beijing, China, 3Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, United Kingdom |
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Reduced-FOV DWI (rFOV-DWI) of the pancreas has been applied in small cohorts and demonstrated improved image quality, but it has not been studied in the detection and characterization of insulioma. In this study, we compared the imaging quality (IQ) of rFOV-DWI and full FOV DWI sequence in insulioma detection. We also explored the correlation between the ADC value and WHO classification. |
| 646 | 17:21
|
Pancreatic T1 Mapping and Extracellular Volume Fraction in Patients with Impaired Glucose Tolerance |
1Radiology, Gifu University, Gifu, Japan, 2Radiology, Kyoto Prefectural University of Medicine, Kyoto, Japan, 3Philips Healthcare, Tokyo, Japan |
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The presence of pancreatic fibrosis is a representative feature of the pancreas in patients with impaired glucose tolerance (IGT). The extracellular volume fraction (ECV) is reported to be associated with cardiac and hepatic fibrosis. In this study, we evaluated the feasibility of the ECV of the pancreas based on T1 mapping for the assessment of HbA1c values. Our results showed that increased ECV of the pancreas was significantly correlated with HbA1c values, so the ECV of the pancreas could serve as a potential imaging biomarker for the assessment of patients with IGT. |
| 647 | 15:45
|
Validating axonal directionality with 3D X-ray scattering |
1NYU School of Medicine, New York, NY, United States, 2ETH Zurich, Zurich, Switzerland, 3Paul Scherrer Institute, Villigen PSI, Switzerland, 4Brookhaven National Laboratory, Upton, NY, United States, 5Johns Hopkins Medicine, Baltimore, MD, United States |
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Diffusion MRI (dMRI) is sensitive to neuronal alignment, yet its directional signal does not depend only on the fiber orientation distribution function (fODF). Current validation methods for measuring and modeling the ODF have major limitations. Small-angle X-ray scattering (SAXS) produces directly structural signal, specific to myelin’s repetitive structural arrangement. We apply 3D scanning SAXS on mouse brain sections, retrieve fODFs and compare against dMRI-derived axonal directionality. We also apply SAXS-tensor tomography to mouse spinal cord, produce tractography maps and correlate dMRI- and SAXS-TT-derived fODF parameters. These demonstrate SAXS’s potential for providing novel microstructural insights and structurally validating dMRI-derived fODFs. |
| 648
|
15:57
|
X-ray microcomputed tomography as a natively isotropic, nondestructive, 3D validation dataset for diffusion MRI |
1Department of Radiology, The University of Chicago, Chicago, IL, United States, 2Department of Neurobiology, The University of Chicago, Chicago, IL, United States, 3Argonne National Lab, Lemont, IL, United States |
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In this work, we present the use of synchotron x-ray microcomputed tomography (microCT) as a validation dataset for diffusion tensor imaging (DTI). DTI data were acquired of a post-mortem mouse brain. After metal staining, synchrotron microCT data of the sample were acquired, with 1.2 μm isotropic resolution across the whole brain. Orientation distribution functions were calculated from the microCT data using structure tensor analysis, and tractography was performed on the anterior commissure tract. Comparisons with tractography results from the diffusion MRI data show good agreement. |
| 649
|
16:09
|
Microstructural characterization and validation of a 3D printed phantom for diffusion MRI |
1Centre for Functional and Metabolic Mapping, Robarts Research Institute, London, ON, Canada, 2Biomedical Engineering, Western University, London, ON, Canada, 3Imaging Research Laboratories, Robarts Research Institute, London, ON, Canada, 4Medical Biophysics, Schulich School of Medicine and Dentistry, London, ON, Canada, 5The Brain and Mind Institute, London, ON, Canada |
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Validating diffusion MRI (dMRI) representations and models of brain tissue is challenging because there is no reference ground-truth for in vivo scans. We propose a form of 3D printed phantoms as a flexible paradigm for investigating and validating microstructural indices and crossing fibres that is reproducible with inexpensive materials. As a proof of concept, we obtained multishell dMRI data in samples with varying crossing angles and printing parameters, and investigated the performance of constrained spherical deconvolution to extract diffusion parameters that accurately describe the crossing fibre bundles. We also investigated the effect of printing parameters on the phantoms’ microstructural anisotropy. |
| 650 | 16:21
|
Exploring the effect of varying axonal shape on the transverse diffusion inside EM-reconstructed axons using 3d Monte Carlo simulations |
1Center for Biomedical Imaging, New York University School of Medicine, New York, NY, United States, 2Center for Advanced Imaging Innovation and Research (CAI2R), New York University School of Medicine, New York, NY, United States |
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Diffusion inside axons is restricted and thus non-Gaussian, with diffusion MRI (dMRI) signal strongly sensitive to the shape of the confining axon. This sensitivity is confounded by the coarse-graining of the diameter/shape variation along the fiber during the diffusion time. Here, we analytically relate dMRI metrics to the axonal shape, and validate our theory using 3d Monte-Carlo simulations in beaded cylinders and realistic axons reconstructed from electron microscopy images of the mouse brain white matter. Our simulation results show that the intra-axonal space has a non-trivial kurtosis transverse to axons. Its value is different from that in a perfectly straight cylinder, and needs to be considered in axonal diameter measurements (e.g., spinal cord, strong gradients, intra-axonal metabolites). |
| 651 | 16:33
|
Validating MR axon diameter mapping using confocal microscopy |
1Champalimaud Centre for the Unknown, Lisbon, Portugal, 2iMinds - Vision Lab, University of Antwerp, Antwerp, Belgium, 3Center for Biomedical Imaging, NYU School of Medicine, New York, NY, United States |
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Axon diameter mapping using diffusion MRI in the rat corpus callosum was validated using confocal microscopy with a staining for neurofilaments. When confounding factors such as extra-axonal water and dispersion are addressed, the effective MR axon radii are in good quantitative agreement with histology. However, using MRI, we are limited to the estimation of a single metric representing the entire distribution, which has shown to be dominantly sensitive to the largest axons in the voxel volume of interest. |
| 652
|
16:45
|
Histological validation of the brain cell body imaging with diffusion MRI at ultrahigh field |
1Centre for Medical Image Computing, Department of Computer Science, University College London, London, United Kingdom, 2Champalimaud Research, Champalimaud Centre for the Unkown, Lisbon, Portugal |
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Biophysical modelling of diffusion-weighted MRI (DW-MRI) data can help to gain more insight into brain microstructure. However, models need to be validated. This work validates a recently-developed technique for non-invasive mapping of brain cell-body (soma) size/density with DW-MRI, by using ultrahigh-field DW-MRI experiments and histology of mouse brain. Predictions from numerical simulations are experimentally confirmed and brain’s maps of MR-measured soma size/density are shown to correspond very well with histology. We provide differential contrasts between cell layers that are less expressed in tensor analyses, leading to novel complementary contrasts of the brain tissue. Limitations and future research directions are discussed. |
| 653
|
16:57
|
The BigMac dataset: ultra-high angular resolution diffusion imaging and multi-contrast microscopy of a whole macaque brain |
1FMRIB Centre, Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom, 2CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom, 3Wellcome Centre for Integrative Neuroimaging, Experimental Psychology, Medical Sciences Division, University of Oxford, Oxford, United Kingdom, 4Department of Anatomy, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, Netherlands, 5Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom |
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Diffusion MRI has the ability to reveal the complex connectivity of the human brain. However, the link between the diffusion signal and the underlying tissue microstructure remains elusive. To drive diffusion MRI validation, we present BigMac: a unique dataset which combines ultra-high angular resolution diffusion MRI with microscopy throughout an adult macaque brain. With this dataset we ask how under-sampling q-space biases our reconstruction of the ‘true’ diffusion profile. Our results indicate that the error associated with interpolating under-sampled data decays exponentially with the angular resolution of sampling, and that high angular resolution is necessary to characterise acutely crossing fibres. |
| 654
|
17:09
|
CHENONCEAU: towards a novel mesoscopic (100/200µm) post mortem human brain MRI atlas at 11.7T |
1UNIRS, CEA/DRF/Neurospin, Gif-sur-Yvette, France, 2Université Paris Saclay, Orsay, France, 3FLI/Noeud Paris-Sud, Orsay, France, 4UNATI, CEA/DRF/Neurospin, Gif-sur-Yvette, France, 5http://cati-neuroimaging.com/, Gif-sur-Yvette, France, 6INSERM UMR 1253 iBrain, Université de Tours, Tours, France |
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Ultra-high field MRI combined with strong gradients gives access to ex-vivo anatomical and diffusion MRI datasets at the mesoscopic scale. This |
| 655 | 17:21
|
The two-compartment diffusion “standard model” misestimates microscopic anisotropy in-vivo |
1Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown, Lisbon, Portugal, 2Center of Functionally Integrative Neuroscience (CFIN) and MINDLab, Clinical Institute, Aarhus University, Aarhus, Denmark, 3Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark |
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Several microstructural models have been proposed to increase the specificity of diffusion MRI. However, improper model assumptions can compromise the accuracy of model estimates. Here, we compared model-independent metrics extracted from double diffusion encoding (DDE) with the metrics arising from the current (two-compartment) diffusion “standard model” (SM) in in-vivo rat brains. Our results revealed that SM produces overestimated microscopic anisotropy for both white and grey matter. These findings question the validity of SM and calls for future developments of more accurate models. |
| 656
|
17:33
|
Validation of diffusion models: a post-mortem MRI and histology study |
1Center for Brain Imaging Science and Technology, Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrumental Science, Zhejiang University, Hangzhou, China, 2China Brain Bank and Department of Neurology in Second Affiliated Hospital, Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Zhejiang University, Hangzhou, China, 3Department of Anatomy and Neurosciences, Amsterdam Neuroscience, Amsterdam UMC, location VUmc, Amsterdam, Netherlands, 4Department of Imaging Sciences, University of Rochester, Rochester, NY, United States |
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The Diffusion Kurtosis Imaging (DKI) model can successfully characterize non-Gaussian diffusion. In turn, the White Matter Tract Integrity (WMTI) model is proposed to be based on the DKI model to further characterize the intra- and extra-axonal compartments. However, the accuracy with which model parameters reflect the underlying tissue characteristics has not been tested. Here, we compared two MRI model metrics using a unique combined post-mortem MRI and histopathology approach. Preliminary results show that AWF, $$$D_{e,\perp}$$$and MD from MRI correlate strongly with myelin fraction and that $$$D_{e,\parallel}$$$ from MRI correlates strongly with astrocyte fraction. |
| 657 | 15:45
|
fastMRI: a publicly available raw k-space dataset for accelerated MRI reconstruction using machine learning |
1Center for Advanced Imaging Innovation and Research, Department of Radiology, New York University School of Medicine, New York, NY, United States, 2Facebook Artificial Intelligence Research, Menlo Park, CA, United States, 3Medical Center IT, New York University School of Medicine, New York, NY, United States |
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Despite the substantial increase in research activity in machine learning for MR image reconstruction, no large scale raw k-space data set is publicly available. This makes it challenging to reproduce and validate comparisons of different approaches, and it restricts access to work on this problem to researchers associated with large academic medical centers. This abstract introduces the first large-scale database of MRI data for reconstruction. The database currently includes about 7500 raw MRI k-space data sets from a range of MRI systems and clinical patient populations, with corresponding images derived from the rawdata using reference image reconstruction algorithms. Approximately 30000 additional clinical image datasets not directly associated with the rawdata are also included, and we plan to add to the database over time. |
| 658 | 15:57
|
dAUTOMAP: Decomposing AUTOMAP to Achieve Scalability and Enhance Performance |
1Department of Computing, Imperial College London, London, United Kingdom, 2Biomedical Engineering, King's College London, London, United Kingdom, 3Faculty of Medicine, Institute of Clinical Sciences, Imperial College London, London, United Kingdom |
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AUTOMAP is a promising generalized reconstruction approach, however, it is not scalable and hence the practicality is limited. We present a novel way for decomposing the domain transformation, which makes the model scale linearly with the input size. We show the proposed method, termed dAUTOMAP, outperforms AUTOMAP with significantly fewer parameters. |
| 659
|
16:09
|
DL-ESPIRiT: Improving robustness to SENSE model errors in deep learning-based reconstruction |
1Electrical Engineering, Stanford University, Stanford, CA, United States, 2Applied Sciences Laboratory, GE Healthcare, Menlo Park, CA, United States, 3Radiology, Stanford University, Stanford, CA, United States |
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Parallel imaging concepts, such as sensitivity encoding (SENSE), have been incorporated into DL reconstruction frameworks by augmenting the acquisition model with knowledge of the coil sensitivities. However, SENSE-based methods rely on accurate estimation of sensitivity maps; otherwise, residual aliasing may arise due to model errors such as in reduced field-of-view imaging. Here we propose DL-ESPIRiT, an ESPIRiT-based neural network architecture with improved robustness to model errors. We show that DL-ESPIRiT can reconstruct 10X accelerated 2D cardiac CINE data with higher fidelity and allow for more accurate automatic assessment of cardiovascular function than l1-ESPIRiT. |
| 660
|
16:21
|
Unsupervised Deep Basis Pursuit: Learning Reconstruction without Ground-Truth Data |
1Electrical Engineering and Computer Sciences, University of California, Berkeley, Berkeley, CA, United States, 2International Computer Science Institute, Berkeley, CA, United States |
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Basis pursuit is a compressed sensing optimization in which the l1-norm is minimized subject to model error constraints. Here we use a deep neural network prior instead of l1-regularization. Using known noise statistics, we jointly learn the prior and reconstruct images without access to ground-truth data. During training, we use alternating minimization across an unrolled iterative network and jointly solve for the neural network weights and training set image reconstructions. At inference, we fix the weights and pass the measurements through the network. We compare reconstruction performance between unsupervised and supervised (i.e. with ground-truth) methods. We hypothesize this technique could be used to learn reconstruction when ground-truth data are unavailable, such as in high-resolution dynamic MRI. |
| 661 | 16:33
|
Dynamic MRI using Model-based deep learning and SToRM priors: MoDL-SToRM |
1University of Iowa, Iowa city, IA, United States |
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We introduce a novel framework to combine deep-learned priors along with complementary image regularization penalties to reconstruct free breathing & ungated cardiac MRI data from highly undersampled multi-channel measurements. Image recovery is formulated as an optimization problem, where the cost function is the sum of data consistency term, convolutional neural network (CNN) denoising prior, and SmooThness regularization on manifolds (SToRM) prior that exploits the manifold structure of images in the dataset. Our results show the benefit in combining deep learned CNN priors with complementary image regularization penalties. |
| 662 | 16:45
|
Undersampled MR Image Reconstruction Using an Enhanced Recursive Residual Network |
1Department of Electronic Science, Xiamen University, Xiamen, China |
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We propose an enhanced recursive residual network (ERRN) that improves the basic recursive residual network with both a high-frequency feature guidance and dense connections. The feature guidance is designed to predict the underlying anatomy based on image a priori learning from the label data, playing a complementary role to the residual learning. The ERRN is adapted to include super resolution MRI and compressed sensing MRI, while an application-specific error-correction unit is added into the framework, i.e. back projection for SR-MRI and data consistency for CS-MRI due to their different sampling schemes. |
| 663
|
16:57
|
Accelerated MRI Using Residual RAKI: Scan-specific Learning of Reconstruction Artifacts |
1Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, United States, 2Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 3Computer Assisted Clinical Medicine, University Medical Center Mannheim, Heidelberg University, Mannheim, Germany |
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Recently, there has been an interest in machine learning reconstruction techniques for accelerated MRI, where the focus has been on training regularizers on large databases. Another line of work, called Robust Artificial-neural-networks for k-space Interpolation (RAKI) explored the use of CNNs, trained on subject-specific ACS data for improving parallel imaging. In this work, we propose a ResNet architecture, called Residual RAKI (rRAKI) for training a subject-specific CNN that simultaneously approximates a linear convolutional operator and a nonlinear component that compensates for noise amplification artifacts that arise from coil geometry. Brain data shows improved noise resilience at high acceleration rates. |
| 664
|
17:09
|
Rapid Reconstruction of Accelerated, Free-Breathing, Thoracic, Non-Contrast Magnetic Resonance Angiography using Convolutional Neural Network |
1Department of Radiology, Northwestern University, Chicago, IL, United States, 2Department of Biomedical Engineering, Northwestern University, Evanston, IL, United States, 3Department of Computer Science & Engineering, Northwestern University, Evanston, IL, United States |
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In this study we developed a convolutional neural network (CNN) for reconstructing 3D non-contrast magnetic resonance angiography (NC-MRA) images. We trained our proposed CNN using 4,800 zero-filled images and the corresponding GRASP reconstructed images from 10 patients as input and output, respectively. For validation, we used 6,720 zero-filled images from 14 patients as input to our trained CNN. Comparison between CNN and GRASP reconstructions showed excellent agreement using quantitative metrics and quantified aortic diameters . The mean reconstruction time, excluding the pre- and post-processing steps, for CNN (74 s) was 99% shorter than GRASP (12,703 s). |
| 665
|
17:21
|
Joint multi-contrast Variational Network reconstruction (jVN) with application to Wave-CAIPI acquisition for rapid imaging |
1Martinos Center for Biomedical Imaging, Charlestown, MA, United States, 2University of Heidelberg, Heidelberg, Germany, 3Siemens Healthcare GmbH, Erlangen, Germany, 4MIT, Cambridge, MA, United States, 5Harvard Medical School, Boston, MA, United States, 6German Cancer Research Center, Heidelberg, Germany, 7Harvard-MIT Health Sciences and Technology, Cambridge, MA, United States |
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We introduce a joint Variational Network (jVN) to reconstruct multi-contrast data jointly from accelerated MRI acquisitions. By taking advantage of the shared structural information among different clinical contrasts, jVN better preserved small anatomical features when compared to standard single-contrast VN. Combining jVN with the efficient Wave-CAIPI acquisition scheme enabled rapid 3D volumetric scans at R=16x acceleration. This approach was evaluated at 3T using in-vivo data from three clinical contrasts, resulting in up to a 54% reduction in RMSE when compared to standard Wave-CAIPI reconstructions. The jVN reconstructions preserved both high spatial resolution and good image quality. |
| 666
|
17:33
|
Joint recovery of variably accelerated multi-contrast MRI acquisitions via generative adversarial networks |
1Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey, 2Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Turkey, 3Neuroscience Graduate Program, Bilkent University, Ankara, Turkey |
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Two frameworks to recover missing data in accelerated MRI are |
15:45
|
Probing Mechanics of the Mammalian Brain | |
16:05
|
Brain MRE in the Transition to Clinical Routine | |
16:25
|
High-Resolution MR Elastography in Mapping the Aging Brain | |
1University of Delaware, Wilmington, DE, United States |
16:45
|
The (Very Complex) Mechanics of Liver Fibrosis | |
17:05
|
Clinical Applications of MRE in Liver Disease | |
1Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States |
17:25
|
Current Technical Trends & Challenges in Abdominal MRE | |
1ETH Zurich, Gloriastrasse 35, Switzerland |
15:45
|
Introduction | |
1Max Planck Institute for Human Cognitive and Brain Sciences, Germany |
15:50
|
Regional & Cellular Iron Distribution in the Brain in Normal & Disease States | |
1The Pennsylvania State University - College of Medicine, United States |
16:10
|
Mechanisms of Iron-Induced Relaxation in the Human Brain | |
1Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany |
16:30
|
Quantitative MRI of the Postmortem Brain for the Validation of MRI Measures | |
16:50
|
In Vivo Evaluation of Brain Tissue Cellular, BOLD & Iron Content in Basal Ganglia With Quantitative Gradient Recalled Echo MRI | |
1Mallinckrodt Institute of Radiology, St. Louis, MO, United States |
17:10
|
Understanding the Underlying Contrast Mechanisms in Neuromelanin-MRI | |
1Neurology, Vanderbilt University Medical Center, Nashville, TN, United States |
17:30
|
Discussion: Towards Sensitive & Specific Iron Biomarkers in the Human Brain |
| 7:00 | Microstructure Imaging for Clinical Use |
| Kouhei Kamiya |
| 7:30 | Basic Overview of Microstructure Models |
| Jennifer Campbell |
| 8:00 | Adjournment |
| 7:00 | Diffusion Techniques |
| Markus Nilsson |
| 7:30 | Clinical Applications of Brain Diffusion |
| Susie Huang |
| 8:00 | Adjournment |
| 7:00 | How to Use 31P & 13C MR to Probe Metabolism |
| Martin Meyerspeer |
| 7:30 | Metabolic Processes Studied with 31P or 13C MRS |
| Jeanine Prompers |
| 8:00 | Adjournment |
| 7:00 | Preclinical MR-PET |
| Stephen Sawiak |
| 7:30 | Introduction to Magnetic Particle Imaging (MPI) |
| JEFFREY GAUDET |
| 8:00 | Adjournment |
| 7:00 | From Magnetism to Fieldmaps & Back |
| Karin Shmueli |
| 7:30 | QSM Tools & Their Biases |
| Berkin Bilgic |
| 8:00 | Adjournment |
| 7:00 | Whole-Gland Therapy: Radiation & Androgen Deprivation |
| Silvia Chang |
| 7:30 | Focal Therapy: Laser, Cryo & HIFU |
| Jurgen Fütterer |
| 8:00 | Adjournment |
| 7:00 | Fat Suppression & Quantification: Friend or Foe?: Research Perspective |
| Hermien Kan |
| 7:30 | Fat Suppression & Quantification: Friend or Foe?: Clinical Perspective |
| Jung-Ah Choi |
| 8:00 | Adjournment |
| 7:00 | Cardiovascular MR: Analysis Today |
| Einar Heiberg |
| 7:30 | Cardiovascular MR: Analysis in the Future |
| Robert Judd |
| 8:00 | Adjournment |
8:15
|
Viability Assessment | |
1University of Pennsylvania, United States |
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The purpose of this educational talk is to discuss imaging techniques for cardiac MRI assessment of myocardial viability using endogenous contrast. We will first define viability in the context of non-advanced imaging methods and understand the fundamental pathophysiologic changes that occur in the cardiomyocyte and heart. We will then review the basic physical principles of endogenous contrast techniques, show their application to viability assessment, recommend best practices and briefly show a vision for their application 5 and 10 years from now. Some endogenous contrast techniques we will look at include cardiac T1 and T2 MRI, magnetization transfer, T1rho, chemical exchange saturation transfer, spectroscopy, and multiparametric approaches. |
8:45
|
Vascular & Anatomical Imaging | |
1Austin Health, Australia |
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Cardiac MRI in kidney failure can be challenging, however anatomic assessment of the heart and vessels can be readily performed without requirement for intravenous contrast. The information obtained may have value in prognosis and for therapeutic monitoring. Applicable techniques will be reviewed and changes that may be observed in chronic kidney disease (e.g. left ventricular remodelling) will be discussed. |
9:15
|
Myocardial Perfusion | |
1CRMBM, CNRS, Aix-Marseille Univ, Marseille, France |
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This overview will discuss expectations, solutions, advantages and limitations related to measuring perfusion in the human heart without contrast agents. The major existing approaches to Arterial Spin Labeling (ASL) in the heart will be outlined. The reasons why myocardial ASL is challenging compared with other organs will be outlined. It should also become clear why cardiac ASL is a well-working and validated method in the rodent heart whereas human applications are still scarce. |
9:45
|
Panel Discussion |
10:15
|
Adjournment |
8:15
|
MRS Data Acquisition from Irregularly Shaped Regions by Coil Sensitivity Heterogeneity | |
1NIMH, Bethesda, MD, United States |
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This talk focuses on a recently developed technique (SPLASH) for rapid spatial localization of irregularly shaped regions using high-resolution anatomical imaging and sensitivity heterogeneity of phased array coils. Fast MRS data acquisition and reconstruction of ischemic and healthy tissue compartments are demonstrated. |
8:45
|
MRSI Using Spatial-Spectral Prior Knowledge | |
1Electrical and Computer Engineering, University of Illinois, Urbana-Champaign, Urbana, IL, United States, 2Bioengineering, University of Illinois, Urbana-Champaign, United States |
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Recently, several novel methods that exploit spatiospectral priors have been developed to address the dimensionality, sensitivity and nuisance signal challenges of MR spectroscopic imaging, and enabled significantly improved combinations of speed, resolution, SNR and organ coverage. This talk will review the new low-dimensional models, special acquisition and reconstruction strategies underlying these exciting developments, as well as potential neuroscience and clinical applications of these new techniques. Current limitations and future research opportunities will also be discussed. |
9:15
|
MRSI Processing & Automation | |
1Duke University Medical Center, United States |
||
This section of the course provides an overview of the processing requirements required by emerging MR spectroscopic imaging approaches and describes a roadmap towards their automation and adoption within a clinical context. |
9:45
|
Spatial-Spectral MRSI Encoding | |
1GE Healthcare, Munich, Germany |
||
This lecture introduces different spectral-spatial sampling schemes for 1H as well as x-nuclei MRSI. These are Cartesian and non-Cartesian k-space trajectories as well as additional ways of encoding spatial information. Advantages and disadvantages are discussed, and a few examples are shown. |
10:15
|
Adjournment |
| 667
|
Pitch: 8:15 Poster: 9:15 Plasma 1
|
Automated whole-body adipose tissue segmentation in T1-weighted fast spin echo imaging in a cohort of subjects at increased risk for type 2 diabetes |
1King's College London, London, United Kingdom, 2Department of Radiology, University Hospital Tübingen, Tübingen, Germany, 3Institute of Signal Processing and System Theory, University of Stuttgart, Stuttgart, Germany |
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Quantification and localization of adipose tissues in whole-body T1-weighted MR images is of high interest to examine metabolic conditions. For correct identification and phenotyping of subjects at increased risk for metabolic diseases, reliable automatic segmentation of adipose tissue into subcutaneous adipose tissue and visceral adipose tissue is required. Full manual tissue delineation is a time-and cost-intensive task which is not advisable especially in cohort studies. We propose a 3D convolutional neural network to perform automated adipose tissue segmentation from T1-weighted whole-body fast spin echo images in a fast and robust way with reliable separation of visceral and subcutaneous fat masses. |
| 668
|
Pitch: 8:15 Poster: 9:15 Plasma 2
|
Deriving Brain Myelin Water Fraction Maps from Relaxometry: a Data-Driven Approach |
1Advanced Clinical Imaging Technology, Siemens Healthcare AG, Lausanne, Switzerland, 2Department of Radiology, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland, 3LTS5, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland |
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Currently, one of the gold-standard methods to obtain brain myelin water fraction (MWF) maps is the multi-echo spin-echo sequence. To overcome some of its limitations (e.g. long acquisition times), a data-driven approach for deriving MWF maps is proposed here. A general linear model (GLM) and a conditional generative adversarial network (cGAN) were trained to learn the reference MWF from T1 and T2 maps acquired in a healthy cohort. While GLM-derived maps exhibited MWF overestimation, especially in WM tissue, the cGAN yielded images in agreement with the reference. The proposed methods were preliminarily tested in patients and revealed myelin degradation in expected areas. |
| 669
|
Pitch: 8:15 Poster: 9:15 Plasma 3
|
Simultaneous Denoising of Multi-contrast MR Images Using a Novel Weighted Nuclear Norm Minimization Approach |
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, China, 2Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China, 3Diagnostic Radiology, The University of Hong Kong, Hong Kong, China |
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A typical clinical MRI scanning session produces image sets with same geometries but different contrasts. These multi-contrast images often share strong structural similarities or correlations despite their contrast differences. Most existing MRI denoising methods deal with single-contrast images independently, and fail to explore and utilize such correlations across contrasts. In this study, we present a simultaneous denoising method for multi-contrast images based on low rank multi-contrast patch matrix completion. This denoising method exploits the structural similarities across contrasts, and outperforms the traditional method. Further, it does not compromise the image fidelity in absence of any structural similarities across contrasts. |
| 670 | Pitch: 8:15 Poster: 9:15 Plasma 4
|
A generalized deep learning framework for multi-landmark intelligent slice placement using standard tri-planar 2D localizers |
1GE Global Research, Bangalore, India, 2GE Global Research, Niskayuna, NY, United States, 3GE Healthcare, Rio de Janeiro, Brazil, 4GE Healthcare, Rochester, MN, United States, 5GE Healthcare, Waukesha, WI, United States |
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We demonstrate a deep learning-based MRI scan workflow for intelligent slice placement (ISP) for multiple brain landmarks (MSP, AC-PC, entire visual pathway, pituitary, IAC, hippocampus, TOF-Angiography) based on standard 2D tri-planar localizer images. Unlike prior approaches to automatic plane prescription, this method uses deep learning to determine all necessary planes without the need for explicit delineation of landmark structures and provides visual feedback to the user. For all the landmarks, we demonstrate that the proposed method can achieve landmark slice placement with mean distance error < 1 mm (N = 505) on localizer images itself and is comparable or better to slice placement obtained using higher resolution images. Results indicate excellent feasibility of the method for clinical usage. |
| 671 | Pitch: 8:15 Poster: 9:15 Plasma 5
|
Generalization and Analysis of a Deep Convolutional Neural Networks (DCNN)-Based Cerebral Microbleed Detection Algorithm |
1The UC Berkeley - UCSF Graduate Program in Bioengineering, San Francisco, CA, United States, 2Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States, 3Department of Anesthesia, University of California, San Francisco, San Francisco, CA, United States |
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We tested and analyzed a deep learning based CMB detection algorithm previously developed using 7T SWI images we found that this method can be well generalized to different scan environment, parameters and pathologies. |
| 672 | Pitch: 8:15 Poster: 9:15 Plasma 6
|
Learning Systematic Imperfections and Image Reconstruction with Deep Neural Networks for Wave-Encoded Single-Shot Fast Spin Echo |
1Electrical Engineering, Stanford University, Stanford, CA, United States, 2Radiology, Stanford University, Stanford, CA, United States, 3GE Healthcare, Menlo Park, CA, United States |
||
Wave-encoded single-shot fast spin echo imaging (SSFSE) achieves good structural delineation in less than a second while its calibration and reconstruction usually take more than a minute to finish. This study proposes a method to accelerate the calibration and reconstruction for wave-encoded SSFSE with a deep-learning-based approach. This method first learns the systematic imperfections with a deep neural network, and then reconstructs the image with another unrolled convolutional neural network. The proposed approach achieves 2.8-fold speedup compared with conventional approaches. Further, it can also reduce the ghosting and aliasing artifacts generated in conventional calibration and reconstruction approaches. |
| 673 | Pitch: 8:15 Poster: 9:15 Plasma 7
|
Calibrationless Deblurring of Spiral RT-MRI of Speech Production Using Convolutional Neural Networks |
1University of Southern California, Los Angeles, CA, United States |
||
Spiral acquisitions are preferred in speech real-time MRI because of their high efficiency, making it possible to capture vocal tract dynamics during natural speech production. A fundamental limitation is signal loss and/or blurring due to off-resonance, which degrades image quality most significantly at air-tissue boundaries. Here, we present a machine learning method that corrects for |
| 674 | Pitch: 8:15 Poster: 9:15 Plasma 8
|
Robust Region-Growing Fat-Water Imaging Using MT-Based B0 Field Priors |
1Radiology, University of Wisconsin, Madison, WI, United States, 2Medical Physics, University of Wisconsin, Madison, WI, United States |
||
Region-growing (RG) is one of most computationally efficient fat-water separation methods, which exploits B0 smoothness assumption for separation with improved accuracy. However, practical robustness of RG method is majorly limited by low accuracy of initial seeded B0 values, which are problematic to select due to competing off-resonance from fat. Recently, it was demonstrated that insensitivity of fat to magnetization transfer (MT) preparation can be utilized to produce fat-insensitive B0 field priors. Here, we present a modified RG method that exploits this phenomenon to solve problems of seeding and stability of the original method and to attain robust F/W separation. |
| 675
|
Pitch: 8:15 Poster: 9:15 Plasma 9
|
High resolution imaging of the arterial and venous vasculature in deep gray matter |
1Biomedical Magnetic Resonance, Otto-von-Guericke-University, Magdeburg, Germany, 2Wellcome Centre for Human Neuroimaging, London, United Kingdom, 3German Center for Neurodegenerative Disease, Magdeburg, Germany, 4Center for Behavioral Brain Sciences, Magdeburg, Germany, 5Leibniz Institute for Neurobiology, Magdeburg, Germany |
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Recent studies investigated the human vasculature by building vascular atlases and performing vessel morphometry. Even though these studies showed great potential, the used resolution might not be sufficiently high to study changes the microvasculature as there occur in i.e. Alzheimer’s. Therefore, an approach to assess the arterial and venous microvasculature in deep gray matter regions is presented. Based on high resolution ToF angiography and QSM acquired at 7T vascular densities and vessel probability maps were computed. |
| 676 | Pitch: 8:15 Poster: 9:15 Plasma 10
|
Automatic Detection of Cerebral Microbleeds using Susceptibility Weighted Imaging and Deep Learning |
1the MRI Institute for Biomedical Research, Bingham Farms, MI, United States, 2Magnetic Resonance Innovations, Bingham Farms, MI, United States, 3Department of Radiology, Tianjin First Central Hospital, Tianjin, China, 4Department of Radiology, Wayne State University, Detroit, MI, United States |
||
Detecting cerebral microbleeds can be time-consuming and prone to errors. Susceptibility weighted imaging (SWI) offers exquisite sensitivity to blood products. Furthermore, the use of SWI phase data makes it possible to differentiate diamagnetic calcifications from paramagnetic microbleeds. In this paper, we present a machine learning model based on residual neural networks, using SWI magnitude and phase data. The model was tested on 41 cases and compared with human raters with different levels of experience. A sensitivity of 93%, a positive predictive value of 80%, and 1.5 false positives per subject were achieved, outperforming both human raters and previously reported methods. |
| 677
|
Pitch: 8:15 Poster: 9:15 Plasma 11
|
How to Generalize a Deep Learning Model to New Data Lacking Appropriate MR Inputs? An Exploration using Ultra-low-dose Amyloid PET/MRI |
1Stanford University, Stanford, CA, United States, 2University of Leipzig, Leipzig, Germany |
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When generalizing a deep learning model to data acquired from different sites, non-harmonized protocols might result in missing or different data for use as model inputs. For an ultra-low-dose amyloid PET/MRI network we trained previously and wish to apply to other data, protocol differences resulted in missing MRI data and different PET image qualities. In this project we showed that structurally similar contrasts for substitution is a viable alternative in the case of missing input data and that noise reduction was observed when applying the network on any of the low-dose PET images. |
| 678 | Pitch: 8:15 Poster: 9:15 Plasma 12
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Visualizing and understanding deep learning features for MRI motion artifact detection |
1School of Electrical and Computer Engineering, UNICAMP, Campinas, Brazil, 2Faculty of Medical Sciences, UNICAMP, Campinas, Brazil |
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The high performance reported by Deep Convolutional Neural Networks (CNNs) on image classification, detection and segmentation are contributing to its usage increase, including the CNNs applied to Medical Image. To automatically detect motion artifacts on MRI we fine-tuned four different CNNs. Visualizing the features extracted by the CNN is crucial to understand the reported result from each architecture. Using a gradient-based visualization method, we noticed that all architectures have salient points on Cerebrospinal Fluid (CSF) and background. Furthermore, the architectures that reported better results also extract information from white-matter, confirming that this anatomical structure has essential information regarding the task. |
| 679
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Pitch: 8:15 Poster: 9:15 Plasma 13
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Accelerating Acquisition for the Reconstruction of Fiber Orientation Distribution Function Using Convolutional Neural Network |
1Center for Brain Imaging Science and Technology, Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrumental Science, Zhejiang University, Hangzhou, China, 2Department of Instrument Science & Technology, Zhejiang University, Hangzhou, China, 3Department of Imaging Sciences, University of Rochester, Rochester, NY, United States |
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Fiber orientation distribution function (fODF) is one of the key components for establishing brain connectivity maps. However, its reliable reconstruction usually requires a large number of diffusion weighted image (DWI) volumes leading to long acquisition time. Our previous study has shown the potential of multi-layer perceptron in recovering fODF directly from a small number of DWIs. In this study, we proposed a 3-dimentional convolution neural network to take the spatial correlation into consideration, allowing robust fODF reconstruction with up to eleven-fold reduction of number of DWIs. This method offers a new approach for fast fODF reconstruction which could facilitate its clinical applications. |
| 680 | Pitch: 8:15 Poster: 9:15 Plasma 14
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Variational vs Adversarial Autoencoders for Visualization and Interpretation of Deep Learning Features of Brain Aging |
1Biomedical Engineering, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada, 2Seaman Family MR Research Centre, Foothills Medical Centre, Calgary, AB, Canada, 3Radiology and Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada, 4Calgary Image Processing and Analysis Centre, Foothills Medical Centre, Calgary, AB, Canada |
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Deep learning models are state-of-the-art for numerous medical imaging prediction tasks. Exact understanding of learned prediction features is hard, slowing down their clinical application. New methods for interpreting such models are needed to enable clinical translation. Autoencoders are models that allow visualization of learned features, however they can lack detail in their visualizations and thus, cannot provide guidance on features that hinders their use. We propose a method for understanding relevant learned features by visualizing them in detailed images. We show that a model trained to predict age based on brain MR data learns known features of the aging brain. |
| 681
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Pitch: 8:15 Poster: 9:15 Plasma 16
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Inhomogeneous Neural Network Inversion (NNI_inh) for stiffness estimation in Magnetic Resonance Elastography |
1Medical Scientist Training Program, Mayo Clinic, Rochester, MN, United States, 2Radiology, Mayo Clinic, Rochester, MN, United States, 3Biomedical Engineering and Physiology, Mayo Clinic, Rochester, MN, United States |
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Stiffness estimates in small focal lesions by magnetic resonance elastography are often inaccurate. One factor contributing to these errors is the assumption of local material homogeneity made by most inversion algorithms. Here we describe an artificial neural network based inversion technique that accounts for material inhomogeneity (NNI_inh) and evaluate it in simulation, phantom, and in-vivo experiments. NNI_inh provides higher contrast-to-noise ratio for inclusions and may provide clearer delineation of inclusion boundaries when compared to two inversion algorithms that assume local material homogeneity. Preliminary clinical results in a case of hepatocellular carcinoma are also shown. |
| 682 | Pitch: 8:15 Poster: 9:15 Plasma 17
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How tumour pressure components are related to tumour blood perfusion and mechanical properties |
1Laboratory of Imaging Biomarker, INSERM-University Paris Diderot, Paris, France, 2Sanofi, Vitry sur seine, France, 3Department of Radiology, Beaujon University Hospital Paris Nord, Clichy, France |
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The purpose of this study was to assess the influence of |
| 683
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Pitch: 8:15 Poster: 9:15 Plasma 18
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Constant gradient magnetic resonance elastography experiments on phantom and bovine liver. |
1Univ Lyon, INSA‐Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, Lyon, France, 2Université de Toulouse, CNRS, INPT, UPS, IMFT, Toulouse, France, 3Department of Chemistry, Technische Universität München, Munich, Germany, 4ICB, CNRS UMR6303, Université de Bourgogne, Dijon, France |
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Magnetic Resonance Elastography (MRE) is performed by the application of motion-sensitive gradients. In this study, RF pulses are designed with an optimal control algorithm to obtain a desired magnetization phase distribution. Such pulse, in presence of a constant gradient, allows to simultaneously perform spatially selective excitation and motion encoding. This offers some advantages when compared to standard MRE encoding strategy. Simulations, phantom and ex vivo experiments show that phase-to-noise ratios are improved. These results demonstrate that optimal control-based pulses can be used to encode motion in the MRE excitation phase with relevant advantages for further in vivo liver rat studies. |
| 684 | Pitch: 8:15 Poster: 9:15 Plasma 19
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Motion robust distortion-free Arterial Spin Labeling |
1Fraunhofer MEVIS, Bremen, Germany |
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An improved reconstruction pipeline for arterial spin labeling (ASL) by means of a 3D GRASE PROPELLER (3DGP) acquisition is presented. Quality of ASL perfusion images is affected by motion artefacts, which can be mitigated by self-referred motion correction with 3DGP. However, since 3DGP is based on an EPI readout, geometric distortion is introduced in images, especially for long echo train lengths (ETL). The proposed method allows self-referred correction of motion as well as geometric distortion by playing each PROPELLER brick twice with toggled phase-encoded direction. The Topup technique then enables distortion correction followed by PROPELLER motion correction. |
| 685 | Pitch: 8:15 Poster: 9:15 Plasma 20
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High Resolution Perfusion Imaging using Golden Angle Radial Arterial Spin Labelling |
1WIN, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom |
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Arterial spin labeling perfusion imaging at clinical field strengths is generally confined to relatively coarse voxels (~4 mm), preventing the investigation of perfusion variations on small spatial scales and leading to problems with partial volume effects. In this work we demonstrate the ability of a golden angle radial approach combined with a regularized reconstruction technique to produce time-resolved perfusion images with isotropic voxel sizes lower than 2 mm. This was shown to improve grey matter definition and reduce partial volume effects. |
| 686
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Pitch: 8:15 Poster: 9:15 Plasma 21
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Mapping water exchange across the blood-brain barrier using three-dimensional diffusion-prepared arterial spin labeled perfusion MRI |
1Laboratory of FMRI Technology (LOFT), Mark & Mary Stevens Neuroimaging and Informatics Institute, Los Angeles, CA, United States, 2Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States |
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We present a novel pulse sequence and modeling algorithm to quantify the water exchange rate (kw) across the BBB without contrast, and to evaluate its clinical utility in a cohort of elderly subjects at risk of cerebral small vessel disease (SVD). A diffusion preparation module was integrated with pseudo-continuous ASL (pCASL) with background suppressed 3D GRASE readout. The results showed good reproducibility of kw measurements (ICC=0.75) in elderly subjects with repeated scans ~2 weeks apart. Average kw was increased in subjects with diabetes and hypercholesterolemia, and was correlated with vascular risk factors, cognitive function and white matter hyperintensities. |
| 687 | Pitch: 8:15 Poster: 9:15 Plasma 22
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Regional Variation of Water Permeability at the Blood-Brain Interface in the Mouse Brain using Multi-TE ASL: The Role of Aquaporin-4 |
1UCL Centre for Advanced Biomedical Imaging, University College London, London, United Kingdom, 2Office of the President, Karolinska Institutet, Stockholm, Sweden, 3GliaLab and Letten Centre, University of Oslo, Oslo, Norway, 4Neuroradiological Academic Unit, UCL Institute of Neurology, University College London, London, United Kingdom, 5Leonard Wolfson Experimental Neurology Centre, UCL Institute of Neurology, University College London, London, United Kingdom |
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We apply a multi-TE ASL technique to the mouse brain to assess the regional variation of water permeability at the blood brain interface, and measure the expression of brain AQP4 water channels as a marker of water transport. We report a significant decrease in the intravascular fraction of the ASL signal in the cerebellum compared to the cortex, 0.61 (± 0.22) and 0.90 (± 0.08) respectively, which is consistent with a marked increase (~400%) in Aqp4 expression in the cerebellum. This technique is a promising tool to better understand the dynamic role of AQP4 in pathological conditions. |
| 688 | Pitch: 8:15 Poster: 9:15 Plasma 23
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Ultra-High Resolution Whole-Brain DCE MRI makes Significant Difference in Estimating Permeability Maps for Cancer Patients |
1Sungkyunkwan University, Korea, Korea, Republic of, 2Seoul National University Hospital, Seoul, Korea, Republic of |
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An ultra-high resolution, whole-brain DCE MRI with a temporal resolution of 1.5sec (3~4 times higher than conventional routine) and a spatial resolution of isotropic 1.0mm3 (5~6 times higher than conventional routine) is introduced in a real clinical setting to address problems related to arterial input function and partial volumes for precise estimation of vascular permeability information in brain cancer patients. Compared with conventional routine vendor-provided method, the proposed ultra-high resolution DCE MRI produces significant differences in permeability maps particularly for both Ktrans and ve. |
| 689
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Pitch: 8:15 Poster: 9:15 Plasma 24
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Dynamic Water/Fat Separation and Field Inhomogeneity Mapping at a Temporal Resolution of 40 ms |
1Biomedizinische NMR, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany, 2Department of Diagnostic and Interventional Radiology, University Medical Center Göttingen, Göttingen, Germany, 3DZHK (German Center for Cardiovascular Research), Göttingen, Germany |
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To achieve dynamic water/fat separation even in the presence of rapid physiological motions and large magnetic field inhomogeneities, this work presents a multi-echo multi-spoke radial FLASH sequence and a model-based non-linear inverse reconstruction. Asymmetric echoes are integrated into the sequence to shorten echo times. A spatial-smoothness constraint on field inhomogeneity maps is developed to counteract local minima in the non-convex inverse problem. |
| 690
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Pitch: 8:15 Poster: 9:15 Plasma 25
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Water/fat separation for distortion-free EPI with point spread function encoding |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, 2Philips Healthcare, Beijing, China |
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Effective removal of chemical-shift artifacts in EPI is a challenging problem especially with severe field inhomogeneity. In this study, water/fat separation thus fat suppression is achieved using the intrinsic signals of point spread function (PSF) encoded EPI (PSF-EPI), in which chemical-shift encoding is realized in the intermediate images with different time shifts. The results from three imaging regions show that this PSF-EPI based method can separate water/fat robustly. Thus fat signals can be effectively removed from EPI even with severe field inhomogeneity. |
| 691
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Pitch: 8:15 Poster: 9:15 Plasma 26
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Brain-component mapping with Inversion-Recovery bSSFP |
1Magnetic Resonance and X-ray Imaging, Fraunhofer Development Center X-ray Technology (EZRT), Würzburg, Germany, 2Experimental Physics 5, University of Würzburg, Würzburg, Germany, 3Institute of Medical Engineering, University of Applied Sciences Würzburg-Schweinfurt, Schweinfurt, Germany, 4Neuroradiology, University of Heidelberg, Heidelberg, Germany |
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An inversion recovery (IR) bSSFP measurement allows to calculate quantitative parameter maps assuming mono-exponential signals. However, the measured signals often show multi-exponential behavior due to partial volume effects or tissue microstructure. With IR bSSFP it is possible to extract a spectrum of the apparent relaxation times T1* and hence to identify multiple components in each voxel. By integration over specific T1* ranges, different brain-components like white matter, gray matter or CSF can be mapped. In this work, we demonstrate that even short-living components such as myelin water are detected providing helpful information for diagnostic purposes, e.g. in neurodegenerative diseases. |
| 692 | Pitch: 8:15 Poster: 9:15 Plasma 27
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Ultra-high temporal resolution on the inversion recovery curve: new insight into T1 relaxometry of the human brain |
1Institute of Neuroscience and Medicine (INM-4), Research Centre Juelich, Juelich, Germany, 2JARA-BRAIN-Translational Medicine, Research Centre Juelich, Aachen, Germany, 3Institute of Neuroscience and Medicine (INM-11, JARA), Research Centre Juelich, Juelich, Germany, 4Department of Neurology, RWTH Aachen University, Aachen, Germany |
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Tissue T1 relaxation is considered to be monoexponential. This is, however, an assumption, since it is seldom measured with sufficiently dense sampling of the relaxation curve. We hypothesized that a spatially-resolved investigation of tissue T1 relaxation curve with ultra-high temporal resolution might reveal previously unidentified characteristics of this fundamental NMR parameter. We imaged 10 healthy volunteers using a Look-Locker sequence with 460 time points 17ms apart on the inversion recovery curve. Denoising using PCA and NNLS decomposition of the recovery curves revealed, among others, a moderately short T1 component (4-500ms) in both WM and GM, tentatively assigned to myelin water. |
| 693
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Pitch: 8:15 Poster: 9:15 Plasma 28
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Improved Body Quantitative Susceptibility Mapping by Using a Variable-Layer Single-Min-Cut Graph-Cut Algorithm for Field-Mapping |
1Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany, 2Philips Research, Hamburg, Germany, 3Munich School of Bioengineering, Technical University of Munich, Munich, Germany |
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Body QSM relies on accurate magnetic field-mapping that accounts for the presence of fat and is robust to large background fields. This work proposes the application of a single-min-cut graph-cut-based pipeline aiming at accurate, non-smoothed and unwrapped field-mapping without the need for further computationally expensive or problematic voxel-wise fitting or unwrapping techniques. The used body QSM pipeline achieves higher accuracy in field-map and susceptibility values, which is demonstrated in a numerical phantom and in in-vivo spine datasets. |
| 694
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Pitch: 8:15 Poster: 9:15 Plasma 29
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Single-step Quantitative Susceptibility Mapping Reconstruction without Brain Extraction using Deep Learning |
1University of California, Berkeley, Berkeley, CA, United States, 2Rui Jin Hospital, Shanghai Jiao Tong University, Shanghai, China, 3Department of Radiology, Stanford University, Palo Alto, CA, United States |
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We propose a deep learning-based single-step QSM reconstruction method that directly estimates magnetic susceptibility from total phase images without brain extraction. 209 healthy subjects with ages ranging from 11 to 82 years were employed for network training. The trained network provides superior image quality and high reconstruction speed compared to other single-step QSM methods. In addition, the elimination of the brain extraction step makes it possible to estimate susceptibility near the boundaries and explore the magnetic susceptibility of whole brain vascular images. |
| 695 | Pitch: 8:15 Poster: 9:15 Plasma 30
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Estimation of low frequency conductivity from Larmor frequency conductivity |
1Philips Research, Hamburg, Germany |
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EEG source localization requires the conductivity map of the patient's head. Patient-individual conductivity maps can be measured in the framework of MRI using "Electric Properties Tomography" (EPT). However, EEG source localization requires the conductivity belonging to low frequency (LF) range instead radiofrequency (RF) range, as it is the case for EPT. To solve this problem, this study suggests two EPT measurements at different B0, and to transform the resulting conductivities from RF to LF via a simplified Cole-Cole-model. The approach has been validated with organic and non-organic phantoms as well as with volunteer brain experiments. |
| 696 | Pitch: 8:15 Poster: 9:15 Plasma 31
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First human imaging studies at 10.5 Tesla: body studies at 450 MHz |
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 2University of Minnesota, Minneapolis, MN, United States |
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This work presents the first in vivo human images from a whole body 10.5T MRI system. An initial coil was validated for safe operation at 10.5T allowing anatomic targets in the pelvis and abdomen to be explored. The translation of RF management strategies developed at 7T were employed to tackle the challenges at 10.5T demonstrating that high quality anatomic and quantitative data can be achieved at 450 MHz in the human torso. |
| 697 | Pitch: 8:15 Poster: 9:15 Plasma 32
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Precision medicine advanced by full body imaging biomarkers, whole genomic sequencing and blood-based measures |
1Human Longevity, Inc., San Diego, CA, United States |
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We present the findings from 1190 presumed healthy patients evaluated at a precision medicine clinic. We performed deep quantitative multimodal phenotyping and genotyping comprising quantitative whole-body imaging, whole genome sequencing, and advanced blood-based biomarkers. Within this cohort, medically significant findings included aneurysms, newly identified tumors, coronary artery disease, metabolic disease, cardiac arrhythmia, myocardial disease, and neurodegenerative risk. Forty percent of “healthy” patients had a new clinically significant finding that was not previously known. For this 40%, we are able to provide quantitative continuous metrics that enable individuals to make informed decisions to mitigate their health risks. |
| 698 | Pitch: 8:15 Poster: 9:15 Plasma 33
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Free-breathing Volumetric Body Imaging for Combined Qualitative and Quantitative Tissue Assessment using MR Multitasking |
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 2Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 3Radiologic Department, Chaoyang Hospital, Beijing, China, 4Siemens Healthineers, Los Angeles, CA, United States, 5Department of Radiology, Fujian Medical University Union Hospital, Fuzhou, China, 6Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, United States |
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MR has broad clinical applications in body imaging with excellent soft-tissue contrast and qualitative and emerging quantitative assessments, however, |
| 699 | Pitch: 8:15 Poster: 9:15 Plasma 34
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Early Assessment of the Response of Esophageal Squamous Cell Carcinoma to Chemoradiotherapy by Intravoxel Incoherent Motion MRI |
1Department of Radiology, Drum Tower Hospital, School of Medicine, Nanjing University, Nanjing, China, 2Philips Healthcare, Shanghai, Shanghai, China |
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Twenty-three patients with esophageal squamous cell carcinoma (ESCC) underwent intravoxel incoherent motion (IVIM) MRI at four timepoints: pre, mid, end, and post-CRT to assess the value of IVIM parameters in the early assessment of treatment response to CRT. The parameters and their change percentages were compared between complete response (CR) and partial response (PR). ADC, f, %ADC, and %D at mid-CRT in CR group were significantly higher than those in the PR group. D combined with f and ADC had highest area under curve in identifying CR from PR. IVIM parameters proved useful in assessing response to definitive concurrent CRT. |
| 700
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Pitch: 8:15 Poster: 9:15 Plasma 35
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MRI radiomics features for characterization of RCC subtypes |
1Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 2Department of Radiology, Universidad de los Andes, Santiago, Chile, 3Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 4Department of Urology, Icahn School of Medicine at Mount Sinai, New York, NY, United States |
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The goal of this study was to evaluate the use of quantitative radiomics features from contrast-enhanced MRI in differentiating common subtypes of solid renal cell carcinomas (RCCs). We found that several radiomics features were associated with common subtypes of RCC. Thus, radiomics features may help in the diagnosis of histologic subtypes of RCC. |
| 701 | Pitch: 8:15 Poster: 9:15 Plasma 36
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Functional Renal Imaging using Urea CEST-MRI |
1Department of Bioengineering, University of California, Berkeley, Berkeley, CA, United States, 2Berkeley Preclinical Imaging Core, University of California, Berkeley, Berkeley, CA, United States |
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Current diagnosis of renal disease and injury relies on blood urea nitrogen and serum creatinine measurements, which provide generic information about kidney function but do not provide spatial specificity during kidney failure. Urea has previously been used as a vehicle for hyperpolarized MR imaging of renal function, and as a contrast agent of CEST MRI. Here, we examine whether injection of urea can provide CEST contrast for quantitation of renal integrity via probing the spatially varying urea concentrating capacity of a kidney. |
| 702 | Pitch: 8:15 Poster: 9:15 Plasma 37
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Free-breathing renal perfusion measurement with volumetric ASL using variable-density FSE and 4D Compressed-Sensing |
1Division of MRI research, Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boson, MA, United States, 2Global MR Applications and Workflow, GE Healthcare, Boston, MA, United States, 3Global MR Applications and Workflow, GE Healthcare, New York, NY, United States |
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While single or 2D multi-slice body ASL implementations have been shown to be compatible with free-breathing for abdominal perfusion measurement even in uncooperative clinical populations, free-breathing volumetric encoding has not been reported yet. We propose a free-breathing volumetric ASL acquisition relying on a motion-robust variable-density 3D-FSE sequence with redundant k-space center and pseudo-random variable outer k-space sampling and 4D-Parallel-Imaging-Compressed-Sensing reconstruction. High-quality whole kidneys perfusion images were obtained in less than 5 minutes in free-breathing, potentially extending the clinical applications of non-contrast ASL perfusion in the abdomen. |
| 703
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Pitch: 8:15 Poster: 9:15 Plasma 38
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Quantitative Transport Mapping (QTM) of the Kidney using a Microvascular Network Approximation |
1Weill Medical College of Cornell University, New York, NY, United States, 2Cornell University, Ithaca, NY, United States |
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The blood flow quantification is of great importance in the diagnosis of many diseases. The current blood flow quantification methods are mainly based on the Kety’s method, which highly replies on the practically unmeasurable arterial input function (AIF). To void using the AIF as an input, we propose quantitative transport mapping ( |
| 704 | Pitch: 8:15 Poster: 9:15 Plasma 39
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Fatty kidney assessed by renal spectroscopy: a reproducibility study and clinical randomised controlled trial in type 2 diabetes |
1Radiology, Leiden University Medical Center, Leiden, Netherlands, 2Endocrinology, Leiden University Medical Center, Leiden, Netherlands, 3Radiology, Amsterdam Medical Center, Amsterdam, Netherlands, 4Nephrology, Leiden University Medical Center, Leiden, Netherlands |
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Renal steatosis is a potential biomarker for obesity-related renal disease and this has been suggested as underlying biological pathway of renoprotective effects of Liraglutide in type 2 diabetes (T2DM). Proton magnetic resonance spectroscopy (¹H-MRS) has the ability to non-invasively quantify triglycerides. We examined the reproducibility of ¹H-MRS in healthy volunteers, and explored the application in a clinical trial evaluating the differences in renal triglyceride content after 9-month treatment with liraglutide. We demonstrated that ¹H-MRS is a reproducible technique and comparison with healthy volunteers suggests increased renal triglycerides in T2DM. Renoprotective effects of liraglutide might be based on reduced renal triglycerides. |
| 705 | Pitch: 8:15 Poster: 9:15 Plasma 40
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Time-efficient fully 3D non-Cartesian dynamic contrast-enhanced free-breathing MRI of the pelvis with an ultrashort TE cones trajectory |
1Radiology, Stanford University, Stanford, CA, United States, 2Electrical Engineering and Computer Sciences, University of California, Berkeley, Berkeley, CA, United States, 3Applied Science Laboratory, GE Healthcare, San Diego, CA, United States, 4Electrical Engineering, Stanford University, Stanford, CA, United States |
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A 3D cones k-space trajectory with golden angle ordering was developed along with a multiscale low rank reconstruction for dynamic contrast enhancement with ultrashort echo time (DCE-UTE) and with fast image reconstruction time. With IRB approval and informed consent the sequence was tested in 21 consecutive subjects referred for 3T contrast-enhanced pelvic MRI. For comparison, a Cartesian DCE SPGR sequence with golden angle radial k-space ordering, soft-gated self navigation, and low rank reconstruction (DCE-SPGR) served as case controls. DCE-UTE performed significantly better than DCE-SPGR in delineation of anatomic structures (p=0.004) and overall perceived image quality (p=0.003). These results indicate a 3D fully noncartesian DCE-UTE sequence and reconstruction improves image quality in pelvic DCE. |
| 706 | Pitch: 8:15 Poster: 9:15 Plasma 41
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Motion-robust pediatric abdominal angiography using dynamic 3D image self-navigator with 3D cones |
1Electrical Engineering, Stanford University, Stanford, CA, United States, 2Electrical Engineering and Computer Science, University of California, Berkeley, Berkeley, CA, United States, 3Radiology, Stanford University, Stanford, CA, United States |
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Respiratory motion detection using the k-space center (DC signal) can be problematic in pediatric subjects exhibiting highly irregular breathing patterns. To address this problem, we extract respiratory motion information from high frame rate (3.3 Hz), low-resolution (7.7 mm) 3D self-navigators derived from the imaging data (i.e., central portion of 3D cones k-space data) and reconstructed with a multi-scale low-rank framework. Localized motion estimates are obtained from the 3D self-navigators using optical flow registration. We demonstrate that region-specific motion information from 3D self-navigators better mitigates motion artifacts compared to the low-pass filtered DC signal in pediatric abdominal angiography exams. |
| 707 | Pitch: 8:15 Poster: 9:15 Plasma 42
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Imaging wound-healing related fibrosis using short inversion time ultra-short TE (STIR-UTE) |
1Medicine (Cardiology), The Johns Hopkins University, Baltimore, MD, United States, 2Radiology, Brigham and Womens Hospital, Boston, MA, United States, 3Application Development, Siemens Healthcare GmbH, Erlangen, Germany, 4MRI, Siemens Healthineers, Boston, MA, United States, 5Medicine (Cardiology), Johns Hopkins University, Baltimore, MD, United States, 6Radiation Oncology, Johns Hopkins University, Baltimore, MD, United States |
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Collagen deposition occurs during wound-healing processes in several diseases, and following therapy (acute myocardium infarction, radiation induced fibrosis). There is interest in intervening during wound-healing, since chronic scar leads to complications (ventricular tachycardia, gastrointestinal bleeding), with novel medications possibly reducing fibrosis. Intervention requires early detection of diffuse fibrosis (<50% content/voxel) during acute wound-healing. Fibrosis detection with gadolinium-perfusion (LGE, T1 mapping) is problematic during acute disease, due to irregular vascularity. Ultrashort-Time-to-Echo’s (UTE’s) collagen-sensitivity is reduced by fat’s masking signal. With STIR-UTE, we utilize collagen’s short TE and short T1 to suppress fat and map fibrosis in the pelvis, in normal and in post-infarction hearts. |
| 708
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Pitch: 8:15 Poster: 9:15 Plasma 43
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Hyperpolarized 13C MRI of Patients with Metastatic Prostate Cancer to Bone and Liver |
1Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States, 2School of Medicine, University of California, San Francisco, San Francisco, CA, United States |
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In this feasibility study, hyperpolarized 13C-pyruvate MR exams were conducted on 5 patients who had metastatic prostate cancer to bone or liver. In one man with liver metastasis, serial scans showed a decrease of pyruvate-to-lactate conversion kPL (0.026 to 0.015 s-1) at 2 months after initiation of chemotherapy that was consistent with response based on PSA and RECIST criteria. High kPL was found in patients with bone lesions comparable to that in high-grade primary prostate cancer. Overall, HP-13C MR imaging showed great promise as a biomarker to evaluating treatment responses in metastatic prostate cancer. |
| 709 | Pitch: 8:15 Poster: 9:15 Plasma 44
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Utility of simultaneous T1 and T2 mapping with MR Fingerprinting (MRF) for bowel wall imaging in Crohn’s Disease |
1Radiology, Case Western Reserve University, Cleveland, OH, United States, 2Diagnostic, Interventional and Pediatric Radiology, Inselspital, Bern, Switzerland, 3School of Medicine, Case Western Reserve University, Cleveland, OH, United States, 4Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 5Radiology, Mayo Clinic, Rochester, MN, United States, 6Gastroenterology and Digestive Health, University Hospitals Cleveland Medical Center, Cleveland, OH, United States, 7Biostatistics, Case Western Reserve University, Cleveland, OH, United States |
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The feasibility of using MRF to assess T1 and T2 relaxation times in the intestine for the evaluation of inflammatory bowel disease was explored. 52 patients with Crohn’s Disease underwent MR enterography with MRF acquisitions through the bowel. T1 relaxation times allowed quantitative differentiation between unaffected segments and inflamed segments, p = 0.004. T2 relaxation times further allowed distinction between segments with active and chronic fibrotic changes, p = 0.003. |
| 710
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Pitch: 8:15 Poster: 9:15 Plasma 45
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MRI assessed dysmotility and texture analysis in the terminal ileum and small bowel: A pilot study comparison between Irritable Bowel Syndrome (IBS) patients with bloating and healthy controls |
1CMI, UCL, London, United Kingdom, 2Department of Gastroenterology, University College London Hospitals, London, United Kingdom |
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Gastrointestinal symptoms in irritable bowel syndrome (IBS) occur without any obvious structural gut abnormality. This pilot study is based on abnormal ileo-caecal motility function suggested by wireless capsule data, with potential reflux of caecal contents back into the terminal ileum (TI). We compared constipation-predominant IBS (IBS-C) patients with bloating to healthy controls, through texture analysis and motility measures. We found TI temporal variation of motility was significantly higher in healthy controls. There was also a difference in the TI to small bowel texture analysis contrast ratio, but this was only significant in BTFE sequences. |
8:15
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The Long Road to Psychoradiology | |
1University of Cincinnati, Cincinnati, OH, United States |
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Starting 40 years ago, CT studies and then MRI demonstrated brain alterations particularly in psychotic disorders such as schizophrenia, but also in mood disorders, drug abuse, autism and most other more serious psychiatric conditions. With their increasing robustness following technical advances in image acquisition and analysis, psychiatric imaging research has begun evaluating the clinical relevance of these findings for diagnosing and treating individual patients. A review of past progress and pathways forward in this next step for psychiatric imaging research will be the focus of this presentation. |
8:35
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Current Psychoradiology Toolbox | |
1Matinos Center, Boston, United States |
8:55
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Current Imaging of Autism | |
1Department of Medical Imaging, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada |
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Autism Spectrum Disorder (ASD) is a pervasive disorder with a relatively high prevalence that manifests in early childhood. Magnetic Resonance Imaging (MRI) is currently not a screening tool for ASD and it is not used in the routine evaluation of the disorder unless other concerning clinical features are present. However, it plays an important role in ASD research and multiple advanced imaging and post-processing strategies are currently being employed to subgroup and to elucidate potential mechanisms of disease. When performing neuroimaging research in ASD it is important to keep the pronounced heterogeneity of the disorder in mind. |
9:15
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Surface-based diffusion MRI analysis of the superficial white matter in autism: association with functional networks and symptom severity | |
1Multimodal Imaging and Connectome Analysis Lab, Montreal Neurological Institute, Montreal, Quebec, QC, Canada, 2Center for the Developing Brain, Child Mind Institute, New York, NY, United States |
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Our study focused on a region that remains relatively unexplored by autism neuroimaging: the superficial white matter (SWM) immediately beneath the cortical interface, a compartment known to play a key role in corticogenesis and connectivity. A surface-based diffusion-MRI analysis revealed SWM anomalies in a multicentric ASD cohort compared to neurotypical controls in medial parietal and |
| 713 | 9:30
|
Total suicide attempts associated with distinct functional neuroimaging correlates in bipolar disorder |
1Radiology, University of Iowa, Iowa City, IA, United States, 2Psychiatry, University of Iowa, Iowa City, IA, United States, 3Electrical and Computer Engineering, University of Iowa, Iowa City, IA, United States |
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Suicidal behavior is a major cause of injury and death in bipolar disorder. We measured the relationship between a history of suicide attempt and brain activation to a flashing checkerboard task in bipolar disorder using functional magnetic resonance imaging (fMRI). We compared activity between suicide attempters and non-attempters and we separately tested the relationship between brain activity and the number of past suicide attempts. These two analyses produced distinct patterns of results that indicated a mood-state independent relationship between suicide attempts and prefrontal and cerebellar activity. These findings suggest that accounting for multiple attempters may strengthen studies of suicidal behavior. |
| 714 | 9:45
|
Analysis of feature importance in deep neural networks in psychiatric disorders using magnetic resonance imaging |
1QMENTA Inc, Barcelona, Spain, 2Bellvitge Biomedical Research Institute-IDIBELL, Barcelona, Spain, 3CIBERSAM, Madrid, Spain, 4School of Psychological Sciences and Monash Institute of Cognitive and Clinical Neurosciences, Melbourne, Australia, 5Department of Mental Health, Corporació Sanitaria Parc Taulí, Sabadell, Spain, 6CIBEROBN, Madrid, Spain |
||
Current methods to |
| 715 | 10:00
|
Targeting emotional dysregulation in adult attention-deficit hyperactivity disorder |
1Department of Radiology and Nuclear Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands, 2Amsterdam Neuroscience, Amsterdam, Netherlands, 3Swammerdam Institute for Life Sciences, Center for Neurosciences, University of Amsterdam, Amsterdam, Netherlands, 4Dept. Anatomy and Neuroscience, Neuroscience Campus Amsterdam, Amsterdam UMC, Vrije Universiteit, Amsterdam, Netherlands, 5Addiction Development and Psychopathology (ADAPT) Lab, Department of Psychology, University of Amsterdam, Amsterdam, Netherlands, 6Department of Psychiatry, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands, 7Spinoza Centre for Neuroimaging, Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, Netherlands |
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Emotional dysregulation (ED) is a core symptom of ADHD. Previous studies suggested that taxing WM can reduce amygdala hyper-responsiveness (associated with ED), using traditional emotional interference tasks. However, these tasks make it impossible to disentangle emotional and WM mechanisms. We |
10:15
|
DRD2 TaqIA Polymorphism related Functional Connectivity Between Anterior Insula and Dorsolateral Prefrontal Cortex in Heroin-dependent Individuals under Methadone Maintenance Treatment Predicts Retention Time | |
1The First Affilicated Hospital of Xi'An JiaoTong University, Xi'an, China, 2Department of Radiology, The Hospital of Shannxi provincial geology and mineral resources bureau, Xi'an, China, 3Department of Radiology, The First Affilicated Hospital of Xi'An JiaoTong University, Xi'an, China |
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The present study adopted functional parcellation method to get functional-different subdivisions atlas of insula from healthy controls, and performed whole brain functional connectivty(FC) based on these subdivisions with resting-state fMRI data aquired from heroin-dependent participants under methadone maintantreatment (HDM). These HDM were grouped by DRD2 Taq1A polymorphism, and compared the FC differences of each insula subdivisions group-wise. Results showed the way DRD2 gene influence the FC between the left anterior insula and right dorsolateral prefrontal cortex. This gene-influenced FC further demonstrated its positive association with retention time, in a survival analysis. |
10:20
|
Adjournment |
| 716
|
8:15
|
First in cellulo and in vivo metabolic studies using ParaHydrogen Hyperpolarized [1-13C]pyruvate |
1Torino University, Torino, Italy |
||
Hyperpolarized (HP) [1-13C]pyruvate [1] has been widely exploited for the metabolic processes. The development of this agent has enabled the in vitro and in vivo real-time detection of pyruvate-lactate metabolic conversion. The possibility of obtaining HP pyruvate using the cost effective and fast PHIP (ParaHydrogen Induced Polarization) method, instead of the dissolution Dynamic Nuclear Polarization (d-DNP), would allow a widespread application of this powerful diagnostic tool, that so far has been hampered by cost, technical complexity and intrinsically low polarization time. Here we report an in vitro and in vivo study carried out on different cancer cell lines and in vivo using PHIP-SAH HP-[1-13C]pyruvate. |
| 717 | 8:27
|
Probing the metabolic response to acute renal injury in mice using multiple hyperpolarized 13C substrates. |
1Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland, 2Centre d'imagerie biomédicale (CIBM), Ecole polytechnique fédérale de Lausanne (EPFL), Lausanne, Switzerland, 3Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Tokyo, Japan, 4Laboratory for Functional and Metabolic Imaging (LIFMET), Ecole polytechnique fédérale de Lausanne (EPFL), Lausanne, Switzerland |
||
Arginase-2 is upregulated following renal injury. This study used hyperpolarized pyruvate, arginine, citrulline and γ-glutamylglycine to probe changes in renal metabolism following ischemia-reperfusion in mice deficient in renal arginase-2. The kidney is a major site of arginine synthesis, and conversion of hyperpolarized citrulline to arginine can be detected, as can a signal consistent with argininosuccinate. While metabolic differences in mice lacking arginase-2 compared to controls are not readily apparent by this method, ischemia has a clear effect on several metabolite signals. Of the pyruvate metabolites, conversion to aspartate is significantly diminished, as is arginine and argininosuccinate production from citrulline. |
| 718 | 8:39
|
Hyperpolarized [1-13C]Pyruvate MRSI at 48 hrs post anti-VEGF Treatment Predicts Response in C6 Glioma Implanted Rats |
1Radiology, Stanford University, Stanford, CA, United States, 2Electrical Engineering, Stanford University, Stanford, CA, United States, 3Neurology, Stanford University, Stanford, CA, United States |
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Using a bolus injection of hyperpolarized [1-13C]Pyruvate, we show that measurement of the resulting 13C-Lactate to 13C-Bicarbonate ratio 48-hours post-treatment with anti-angiogenic drug Bevacizumab (Bev20) predicts survival in a C6-Glioma rat model. A positive correlation of Lac/Bic with tumor growth rate further supports our hypothesis that the effect of the drug in survivors is to reverse the tumor Warburg metabolic phenotype necessary to support rapid proliferation. |
| 719
|
8:51
|
Hyperpolarized [1-13C] Alanine Ethyl Ester for Assessment of Hepatic Alanine Metabolism |
1Advanced Imaging Research Center, UT Southwestern Medial Center at Dallas, Dallas, TX, United States, 2Radiology, UT Southwestern Medical Center at Dallas, Dallas, TX, United States, 3Electrical Engineering, University of Texas at Dallas, Dallas, TX, United States |
||
[1-13C] alanine ethyl ester was studied as hyperpolarized substrate to measure the alanine metabolism in rat liver. The results show that [1-13C] alanine ethyl ester enters the cell converts to [1-13C] lactate more efficiently. Therefore, [1-13C] alanine ethyl ester is a potential compound to assess hepatic alanine metabolism with improved sensitivity. |
| 720
|
9:03
|
Mildronate Modulates In-Vivo Metabolism and Improves Ex-Vivo Functional Recovery Post-ischemia in the Diabetic Heart |
1University of Oxford, Oxford, United Kingdom, 2University of Cambridge, Cambridge, United Kingdom |
||
Carnitine acts as a buffer of acetyl-CoA units in the mitochondria, as well as facilitating |
| 721
|
9:15
|
Longitudinal Hyperpolarized 13C Imaging of Metabolic Changes Following Myocardial Infarction in Pigs |
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 2Department of Cardiology, University Heart Center, University Hospital Zurich, Zurich, Switzerland, 3Department Cardiology, Pneumology and Angiology, Heinrich Heine University, Duesseldorf, Germany, 4Division of Surgical Research, University Hospital Zurich, Zurich, Switzerland |
||
The heart’s dynamic, bimodal response to myocardial infarction warrants longitudinal study designs to better understand the interplay between perfusion deficits, metabolic processes and function. To this end, a longitudinal study over 12 weeks was set up to probe myocardial metabolism post-infarction in an infarct pig model using hyperpolarized [13C]-pyruvate. Image acquisition was optimized for improved spatial and temporal image fidelity based on spectrally-selective excitation and EPI readouts. Initial results demonstrate good agreement with supplementary gadolinium enhanced imaging and indicate a temporal metabolic shift towards increased lactate-to-bicarbonate ratios in the lesion territory caused by cardiac infarction. |
| 722
|
9:27
|
Metabolism of hyperpolarized [1-13C]pyruvate in awake, isoflurane and urethane anesthetized rat brain |
1Biomedical Imaging Unit, Department of Neurobiology, A. I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland, 2Technical University of Denmark, Kongens Lyngby, Denmark |
||
Pre-clinical MRI/MRS routinely uses anesthesia, which alters hemodynamics and metabolism. Here, we used hyperpolarised [1-13C]pyruvate to compare brain metabolism under isoflurane or urethane anesthesia and in awake rats. Spectroscopic [1-13C]pyruvate time courses were measured in sequence in awake, isoflurane and urethane anesthetized rats. Bicarbonate- and lactate-to-total carbon ratios decreased in order from awake animals to urethane to isoflurane anesthetized animals. No change was observed in bicarbonate-to-lactate ratio between the groups, however. The study shows dDNP experiments can be performed in awake rats thus avoiding issues related to anesthesia. However, the ratios between intracellular metabolites did not alter in awake rats. |
| 723
|
9:39
|
Metabolic imaging of brain inflammation using hyperpolarized 13C MRSI of pyruvate and urea in a mouse model of multiple sclerosis |
1Department of Physical Therapy and Rehabilitation Science, University of California San Francisco, San Francisco, CA, United States, 2Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, 3Division of Neuroimmunology and Glial Biology, Department of Neurology, University of California San Francisco, San Francisco, CA, United States, 4Department of Radiology, C.J. Gorter Center for High Field MRI, Leiden University Medical Center, Leiden, Netherlands, 5Department of Ophthalmology, University of California San Francisco, San Francisco, CA, United States |
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We used conventional MRI and hyperpolarized 13C magnetic resonance spectroscopy (HP 13C MRSI) quantitative imaging of pyruvate and urea to assess lesion pathology and the metabolic signature in a model of multiple sclerosis (MS). T2 sequences detected white matter lesions and gadolinium-enhanced MRI showed blood-brain-barrier breakdown. HP 13C MRSI revealed increased lactate production and lactate-to-pyruvate ratios while urea levels remained unchanged. This is consistent with macrophage/monocyte infiltration into the CNS found in the model. Altogether, these findings demonstrate that HP 13C MRSI has potential to monitor macrophage infiltration and innate immune activation in inflammatory diseases of the central nervous system. |
| 724 | 9:51
|
First Hyperpolarized [2-13C]Pyruvate MR Studies of Human Brain Metabolism |
1Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, 2UCSF – UC Berkeley Graduate Program in Bioengineering, University of California, San Francisco, CA, United States, 3Department of Physical Therapy and Rehabilitation Science, University of California San Francisco, San Francisco, CA, United States, 4ISOTEC Stable Isotope Division, MilliporeSigma, Merck KGaA, Miamisburg, OH, United States, 5Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, United States |
||
We investigated hyperpolarized (HP) [2-13C]pyruvate conversion to [2-13C]lactate and [5-13C]glutamate for the first time in the healthy human brain, with a focus on the development of hyperpolarization and preparation techniques for sterile [2-13C]pyruvate with FDA-IND & IRB approval. HP [2-13C]pyruvate, [2-13C]lactate, [5-13C]glutamate and other metabolites were successfully observed and quantitatively measured for the first time in four volunteers, and initial EPI studies confirmed a feasibility of imaging [2-13C]pyruvate to [5-13C]glutamate conversion, demonstrating a significant first step for HP metabolic imaging to diagnose and detect early stage neurological disorders. |
| 725
|
10:03
|
Hyperpolarized 13C Metabolic Imaging of a Renal Cell Carcinoma Patient with Brain Metastasis |
1Medical Biophysics, University of Toronto, Toronto, ON, Canada, 2Physical Sciences, Sunnybrook Research Institute, Toronto, ON, Canada, 3Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto, ON, Canada, 4GE Healthcare Technologies, Toronto, ON, Canada, 5Pharmacy, Sunnybrook Health Sciences Centre, Toronto, ON, Canada |
||
The application of hyperpolarized 13C MRI to non-invasively acquire metabolic images of [1-13C]lactate and 13C-bicarbonate from the injected [1-13C]pyruvate in the brain of metastatic renal cell carcinoma patient, as well as that of 7 healthy volunteers are investigated. Elevated [1-13C]lactate and [1-13C]pyruvate signals were observed from the metastasis, as well as high lactate-to-bicarbonate ratio. The clinical history of the patient suggests that the elevated signals observed in the metastasis may be reflecting the progressive state of the patient’s disease. |
| 726
|
8:15
|
The PNS oracle: a modified neural activation function metric for rapid assessment of Peripheral Nerve Stimulation (PNS) |
1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany, 2A.A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States, 3Harvard Medical School, Boston, MA, United States, 4Harvard-MIT Division of Health Sciences Technology, Cambridge, MA, United States |
||
As gradient engineering advances, Peripheral Nerve Stimulation (PNS) increasingly limits MRI gradient coil use. The ability to predict a winding pattern’s PNS threshold could be useful during design iteration, but recently introduced methods for simulating the threshold in full body models including nerve atlases and neurodynamic simulations are computationally slow. Here we present a simple PNS oracle which is linear (with respect to the E-field) that allows prediction of the gradient-induced stimulation threshold without relying on full neurodynamic modeling. We validated the fast oracle against the full neurodynamic model in multiple gradient coils and two body models. |
| 727
|
8:27
|
Reconfigurable coil technology significantly reduces the SAR at the tips of bilateral deep brain simulation leads during MRI at 3T: A realistic case study of isolated leads and fully-implanted systems |
1Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey, 2Radiology, Northwestern University, Chicago, IL, United States, 3Life Science Engineering, Institute of Medical Physics and Radiation Protection, Giessen, Germany, 4Neurosurgery, Albany Medical Center, Albany, NY, United States, 5Northwestern University, Chicago, IL, United States |
||
We report simulation results of specific absorption rate (SAR) at tips of bilateral deep brain stimulation (DBS) implants using a recently introduced reconfigurable MRI coil technology which uses a mechanically rotating linearly polarized birdcage transmitter. Using patient-derived realistic models of DBS leads both in isolation (i.e., leads that are not yet connected to the pulse generator) and fully-implanted DBS systems with different implanted pulse generator (IPG) configurations (i.e., a single dual-channel IPG feeding both leads, or two single-channel IPGs feeding left and right leads separately), we show that the rotating coil technology significantly reduces the SAR simultaneously at left and right leads during MRI at 3T. |
| 728
|
8:39
|
Parallel transmission medical implant safety testbed: First application using time-domain E-field probes to measure and mitigate RF induced currents |
1Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany |
||
A parallel transmission (pTx) implant safety testbed has been developed, that allows to investigate manifold MR safety related scenarios. The testbed can be used to investigate sensor-feedback methods, perform validation measurements of MR based current detection methods and investigate the MR safety of a variety of implants for various clinical MR settings from 1.5T to 7T. Preliminary results were acquired using a time-domain E-field probe to measure RF induced currents on a guidewire substitute at f=297 MHz and to mitigate these currents with pTx pulses. |
| 729
|
8:51
|
Simulation of MRI gradient-induced cardiac stimulation: Are the current safety regulations too conservative? |
1Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany, 2A. A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, United States, 3Harvard Medical School, Boston, MA, United States, 4Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, United States |
||
Current MR safety standards significantly limit the use of some MRI gradient systems to prevent cardiac stimulation, even though there is suspicion that these limits are too restrictive. This work combines a recently developed simulation framework for Peripheral Nerve Stimulation (PNS) with electrical models of excitable cardiac tissue (ventricular muscle and Purkinje fibers) to investigate the relationship between PNS and cardiac stimulation thresholds. Considering the lack of experimental data on gradient-induced cardiac stimulation in humans, the presented simulation approach could provide valuable new insights on the mechanisms behind cardiac magnetostimulation and might eventually help to determine appropriate safety limits. |
| 730 | 9:03
|
Computational modeling of RF-induced heating due to a titanium-alloy rod: An Interlaboratory Comparison for the ASTM F2182 task group |
1MED Institute Inc., West Lafayette, IN, United States, 2ANSYS, Inc., Canonsburg, PA, United States, 3Bemcalc, West Lafayette, IN, United States, 4DePuy Synthes, Raynham, MA, United States, 5Exponent, Philadelphia, PA, United States, 6Healtis, Nancy, France, 7Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, 8MRCOMP, Gelsenkirchen, Germany, 9Stryker Trauma GmbH, Kiel, Germany, 10U.S. Food and Drug Administration, Center for Devices and Radiological Health, Silver Spring, MD, United States |
||
Computational modeling of RF-induced heating due to a titanium-alloy rod was conducted by nine independent institutions with a primary goal to compare the impact of common, independent modeling choices on temperature rise results. Results showed that when the rod is located 2 cm from the enclosure, the temperature rise can be used to estimate the local background electric-field exposure. Temperature rise depends not only on the background exposure but also on the location of the rod within the phantom. |
| 731
|
9:15
|
Predicting In Vivo MRI Gradient-Induced Voltage Levels on Deep Brain Stimulation Systems Using Artificial Neural Networks |
1Restorative Therapies Group, Medtronic, Minneapolis, MN, United States |
||
MRI gradient-fields may cause unintended interactions due to induced voltage potential along elongated conductive components of active implanted medical devices, therefore devices must be tested at clinically-relevant exposure levels. In vivo gradient-induced voltage levels on implanted deep brain stimulation (DBS) systems are simulated in adult human anatomical models. Then, artificial neural network (ANN) models are trained to predict gradient-induced voltages on DBS systems. Predictive ANN models demonstrated good accuracy (RMSE<0.180V). Leave-one-model-out cross-validation results demonstrate that ANN models can perform accurate predictions in general population if a variety of anatomical models representative of the population are included in the training dataset. |
| 732
|
9:27
|
A New Coil Element for Highly-Dense Transmit Arrays : An Introduction to Non-Uniform Dielectric Substrate (NODES) Antenna |
1Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey, 2Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 3Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, United States, 4National Magnetic Resonance Research Center (UMRAM), Ankara, Turkey |
||
Ultra-high field (UHF)-magnetic resonance imaging (MRI) provides numerous benefits such as a significant increase in signal-to-noise ratio (SNR) however, the local specific absorption rate (SAR) becomes a limiting factor in many applications. Utilizing a proper TxArray coil with an adequate number of elements and improved SAR performance may provide a good solution for this issue. In this work, we propose to use a short antenna with a Non-uniform Dielectric Substrate (NODES) which provides an opportunity to design a highly-dense TxArray with improved SAR performance. |
| 733 | 9:39
|
Gadolinium retention in tissues: yttrium as a gadolinium surrogate to investigate the in vivo biodistribution of the retained gadolinium |
1Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, United States |
||
Gadolinium has been found in the brain, skin and bone of patients with normal renal function months to years after the last administration of a gadolinium-based contrast agent (GBCA). Yttrium (Y3+) has similar size and chemical properties to Gd3+. We investigated whether yttrium can be used as a gadolinium surrogate by measuring the biodistribution of Gd-DTPA/Y-DTPA and Gd-DOTA/Y-DOTA (0.6 mmol/kg) in mice. Residual Gd and Y levels 7 days after injection showed a Y:Gd ratio close to 1 in all organs demonstrating that Y can act as a surrogate for Gd. |
| 734
|
9:51
|
MRI RF Heating: The Effect of Vasculature Detailedness on Numerical Temperature Increase Estimations |
1IT'IS Foundation, Zurich, Switzerland, 2Swiss Federal Institute of Technology (ETH), Zurich, Switzerland |
||
The numerical assessment of the radiofrequency (RF)-induced local temperature increase inside a patient undergoing magnetic resonance imaging (MRI) diagnostics is state-of-the-art in MRI safety studies. In light of the continuous improvement in the resolution of anatomical models, we investigated the impact of the level of detail in the vasculature models on estimates of temperature increase. Results show that the difference of the peak temperature increase for the investigated high-exposure scenario is in the order of 20%. Future investigations should broaden the studied exposure scenarios and consider vascular convection. |
| 735 | 10:03
|
Accelerated SAR Computations by Exploiting Sparsity in the Anatomical Domain |
1Leiden University Medical Center, Leiden, Netherlands, 2Delft University of Technology, Delft, Netherlands |
||
Accelerated SAR computations can improve awareness on actual RF exposure levels, which are known to depend heavily on subject anatomy. In this work, we accelerate SAR computations by reformulating the underlying electromagnetic field equations in terms of anatomical differences rather than the entire anatomy itself. This yields a “sparse” representation of the target anatomy, reducing problem complexity without compromising accuracy. |
| 736 | 8:15
|
On the nodal degree configuration of multimodal brain connectomics in severe asymptomatic carotid stenosis |
1Department of Radiology, Zhongnan Hospital of Wuhan University, Wuhan, China, 2Department of Nneurology, Zhongnan Hospital of Wuhan University, Wuhan, China |
||
Patients with severe asymptomatic carotid stenosis (SACS) are at high risk of cognitive impairment and future strokes. The basis of remote brain consequences is less well known. We investigated nodal configuration (centrality, hubs, efficiency, resilience, and wiring cost) of multimodal MRI brain connectomics in twenty-four patients with SACS and 24 comorbidities-matched controls. Our results suggest that patients with SACS is predominantly characterized by hub pathology and maladaptive pattern of network efficiency and wiring cost, following primary sensorimotor-transmodal cortical gradient. These results will contribute to a better understanding of the cognitive impairment and future cerebrovascular events in these patients with SACS. |
| 737
|
8:27
|
T2 relaxation times identify acute ischaemic stroke patients within the thrombolysis treatment window with higher accuracy than T2-weighted signal intensities |
1School of Psychological Science, University of Bristol, Bristol, United Kingdom, 2North Bristol NHS Trust, Bristol, United Kingdom, 3University of Oxford, Oxford, United Kingdom, 4University of Glasgow, Glasgow, United Kingdom |
||
Unknown symptom onset time is a common contraindication for thrombolysis of hyperacute ischaemic stroke. MRI may identify patients within the 4.5-hour thrombolysis treatment window, but it is unclear which parameter is most accurate. We compared the ability of hemispheric differences in quantitative T2 (qT2), ADC, and signal intensities of DWI, T2-weighted and T2-weighted FLAIR images at distinguishing between patients scanned within and beyond 4.5-hours. qT2 correlated significantly with time from onset (r = .491, p =.003) and had the highest and only significant AUC (0.77, p = .007). These data point to qT2 as a stroke timer. |
| 738
|
8:39
|
Impaired blood-brain barrier function in pediatric sickle cell disease |
1Department of Radiology, Johns Hopkins University, Baltimore, MD, United States, 2Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States, 3Kennedy Krieger Institute, Baltimore, MD, United States, 4Department of Pediatric Hematology, Johns Hopkins University, Baltimore, MD, United States |
||
Sickle cell disease (SCD) is associated with endothelium dysfunction, but the role of the blood-brain barrier (BBB) in SCD has not been evaluated. We evaluated BBB function in pediatric SCD using a novel non-invasive method, water-extraction-with-phase-contrast-arterial-spin-tagging (WEPCAST) MRI. Children with SCD showed lower water extraction compared with healthy individuals. Higher permeability-surface-area-product (PS), i.e. leaky BBB, was associated with a number of known abnormalities in SCD, including lower hematocrit, lower hemoglobin, higher HbS fraction, impaired cognition, and a higher risk for silent cerebral infarction. Collectively, these findings support a potential role for BBB dysfunction in SCD pathogenesis. |
| 739
|
8:51
|
Recovery of cerebrovascular reactivity after asymptomatic carotid artery stenosis treatment is assessable by Breathhold-fMRI within global watershed areas |
1Department of Neuroradiology, Technical University of Munich, Munich, Germany, 2MRRC, Yale University, New Haven, CT, United States, 3Clinic for Radiology, Technical University of Munich, Munich, Germany, 4Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark, 5Philips Healthcare, Hamburg, Germany, 6Clinic for Neurology, Technical University of Munich, Munich, Germany, 7Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany |
||
Asymptomatic unilateral internal carotid-artery stenosis (ICAS) causes complex and currently poorly understood hemodynamic impairments which could possibly improve treatment decisions. Cerebrovascular reactivity (CVR) is an important biomarker of vascular health and can potentially serve to evaluate ICAS-treatment efficacy. We present perfusion MRI-data from a longitudinal study in 16 asymptomatic ICAS-patients before and after treatment plus 17 age-matched healthy controls. We hypothesize that CVR impairments in ICAS and their recovery after treatment can be assessed by Breathhold-fMRI analyzed by a data-driven approach. Our results demonstrate statistically significant CVR impairments within global watershed areas before treatment and significant CVR recovery after treatment. |
| 740
|
9:03
|
Intracranial vessel wall thickness measurements: A post-mortem comparison between hypertensive patients and controls |
1Center for Image Sciences, University Medical Center Utrecht, Utrecht, Netherlands, 2Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands, 3Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands |
||
For the intracranial arteries, only a few studies have investigated arterial wall thickening. In this post-mortem, explorative study we investigated the effect of hypertension on vascular remodeling in the Circle of Willis in male and female groups using 7T MRI. Circle of Willis specimens were scanned at ultra-high resolution(0.11mm isotropic). Vessel wall thickness and vessel wall area were measured at 21 locations across the major arterial branches. Results showed a larger vessel wall thickness and area in the female hypertension subgroup in four different arteries as compared to the control group(p<0.05). Male hypertension and control groups showed no significant difference. |
| 741
|
9:15
|
Elevated oxygen extraction fraction is a tissue biomarker of chronic ischemia for cerebral small vessel disease |
1Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, United States, 2Department of Neurology, Washington University School of Medicine, St. Louis, MO, United States |
||
Cerebral small vessel disease (CSVD) increases stroke risk and often leads to vascular cognitive impairment. We hypothesized that elevated oxygen extraction fraction (OEF) is a tissue biomarker of chronic ischemia in patients with CSVD. We found that reduction of cerebral blood flow (CBF) in gray matter depends on age, but not on CSVD. In contrast, OEF is increased in watershed and white matter in patients with CSVD and watershed OEF is significantly associated with white matter hyperintensities (WMH) lesion volumes after adjusting for age. |
| 742 | 9:27
|
Cerebral Perfusion Territory Changes after Direct Revascularization Surgery in Moyamoya Disease: A Super Selective Arterial Spin Labeling Study |
1Radiology Department, Beijing Tiantan Hospital, Capital Medical University, Beijing, China, 2MR Research, GE Healthcare, China, Beijing, China |
||
The super selective arterial spin labeling (ssASL) was used in the early postoperative period to evaluate the revascularization area (RA) obtained by a bypass from the superficial temporal artery to the middle cerebral artery in Moyamoya disease, and the perfusion territory changes of the major cerebral arteries were evaluated. The results indicated the postoperative perfusion territory changes of the major cerebral arteries differed between the RA-positive group and the RA-negative group. The incidence of preoperative external carotid artery compensation was significantly higher in the RA-negative group than the RA-positive group. There was good intermodality agreement between ssASL and CT angiography. |
| 743 | 9:39
|
Comparison of Four 3D Black Blood MRI Sequences for the Characterization of Unruptured Intracranial Aneurysm Wall Enhancement |
1Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States, 2Radiology, Changhai Hospital, Shanghai, China |
||
Aneurysm wall enhancement (AWE) post Gadolinium contrast on high-resolution black blood MRI has been studied as a marker of unstable intracranial aneurysms. However, a recent study showed slow flow could mimic AWE. This study evaluated four black blood sequences with high- and low-resolution fast-spin-echo (SPACE), with and without MSDE/DANTE blood suppression modules. In 30 unruptured saccular aneurysms, we found low-resolution SPACE significantly overestimated AWE (20/30 enhanced) compared to high-resolution SPACE (16 enhanced) and sequences with MSDE/DANTE (14 and 13 enhanced). High-resolution DANTE-SPACE has the best blood suppression and image quality, which is a preferred method for AWE assessment. |
| 744
|
9:51
|
Highly Accelerated Dynamic 2D and 3D Vessel-Encoded Arterial Spin Labelling Angiography |
1Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom |
||
Vessel-encoded ASL can produce vessel-selective cerebral angiograms, but to separate blood from multiple arteries more images are needed than for standard ASL angiography, which increases scan time. Angiograms are however well suited for under-sampling and compressed sensing reconstruction because of their high intrinsic sparsity. In this work we demonstrate in-vivo that vessel-selective angiograms allow for higher acceleration factors, yielding comparable image quality to conventional angiography with matched scan time using 2D and 3D time-resolved golden angle radial acquisitions. With this optimised acquisition and reconstruction method, scan time of the 3D case can be reduced from 8:35 hours to ~5 minutes. |
| 745 | 10:03
|
Characterization of Lenticulostriate Arteries using High-resolution 3D Black Blood MRI and Subcortical CBF using 3D pCASL as a Biomarker in Vascular Cognitive Impairment and Dementia |
1Stevens Institute of Neuroimaging and Informatics, University of Southern California, Los Angeles, CA, United States, 2Neurology, University of Southern California, Los Angeles, CA, United States |
||
Lenticulostriate arteries (LSAs) with small diameters of 280-510 µm take origin directly from the high flow middle cerebral artery (MCA), making them especially susceptible to damage by small vessel disease (SVD). In this study, we characterized the morphology of LSAs using High-resolution 3D Black Blood MRI and measured CBF in the MCA perforator territory (MCAperf) using 3D pCASL in a cohort of elderly Latino subjects. Our results show that the product of LSA delineation rating and MCAperf CBF are positively correlated with cognitive functions, and are reduced in subjects with mild cognitive impairment and hyperlipidemia. |
| 746
|
8:15
|
High resolution T2-prepared MRI enables non-invasive assessment of CSF flow in perivascular spaces of the human brain |
1Radiology, Leiden University Medical Center, Leiden, Netherlands, 2Mathematical Sciences, University of Southampton, Southampton, United Kingdom, 3LKEB, Leiden University Medical Center, Leiden, Netherlands |
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Recently, flow of cerebrospinal fluid (CSF) has been shown to play an important role in the transport of brain metabolites, ushering in the concepts of glymphatics and intramural periarterial drainage. Failure of waste-drainage has been linked to incurable neurodegenerative diseases such as Alzheimer’s disease and cerebral amyloid angiopathy. The lack of a non-invasive imaging technique for the investigation of perivascular drainage mechanisms in the human brain strongly hinders the assessment of brain clearance in human subjects. In this study, we present the first non-invasive technique to visualize the CSF-flow along the middle cerebral artery (MCA), as well as along perivascular spaces of smaller arteries in the human brain. |
| 747 | 8:27
|
A Novel MRI Phantom to Study Interstitial Fluid Transport in the Glymphatic System |
1NICHD, NIH, Bethesda, MD, United States, 2CNRM, USUHS, Bethesda, MD, United States, 3NIBIB, NIH, Bethesda, MD, United States |
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The glymphatic system transports cerebral spinal fluid throughout the brain to clear metabolic and cellular waste during sleep. While there is growing recognition of the critical role this system plays in maintaining normal brain health and in explaining pathology, there are no known noninvasive imaging methods to measure and characterize the efficacy of glymphatic transport in vivo. In this study, we designed, constructed, and tested a glymphatic transport magnetic resonance imaging (MRI) flow phantom. Using it, we determined it may be possible to detect interstitial glymphatic flows via diffusion MRI acquisition methods. |
| 748 | 8:39
|
Gd-DOTA mass distribution from the Glymphatic Pathway into rat brain measured by 3D DCE-MRat 9.4T |
1Anesthesiology, Yale School of Medicine, New Haven, CT, United States, 2Yale University, New Haven, CT, United States, 3Medical imaging center, First Affiliated Hospital of JINAN University, Guangzhou, China |
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The recently discovered the "glymphatic pathway" for brain waste clearance, comprises a brain-wide peri-vascular transit passageway for facilitating CSF-ISF ‘cross-talk’, in an AQP4 water channel driven manner. In this study, we report a method to calculate time-resolved 3D Gd-DOTA mass distribution maps to depict the glymphatic transport. We detected higher mass retention in GM compared to WM, due to the tissue volume differences. High Gd uptake in the cerebellum coincides with the high expression of AQP4 water channels in this area. These findings emphasize the importance of the anatomical glymphatic network with high Gd uptake capacity may be related |
| 749
|
8:51
|
Brain state and CSF production define glymphatic washout in the rat brain |
1Translational Research Imaging Center (TRIC), University Hospital Muenster, Muenster, Germany |
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The Glymphatic System, which is essential for brain-wide waste clearance, is enhanced during sleep. Here, we investigate the effect of brain state and CSF formation using constrast enhanced MRI in a rat model. Our data support the hypothesis that sleep enhances glymphatic clearance due to better CSF intrusion into the brain parenchyma caused by higher CSF formation and smaller arteries. Higher diffusion in cortex associated with altered brain state during sleep influence CSF distribution within parenchyma. |
| 750
|
9:03
|
Impaired glymphatic transport and loss of peri-arterial AQP4 expression in spontaneously hypertensive stroke prone rats compared to normotensive WKY controls |
1Department of Anesthesiology, Yale school of medicine, new haven, CT, United States, 2Center for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, United Kingdom, 3UK Dementia Research Institute, The University of Edinburgh, Edinburgh, United Kingdom, 4Row Fogo Centre for Research into Ageing and the Brain, The University of Edinburgh, Edinburgh, United Kingdom, 5Center for Translational Neuromedicine, University of Rochester Medical School, Rochester, NY, United States, 6Center for Translational Neuromedicine, University of Copenhagen, Copenhagen, Denmark |
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Cerebral small vessel disease (CSVD) is one of the important vascular factor contributing to the cognitive impairment and dementia. Clinically, CSVD hallmarks includes MR white matter hyperintensities and dilated perivascular spaces. Brain-wide perivascular transit passageways for CSF, also known as Glymphatic system has recently been described as cerebral metabolic waste clearance pathway. We evaluated Glymphatic transport by DCE-MRI in middle aged spontaneously hypertensive stroke prone (SHRSP) rats and normal Wistar Kyoto (WKY) rats, which demonstrated significant impairment of Glymphatic transport in brain parenchyma in 7-month old SHRSP rats in comparison to controls. |
| 751 | 9:15
|
Elucidating brain water management in hypertension: a preclinical MRI study |
1Department of Biomedical Engineering and Physics, Amsterdam UMC, Amsterdam, Netherlands |
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Hypertension has been associated with alterations in vascular function and an imbalanced water management of brain tissue, yet the underlying mechanisms for these pathologies remain unclear. To further elucidate possible mechanisms of the fluid homeostasis in the brain, we performed non-invasive MR imaging on normotensive and spontaneous hypertensive rats. We assessed total brain and regional brain volumes, as well as diffusional and water exchange properties of the brain tissue. |
| 752 | 9:27
|
Sleep-related changes in diffusivity overnight: a window into glymphatic activity in humans? |
1University Children's Hospital, Zurich, Switzerland |
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This study examined overnight changes in diffusivity as a proxy marker for clearance in the glymphatic system, a recently proposed pathway for waste clearance in the brain. In 18 healthy adults, the mean diffusivity increased overnight in multiple brain regions, consistent with the hypothesised expansion of the extracellular space during sleep. In contrast, the diffusivity within CSF decreased overnight, possibly due to temperature effects. The overnight reduction in CSF diffusivity did not correlate with sleep parameters, but the overnight increase in diffusivity in the brain was positively correlated with the percentage of time spent in REM sleep, assessed with EEG. |
| 753 | 9:39
|
Accuracy of real-time quantitative flow imaging in small diameters using compressed sensing at 7T: a phantom study |
1Department of Clinical Sciences, Diagnostic Radiology, Lund University, Lund, Sweden, 2Philips Healthcare, Copenhagen, Denmark, 3Lund University Bioimaging Center, Lund University, Lund, Sweden |
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Recent studies have shown that cerebrospinal fluid (CSF) flow is strongly affected by respiration, which may potentially be used for future diagnosis and treatment follow-up in diseases such as normal pressure hydrocephalus and congenital malformations. However, quantitative measurements of respiratory effects on CSF flow in small diameters are not currently available. Therefore, this abstract shows a phantom validation of flow measurement using a radial golden-angle real-time flow sequence, reconstructed using compressed sensing. Results show that mean velocities can be quantified with a small underestimation, suggesting that the protocol is promising for future study of respiratory effects on CSF flow. |
| 754 | 9:51
|
Real-time phase contrast magnetic resonance imaging for assessment of cerebral haemodynamics during breathing. |
1EA 7516 Chimère, Jules Verne university, amiens, France, 2Image Processing, Jules Verne University Hospital, Amiens, France, 3Neuro Radiology, Jules Verne University Hospital, Amiens, France, 4MRI Research GIE-IFF CHU Amiens Picardie, Amiens, France |
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To investigate cerebral blood flows by EPI Phase Contrast (EPI-PC) and Normal Phase contrast sequences, in volunteers. Cerebral arterial and venous blood flows were calculated by homemade software. Arterial cerebral blood flows measured by EPI-PC were significantly higher than those measured by normal PC. Whereas venous cerebral blood flows were not different between the two technics. Post processing of continuous EPI-PC flow signal provides blood flows curves during inspiration and expiration. Blood flows during inspiration were respectively higher than during expiration. EPI-PC flow quantify arterial and venous intracranial blood flows in few seconds without any cardiac or respiratory gating. |
| 755 | 10:03
|
Macroscopic Hyperdynamic CSF Flow and CSF Volume Analysis in Children and Adolescents with Congenital Heart Disease |
1University of Pittsburgh, Pittsburgh, PA, United States |
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In this study we investigate whether there are differences in CSF volumes between CHDs and healthy controls, as well as examining any correlation between CSF volume and CSF flow, and whether this relationship is altered in CHDs. We showed that certain CSF volumes are elevated in CHD. We also observed that increased flow metrics are correlated with both increased volume in some CSF compartments and decreased volume in other CSF compartments. Lastly, there maybe interplay between CSF flow and volume within CHDs. |
| 756 | 8:15
|
SmartPulse, a Machine Learning Approach for Calibration-Free Dynamic RF Shimming in Body Imaging |
1NeuroSpin, CEA, Université Paris-Saclay, Gif-sur-Yvette, France, 2Parietal, Inria, Université Paris-Saclay, Gif-sur-Yvette, France, 3Siemens Heathcare SAS, Saint-Denis, France, 4Department of Radiology, AP-HP, CHU Henri Mondor, Créteil, France, 5Université Paris-Est Créteil Val-de-Marne, Créteil, France, 6INSERM Unité U955, Equipe 18, Créteil, France |
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At high field, tailored static or, better, dynamic RF shimming can be used to reduce artifacts due to transmit B1 field inhomogeneity, but those methods require extra time for calibration, which can disrupt clinical workflows. Recently, universal pulses (UP) were introduced in brain imaging to get rid of calibration. In this work, a machine learning method is proposed to extend universal pulse kT-point design to body imaging where inter-subject variability is more pronounced, by classifying subjects into one of several predefined categories. This method outperforms UP design, and yields images similar to those obtained with state-of-the-art tailored design. |
| 757
|
8:27
|
Deep reinforcement learning designed RF pulse |
1Department of Electrical and Computer Engineering, Seoul National University, Seoul, Korea, Republic of, 2Department of Biomedical Engineering, Hankuk University of Foreign Studies, Gyeonggi-do, Korea, Republic of |
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In this study, we developed an approach |
| 758 | 8:39
|
Spread-spectrum MRI: acceleration of image acquisition using locally modulated magnetic fields |
1Max Planck, Tuebingen, Germany, 2University of Tuebingen, Tuebingen, Germany |
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We introduce the principles of a novel approach for the acceleration of signal acquisition that is based on a rapid and unique modulation of localized magnetic fields superimposed to the conventional linear gradient-based spatial encoding. |
| 759 | 8:51
|
Spiral Time of Flight with Sliding Slice Localized Quadratic Encoding |
1Department of Radiology, Mayo Clinic, Rochester, MN, United States, 2Philips Healthcare, Gainesville, FL, United States, 3Hyperfine Research, Guilford, CT, United States, 4Department of Neuroradiology, Barrow Neurological Institute, Phoenix, AZ, United States |
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In this work, a fast and flexible TOF technique is proposed by applying sliding-slice spiral acquisition with localized quadratic encoding RF pulse. Due to the fast acquisition, water-fat separation and deblurring can also be applied using data from two TEs to improve the visualization over the conventional out of phase method. Volunteer scans in head and neck have demonstrated that the proposed method is 0.4 - 2 times faster than the conventional 2D Cartesian TOF and 3D Cartesian multi-slab TOF, yet provides slightly better visibility of the flow. |
| 760 | 9:03
|
Simulation of Bloch and Bloch-McConnell equations - speed and accuracy |
1Institute of Medical Engineering, Graz University of Technology, Graz, Austria, 2Institute of Mathematics and Scientific Computing, Karl-Franzens-University Graz, Graz, Austria |
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Accurate Bloch and Bloch-McConnell model simulation is essential for proper modelling and becomes crucial for iterative RF pulse design methods. This work demonstrates the advantages of a piecewise analytical solution using eigenvalues and eigenvectors and an asymmetric and symmetric operator splitting scheme. Those three solvers are compared to five other numerical solution methods regarding accuracy and runtime. The symmetric operator splitting prevails in both compared to the others. Moreover, it is quadratic convergent with respect to the time step and therefore seems to be a good choice for optimal control approaches for Bloch and for Bloch-McConnell models. |
| 761
|
9:15
|
Unifying Extended Phase Graphs and k-space Readout |
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland |
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Conventional Extended Phase Graphs (EPGs) allow for an efficient analysis of signal behavior in MRI sequences involving spoiling gradients. The concept has been adapted to spatially resolved EPGs, where spoiling and spatial information is assumed to be fully uncoupled. In this work, we formulate an approach for the combination of configuration state theory and the conventional k-space concept, by re-coupling spoiling and spatial information. The concept not only permits investigating the interference of spoiled signals leading to additional ringing artifacts, but also allows to study arbitrary readout trajectories in the realm of EPGs. |
| 762
|
9:27
|
Prospective GIRF-based RF phase cycling to prevent eddy current-induced steady-state disruption in balanced SSFP imaging |
1Radiotherapy, University Medical Center Utrecht, Utrecht, Netherlands, 2MR Code BV, Zaltbommel, Netherlands |
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Balanced steady-state free precession sequences offer the highest signal-to-noise ratio and encode multiple physical parameters into the signal. However, the sequence is prone to eddy current-induced steady-state disruptions that can severely compromise the image quality or the physical parameter quantification. In this work we describe how the eddy currents act on the signal evolution and propose a novel prospective solution that in principle is applicable to any MRI examination. |
| 763
|
9:39
|
T-Hex: Spiral sampling on a tilted hexagonal grid |
1Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zürich, Switzerland, 2ETH, Zürich, Switzerland, 3Skope Magnetic Resonance Technologies, Zurich, Switzerland |
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In this work, we show a stack of spirals on a tilted hexagonal grid. This trajectory is used for fast 3D acquisitions with long readouts and combines the optimal hexagonal 3D sampling with the high acquisition efficiency of spirals. Isotropic 2.8 mm whole-brain coverage is achieved in 200 ms relying on cg-SENSE reconstruction, without the need for non-linear regularization. |
| 764 | 9:51
|
Time-Resolved MRI of the Human Brain with 3.5 ms per Frame |
1Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland |
||
MR imaging with shortest possible acquisition times is targeted by single-shot spiral readouts and extremely rapid gradient encoding. The implementation involves a first demonstration of spiral imaging using a gradient insert to achieve a slew rate of 1200 T/m/s. The achievable imaging performance is evaluated and in-vivo results are presented. The setup permitted imaging with more than 280 frames per second, which also allowed the extraction of rudimentary spectral imaging information from a single MR readout. The newly available temporal resolution in MR may be utilized to gain new insights in brain function and physiology. |
| 765 | 10:03
|
Efficient 3D low-discrepancy $$$k$$$-space sampling using highly adaptable Seiffert Spirals |
1Core-Facility Small Animal Imaging (CF-SANI), Ulm University, Ulm, Germany, 2Experimental Cardiovascular MRI (ExCaVI), Ulm University Medical Center, Ulm, Germany |
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The overall duration of acquiring a Nyquist sampled 3D dataset can be significantly shortened by enhancing the efficiency of $$$k$$$-space sampling. This can be achieved by increasing the coverage of $$$k$$$-space for every trajectory interleave. Further acceleration is possible by making use of advantageous undersampling properties. This work presents a versatile 3D centre-out $$$k$$$-space trajectory, based on Jacobian elliptic functions (Seiffert's spiral). The trajectory leads to a low-discrepancy coverage of $$$k$$$-space, using a considerably reduced number of read-outs compared to other approaches. Such a coverage is achieved for any number of interleaves and therefore even single-shot trajectories can be constructed. Simulations and in-vivo studies compare Seiffert's spiral to the established 3D Cones approach. |
| 766
|
8:15
|
Diffusion MRI with b=1000 s/mm2 at TE < 22 ms using single-shot spiral readout and ultra-strong gradients: Implications for microstructure imaging |
1CUBRIC, School of Psychology, Cardiff University, Cardiff, United Kingdom |
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The development of 300 mT/m gradients has opened new opportunities for exploring much shorter echo times (TE) in human diffusion imaging. Here, to further shorten TE, we developed a robust pulse-gradient spin-echo sequence with single-shot spiral readout on this hardware. The ultra-strong gradients induced vibrations, which were addressed by hardware modifications, while challenges posed by B0-inhomogeneity, eddy currents (captured using a field camera) and gradient-nonlinearity were addressed using iterative reconstructions. With this combination, for a b-value of 1000 s/mm2, we achieved TE = 21.7 ms. In this previously unchartered domain, we demonstrated enhanced sensitivity to myelin in spin-echo diffusion MRI. |
| 767
|
8:27
|
High-Resolution Diffusion MRI: In-Vivo Demonstration of the SNR Benefit of Single-Shot Spiral Acquisition vs. EPI |
1Institute for Biomedical Engineering, ETH Zürich, Zürich, Switzerland, 2Laboratory for Social and Neural Systems Research, University of Zürich, Zürich, Switzerland |
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Spiral acquisition for diffusion-weighted imaging (DWI) has become possible with recent development of dynamic field monitoring and image reconstruction. In this work, we demonstrate high-quality in-vivo spiral DWI at high in-plane resolution (1mm) with minimal artifacts. In addition, we confirm the expected signal-to-noise ratio (SNR) gain of spiral- compared to echo-planar-imaging (EPI) readouts both theoretically and experimentally at varied resolutions and acceleration factors. An SNR gain up to 91% was measured in white matter. In conclusion, spiral acquisition provides improved SNR especially at high image resolutions. |
| 768
|
8:39
|
High-fidelity, high-isotropic resolution diffusion imaging through gSlider acquisition with B1+ & T1 corrections and multi-coil B0 shim array |
1Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 2Department of Radiology, Harvard Medical School, Charlestown, MA, United States |
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gSlider is an SNR-efficient simultaneous multi-slab acquisition that has shown great potential for high-resolution diffusion imaging (DI). In this work, approaches to improve the fidelity of gSlider are proposed. A modified reconstruction which incorporates B1+ inhomogeneity and T1 recovery information was developed and demonstrated to successfully mitigate slab-boundary artifacts in short-TR gSlider acquisitions. Slice-by-slice B0-shimming through multi-coil shim-array, and high in-plane acceleration through virtual-coil GRAPPA were also incorporated into the acquisition and demonstrated to achieve 8-11x reduction in B0 distortion in single-shot EPI. The modified gSlider acquisition/reconstruction was used to acquire high-fidelity whole-brain 1mm isotropic DI with 64 diffusion-directions in 20-minutes at 3T. |
| 769 | 8:51
|
Double Echo Steady State (DESS) Cones for Motion-Robust Steady-State Diffusion-Weighted Imaging |
1Radiology, Stanford University, Stanford, CA, United States, 2Electrical Engineering, Stanford University, Stanford, CA, United States, 3Global MR Applications and Workflow, GE Healthcare, San Diego, CA, United States |
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Diffusion-Weighted Imaging (DWI) has shown potential for oncologic imaging without a contrast injection. However conventional methods are limited by low resolution and distortion. Steady-state DWI methods provide 3D, distortion-free images but are susceptible to motion artifacts. A Double Echo Steady State (DESS) method with a conical k-space trajectory is presented and assessed for motion artifact and diffusion-weighting with a focus on breast cancer imaging. |
| 770
|
9:03
|
Achieving sub-mm clinical diffusion MRI resolution by removing noise during reconstruction using random matrix theory |
1Radiology, NYU School of Medicine, New York, NY, United States |
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We show how to achieve the benefits of inline-scan averaging for reducing thermal noise and lowering the Rician noise floor prior to image reconstruction, albeit in inequivalent diffusion MRI (dMRI) acquisitions. For that, we identify and remove the pure-noise principal components in joint coils x q-space x voxels dMRI data, as they follow the universal Marchenko-Pastur distribution. The method is demonstrated on 0.8mm isotropic voxels for b=1000 and 2000 protocol (3T), showing an increase of SNR and decrease of the Rician noise floor by 5-fold. We discuss applications in dMRI parameter estimation, tractography and functional neurosurgery. |
| 771 | 9:15
|
Cross-scanner and cross-protocol harmonisation of multi-shell diffusion MRI data: open challenge and evaluation results |
1Harvard Medical School, Boston, MA, United States, 2Brigham and Women's Hospital, Boston, MA, United States, 3University College London, London, United Kingdom, 4University of Southern California, Los Angeles, CA, United States, 5New York University, New York, NY, United States, 6Boston Children's Hospital, Boston, MA, United States, 7RWTH Aachen University, Aachen, Germany, 8King's College London, London, United Kingdom, 9Eindhoven University of Technology, Eindhoven, Netherlands, 10Cardiff University, Cardiff, United Kingdom |
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We present a comparison of twelve different methods that estimate mappings between scanners for multi-shell diffusion MRI data harmonisation. The methods are evaluated on a benchmark dataset acquired from 15 subjects using two scanners that both have a standard and a state-of-the-art protocol. The results show that cross-vendor harmonisation and spatial/angular resolution enhancement of multi-shell diffusion data sets can be performed reliably using suitable algorithms. The dataset is available upon request and can serve as a useful testbed for the development diffusion MRI harmonisation algorithms. |
| 772
|
9:27
|
Toward high-SNR, motion-robust diffusion MRI of the liver using optimized gradient waveforms, non-gated free-breathing acquisitions, and motion-corrected averaging |
1Radiology, University of Wisconsin, Madison, Madison, WI, United States, 2Medical Physics, University of Wisconsin, Madison, Madison, WI, United States, 3Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, 4Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States |
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Liver DWI suffers from signal voids introduced by elastic motion, mis-registration due to respiratory motion and low SNR. We propose to develop and evaluate a novel free-breathing DWI technique appropriate for the abdomen, in order to provide high SNR efficiency with predictable scan times, while avoiding motion-related artifacts. Evaluations showed that compared to respiratory-triggering acquisitions, the proposed DWI technique provided higher SNR and predictable scan times. Further, a motion-corrected averaging algorithm has the potential to correct for motion-related artifacts. Using optimized gradient waveforms, non-gated free-breathing acquisitions, and motion-corrected averaging techniques, high-SNR and motion-robust DWI of the liver may be achieved. |
| 773 | 9:39
|
An efficient reconstruction by combining tilted-CAIPI with eddy-current calibration for high-resolution distortion-free diffusion imaging using DIADEM |
1Department of Radiology, Mayo Clinic, Rochester, MN, United States, 2A. A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, United States, 3Department of Electrical Engineering and Computer Science, MIT, Cambridge, MA, United States, 4Harvard-MIT Health Sciences and Technology, MIT, Cambridge, MA, United States |
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As a variant of multi-shot echo-planar imaging, DIADEM (Distortion-free Imaging: A Double Encoding Method) enables high-resolution distortion-free imaging, but the prolonged scan time can be a major challenge. Recently, a novel parallel imaging approach, termed tilted-CAIPI, was suggested to unfold highly accelerated DIADEM data and to substantially reduce the acquisition time. However, the reconstructed image still suffers from eddy-current-induced geometric distortions in diffusion-weighted data. In this work, it is demonstrated that the DIADEM reconstruction becomes more efficient and practical after combining the tilted-CAIPI with the eddy-current calibration approaches. |
| 774
|
9:51
|
High-Resolution Isotropic Diffusion MRI Using Simultaneous Multi-slab (SMSlab) Acquisition |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, 2Radiology, Stanford University, Stanford, CA, United States |
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3D multi-slab acquisition is an important technique for high-resolution isotropic diffusion MRI. To further accelerate the acquisition, simultaneous multi-slice (SMS) excitation can be combined with multi-slab, termed simultaneous multi-slab (SMSlab). Previously it has been demonstrated that the SMSlab un-folding problem can be solved using a 3D Fourier encoding framework. When applying SMSlab to diffusion MRI, the main challenge is how to simultaneously un-fold the excited multiple slices/slabs and correct the inter-shot phase variations. To achieve this, a delicate navigator acquisition is designed and a POCS-enhanced k-space phase correction method is used in this study. |
| 775 | 10:03
|
Validation of DSI compressed sensing reconstruction in ex vivo human brain |
1Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 2Harvard-MIT Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States, 3Boston University, Boston, MA, United States, 4Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA, United States |
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Compressed sensing algorithms for accelerating DSI acquisitions (DSI-CS) have helped bring DSI into the realm of clinical feasibility. Here, we assess the efficacy of dictionary-based CS methods in reconstructing high resolution ex vivo DSI of human brain blocks, and provide validation of ex vivo DSI-CS with ground truth optical imaging. We find that reconstruction accuracy, computation time and inter-subject dictionary generalizability are comparable to in vivo results, and that SNR appears influential in determining the limit of attainable reconstruction quality. We also show that fiber orientation estimates of reconstructed data are as accurate as fully-sampled estimates at a microscopic level. |
8:15
|
Multiparametric MRI for Myelin Quantification & AI in Multiple Sclerosis | |
8:45
|
Imaging Markers of Axonal Pathology in White Matter: Progress & Challenges | |
1Massachusetts General Hospital, United States |
9:15
|
Clinical Translation of Quantitative Myelin Imaging in White Matter Disorders | |
1Radiology, The University of Tokyo Hospital, Tokyo, Japan |
9:45
|
Moving Quantification Into Clinical Neuroradiology Practice (Really This Time!): Major Challenges bu | |
8:15
|
(Pre)-Clinical Proton & Phosphorous MRS of Breast Cancer to Assess Phospholipid Metabolism | |
8:35
|
State-of-Art Clinical Assessment of Breast Cancer | |
8:55
|
Diffusion-Weighted Imaging for Microstructural Characterization | |
9:15
|
Integrated PET/MRI Systems & Targeted Tracers for Local & Whole-Body Staging in Breast Cancer | |
9:35
|
AI in Breast MRI: How to Do It! | |
9:55
|
Imaging for the Completion of the ‘Omics in Breast Cancer | |
1Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, United States |
| 10:30 | When Stress Rules |
| 11:00 | Connecting MRI to Neurophysiology: Collective Brain Dynamics |
| 11:20 | Connecting MRI to Applied Mathematics: Fluid Dynamics of the Blood & Lymph Flow |
1University of Trento, Trento, Italy |
| 11:40 | Connecting MRI to Molecular Engineering: Genetically Encoded MR Reporters |
13:30
|
Introduction | |
1Physikalisch Technische Bundesanstalt (PTB), Berlin, Germany |
13:35
|
MR from a Global Perspective: Looking Beyond North America & Europe | |
1Memorial Sloan-Kettering Cancer Center, United States |
13:50
|
What Do We Have & What Do We Need? - MRI in Africa | |
1Biomedical Engineering, Mbarara University of Science & Technology, Mbarara, Uganda, 2Biomedical Magnetic Resonance, Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany, 3Engineering Science and Mechanics, The Pennsylvania State University, State College, PA, United States |
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The structural, technical and operational requirements of conventional high field MRI are very high. As a result, there are very few MRI units in developing countries especially Sub-Saharan Africa. In order to improve MRI distribution in such low resource countries, development of local technical capacity is very vital. This can only be possible in collaboration with the developing world where is already high technical capacity. The aim of this project is to develop a training software for MRI that will link developing and developed countries to promote MRI training and sharing of knowledge and data. |
14:10
|
What Do We have & What Do We Need? - MRI in South America | |
1University of São Paulo, Brazil, 2University of São Paulo, São Paulo, Brazil |
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In this presentation we will give an overview of MRI in Brazil, and we will present a challenge that is potentially of interest to other South American countries. The challenge proposed is to merge clinical data with MRI brain scans of people with not known neurological problem, in order to establish which is the age/gender specific treshold at which MRI lesions compatible with vascular dementia start to occur. The goal would be then to identify who are the patients at risk of vascular dementia in order to make an early intervention. |
14:30
|
What Do we Have & What Do We Need? - MRI in India | |
1MR Research Program, Columbia University, new york, NY, United States |
14:50
|
Africa Challenge: Virtual Scanner Software | |
1Biomedical Engineering, Columbia University, New York, NY, United States |
14:50
|
Africa Challenge: All You Need is a Browser – Eliminating Barriers to MRI Education with Open Source Interactive Tutorials | |
1Montreal Heart Institute, Canada |
14:50
|
South America Challenge: A Web-Based Data Management & Processing System to Support the Prevention of Vascular Dementia | |
14:50
|
South America Challenge: Prevention of Vascular Dementia | |
1German Cancer Research Center, Heidelberg, Germany |
14:50
|
India Challenge: Generative Adversarial Network Driven Synthetic MRI | |
1All India Institute of Medical Sciences, India |
14:50
|
India Challenge: Concept of Screening MRI for Stroke in India | |
1Department of NMR and MRI Facility, All India Institute of Medical Sciences, New Delhi, India |
15:10
|
Team Building Phase |
15:25
|
Conclusion & Outlook |
15:30
|
Adjournment |
| 776
|
Pitch: 13:30 Poster: 14:30 Plasma 1
|
Quantitative Magnetization Transfer Imaging of Human Myocardial Tissue and Scar |
1King's College London, London, United Kingdom, 2MR Research Collaborations, Siemens Healthcare Limited, Frimley, United Kingdom |
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We have developed a contrast-free single breath-hold 2D MT mapping technique using a two-pool exchange model and dictionary matching to parametrize macromolecular changes associated with myocardial fibrosis. The model was validated in vials with different albumin concentrations and bovine leg. Pool sizes ratio and bound pool T2 maps were obtained from 7 healthy subjects and two patients with ischemic or non-ischemic scar/fibrosis. . Reduced PSR and T2B values were found to correlate with LGE areas in both patients. In vivo quantitative MT mapping of the heart was performed for the first time, showing promising results for the detection of myocardial fibrosis. |
| 777 | Pitch: 13:30 Poster: 14:30 Plasma 2
|
Myocardial Infarct Characterization using Relaxation along Fictitious Field in the nth Rotating Frame |
1Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland, 2Department of Radiology, Oulu University Hospital, Oulu, Finland, 3Department of Applied Physics, University of Eastern Finland, Kuopio, Finland, 4Department of Cardiology, Oulu University Hospital, Oulu, Finland |
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Based on the previous promising relaxation along fictitious field in nth frame (RAFFn) findings in myocardial infarct mouse model at 9.4 T, we adjusted RAFFn measurement to standard clinical 1.5 T scanner with γB1 = 500 Hz. We demonstrate with five myocardial infarct patients that fitted steady state from RAFF2 and RAFF3 weighted images can separate the infarct from remote myocardium using clinical main and RF fields. We also demonstrate association between RAFF3 steady state and extra cellular volume that is calculated based on pre and post contrast T1 maps and hematocrit. |
| 778
|
Pitch: 13:30 Poster: 14:30 Plasma 3
|
A ROI Focused Multi-Scale Super-Resolution Method for the Diffusion Tensor Cardiac Magnetic Resonance |
1Department of Computer Science and Technology, University of Cambridge, Cambridge, United Kingdom, 2National Heart and Lung Institute, Imperial College London, London, United Kingdom, 3Cardiovascular Research Centre, Royal Brompton Hospital, London, United Kingdom |
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Diffusion Tensor Cardiovascular Magnetic Resonance (DT-CMR) is a promising contrast-free and non-invasive technique to characterize the tissue integrity and microstructure of the myocardium. However, the complex acquisition protocol results in prolonged scan times and often results in images with low spatial resolution and relatively poor signal-to-noise ratio. Here a novel ROI focused multi-scale super-resolution approach is proposed to improve the apparent spatial resolution of in vivo DT-CMR. Based on simulation studies, our proposed method can achieve increases in apparent spatial resolution by a factor of 4 with preserved image quality and no obvious degradation in the derived DT-CMR parameters. |
| 779 | Pitch: 13:30 Poster: 14:30 Plasma 4
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Efficient high-resolution cardiac motion-corrected T1 mapping |
1Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany, 2Charité Medical Faculty University Medicine, Berlin, Germany, 3Working Group on Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center (ECRC), DZHK partner site Berlin, Berlin, Germany, 4Department of Cardiology and Nephrology, HELIOS Klinikum Berlin Buch, Berlin, Germany, 5Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom |
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Cardiac T1 mapping provides valuable information on fibrosis in various cardiomyopathies. Commonly, data acquisition is restricted to a small percentage (mid-diastole) of the cardiac cycle to prevent motion artefacts. This leads to low scan efficiency and limits the achievable resolution. We present an 8s T1 mapping approach, which employs a large acquisition window (80% of the cardiac cycle) and corrects for cardiac motion using the same data. The approach was evaluated in native T1 mapping in healthy volunteers and post-contrast T1 mapping in patients. It significantly improved the precision of the obtained T1 maps while successfully minimizing cardiac motion artefacts. |
| 780 | Pitch: 13:30 Poster: 14:30 Plasma 5
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Diffusion tensor cardiovascular magnetic resonance in myocardial infarction: A comparison between high resolution spiral and standard resolution EPI STEAM |
1National Heart and Lung Institute, Imperial College London, London, United Kingdom, 2Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, London, United Kingdom |
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Diffusion tensor cardiovascular magnetic resonance can provide insight into the function and microstructure of the scar and adjacent region in myocardial infarction (MI). Imaging the thinned infarcted myocardial wall requires a high-resolution acquisition while frequent arrhythmia, shortness of breath and fatigue make the cohort especially challenging for imaging. A high-resolution STEAM acquisition with an interleaved variable density spiral readout and an off-resonance and T2* correction was previously demonstrated in a healthy cohort. Here, this sequence was successfully applied in 7 MI patients at a spatial resolution of 1.8x1.8x8mm3 and compared to a standard resolution EPI sequence. |
| 781 | Pitch: 13:30 Poster: 14:30 Plasma 6
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Cardiac Magnetic Resonance Fingerprinting for the Investigation of Suspected Inflammatory Cardiomyopathy |
1Cardiology, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, 2Radiology, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, 3Department of Biomedical Engineering, Case School of Engineering, Case Western Reserve University, Cleveland, OH, United States |
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Inflammatory cardiomyopathy (ICMP) needs to be diagnosed early, and cardiac T1 and T2 mapping both have been shown to increase the accuracy of ICMP diagnosis. Cardiac magnetic resonance fingerprinting (cMRF) can be used to robustly acquire both maps in a single breath-hold, so the goal of this preliminary study was to compare the performance of cMRF and routine parameter mapping in patients with suspected ICMP, including those with implantable cardioverter-defibrillators (ICDs), which often cause significant artifacts. The relaxation times in 24 patients were similar in cMRF and routine mapping, while cMRF may have superior performance in patients with an ICD. |
| 782
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Pitch: 13:30 Poster: 14:30 Plasma 7
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Motion-Compensated 3D Whole-heart Water-Fat Late Gadolinium Enhancement Imaging for Assessment of Myocardial Viability |
1School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 2MR Research Collaborations, Siemens Healthcare GmbH, Frimley, United Kingdom, 3Cardiovascular MR Predevelopment, Siemens Healthcare GmbH, Erlangen, Germany |
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Water/fat 2D LGE imaging has shown promising results for assessment of fibro-fatty infiltration in the myocardium and characterisation of cardiac masses. However, spatial resolution and volumetric coverage within a clinically feasible scan time remain a challenge. Here we propose a highly efficient respiratory motion-compensated 3D whole-heart water/fat inversion recovery (IR)-prepared LGE imaging sequence. Preliminary results from patients with cardiovascular disease demonstrate the feasibility of the approach, with scan duration of ~8 min. Motion-compensated 3D LGE water images offer a good depiction of myocardial scar, while motion-compensated fat images offer complementary diagnostic information, with clear delineation of epicardial and pericardial fat. |
| 783
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Pitch: 13:30 Poster: 14:30 Plasma 8
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Heartbeat-to-Heartbeat Quantitative Myocardial Oxygenation Imaging within a Single Breath-Hold using a Combined Gradient Echo-Spin Echo EPI (GESE-EPI) Sequence in Patients with Hypertension |
1A.A. Martinos Center for Biomedical Imaging, Boston, MA, United States, 2Department of Radiology, University Medical Center Groningen, Groningen, Netherlands, 3Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA, United States, 4Medicine, Harvard Medical School, Boston, MA, United States, 5Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, Groningen, Netherlands, 6Department of Radiology, Harvard Medical School, Boston, MA, United States, 7Medical Imaging Centre of Southwest Finland, Turku University Hospital, Turku, Finland, 8Division of Health Sciences and Technology, Harvard-MIT, Cambridge, MA, United States |
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Dynamic Cardiac BOLD imaging techniques can suffer from signal variabilities due to changes in heartrate during a breath-hold. We demonstrate that a 2-echo-GESE-EPI sequence can provide T2- and T2*-weighted images simultaneously per heartbeat, but the dynamic changes in these images represent physiological effects mixed with heartrate changes. We then proposed a 5-echo-GESE-EPI for dynamic T2- and T2*-mapping per heartbeat as a readout for myocardial oxygenation. These dynamically acquired T2- and T2*-values were demonstrated to increase over the time of a breath-hold for healthy volunteers, while shown to remain constant and even reverse in hypertension patients. |
| 784 | Pitch: 13:30 Poster: 14:30 Plasma 9
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An Analysis of DiffNet Reconstruction Performance in Healthy and Infarcted Cardiac Diffusion Tensor Images |
1Radiological Sciences Laboratory, Stanford University, Stanford, CA, United States, 2Bioengineering, Stanford University, Stanford, CA, United States, 3University of Virginia, Charlottesville, VA, United States, 4Radiological Sciences, University of California - Los Angeles, Los Angeles, CA, United States |
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Cardiac diffusion tensor imaging (cDTI) suffers from low signal-to-noise ratios, which results in tensor variability. In order to decrease tensor variability, the number of diffusion directions or number of averages must increase, consequently increasing the scan time. Recent implementations of artificial neural network (ANN) have proven that a non-linear mapping between diffusion signals and tensors is possible and can decrease tensor variability without increasing scan time. We implement an ANN tensor reconstruction for ex vivo porcine hearts to evaluate if a robust ANN diffusion tensor reconstruction is a beneficial technique to decrease tensor variability at no cost in scan time. |
| 785 | Pitch: 13:30 Poster: 14:30 Plasma 10
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Fully Self-Gated Cardiac and Respiratory Motion-Resolved Isotropic 5D T1 Mapping of the Heart: Preliminary Results |
1Department of Radiology, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, 2Center for Biomedical Imaging (CIBM), Lausanne, Switzerland, 3Advanced Clinical Imaging Technology, Siemens Healthcare AG, Lausanne, Switzerland, 4LTS5, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland |
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Current solutions for T1 mapping rely on 2D images of the heart, and require time-inefficient cardiac gating as well as long breath-holds. To address these drawbacks, a Free-running framework for fully self-gated cardiac and respiratory motion-resolved 5D imaging of the heart was extended to include T1 recovery contrast as a 6th dimension. The framework was tested at 3T in an ISMRM-NIST phantom and demonstrated good agreement between the estimated T1 values and reference standard. Preliminary 3D T1 maps in 3 healthy volunteers showed good resolution of the physiological motion and accurate T1 values of the myocardium and blood. |
| 786
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Pitch: 13:30 Poster: 14:30 Plasma 11
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Mitochondrial dysfunction in a rat model of doxorubicin-induced heart failure assessed by hyperpolarized 13C MRS |
1Physiology Anatomy and Genetics, University of Oxford, Oxford, United Kingdom, 2Oxford Centre for Magnetic Resonance, John Radcliffe Hospital, Oxford, United Kingdom, 3Department of Physics, University of Oxford, Oxford, United Kingdom, 4Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom, 5MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, United Kingdom |
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Doxorubicin-chemotherapy can lead to serious cardiac side effects in cancer-patients, culminating in heart failure. Cardiac oxidative stress and impaired energetics are hypothesized to be at the core of this toxicity. We established a clinically relevant rat model of doxorubicin-induced heart failure characterized with CINE MRI by decreased cardiac function. We show here that these functional changes are preceded by a shift from oxidative to anaerobic glucose metabolism measured with hyperpolarized MRS. These changes are likely due to a loss and impairment of mitochondria, which cannot be alleviated with the mitochondrially targeted antioxidant, MitoQ. |
| 787 | Pitch: 13:30 Poster: 14:30 Plasma 12
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Assessment of postinfarct myocardium metabolic degradation with amide proton transfer magnetic resonance imaging at 3 Tesla |
1Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China, 2Department of Radiology, West China Hospital, Sichuan University, Chengdu, China, 3Department of Cardiology, West China Hospital, Sichuan University, Chengdu, China, 4Department of Radiology, West China Second Hospital, Sichuan University, Chengdu, China |
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Myocardium ischemia irritates a series of metabolic degradations, including intracellular acidosis and cell damage. Amide proton transfer (APT) effect is associated with microenvironment acidosis and amide protons inside of cytoplasm. In this study, APT imaging was performed on MI patients at 3 Tesla. Results show significant APT effect reduction from the remote (4.29±2.00%), adjacent (2.74±1.18%) to the infarct (1.43±0.80%) regions (P<0.05), implying progressively metabolic alterations from surrounding tissue to the infarct core. The method provides a novel way for noninvasive assessment of myocardium metabolic degradation postinfarction, promising to facilitate therapeutic decision and treatment evaluation. |
| 788 | Pitch: 13:30 Poster: 14:30 Plasma 13
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A Deep Learning Based Left Atrium Anatomy Segmentation and Scar Delineation in 3D Late Gadolinium Enhanced CMR Images |
1National Heart and Lung Institute, Imperial College London, London, United Kingdom, 2Cardiovascular Research Centre, Royal Brompton Hospital, London, United Kingdom, 3Anhui University, Anhui, China, 4Department of Medical Imaging, Western University, London, ON, Canada, 5Department of Mathematics, University College London, London, United Kingdom, 6Alan Turing Institute, London, United Kingdom, 7NIHR Imperial Biomedical Research Centre, Imperial College London, London, United Kingdom, 8Department of Radiology, Beijing Anzhen Hospital, Beijing, China, 9School of Biomedical Engineering, Sun Yat-Sen University, Shenzhen, China |
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3D late gadolinium enhanced (LGE) CMR images of left atrial (LA) scar tissue can be used to stratify patients with atrial fibrillation and to guide subsequent ablation therapy. This requires a segmentation of the LA anatomy (usually from an anatomical acquisition) and a further segmentation of the scar tissue within the LA (from a 3D LGE acquisition). We propose a deep learning based framework incorporating multiview information and attention mechanism to solve both LA anatomy and scar segmentations simultaneously from a single 3D LGE acquisition. Compared to existing methods, we show improved segmentation accuracy (mean Dice=93%/87% for LA/scar). |
| 789 | Pitch: 13:30 Poster: 14:30 Plasma 14
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Simultaneous myocardial T1 and T2 mapping in 11 heartbeats using a radial sequence with inversion recovery and T2 preparation |
1Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 2Department of Medicine, Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 3Division of Cardiology, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, United States, 4Biomedical Physics Inter-Departmental Graduate Program, University of California, Los Angeles, Los Angeles, CA, United States |
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Myocardial T1 and T2 mapping are promising cardiovascular magnetic resonance (CMR) techniques for quantitative tissue characterization and provide complementary information. Simultaneous T1 and T2 mapping strategies are attractive because of shorter scan time and the potential for inherently co-registered T1/T2 maps. By estimating T1 and T2 at the same time, the T2/T1 bias present in conventional T1 and T2 mapping sequences can be minimized and more accurate T1 and T2 estimation accomplished. In this work, we sought to develop a simultaneous T1 and T2 mapping technique that can achieve high accuracy and precision, without heart-rate dependence, and with high reproducibility comparable to the standard MOLLI and conventional T2 mapping techniques. |
| 790 | Pitch: 13:30 Poster: 14:30 Plasma 15
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Diffusion Tensor CMR a potential early marker of remodelling after myocardial infarction |
1Royal Brompton Hospital, London, United Kingdom, 2Imperial College London, London, United Kingdom, 3National Institutes of Health, Bethesda, MD, United States |
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We performed a longitudinal large animal pre-clinical study to assess post-MI temporal alterations of myocardial microstructure, using Diffusion Tensor Cardiac Magnetic Resonance (DT-CMR). In vivo CMR was performed before, at 3 days, and 4 months after the reperfused MI procedure. Remodeled hearts demonstrated reduced right-handed helix angles in the endocardium of the infarct region, as well as a decreased gradient in the healix angle line profiles with associated thinning of the myocardium. Reduced sheetlet angle (E2A) mobility in the acute stage was associated with the development of adverse LV remodeling. |
| 791 | Pitch: 13:30 Poster: 14:30 Plasma 16
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Reconfigurable coil technology can substantially reduce RF heating of bilateral deep brain simulation leads during MRI at 1.5 T: First in-vitro studies with realistic implant trajectories |
1Northwestern University, Chicago, IL, United States, 2Department of Life Science Engineering, Institute of Medical Physics and Radiation Protection, Giessen, Germany, 3Massachusetts General Hospital, Charlestown, MA, United States, 4Albany Medical Center, Albany, NY, United States |
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Patients with deep brain stimulation (DBS) implants significantly benefit from MRI, however their access is restricted in these patients because of safety concerns due to RF heating of the leads. Recently we introduced a patient-adjustable reconfigurable MRI coil system that significantly reduced the SAR at the tip of single DBS leads (unilateral) in simulation studies during MRI at 1.5T. Here we present the first in-vitro measurements of RF heating-reduction performance of the coil system showing a significant reduction in heating of realistic bilateral DBS implants. |
| 792
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Pitch: 13:30 Poster: 14:30 Plasma 17
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MR Safety Watchdog for Safe Active Catheters: Wireless Impedance Controller with Real-time Feedback |
1Department of Radiology, Medical Physics, Medical Center ‐ University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany, 2German Cancer Consortium Partner Site Freiburg, German Cancer Research Center (DKFZ), Heidelberg, Germany, 3National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Turkey, 4Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany, 5Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey |
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RF-induced heating of implants or devices can be controlled through manipulation of their termination impedance which is dependent on the dielectric properties of the medium and the incident field configurations. We designed a wireless module that modifies the input impedance of an active catheter to keep the temperature increase below a threshold, ΔTmax. The wireless module monitors local heating at the tip of the catheter or can receive data from an external temperature measurement device to search for the optimal impedance that minimizes temperature rise. RF transmission is blocked via a feedback system when ΔTmax is exceeded. |
| 793
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Pitch: 13:30 Poster: 14:30 Plasma 18
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Explaining current patterns on linear metallic implants during MRI exams using the transfer matrix. |
1Center for Image Sciences, UMC Utrecht, Utrecht, Netherlands, 2Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands |
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Currents induced on relatively(<20cm) short linear metallic implants typically occur in certain patterns. Knowledge of these patterns can help current monitoring and identification of hazardous exposure conditions. The transfer matrix (TM) of an implant predicts what patterns will appear. The eigenvalues of the TM indicate which modes are induced naturally. The projection of the eigenvectors onto realistic incident electric fields obtained from electromagnetic simulations explain which modes are likely and effectively excited. Over 80% of electric field distributions excite the first eigenmode of the investigated structures more efficiently. Moreover, all severe currents follow the pattern of this first eigenmode. |
| 794 | Pitch: 13:30 Poster: 14:30 Plasma 19
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Lower risk of hearing loss without sacrificing image quality in fetal MR imaging: a feasibility study using acoustic reduction technique |
1The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China, 2MR Research China, GE Healthcare, Bei Jing, China |
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3.0T MR scanner can achieve superior image quality depicting fetal anatomic details over 1.5T, but may poses higher risk of adverse impact on fetal auditory development due to its intrinsically higher acoustic noise level. This comparative study investigated the value of acoustic noise reduction technique in fetal exam. The result shows the technique can acquire equivalent quality images in 3.0T scanner, meanwhile decrease hearing loss risk in fetal head examinations compared with the conventional method. |
| 795 | Pitch: 13:30 Poster: 14:30 Plasma 20
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Acquisition, reconstruction and uncertainty quantification of 3D non-rigid motion fields directly from k-space data at 100 Hz frame rate |
1UMC Utrecht, Utrecht, Netherlands |
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We introduce a method based on Gaussian Processes to rapidly acquire and reconstruct non-rigid motion fields of the human body directly from few points in k-space. Overall, the acquisition and processing time is less than 10 milliseconds for 3D applications leading to 100 Hz frame rate. Uncertainty quantification is also provided, making the method suitable for clinical real-time applications such as MR-guided radiation therapy. |
| 796
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Pitch: 13:30 Poster: 14:30 Plasma 21
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Creating a diffusion tractography-based atlas of human thalamic ventral intermediate nucleus aided by deep learning |
1Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States, 2Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States, 3Radiological Sciences Laboratory, Department of Radiology, Stanford University, Stanford, CA, United States |
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Tremor suppression in the hands of patients with essential tremor can be achieved by lesioning the ventral intermediate nucleus (Vim) of the thalamus using transcranial MR-guided focused ultrasound. Recent work has shown that diffusion MR tractography identifies the Vim more precisely and predicts the degree of tremor suppression. Here, we trained a convolutional neural network (CNN) to automatically segment relevant regions-of-interest including the thalamus, red nucleus, dentate nucleus and handknob region for probabilistic tractography to identify the Vim. We applied the CNN to 200 HCP healthy subjects and created a tractography-based atlas of Vim location, which could aid in neurosurgical guidance. |
| 797 | Pitch: 13:30 Poster: 14:30 Plasma 22
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Safety evaluation of human exposure to a 10.5T whole body magnet: protocol design and preliminary results. |
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 2Psychology, University of Minnesota, Minneapolis, MN, United States, 3School of Public Health Biostatistics, University of Minnesota, Minneapolis, MN, United States, 4Otolaryngology, Head and Neck Surgery, University of Minnesota, Minneapolis, MN, United States, 5Neurology, University of Minnesota, Minneapolis, MN, United States |
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We present the initial results of our 10.5T safety study measuring the impact on cognitive, vestibular, and physiological metrics. Data from 17 subjects show evidence of short term (same day) but no long term (weeks) fatigue, increased nystagmus upon initial exposure to static field, with no relevant effect on physiological measures when at isocenter. |
| 798 | Pitch: 13:30 Poster: 14:30 Plasma 23
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Residual magnetization of human subjects after exposure to magnetic fields |
1SIr Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom |
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It is known that subjects who have recently had an MRI scan can produce greater "magnetic noise" in magnetoencephalography (MEG) studies. We investigated this phenomenon, which may be related to remanent magnetization of magnetite particles that have been identified in post mortem tissue, by analyzing the field variation produced by controlled head movements in a MEG scanner, before and after subjects had been exposed to the local magnetic field of a small permanent magnet or inserted in a 3T magnet. The results show significant variability across subjects, but with a general elevation of the measured field variation after field exposure. |
| 799 | Pitch: 13:30 Poster: 14:30 Plasma 24
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Magnetic resonance shear wave elastography in cadaver breast |
1Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, United States, 2Bioengineering, University of Utah, Salt Lake City, UT, United States |
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Tissue stiffness is a known marker of malignancy and has been shown to change due to thermal therapies. A shear wave elastography technique compatible with magnetic resonance guided focused ultrasound technology is demonstrated in a cadaver breast specimen. Volumetric shear wave speed maps acquired using a multiple-point sonication pattern before and after an MRgFUS ablation demonstrate that a change in shear wave speed can be detected. This technique provides a functional stiffness metric that is complementary to currently used monitoring and assessment techniques in MRgFUS treatments. |
| 800
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Pitch: 13:30 Poster: 14:30 Plasma 25
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Localization of GPi for MRgFUS pallidotomy: a comparison between high-resolution FGATIR, R2* and QSM at 3 T |
1Radiology, University of Calgary, Calgary, AB, Canada |
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Precise localization of the internal globus pallidus (GPi) is critical for MRgFUS pallidotomy for movement disorders such as Parkinson’s disease. In this study, high-resolution FGATIR, R2* and QSM are compared for localizing GPi in six healthy subjects (age from 21 to 41). All three methods displayed some image contrasts in the GP area. QSM demonstrated the best delineation of GPi from the internal capsule, which is generally considered a risk zone for pallidotomy. GPi also appeared smaller in FGATIR, where GPi was hypointense, than in QSM, where GPi was hyperintense. |
| 801 | Pitch: 13:30 Poster: 14:30 Plasma 26
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Simultaneous Multislice MRI Temperature Imaging with a Single Receiver Coil |
1Biomedical Engineering, Vanderbilt University, Nashville, TN, United States |
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The incoherent controlled aliasing SMS method is introduced which increases volume coverage in real-time MR thermometry by acquiring multiple slices simultaneously, and requires only one receiver coil. RF pulses flip the slice phases between TRs, creating incoherent hotspot aliasing. Unaliased heating maps are then recovered from each slice using a sparsity-promoting temperature reconstruction. |
| 802 | Pitch: 13:30 Poster: 14:30 Plasma 27
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Predicting final lesion size using Thermometry information during MR-guided focused ultrasound treatment of Parkinson’s Disease |
1Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, United States |
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Recently, the MR-guided focused ultrasound technology (MRgFUS) offers the possibility to perform subthalamic thermal ablation with reduced risks and optimized accuracy. However, the ability to reliably predict lesion size is still evolving. The goal of this study was to improve the predictability of lesion size by thermal thresholding areas on MR thermometry during treatment procedures. |
| 803 | Pitch: 13:30 Poster: 14:30 Plasma 28
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First in Human: MRI-guided radiation therapy of the heart with implantable cardiac defibrillator |
1Radiation Oncology, Radiology, and Biomedical Engineering, Washington University in St Louis, St Louis, MO, United States, 2Radiation Oncology, Washington University in St Louis, St Louis, MO, United States, 3Cardiovascular Diseases and Electrophysiology, Washington University in St Louis, St Louis, MO, United States, 4Radiation Oncology, Barnes Jewish Hospital, St Louis, MO, United States, 5Radiation Oncology and Biomedical Engineering, Washington University in St Louis, St Louis, MO, United States, 6Cardiology, Loyola University Medical Center, Maywood, IL, United States |
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Low-field (0.35 T) magnetic resonance imaging guided radiation therapy (MR-IGRT) was used for the first time to treat a patient with a cardiovascular implantable electronic device (CIED) and a cardiac fibroma located on the left ventricle. Stereotactic body radiation therapy (SBRT) was delivered in 5 fractions at a dose of 700 cGy/fraction with MRI-based real-time tumor tracking and beam gating. Lessons learned include the need for metal artifact suppression, higher MRI temporal resolution, and MRI safety workflows adapted to radiation oncology. |
| 804 | Pitch: 13:30 Poster: 14:30 Plasma 29
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Feasibility of Thermo-Acoustic Ultrasound for Non-invasive Monitoring of Temperature at Lead Tips During MRI |
1Electrical Engineering, Stanford University, Stanford, CA, United States |
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The amplification of local SAR at device lead tips that causes RF-induced heating has previously been shown to be detectable using thermo-acoustic ultrasound (TAUS). Due to the temperature dependence of the thermal expansion coefficient in tissue, the thermo-acoustic pressure generated at a lead tip is a function of the temperature at the lead tip. By observing how the TAUS signal amplitude changes over time, real-time tracking of lead tip temperature during an MRI scan should be possible. Here, we experimentally demonstrate the temperature-dependence of the TAUS signal, showing the feasibility of TAUS for temperature monitoring at lead tips during MRI. |
| 805 | Pitch: 13:30 Poster: 14:30 Plasma 30
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Multinuclear Absolute MR Thermometry |
1Radiology, New York University School of Medicine, New York, NY, United States, 2Center for Advanced Imaging Innovation and Research (CAI2R), New York University School of Medicine, New York, NY, United States, 3Department of Chemistry, New York University, New York, NY, United States |
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Absolute MR thermometry has been unachievable clinically since the advent of MR and MR practitioners mostly rely on relative measurement of thermal changes using the proton resonance frequency shift method. Here, we introduce the JAMS method for reconstruction of absolute temperature using multinuclear frequency measurements. The method takes advantage of different frequency shifts with temperature of different nuclei (e.g. proton and sodium) for the reconstruction. Theory of the method is presented and proof-of-principle experiments validating the approach. |
| 806
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Pitch: 13:30 Poster: 14:30 Plasma 31
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3D Magnetic Resonance Fingerprinting with Quadratic RF Phase |
1Radiology, Case Western Reserve University, Cleveland, OH, United States, 2Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States |
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Magnetic Resonance Fingerprinting with quadratic RF phase (qRF-MRF) has previously been reported for simultaneous quantitative mapping of T1, T2 and T2* relaxation times and off resonance for 2D acquisitions. Translation of qRF-MRF to 3D bears practical limitations for reconstruction and dictionary matching due to increase in data and dictionary sizes. Here, randomized SVD based time compression and reduction in dictionary size with quadratic fit are combined to overcome prohibitively large datasets and long reconstruction times of 3D qRF-MRF. Whole brain 3D qRF-MRF can be acquired in 5 minutes and is compared to 2D qRF-MRF and 3D FISP. |
| 807 | Pitch: 13:30 Poster: 14:30 Plasma 32
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Deep MR Fingerprinting with total-variation and low-rank subspace priors |
1Computer Science department, University of Bath, Bath, United Kingdom, 2Computer Science department, Technische Universität München, Munich, Germany, 3GE Healthcare, Munich, Germany, 4Imago7 Foundation, Pisa, Italy, 5School of Bioengineering, Technische Universität München, Munich, Germany |
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Deep learning (DL) has recently emerged to address the heavy storage and computation requirements of the baseline dictionary-matching (DM) for Magnetic Resonance Fingerprinting (MRF) reconstruction. Fed with non-iterated back-projected images, the network is unable to fully resolve spatially-correlated corruptions caused from the undersampling artefacts. We propose an accelerated iterative reconstruction to minimize these artefacts before feeding into the network. This is done through a convex regularization that jointly promotes spatio-temporal regularities of the MRF time-series. Except for training, the rest of the parameter estimation pipeline is dictionary-free. We validate the proposed approach on synthetic and in-vivo datasets. |
| 808 | Pitch: 13:30 Poster: 14:30 Plasma 33
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Cardiac motion resolved Magnetic Resonance Fingerprinting with joint reconstruction: jMORE-MRF |
1School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 2Philips Healthcare, Guilford, United Kingdom, 3Philips Research Europe, Hamburg, Germany |
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ECG-triggered cardiac Magnetic Resonance Fingerprinting (cMRF) has been proposed to provide simultaneous myocardial T1 and T2 mapping from a single scan. A “free-running” motion-resolved cardiac MRF (MORE-MRF) approach has been recently introduced to provide T1 and T2 myocardial characterization over the entire cardiac cycle. Here we propose to improve MORE-MRF by exploiting redundancy between the different cardiac phases within a novel motion resolved multi-contrast reconstruction framework. The feasibility of this joint MORE-MRF approach (jMORE-MRF) was evaluated in phantom and healthy subjects and compared against conventional T1 and T2 mapping techniques. |
| 809
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Pitch: 13:30 Poster: 14:30 Plasma 34
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In Vivo Multi-Color Magnetic Resonance Fingerprinting |
1Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 2Radiology, Case Western Reserve University, Cleveland, OH, United States, 3Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, OH, United States, 4NanoEngineering, University of California-San Diego, La Jolla, CA, United States, 5Radiology, University of California-San Diego, La Jolla, CA, United States, 6Neurosciences, Case Western Reserve University, Cleveland, OH, United States, 7Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, United States, 8Pediatrics, Case Western Reserve University, Cleveland, OH, United States |
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Contrast enhanced MRI studies are currently limited to observing a single contrast agent at a time. Meanwhile, optical imaging methods frequently utilize multiple fluorophores in “multi-color” imaging studies to track multiple molecular events simultaneously. We propose the novel DC-MRF method as a way to realize an analagous “multi-color” MRI. Herein, we demonstrate the first in vivo application of multi-color MRF and validate its ability to accurately and dynamically map the concentration of multiple contrast agents in vivo. This method creates the opportunity to perform a wide range of novel multi-agent MRI studies that immediately broadens the scope of contrast enhanced MRI. |
| 810
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Pitch: 13:30 Poster: 14:30 Plasma 35
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Simultaneous Pseudo-CT and Parametric Mapping of Human Brain Using Dual Echo Ultrashort Echo Time MR Fingerprinting (deUTE-MRF) |
1Center for Brain Imaging Science and Technology, Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrumental Science, Zhejiang University, Hangzhou, China, 2State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, China, 3Department of Imaging Sciences, University of Rochester, Rochester, NY, United States |
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A dual echo ultrashort echo time MR fingerprinting (deUTE-MRF) sequence is proposed to simultaneously generate |
| 811 | Pitch: 13:30 Poster: 14:30 Plasma 36
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T1, T2, and T1ρ Magnetic Resonance Fingerprinting of the Abdomen |
1Department of Diagnostic Radiology, Oregon Health and Science University, Portland, OR, United States, 2Advanced Imaging Research Center, Oregon Health and Science University, Portland, OR, United States |
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T1p relaxation mapping is an intensive technique in terms of acquisition time and specific absorption rate (SAR), making it difficult to acquire in the abdomen. In this study, magnetic resonance fingerprinting (MRF) techniques are applied to simultaneously acquire T1, T2, and T1p relaxation times by adding spin lock pulses before periods of flip angle and TR modulation. MRF and conventional sequences were acquired in phantoms and the abdomen of healthy volunteers. Good agreement was found between the T1, T2, and T1p values from MRF and conventional sequences. |
| 812 | Pitch: 13:30 Poster: 14:30 Plasma 37
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Flexible and Efficient Cramér-Rao Bound Optimization for Magnetic Resonance Fingerprinting using Automatic Differentiation of Bloch Simulations |
1Electrical Engineering, Stanford University, Stanford, CA, United States, 2Radiology, Stanford University, Stanford, CA, United States, 3Bioengineering, Stanford University, Stanford, CA, United States, 4IRCCS Fondazione Stella Maris and Fondazione Imago7, Pisa, Italy |
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The Cramér-Rao Lower Bound (CRLB) is a metric for optimizing quantitative sequences that requires an analytical expression for the signal. The CRLB for Magnetic Resonance Fingerprinting (MRF) has a complex formulation that makes it difficult to account for system imperfections or relevant signal contributions such as diffusion. We apply automatic differentiation to Bloch simulations and choose flip angles and repetition times that optimize the CRLB of the MRF sequence without deriving an explicit analytical expression for the signal. This method is computationally efficient and can easily be extended to include B0 and B1 inhomogeneities. Results are validated with in-vivo measurements. |
| 813 | Pitch: 13:30 Poster: 14:30 Plasma 38
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Parameter Encoding Efficiency in Transient and Steady-State Quantitative MRI Methods |
1Biomedical Engineering Department, School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 2Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom |
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This work proposes a neutral measure of encoding efficiency per square-root of time excluding any effects of image reconstruction from the analysis in order to compare spoiled gradient-echo based Magnetic Resonance Fingerprinting and steady-state methods for $$$T_1$$$ and $$$T_2$$$ estimation. The results obtained indicate that gradient spoiled Fingerprinting is up to $$$50\%$$$ more efficient per square-root-time than steady-state methods. The optimal sequences of pulses found have striking features with different duration fingerprint strategies having highest efficiency under different boundary conditions. |
| 814 | Pitch: 13:30 Poster: 14:30 Plasma 39
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Understanding the combined effect of k-space undersampling and transient states excitation in MR Fingerprinting reconstructions: the role of incoherence |
1KdV Institute for Mathematics, University of Amsterdam, Amsterdam, Netherlands, 2University Medical Center Utrecht, Utrecht, Netherlands |
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The main characteristic of an MRF sequence is the simultaneous application of (a) transient states excitation and (b) highly undersampled k-space. Despite the promising empirical results obtained with MRF, no work has appeared that formally describes the combined impact of these two aspects on the reconstruction accuracy. We derive a mathematical model that directly relates the time varying RF excitation and the k-space sampling to the spatially dependent reconstruction errors. An in-depth analysis of the model reveals that, analogously to the compressed sensing framework, incoherence plays a fundamental role also in MRF. |
| 815 | Pitch: 13:30 Poster: 14:30 Plasma 40
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Rapid protocol for T1 and T2* mapping: STrategically Acquired Gradient Echo (STAGE) at 1.5 T MRI |
1IRCCS Fondazione Don Carlo Gnocchi, Milano, Italy, 2Radiology, Wayne State University, Detroit, MI, United States, 3The MRI Institute for Biomedical Research, Bingham Farms, MI, United States, 4Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy |
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Multi-contrast quantitative mapping has become an important research direction for characterizing brain tissue in physiological and pathological conditions. A rapid quantitative mapping acquisition is fundamental for its application in clinical routine. In this study, we adapted the STrategically Acquired Gradient Echo (STAGE) protocol for a clinical 1.5T MRI scanner. Using STAGE, we reconstructed longitudinal and effective transverse relaxation time maps. We obtained values similar to those in the literature in different brain structures with high repeatability. These results suggest that STAGE can be used at 1.5T and provide a variety of quantitative maps with an acquisition time of 7 minutes. |
| 816 | Pitch: 13:30 Poster: 14:30 Plasma 41
|
Chasing True FLAIR: a three-component Magnetic Resonance Fingerprinting approach to synthetic MRI |
1Department of Physics, University of Pisa, Pisa, Italy, 2IMAGO7 Foundation, Pisa, Italy, 3IRCCS Stella Maris, Pisa, Italy, 4Computer Science, Technische Universität München, Munich, Germany, 5GE Healthcare, Munich, Germany |
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MR Fingerprinting is a multiparametric imaging technique which allows to obtain several parametric maps of tissue, such as Proton Density and T1/T2 maps, within a single fast acquisition in transient-state. These maps can be used to synthesize a whole set of different contrast-weighted images, potentially substituting an entire conventional protocol. However, these synthetic images suffer from artifacts due to partial volume effects. This is particularly true for FLuid Attenuated Inversion Recovery (FLAIR) images. Here, we modify the signal model to account for CSF and flowing blood, correcting these artifacts, and we compared the resulting synthetic FLAIR to true FLAIR images. |
| 817 | Pitch: 13:30 Poster: 14:30 Plasma 42
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Rapid open source prototyping of Magnetic Resonance Fingerprinting using Pulseq to enable multi-site two vendor studies |
1Columbia University MR research center, Columbia University, New York, NY, United States, 2Functional MRI Laboratory, University of Michigan, Ann Arbor, MI, United States |
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This work develops an open source package that allows for rapid prototyping of magnetic resonance fingerprinting (MRF) using Pulseq. In this work, an inversion recovery steady state free precession (IR-SSFP) sequence is designed in Pulseq. TR, flip angles, and TE are selected to achieve variations of contrast. The sequence was implemented, simulated, and applied on five health volunteer brain scans. The scan time of one subject for single slice sequence was 35 seconds. The data was sliding window reconstructed and matched with the simulated dictionary. The dictionary matching shows similar T1 and T2 results as reported in literature. |
| 818 | Pitch: 13:30 Poster: 14:30 Plasma 43
|
Deep Learning for Magnetic Resonance Fingerprinting: Data Augmentation with Phase Encoding and SVD Preprocessing for Accurate Parameter Reconstruction of FISP Data. |
1Department of Physics and Astronomy, Univeristy of Bologna, Bologna, Italy, 2Department of Radiology, Stanford, Stanford, CA, United States, 3Department of Electrical Engineering, Stanford, Stanford, CA, United States, 4Department of Physics and Astronomy, University of Bologna, Bologna, Italy, 5Department of Radiology, Stanford University, Stanford, CA, United States, 6Department of Bioengineering, Stanford University, Stanford, CA, United States, 7Department of Electrical Engineering, Stanford University, Stanford, CA, United States, 8University of Bologna, Bologna, Italy, 9Department of Biomedical and NeuroMotor Sciences, University of Bologna and Functional MRUnit, Policlinico S. Orsola - Malpighi, Bologna, Italy |
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Dictionary size limits the number of parameters one can aim to estimate with Magnetic Resonance Fingerprinting (MRF) Deep Neural networks (NN) have been recently proposed for MRF applications, both with numerical simulationsand with phantoms and in-vivo acquisitions. With real-valued NNs only the magnitude of the MRF signal has been considered as input. This choice releases from the need of considering the phase of the signal during training but can affect noise robustness and signal differentiation due to loss of information. In this work we propose a strategy to train a real valued NN that takes the real and imaginary parts of an MRF-FISP signal as input. We also propose to use SVD as preprocessing step for noise reduction. The presented results may help the developing of deep learning approaches for MRF, pushing fingerprinting pulse sequences design to add more meaningful MR parameters, such as diffusion, with no more limitations due to the dictionary size. |
| 819 | Pitch: 13:30 Poster: 14:30 Plasma 44
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Exploring the Accuracy of MR Vascular Fingerprinting: Potential Pitfall and Possible Remedy |
1Medical Biophysics, University of Toronto, Toronto, ON, Canada, 2Rotman Research Institute, Baycrest Health Sciences, Toronto, ON, Canada, 3Grenoble Institute of Neurosciences, Inserm, Grenoble, France, 4Radiology, Stanford University, Stanford, CA, United States |
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MR vascular fingerprinting ( |
| 820 | Pitch: 13:30 Poster: 14:30 Plasma 45
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Deep learning based MR fingerprinting ASL ReconStruction (DeepMARS) |
1Tsinghua University, Beijing, China, 2Johns Hopkins University, Baltimore, MD, United States, 3New York University, New York, NY, United States, 4School of Biomedical Engineering and Imaging Sciences, King's College London, London, London, United Kingdom |
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The purpose of this study is to develop a MRF-ASL reconstruction algorithm using deep learning (DeepMARS). Compared with the traditional dictionary matching, our DeepMARS achieved higher intra-class correlation (ICC) in B1 (0.971 vs 0.921) and BAT (0.926 vs 0.761), similar ICC in T1 (0.957 vs 0.964) and CBF (0.936 vs 0.948) in the reproducibility test with much shorter calculation time per voxel (0.368 ms vs 2.899 s), suggesting that our DeepMARS may be a better alternative than the conventional MR dictionary matching approach. |
13:30
|
Methods for Cell Tracking | |
1Michigan State University, United States |
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MRI has proven to be a powerful imaging modality for non-invasive, whole body imaging, with meaningful image resolution for studying cellular dynamics. MRI contrast is generated by capitalizing on differences in water molecule microenvironment, including diffusion rate and direction, magnetic field differences, and water content. In order to use MRI to distinguish a unique population of cells from other cells in the body, such as a cell transplant, or the infiltration of immune cells to a disease, one of these properties needs to be altered, or a tracer needs to be introduced. This will generate contrast or signal from these cells. |
14:00
|
Clinical Applications of MR Cell Tracking | |
1Johns Hopkins University, Baltimore, MD, United States |
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MRI is expected to play a key role in evaluating the outcome of clinical trials based on stem and immune cell therapy. In order to facilitate and implement the translation of these therapies into the clinic, it will be necessary to monitor the immediate cellular engraftment, subsequent biodistribution and migration, and cell survival and differentiation non-invasively over time. |
| 821 | 14:30
|
In vivo MRI tracking of stem-cell-derived extracellular vesicles |
1Department of Radiology, Johns Hopkins University, Baltimore, MD, United States, 2FM. Kirby center, Kennedy Krieger Institute, Baltimore, MD, United States, 3Institute for Cell Engineering and Department of Medicine, Johns Hopkins University, Baltimore, MD, United States, 4Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States |
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Induced pluripotent stem cell (iPSC) derived extracellular vesicles (EVs) constitute a new class of cell-free regenerative medicine. Non-invasive tracking of the delivery and in vivo distribution of EVs is highly desirable. Traditional labeling methods suffer from either low labeling efficiency or difficulty with purification. Here, we report a new labeling strategy using surface-functionalized magnetic particles, in which the nonencapsulated magnetic particles can be easily separated from the labeled EVs, allowing the preparation of magnetically labeled EVs with high purity. We then demonstrate in vivo tracking of magnetically labeled EVs in the kidney and liver using MRI. |
| 822 | 14:42
|
Multimodality OATP1B3-enhanced reporter gene imaging of engineered cells via fluorescence, photoacoustic, and magnetic resonance imaging |
1Medical Imaging Laboratories, Robarts Research Institute, London, ON, Canada, 2Medical Biophysics, University of Western Ontario, London, ON, Canada, 3Lawson Health Research Institute, London, ON, Canada |
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Reporter genes can generate information on cell fate in vivo. Multimodality imaging can mitigate limitations of individual imaging modalities; thus, multimodality reporters are highly sought. We present a trimodality reporter gene system based on human Organic Anion-Transporting Polypeptide 1b3 (Oatp1b3) and its ability to take up indocyanine green (ICG) for fluorescence and photoacoustic imaging, as well as gadolinium ethoxy benzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) for MRI. This technology should find utility in tracking cell- and gene-based therapies for preclinical studies, and due to the human-derivation of the reporter gene and already clinically-utilized probes, presents with high translational potential. |
| 823 | 14:54
|
Chimeric Mouse Model for MRI Contrast Agent Evaluation |
1Department of Radiology, Michigan State University, East Lansing, MI, United States, 2Institute of Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, United States, 3Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, United States |
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While rodents are the primary models for contrast agent evaluation, there is considerable variability in pharmacokinetics of contrast agents in mice vs humans. OATPs play a role in in vivo pharmacokinetics in mice and humans. This study provides evidence that the OATP1B1/1B3 knock-in mouse is a more useful screening tool for novel MRI contrast agents destined for clinical use as compared to the traditionally used wild-type models. |
| 824
|
15:06
|
MEMRI Can Quantify Myocardial Infarct Size Earlier Than LGE-MRI |
1Division of Medicine, Centre for Advanced Biomedical Imaging, University College London, London, United Kingdom, 2School of Medical Imaging, Universiti Sultan Zainal Abidin, Terengganu Darul Iman, Malaysia, 3Hatter Cardiovascular Institute, University College London, London, United Kingdom |
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Late gadolinium enhanced MRI (LGE-MRI) is an established method for quantification of infarct size after myocardial infarction but is non-specific and reflects the increased membrane rupture and extracellular volume (ECV) that occurs several hours after myocardial infarction. Manganese (Mn2+) is an efficient intracellular MR contrast agent, which acts as an analogue of Calcium (Ca2+) and can provide information on cell viability. The present study shows that manganese-enhanced MRI (MEMRI) can quantify the final infarct size earlier than LGE-MRI. |
| 825 | 15:18
|
Magnetic resonance molecular imaging of EDB fibronectin with a ZD2 peptide Gd(HP-DO3A) conjugate for detecting pancreatic cancer |
1Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 2Radiology, Johns Hopkins University, Baltimore, MD, United States |
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Pancreatic cancer (PC) carries a poor prognosis, partially due to lack of early diagnosis. To address this unmet need, the potential of magnetic resonance molecular imaging of extradomain B fibronectin with an oligopeptide targeted MRI contrast agent was assessed in mouse models of PC. Four PC cell lines were assayed for EDB-FN expression in vitro and found to overexpress EDB-FN. Analysis of ZD2 binding and contrast enhanced MRI demonstrated over two-fold improvement in CNR compared to non-targeted gadoteridol, with little non-specific binding. Histological analysis revealed the expression of EDB-FN in the tumor microenvironment and confirmed the features observed on MRI |
15:30
|
Adjournment |
13:30
|
Assessment of Functional Recovery After Stroke: Connectivity | |
1Neurology, Max Planck Institute for Human Cognitive and Brain Science, Leipzig, Germany |
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Symptoms after stroke are not only determined by location and extent of a lesion, but also by alterations of connectivity. Such changes have been assessed with functional connectivity MRI (fcMRI) based on resting-state recordings. Here, different fcMRI approaches are reviewed ranging from interhemispheric connectivity in one network, simultaneous assessment of many networks to methods based on graph theory. A recent approach overcomes the notion of “fixed separate connectivity networks” but assumes a multidimensional connectivity space (Margulies et al. PNAS 2016). As a perspective, fcMRI will allow to tailor brain stimulation therapies to the pathophysiological state of the individual patient. |
13:50
|
Mapping Asymmetrically Prominent Cortical Veins & Microbleeds Using SWI & QSM | |
1Wayne State University MR Core Facility, United States |
14:05
|
Self Assessment Module (SAM) |
14:10
|
Intracranial Collaterals: The Role of MRI | |
1Chinese PLA General Hospital, China |
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Studies have found collateral circulation was correlated with progression of stroke and clinical outcome. Many advanced imaging approaches appeared regarding the intracranial collaterals, including DSA, CT and MR. Specifically, the newly developed MR sequences, including multiphase contrast enhanced MR angiography, ASL and vessel-encoded ASL etc. have been used in the visualization of collaterals. Additionally, some conventional MR sequences have also been found useful. Learning what MR can do in the field of collaterals is of paramount importance. Application of MR techniques in intracranial collaterals may help elucidate pathophysiological characteristics of collaterals and enhance the therapeutic and prognostic performance in stroke patients. |
| 826
|
14:30
|
Choroid plexus perfusion MRI indicates cerebrospinal fluid production changes after surgically-manipulated vascular tone: implications for glymphatic flow |
1Radiology and Radiological Sciences, Vanderbilt University School of Medicine, Nashville, TN, United States, 2Neurology, Vanderbilt University School of Medicine, Nashville, TN, United States, 3Psychiatry, Vanderbilt University School of Medicine, Nashville, TN, United States |
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The objective of this study was to determine if a feedback circuit between CSF production and arterial health may exist in the human brain. Sequential measurements of CSF volume were obtained, as well as cortical and choroid plexus function measured from pseudo-continuous arterial spin labeling (pCASL) before and after clinically-indicated indirect surgical revascularization. Regression analyses were used to evaluate dependence of study parameters on time. Following surgically-induced angiogenesis, fronto-parietal perfusion increased, which paralleled a reduction in choroid plexus perfusion. This could reflect a homeostatic mechanism where improved perivascular flow and more robust waste clearance prompts decreased choroid plexus CSF production. |
| 827 | 14:42
|
Radiomic analysis on symptomatic and asymptomatic intracranial atherosclerotic plaque using high resolution MRI |
1Radiology, Changhai Hospital, Shanghai, China, 2Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, 3Radiology, Changhai Hosptial, Shanghai, China |
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This study aims to evaluate a quantitative radiomic approach including texture analysis based on HR-MRI to differentiate acute symptomatic plaque from asymptomatic plaque. 158 patients with middle cerebral artery and basilar artery stenosis underwent HR-MRI. The stenosis value, plaque area/burden, lumen area, intraplaque hemorrhage (IPH), contrast enhancement ratio and 109 quantitative radiomic features were extracted. Multivariate logistic analysis and a random forest model were performed. The result was shown that smoking, IPH and enhancement ratio were independently associated with symptomatic plaques. Radiomic features in T2, T1 and CE-T1 images were associated with symptomatic plaques, whose AUC respectively are 0.801,0.835 and 0.846. The combined all radiomic approach had a significantly higher AUC of 0.953. Combination of all features reached an AUC of 0.976, with accuracy of 87.4%. Radiomic analysis accurately distinguished between acutely symptomatic plaques and asymptomatic plaques. |
| 828
|
14:54
|
Reperfusion into Severely Damaged Brain Tissue is Associated with Impending Parenchymal Hemorrhage in Recanalized Acute Ischemic Stroke Patients |
1Stevens Institute of Neuroimaging and Informatics, University of Southern California, Los Angeles, CA, United States, 2Neurology, UCLA, Los Angeles, CA, United States, 3Neurosurgery, Beijing Tiantan Hospital, Beijing, China, 4Radiology, UCLA, Los Angeles, CA, United States, 5Radiology, Chinese PLA General Hospital, Beijing, China |
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While timely reperfusion can reduce more extensive brain tissue injury by salvaging reversibly damaged penumbra, late recanalization also carries the risk of causing additional and substantial brain damage, such as ischemia-reperfusion injury, compared with no revascularization. The reperfusion status after thrombolysis within the DWI lesion territory and its relationship with HT is unclear, leaving the details regarding post-treatment care unspecified. In this study, we aim to quantify the volume of reperfusion into severely damaged brain tissue and investigate its predictive value for impending parenchymal hematoma following recanalization. |
| 829
|
15:06
|
Supervised Learning Techniques Applied to Multi-modal Functional Neuroimaging Data Have Promise for Infarct Prediction |
1Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States, 2Neurosurgery, Vanderbilt University Medical Center, Nashville, TN, United States, 3Pediatric Neurology, Vanderbilt University Medical Center, Nashville, TN, United States |
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Common functional imaging approaches such as cerebral blood flow-weighted arterial spin labeling and cerebrovascular reactivity-weighted blood oxygenation level-dependent MRI are susceptible to quantification errors when applied to patients with significant arterial steno-occlusive disease, due to artifacts that result from delayed blood arrival and arteriolar rigidity. Recently it was suggested that the artifacts from standard quantitation approaches can be exploited together with machine learning algorithms to localize regions of hemodynamic impairment as defined by gold standard catheter angiography. Here, we investigate whether similar algorithms can be applied to identify spatial regions that progress to infarction in a longitudinal study. |
| 830
|
15:18
|
Dual Contrast MRI for Visualization of Whole Brain Macro and Microvascular Remodeling in Rat Ischemic Stroke Model |
1Department of Biomedical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Korea, Republic of |
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Because of therapeutic and prognostic significance, the visualizations and quantifications of vascular remodelings are crucial for ischemic stroke brains. In this work, dual contrast MRI was implemented on tMCAO rats as an ischemic stroke model to visualize whole-brain macro- and micro-vascular remodeling. In additional to R1 based UTE-MRA, which showed macrovascular remodeling, simultaneously acquired VSI, Q and MVD metrics from ΔR2-ΔR2*-MRI showed microvascular remodeling in ischemic reperfused rat brains. |
15:30
|
Adjournment |
| 831 | 13:30
|
Spherical U-Net for Infant Cortical Surface Parcellation |
1Key Laboratory of Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou, China, 2Department of Radiology and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, 3Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States |
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In neuroimaging studies, it is of great importance to accurately parcellate cortical surfaces (with a spherical topology) into meaningful regions. In this work, we propose a novel end-to-end deep learning method by formulating surface parcellation as a semantic segmentation task on the spherical space. To extend the convolutional neural networks ( |
| 832 | 13:42
|
Segmentation-aware adversarial synthesis for registration of histology to MRI |
1Centre for Medical Image Computing, Dept. of Med. Phys. and Biomed. Eng., University College London, London, United Kingdom, 2Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN, United States |
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MRI-histology registration lays the ground for a new generation of high-resolution brain atlases. The task is challenging given the different contrast and the histology-related artifacts. We propose a dataset-specific, synthesis-based approach that uses a generative adversarial network to reduce the problem to intra-modality registration. Exploiting automatic segmentation data and cycle-consistency, the proposed architecture is suitable for small-size datasets. We show the advantages of this approach compared to canonical registration both in quantitative and qualitative terms using data from the Allen Institute’s Human Brain Atlas. |
| 833
|
13:54
|
A Cascaded Residual UNET for Fully Automated Segmentation of prostate and peripheral zone in T2-weighted 3D Fast Spin Echo Images |
1Electrical and Computer Engineering, University of Arizona, Tucson, AZ, United States, 2Department of Medical Imaging, University of Arizona, Tucson, AZ, United States, 3Biomedical Engineering, University of Arizona, Tucson, AZ, United States |
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Multi-parametric MR images have been shown to be effective in the non-invasive diagnosis of prostate cancer. Automated segmentation of the prostate eliminates the need for manual annotation by a radiologist which is time consuming. This improves efficiency in the extraction of imaging features for the characterization of prostate tissues. In this work, we propose a fully automated cascaded deep learning architecture with residual blocks (Cascaded MRes-UNET) for segmentation of the prostate gland and the peripheral zone in one pass through the network. The network yields high dice scores (mean=0.91) with manual annotations from an experienced radiologist. The average difference in volume estimation is around 6% in the prostate and 3% in the peripheral zone. |
| 834 | 14:06
|
SuperSurfer: Cortical surface reconstruction using super-resolution anatomical MR images synthesized by deep learning |
1Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States, 2Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States, 3Radiological Sciences Laboratory, Department of Radiology, Stanford University, Stanford, CA, United States |
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Recent studies have shown that anatomical MR images with sub-millimeter resolution can improve the accuracy of cortical surface and thickness estimation compared to the standard 1-millimeter isotropic resolution. Here we propose a new method, entitled SuperSurfer, that synthesizes sub-millimeter anatomical MR images from standard 1-mm isotropic anatomical images using a convolutional neural network-based super-resolution approach intended for improved cortical surface reconstruction. We quantified the displacement of the reconstructed surfaces and difference in cortical thickness derived from the super-resolution and standard-resolution data and demonstrated that SuperSurfer provides improved cortical surfaces that are similar to those obtained from native sub-millimeter resolution data. |
| 835 | 14:18
|
Radiomic features from enhancing tumor on pre-treatment multiparametric MRI scans are predictive of response to chemo-radiation therapy in Glioblastoma and are associated with histological phenotypes |
1Case Western Reserve University, Cleveland, OH, United States, 2Cleveland Clinic, Cleveland, OH, United States |
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We presented the initial results of employing 3D radiomic descriptors from pre-treatment MP-MRI scans for tumor risk stratification based on patient’s response to chemo-radiation treatment. We demonstrated that the CoLlAGe (captures tumor heterogeneity) and Laws (captures Levels, waves, and ripple appearances) features from the enhancing region were most predictive of response to CRT. These features were also found to be associated with histologic attributes including cellular tumor, infiltrating tumor, and hyperplastic blood vessels, each of which is known to contribute to treatment resistance in the tumor microenvironment |
| 836 | 14:30
|
Automated Analysis of MR Elastography and Quantitative Fat-Water Imaging |
1Radiology, Mayo Clinic, Rochester, MN, United States, 2Gastroenterology, Mayo Clinic, Rochester, MN, United States |
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Evaluation of liver health with quantitative MRI addresses an issue of major global importance. This work extends ALEC, a previously validated automated method for defining ROIs and reporting liver stiffness from MR elastography images, to reporting fat fraction and R2* from multipoint Dixon images. The tool achieves excellent correlation with an expert reader in 102 clinical exams and allows multiparametric quantitative liver MRI exams to be analyzed in a highly reproducible way within 5 minutes. |
| 837 | 14:42
|
Super-resolution 3D MRSI for Mapping 2HG and Tumor Metabolism in Patients with Mutant IDH Glioma |
1A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 2Harvard Medical School, Boston, MA, United States, 3iCAD, Nashua, NH, United States, 4Department of Neurosurgery, Massachusetts General Hospital, Charlestown, MA, United States, 5Department of Neurology, Massachusetts General Hospital, Charlestown, MA, United States |
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To improve the spatial resolution of 3D MRSI, a feature-based nonlocal means approach utilizing the structural information of high-resolution MR images is proposed. By estimating similarity between voxels using a feature vector that characterizes the laminar pattern of brain structures, a more accurate similarity measure is achieved compared to conventional upsampling methods. The preliminary results on simulated and in vivo data indicate the proposed method has great potential for clinically neuroimaging applications. |
| 838
|
14:54
|
Evaluating multi-site rCBV consistency from DSC-MRI imaging protocols and post-processing software across the NCI Quantitative Imaging Network sites using a Digital Reference Object |
1Barrow Neurological Institute, Phoenix, AZ, United States, 2Washington University in St. Louis, St. Louis, MO, United States, 3Medical College of Wisconsin, Milwaukee, WI, United States, 4Mayo Clinic, Rochester, MN, United States, 5The University of Texas at Austin, Austin, TX, United States, 6University of Michigan, Ann Arbor, MI, United States, 7University of Texas Health Science Center at San Antonio, San Antonio, TX, United States, 8Mayo Clinic, Scottsdale, AZ, United States, 9Rhode Island Hospital and Alpert Medical School of Brown University, Providence, RI, United States, 10Massachusetts General Hospital, Boston, MA, United States, 11University of Washington, Seattle, WA, United States, 12The University of Texas Southwestern, Dallas, TX, United States, 13Philips, Gainesville, FL, United States |
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Differences in imaging protocols (IP) and post-processing methods (PM) may influence relative cerebral blood volume (rCBV). Our goal was to leverage a dynamic susceptibility contrast (DSC) DRO to characterize rCBV consistency across 12 sites, focusing on differences due to site-specific IPs and/or PMs. Our results indicate high agreement when one center processes rCBV despite slight variations in the IP. However, substantial disagreement was observed when site-specific software was applied for rCBV measurements. These results have important implications for comparing DSC-MRI data across sites/trials, where PM variability could confound the use of rCBV as a biomarker of therapy response. |
| 839 | 15:06
|
A Deep Learning Approach for Image Quality Assessment of Fetal Brain MRI |
1Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States, 2Harvard-MIT Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States, 3Computer Science and Artificial Intelligence Laboratory (CSAIL), Massachusetts Institute of Technology, Cambridge, MA, United States, 4Fetal-Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Boston, MA, United States, 5Harvard Medical School, Boston, MA, United States, 6Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, United States |
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Fetal MRI plays a critical role in diagnosing brain abnormalities but routinely suffers from artifacts resulting in nondiagnostic images. We aim to automatically identify nondiagnostic images during acquisition so they can be immediately flagged for reacquisition. As a first step, we trained a neural network to classify T2-weighted single-shot fast spin-echo (HASTE) images as diagnostic or nondiagnostic. With novel data, the average Area Under Receiver Operator Characteristic Curve was 0.84 (σ = 0.04). The neural network learned relevant criteria, identifying high contrast boundaries between areas like cerebral spinal fluid and cortical plate as relevant to determining image quality. |
| 840 | 15:18
|
Automated Deep Learning based 3D Hip Segmentation in PD-weighted MR images of a large-scale cohort study |
1Department of Radiology, University Hospital Tübingen, Tübingen, Germany, 2Institute of Signal Processing and System Theory, University of Stuttgart, Stuttgart, Germany, 3School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom |
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Analysis of geometrical and structural properties of the hip is of great importance to allow for meaningful comparison of significant findings. Especially with regard to large cohort studies manual processing of large 3D volumes becomes infeasible and thus automated processing is required. In this work, a Deep Learning driven algorithm is proposed which performs automated hip segmentation of 3D MRI datasets, requiring few training data and being able to perform accurate semantic bone segmentation in spite of complex anatomical structures sharing similar tissue characteristics. |
| 841
|
13:30
|
Improving temporal resolution of 3D Arterial Spin Labeling perfusion imaging by combining CAIPIRINHA encoding and spatio-temporal TGV reconstruction |
1Institute of Medical Engineering, Graz University of Technology, Graz, Austria, 2Laboratory of FMRI Technology (LOFT), Mark & Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States, 3Institute of Mathematics and Scientific Computing, University of Graz, Graz, Austria, 4BioTechMed-Graz, Graz, Austria |
||
Pseudo-continuous arterial spin labeling combined with 3D segmented readouts is recommended for acquiring ASL perfusion data. However, the total number of k-space encodings limits the trade-off between motion sensitivity and image blurring. To tackle this problem we implemented an accelerated 3D-GRASE sequence with a time-dependent 2D-CAIPIRINHA sampling pattern to increase the temporal incoherence between averages or PLDs. High quality images can be gained from the under-sampled time series by a variational image reconstruction approach with total-generalized-variation (TGV) regularization in space and time. This allows acquisition of single-shot 3mm isotropic ASL data with whole brain coverage within 1min22sec. |
| 842 | 13:42
|
High-resolution whole brain ASL perfusion imaging using variably undersampled Cartesian Fast-Spin-Echo and Compressed Sensing reconstruction |
1Division of MRI research, Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States, 2Diagnostic Imaging and Radiology, Children’s National Medical Center, Washington DC, DC, United States |
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3D whole-brain ASL is typically performed using either Stack-of-Spirals FSE or GRASE. However, those readouts suffer from significant image blurring and off-resonance sensitivity. Hence, Cartesian encoding would be highly desirable because of its robustness and high image quality, but acquisition times remain prohibiting. We therefore report the implementation of an accelerated 3D-FSE sequence using variable-density Poisson-disk undersampling to provide redundant k-space center sampling while varying the outer pseudo-random sampling and Parallel-Imaging Compressed-Sensing reconstruction to provide high quality high-resolution whole brain ASL perfusion images. |
| 843
|
13:54
|
Comparison of MR Fingerprinting ASL with Gd-based DSC MRI: validation and direct parametric mapping with deep learning |
1The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2Graduate School of Biomedical Sciences, University of Texas Southwestern Medical Center, Dallas, TX, United States, 3F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, MD, United States, 4Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 5Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 6Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 7Cognitive Science, Johns Hopkins University, Baltimore, MD, United States |
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MR Fingerprinting (MRF)-based Arterial-Spin-Labeling (ASL) has been recently proposed as a new approach to measure multiple hemodynamic parameters in a single scan. However, the previous implementation of MRF-ASL lacks the comparison with clinical standard techniques such as dynamic-susceptibility-contrast (DSC). Therefore, in this work, we validated MRF-ASL by comparing with DSC MRI. The results showed that these two methods provided visually comparable and quantitatively correlated perfusion estimations. Furthermore, we sought to directly estimate DSC-equivalent parameters from the MRF-ASL raw data using a deep-learning (DL) approach. DL-derived maps show better quality and are more consistent with DSC maps, compared to dictionary-matching results. |
| 844
|
14:06
|
Optimization of time-encoded pseudo-continuous ASL angiography with a variable flip-angle scheme |
1Wellcome Center for Integrative Neuroimaging, University of Oxford, Oxford, United Kingdom, 2Insitute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom |
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Time-encoded PCASL angiography is an attractive method for deriving some, or all, of the desired temporal information from the PCASL preparation rather than a dynamic readout. Higher flip-angles can then be used for the remaining excitation pulses in the readout, increasing the signal-to-noise ratio of the angiograms.
However, use of constant flip angles across all excitations leads to abrupt signal changes between images constructed from different time-encoding blocks. A variable flip-angle scheme is presented, which maintains a constant signal across all excitations, removes these discontinuities and ensures optimal signal levels across all images. |
| 845
|
14:18
|
Assessment of renal perfusion in transplanted kidney patients using multi-delay pseudo‑continuous arterial spin labeling |
1Department of Bio & Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea, Republic of, 2Department of Radiology, Bio medical Research Institute of Chonbuk National University Hospital, Jeonju, Korea, Republic of |
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There has been no systemic evaluation for transplanted kidney patients using 3T MRI system with pseudo-continuous ASL (pCASL). In this study, we presented multi-parametric renal perfusion imaging on transplanted kidney patients using multi-delay pCASL with bSSFP readout. Influence of background suppression on temporal signal stability was investigated and two different perfusion quantification models were compared. Multi-parametric perfusion signals including mean renal perfusion and arterial transit time were measured for transplanted kidney patients. The current study would be helpful for applying multi-delay pCASL to routine clinical diagnosis of transplanted kidney patients. |
| 846
|
14:30
|
Glomerular filtration rate estimation by motion-robust high spatiotemporal resolution DCE-MRI with radial VIBE and comparison with plasma clearance of 99mTc-DTPA |
1Radiology, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States, 2Siemens Healthcare, Erlangen, Germany, 3Urology, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States |
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The accuracy of MRI based glomerular filtration rate (GFR) measurements using the standard Cartesian VIBE DCE-MRI is limited by motion and temporal resolution. Instead, we use motion-robust high temporal resolution radial VIBE for DCE-MRI for accurate estimation of GFR. We optimize its temporal resolution and compressed sensing reconstruction temporal regularization parameters to obtain an accurate arterial input function peak while reconstructing good quality images. We also developed a fully automated segmentation and tracer kinetic model-fitting pipeline to compute MRI-GFR. We assessed the accuracy of proposed technique to measure GFR by comparing MRI-GFR to GFR from 99mTcDTPA nuclear medicine study (NMGFR). |
| 847
|
14:42
|
Joint measurement of perfusion and apparent oxygenation in the human placenta (PERFOX) |
1Biomedical Engineering, School of Biomedical Engineering & Imaging Sciences, King's College London, London, United Kingdom, 2Centre for the Developing Brain, School of Biomedical Engineering & Imaging Sciences, King's College London, London, United Kingdom, 3Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 4C.J. Gorter Center for high field MRI, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands, 5Academic Women's Health Department, King's College London, London, United Kingdom |
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Novel insight into placental oxygenation and perfusion was achieved by integrating velocity-selective arterial spin labeling and T2* mapping into one scan. Quantitative values can be obtained dynamically and geometrically fixed, allowing both separation of effects and joint visualization. |
| 848
|
14:54
|
Quantification of cerebral perfusion fraction map using cardiac-triggered, off-resonance calibrated super-selective arterial spin labeling |
1Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States, 2Surgery, University of Michigan, Ann Arbor, MI, United States, 3FMRI Laboratory, University of Michigan, Ann Arbor, MI, United States |
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The impact of off-resonance compensation and cardiac triggering on vessel- selective ASL labeling efficiency and image quality was investigated. A strategy to calculate individual vessel’s perfusion fraction maps based on measurements of vessel-selective labeling efficiency is also presented. This work serves as a practical guideline for acquiring high quality, quantitative perfusion fraction maps with super-selective pseudo-continuous arterial spin labeling. |
| 849
|
15:06
|
7T high-resolution arterial spin labeling reveals layer dependent cerebral blood flow |
1Laboratory of FMRI Technology (LOFT), Mark & Mary Stevens Neuroimaging and Informatics Institute, Los Angeles, CA, United States |
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The microcirculation of cerebral cortex has been investigated by anatomical studies in animals and human brain tissue. For the first time, we applied high resolution (0.5x0.5x1.4mm3) pulsed and pseudo-continuous ASL (pCASL) with inner-volume GRASE readout at 7T to measure CBF in the superficial, middle and deep layers of human cerebral cortex. Our results show higher perfusion in the middle layer using pCASL, while perfusion in the superficial layer of PASL may be affected by pial artery signals. In vivo imaging of layer dependent CBF opens door to investigating neurovascular coupling in a laminar fashion. |
| 850 | 15:18
|
An Extracorporeal Circulation Mouse Model for Simultaneous Measurements of Dynamic Contrast-Enhanced Arterial Input Functions and Radiotracer Blood Concentrations |
1Department of Nuclear Medicine, University of Münster, Münster, Germany, 2European Institute for Molecular Imaging - EIMI, University of Münster, Münster, Germany, 3Translational Research Imaging Center - TRIC, University of Münster, Münster, Germany |
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Quantification of the arterial input function (AIF) in small animals is challenging in both dynamic contrast-enhanced (DCE)-MRI and in radiotracer studies. We present a novel extracorporeal circulation mouse model for DCE-measurements of the AIF in mice. The approach allows parallel measurement of tissue contrast dynamics as well as of radiotracer AIF using a β-microprobe integrated into the extracorporeal circulation. |
| 851 | 13:30
|
Association between tumor acidity and hypervascularity within human gliomas using pH-weighted amine chemical exchange saturation transfer echoplanar imaging (CEST-EPI) and dynamic susceptibility contrast (DSC) perfusion MRI at 3T |
1Department of Radiology, People’s Liberation Army General Hospital, Beijing, China, 2Brain Tumor Imaging Laboratory (BTIL), Center of Computer Vision and Imaging Biomarker, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 3Department of Bioengineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, Los Angeles, CA, United States, 4Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 5Department of Neurosurgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 6UCLA Brain Research Institute (BRI), David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 7Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 8Physics and Biology in Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 9Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States |
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In the current study, we employed a fast pH-weighted molecular MRI technique using amine chemical exchange saturation transfer echoplanar imaging (CEST-EPI) and compared to dynamic susceptibility contrast (DSC) perfusion MRI, in order to examine the association between tumor acidity and vascularity in 82 patients with histologically confirmed gliomas. We observed colocalized regions of altered vascularity and acidity in tumors within individual patients, and significant positive correlation between median magnetization transfer ratio asymmetry (MTRasym) at 3ppm and relative cerebral blood volume (rCBV) within T2 hyperintense lesions. But areas of contrast enhancement were more complex and did not show a strong, predictable relationship. |
| 852 | 13:42
|
Evaluating white matter microstructure in childhood brain tumour survivors: A combined DTI and MTR approach. |
1The Hospital for Sick Children, Toronto, ON, Canada, 2University of Toronto, Toronto, ON, Canada |
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Diffusion tensor imaging has been utilized to study the impact of cancer treatment on white matter microstructure in paediatric brain tumour survivors. We utilized magnetization transfer imaging (MTI), which provides more specific information on myelin, along with DTI, to determine if treatment for paediatric brain tumours has specific or non-specific impacts on white matter structure. When compared to their healthy counterparts, children treated for brain tumours exhibit decreased anisotropy and increased diffusion metrics without any significant differences in MT. This suggests treatment may impact fiber organization rather than myelin structure in this patient population. |
| 853
|
13:54
|
Glutamine Mediated Citrate Elevation- A ‘Metabolic-Rearrangement’ for Proliferation in High Grade Tumors: In vivo MRS Studies at 3T |
1UT Southwestern Medical Center, Dallas, TX, United States, 2Philips Healthcare, Andover, MA, United States |
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Although substantial progress has been made in deciphering genetic and histological events in cancers, metabolic rearrangements that provide building blocks to elicit uncontrolled proliferation in cancers is still not understood. Nucleotide and lipids are the basic units needed for cell proliferation and membrane synthesis. Our in vivo MRS studies at 3 T in glioma patients indicate that tumors rearrange glutamine metabolism to produce citrate for increased lipid biosynthesis for membrane formation, and nucleotide for cell-multiplication. |
| 854
|
14:06
|
Low extracellular acidification in 1p/19q co-deleted gliomas confirmed using pH-weighted amine CEST-EPI, T2 relaxometry, and amino acid PET |
1Brain Tumor Imaging Laboratory (BTIL), Center of Computer Vision and Imaging Biomarker, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 2Department of Bioengineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, Los Angeles, CA, United States, 3Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 4Department of Neurosurgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 5UCLA Brain Research Institute (BRI), David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 6Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 7Physics and Biology in Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 8Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States |
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The 1p/19q co-deletion in gliomas is associated with better response to therapies and better patient prognosis. In this study, we demonstrate that 1p/19q co-deleted gliomas are less acidic than gliomas with intact 1p/19q using a combination of pH-sensitive amine CEST-EPI, T2 relaxometry, and 18F-FDOPA PET. Results suggest amine CEST-EPI may serve as a quick non-invasive imaging biomarker for identifying 1p/19q co-deleted tumors. Our results also support the hypothesis that the better prognosis and higher sensitivity to treatment of 1p/19q co-deleted gliomas may be related to less acidity in tumor microenvironment. |
| 855
|
14:18
|
Noninvasive Assessment of Tumor Histopathology in Glioblastoma Specimen and Patient |
1Radiology, Washington University School of Medicine, Saint Louis, MO, United States, 2Neurological Surgery, Washington University School of Medicine, Saint Louis, MO, United States, 3Medical Scientist Training Program, The University of Alabama at Birmingham, Birmingham, AL, United States, 4Medicine, University of Missouri – Kansas City, Kansas City, MO, United States, 5Radiology, The First Affiliated Hospital of Nanchang University, Nanchang, China, 6Radiology, Guangzhou First People’s Hospital, Guangzhou, China, 7Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO, United States |
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Glioblastoma (GBM) is the most frequent malignant brain tumor in adults, accounting for approximately 45-50% of all primary malignant brain tumors. To circumvent the shortcomings of current clinical MRI techniques, we applied modified diffusion basis spectrum imaging (DBSI) to accurately detect pathology in GBM. In this study, we demonstrate modified-DBSI efficacy in detecting different histopathological structures in ex vivo and in vivo scans of glioblastoma. |
| 856 | 14:30
|
Multimodal Imaging of Brain Tumors Using High-Resolution 1H-MRSI Without Water Suppression |
1Radiology department, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, China, 2Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 3Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 4Institute for Medical Imaging Technology, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China |
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The characterization and grading of brain tumors are challenging using conventional MRI technology because of its poor specificity. MRSI has been recognized as a powerful tool for mapping the metabolic fingerprints of tumors. However, existing MRSI methods have poor spatial resolution which limits their practical applications in brain tumor imaging. In this paper, we investigate the use of a high-resolution MRSI technique for multimodal imaging of brain tumors. We demonstrate the capability of performing simultaneous mapping of brain metabolites (at 2.0×2.4×2.0 mm3 nominal spatial resolution), MWF and QSM using our new MRSI technology. This capability enables us to capture metabolic changes of small brain tumors (<10mm3). |
| 857
|
14:42
|
GLINT: GlucoCEST in neoplastic tumors at 3 T – preliminary application in glioma patients using optimized preparation, imaging, and post-processing |
1High-Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tuebingen, Germany, 2Department of Diagnostic and Interventional Neuroradiology, Eberhard-Karls University Tuebingen, Tuebingen, Germany, 3Institute of Neurology, University College London, London, United Kingdom, 4Department of Biomedical Magnetic Resonance, Eberhard-Karls University Tuebingen, Tuebingen, Germany |
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Dynamic glucoCEST at clinical field strengths is very challenging due to the low effect size. Here, we present a saturation, imaging and post-processing protocol for minimizing possible artifacts to detect dynamic CEST effects reliably, and demonstrate the application in two glioblastoma patients at 3 T. |
| 858 | 14:54
|
Hemispheric Specification of Remote Effect of Cerebral Glioma on White Matter Connectivity |
1Shenzhen Institutes of Advanced Technology,Chinese Academy of Sciences, Shenzhen, China, 2University of Chinese Academy of Sciences, Beijing, China, 3Department of Neurosurgery, Huashan Hospital of Fudan Univesity, Shanghai, China, 4Beijing Tian Tan hospital，Capital Medical University, Beijing, China |
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Biological aggressiveness of glioma extends beyond the radiological territory. Based on the atlas based method and diffusion metrics derived from diffusion tensor imaging, the remote effect of cerebral gliomas on the white matter connectivity was analyzed at the global level. LGGs and HGGs showed difference in the diffusion metrics in the contralesional brain regions with hemispheric and anatomical specifications, which possibly underlie the functional neuroplasticity confounding the aggressiveness assessment and management of glioma. |
| 859 | 15:06
|
Deuterium Metabolic Imaging (DMI) of glucose metabolism in patients with brain tumors. |
1Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States, 2Neurology, Yale University, New Haven, CT, United States, 3Yale University, New Haven, CT, United States |
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Deuterium Metabolic Imaging (DMI) is a novel approach providing high 3D spatial resolution metabolic data from both animal models and human subjects. DMI relies on 2H MRSI in combination with administration of 2H-labeled substrates. Here we describe the first experiences with using DMI to map steady state metabolism of orally administered [6,6’-2H2]-glucose in patients diagnosed with a brain tumor. DMI revealed striking image contrast based on regional differences of glucose metabolism, with high-grade tumor lesions depicting metabolite labeling with consistently high lactate production and low glucose oxidation, a metabolic phenotype known as the Warburg effect. |
| 860
|
15:18
|
Serial characterization of HP [1-13C]pyruvate metabolism in the brains of patients with glioma and healthy controls |
1Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States, 2Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, United States, 3Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, United States |
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Serial dynamic hyperpolarized [1-13C]pyruvate imaging was performed on 3 patients undergoing treatment for recurrent brain tumors and 2 healthy controls using a frequency-specific EPI sequence (20 total scans). To evaluate metabolism within normal-appearing white matter (NAWM), rate constants for pyruvate-to-lactate (kPL) and pyruvate-to-bicarbonate (kPB) conversion were kinetically modeled. Healthy control data provided reference rate constants in NAWM and demonstrated replicabililty of test-retest type scans across hardware platforms. Serial patient data also showed similar, replicable data with standard-of-care treatment, as well as evidence that kPL, NAWM is increased 148-290% following administration of anti-angiogenic agent Bevacizumab, which promotes vascular normalization. |
| 861 | 13:30
|
Diffusion tensor imaging and T2 measurements are sensitive to changes in muscle tear due to healing |
1Leeds Biomedical Research Centre, The University of Leeds, Leeds, United Kingdom, 2Leeds Institute of Cardiovascular and Metabolic Medicine, The University of Leeds, Leeds, United Kingdom, 3Medical Physics and Engineering, Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom, 4Leeds Institute of Rheumatic and Musculoskeletal Medicine (LIRMM), The University of Leeds, Leeds, United Kingdom, 5Siemens Healthcare, Erlangen, Germany |
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The aim of this study was to investigate the ability of diffusion tensor imaging (DTI) and T2 measurements to detect changes due to healing in athletes with muscle tears. 13 professional athletes were imaged within 2 days of injury and at the point that they returned to training. Regions of interest depicting the tear were drawn at visit 1 and were propagated to parameter maps from both visits taking into account motion between images. The study showed significant differences in DTI parameters and T2 values between visits, implying that these measures may be useful quantitative markers in assessing muscle healing. |
| 862 | 13:42
|
T2* and UTE-T2* Evaluations of Anterior Cruciate Ligament Graft Maturation |
1Department of Orthopedic Surgery, Stanford University School of Medicine, Stanford, CA, United States |
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This study tests the hypothesis that quantitative T2* and UTE-T2* are sensitive to ACL graft changes reflective of histological stages of human ACL graft incorporation following ACL reconstruction. T2* variability at 6 months suggests transition from early stage incorporation to remodeling, while stable values from 6 months to 1 year are consistent with remodeling. ACL graft T2* and UTE-T2*, respectively, from two different cohorts decreased between 1 and 2 years suggesting continued graft maturation during the second year. T2* and UTE-T2* of ACL graft incorporation may help to inform decisions concerning return to sports and work activities following ACL reconstruction. |
| 863 | 13:54
|
Changes in ACL T2* over the course of a menstrual cycle: a new biomarker for ACL injury risk? |
1Radiology and Imaging, Hospital for Special Surgery, New York, NY, United States, 2Biostatistics, Hospital for Special Surgery, New York, NY, United States |
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This study assessed changes in ACL T2* metrics throughout the menstrual cycle. In the pre-ovulatory phase, ovulatory case subjects exhibited significant shortening of T2*S and PS in comparison to visit #4 (post-ovulatory phase). Non-ovulatory control subjects displayed no significant changes over time. Results of the current study suggest that there is a shift in bound water (T2*S) within the ACL from pre- to post-ovulatory phases. Shifts in tissue water content have been associated with altered mechanical properties and changes in ligament stiffness may alter proprioceptive sense and contribute to increases in laxity and risk of ACL-injury within the pre-ovulatory phase. |
| 864
|
14:06
|
Gait retraining as a conservative treatment for medial knee OA: preliminary findings |
1Department of Radiology, Stanford University, Stanford, CA, United States, 2Musculoskeletal Research Laboratory, VA Palo Alto Healthcare System, Palo Alto, CA, United States, 3Department of Mechanical Engineering, Stanford University, Stanford, CA, United States, 4Department of Bioengineering, Stanford University, Stanford, CA, United States, 5Department of Orthopaedic Surgery, Stanford University, Stanford, CA, United States |
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Osteoarthritis is a major societal burden and is associated with pain and disability. To cope with the “osteoarthritis epidemic” and its high associated costs, there is a need for new conservative treatments. This study investigates the potential of gait retraining with altered foot progression angle as one inexpensive conservative treatment for medial knee osteoarthritis. Our results show that this treatment may be effective in reducing pain and improving the MRI outcomes in osteoarthritis patients. This suggests the potential of personalized gait retraining with altered foot progression angle as an inexpensive and effective conservative method for the management of osteoarthritis patients. |
| 865
|
14:18
|
Assessment of an In Vitro Model of Rotator Cuff Tendinopathy Using 3D-UTE MRI Biomarkers with Biochemical and Histological Correlation |
1Department of Radiology, University of California, San Diego, San Diego, CA, United States, 2Department of Radiology, Beijing Hospital, Beijing, China, 3Radiology Service, VA San Diego Healthcare System, San Diego, CA, United States |
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Changes in extracellular matrix are seen in cuff tendinopathy, and in particular, alterations in collagen proportion and property are characteristic. Tendon contains an abundance of short T2 components that rapidly decay to background levels. Thus, UTE sequences are better suited for quantitative evaluation of tendon compared with standard clinical MR sequences. In this study, we assess the sensitivity of multiple UTE biomarkers for the evaluation of rotator cuff degeneration in a controlled laboratory experiment. |
| 866 | 14:30
|
Usefulness of enhancement pattern analysis of non-contrast perfusion using arterial spin labeling (ASL) for the evaluation of painful shoulder diseases |
1Radiology, Tobata General Hospital, Kitakyushu, Japan, 2Sakura Clinic, Kitakyushu, Japan, 3Mihagino Hospital, Kitakyushu, Japan, 4Tobata Kyoritsu Hospital, Kitakyushu, Japan, 5Canon Medical Systems, Kasuga, Japan, 6UC San Diego, La Jolla, CA, United States |
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We investigated the usefulness of non-contrast perfusion obtained using arterial spin labeling (ASL) for the evaluation of various shoulder diseases. In 137 consecutive patients, the subacromial space was divided into four areas, in which ASL enhancement patterns were evaluated. Most of the full thickness tear of rotator cuff demonstrated diffuse enhancement. Most of the adhesive capsulitis showed the anterior area enhancement to be consistent with rotator interval. Acromioclavicular (AC) arthritis showed dominant enhancement in the AC joint. The specific enhancement pattern of ASL is well correlated with the pathology of shoulder diseases, which is highly useful for the differential diagnosis. |
| 867
|
14:42
|
The use of relaxometry measurements in synthetic MR in assessing the lumbar intervertebral disk degeneration in patients with chronic low back pain |
1Beijing Hospital, Beijing, China, 2GE Healthcare, Beijing, China |
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Our purpose was to verify the use of synthetic MR in quantitative analysis of lumbar intervertebral disk degeneration in patients with chronic low back pain. Twenty-four patients underwent MR examination including conventional T2map and synthetic MR. Our results showed strong correlations between the two techniques. These absolute parameters obtained can reflect the intervertebral disk degeneration grades quantitatively. Synthetic MR is efficient and reproducible in the assessment of disk degeneration. |
| 868
|
14:54
|
[18F]-NaF PET-MR Imaging Reveals Bone-Cartilage Interactions in Hip Osteoarthritis |
1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States |
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In Osteoarthritis (OA), degeneration of articular cartilage can be accompanied by changes in bone structure. In this study, we analyzed the distribution of [18F]-NaF uptake and blood flow in the femur and acetabulum in 10 hip OA patients and studied associations between bone remodeling and cartilage composition in the presence of morphological abnormalities using PET-MR, quantitative MR and femur shape modeling. Our results showed associations of Standardized Uptake Values (SUV), blood flow to bone (Kpat) with patient reported pain, when different bone shapes like shaft thickness and coxa valga were taken into account. |
| 869 | 15:06
|
Differential Diagnosis Between Normal Marrow and Metastasis of Pelvic Bones Using Relaxation Maps from Synthetic MRI |
1Department of Radiology, Beijing Hospital, National Center of Gerontology, Beijing, China, 2Graduate School of Peking Union Medical College, Beijing, China, 3GE Healthcare, Beijing, China |
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Synthetic MRI enables quantification of T1, T2 and proton density (PD) value. The purpose of our study was to assess the feasibility for distinguishing bone metastasis from normal marrow with synthetic MRI. Our study found that T1 value of metastasis was significantly higher than those of red and yellow marrow. The T2 value of metastasis was significantly lower than those of red and yellow marrow. We concluded that synthetic MRI could be used for differentiating bone metastasis from normal marrow. |
| 870 | 15:18
|
IVIM Analysis in Response Evaluation of Osteosarcoma Treated with Neoadjuvant Chemotherapy: Correlation with Histopathological Necrosis |
1Center for Biomedical Engineering, Indian Institute of Technology, Delhi, India, New Delhi, India, 2Radio Diagnosis, All India Institute of Medical Sciences, New Delhi, India, New Delhi, India, 3Department of Physics, Indian Institute of Technology, Delhi, India, New Delhi, India, 4Medical Oncology, IRCH, All India Institute of Medical Sciences, New Delhi, India, New Delhi, India |
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Histological necrosis is the current gold standard for response evaluation in osteosarcoma treated with neoadjuvant chemotherapy (NACT). However it is applicable only after tumor resection on completion of NACT. Thus, a non-invasive early marker of NACT response is desirable. We performed NACT response prediction and evaluation using Intra-voxel Incoherent Motion (IVIM) Diffusion weighted MRI and histogram analysis. IVIM parameters and its histogram analysis revealed clinically useful information in characterizing and predicting chemotherapy response to Osteosarcoma. |
| 878 | 13:30
|
Super-resolution convolutional neural networks applied to functional lung MRI at 1.5T |
1Division of Radiological Physics, Department of Radiology, University of Basel, Basel, Switzerland, 2Department of Biomedical Engineering, University of Basel, Basel, Switzerland, 3High Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Germany, 4Division of Pediatric Respiratory Medicine, Department of Pediatrics, Inselspital, Bern University Hospital, Bern, Switzerland, 5Department of Radiology, Inselspital, Bern University Hospital, Bern, Switzerland |
||
High-resolution images are needed in many MR applications to enhance the diagnostic information at early stages of the disease. Often, the achievable resolution is limited by acquisition time constraints, in particular in moving organs such as the lung, where rapid imaging is a necessity. The low proton density in the lung parenchyma further constrains the resolution as sufficiently high signal-to-noise ratio (SNR) requires large voxel size. In this work, the concept of super-resolution is investigated to increase the spatial resolution and potentially shorten the acquisition time for functional assessment in the lung without SNR penalty. |
| 874
|
13:42
|
Investigatory usage of a framework for automated cancer annotation of pathology slides of radical prostatectomy specimens: effect on performance of a predictive model for mpMRI detection of prostate cancer. |
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 2Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN, United States, 3Department of Pathology, University of Washington, Seattle, WA, United States |
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The development of CAD systems for prostate cancer detection requires large amounts of training data with correlated pathologic ground truth. The gold standard is manual annotation of cancer by pathologists, which is tedious and difficult to obtain. Here, we retrospectively applied a previously-described digital-pathology framework for automating cancer annotation. We trained a Bayesian predictive model on the original ground truth (from manual annotation) and on the new ground truth, and compared the performances. The results suggest the ground truths are very similar and largely equivalent, which provides support for prospective usage of our approach for automatic annotation of prostate cancer. |
| 875
|
13:54
|
On the prospects of deep learning for automated lung segmentation for functional lung MRI |
1Division of Pediatric Respiratory Medicine, Department of Pediatrics, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland, 2Division of Radiological Physics, Department of Radiology, University Hospital Basel, Basel, Switzerland, Basel, Switzerland, 3Department of Biomedical Engineering, University Basel, Basel, Switzerland, Basel, Switzerland, 4Department of Radiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland |
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Deep learning algorithms have shown promise for precise organ segmentation. In this work, we investigate the prospects of deep learning for automated lung segmentation to assess impaired ventilation and perfusion measures using functional lung MRI. |
| 877 | 14:06
|
Machine Learning-based Analysis of Rectal Cancer MRI Radiomics for Prediction of Metachronous Liver Metastasis |
1Department of Radiology, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical college, Beijing, China, 2Huiying Medical Technology Co., Ltd, Beijing, China |
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Early detecting patients at high risk of metachronous liver metastasis (MLM) in rectal cancer would provide the opportunity for improving prognosis and survival. In this study, we attempted to construct a non-invasive and convenient model based on rectal cancer T2WI and venous phase (VP) MR radiomics to predict MLM using support vector machine (SVM) and logistic regression (LR) algorithms. The results showed that the Modeloptimal using the LR algorithm had high potential for MLM prediction than other models. And except for ModelVP, the LR algorithm was not superior to the SVM algorithm for model construction. |
| 879 | 14:18
|
3D Super-resolution Prostate MRI using Generative Adversarial Networks and unpaired data |
1Applied Physics and Applied Mathematics, Columbia University, New York, NY, United States, 2Information and Computer Engineering, Chung Yuan Christian University, Taoyuan, Taiwan, 3Global MR Applications and Workflow, GE Healthcare, New York, NY, United States, 4Data Science Institute, Columbia University, New York, NY, United States, 5Radiology, Columbia University Medical Center, New York, NY, United States |
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We developed a novel method to generate 3D isotropic super-resolution prostate MR images using a class of machine learning algorithms known as Generative Adversarial Networks (GANs). We use GANs to generate super-resolution images with 3D SVR image slices as inputs. Super-resolution is enforced as the discriminator network is trained to distinguish the output image from in-plane T2 FSE images, resulting in the generation of super-resolution images. We use unpaired GANs since slices of 3D SVR do not usually have corresponding super-resolution images. The result is a generated continuous 3D volume with super-resolution throughout all three planes in isotropic voxel size. |
| 872
|
14:30
|
Fully automated registration of cross-sectional liver images using fully convolutional and affine transformation networks |
1Radiology, University of California, San Diego, San Diego, CA, United States, 2Radiology, Stanford University, Stanford, CA, United States, 3Family Medicine and Public Health, University of California, San Diego, San Diego, CA, United States |
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Proper spatial alignment of anatomical landmarks during and between liver imaging exams is challenging due to the dynamic morphology of the liver. Liver-focused registration algorithms have been developed but are typically semiautomatic. We propose a fully-automated pipeline for affine-based registration of inter- and intra-exam liver images and assess performance on clinical liver MRI exams at 1.5T and 3T. The proposed pipeline achieved comparable or superior accuracy and scalability to that reported for previously proposed algorithms. Retrospective image review by an expert abdominal radiologist confirmed subjective improvement in anatomic registration and lesion co-localization. Proof of concept of multimodal scalability was demonstrated. |
| 880 | 14:42
|
3D Convolutional Neural Network with Contrast-enhanced MR for Microvascular invasion prediction of hepatocellular carcinoma |
1School of Medical Information Engineering, Guangzhou University of Chinese Medicine, Guangzhou, China, 2Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China, 3Department of Radiology, Guangdong General Hospital, Guangzhou, China |
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Microvascular invasion (MVI) of Hepatocellular carcinoma (HCC) is a crucial histopathologic prognostic factor leading to recurrence after liver transplantation or hepatectomy, and preoperative prediction of MVI is significant in clinical practice. In this work, we propose a deep learning framework based on 3D Convolutional Neural Network (CNN) to extract discriminative information from HCCs in Contrast-enhanced MR images for MVI prediction. Experimental results demonstrated that the proposed deep learning framework could make full use of the spatial and temporal information of HCCs from Contrast-enhanced MR for MVI prediction, outperforming the radiomics based approach and the method of 3D deep feature concatenation. |
| 873
|
14:54
|
Optimizing peritumoral features on radiomic analysis of breast cancer |
1Biomedical Engineering, Stony Brook University, Stony Brook, NY, United States, 2Radiology, Guangdong General Hospital/Guangdong Academy of Medical Sciences, Guangzhou, China, 3Radiology, Stony Brook Medicine, Stony Brook, NY, United States, 4Computer Science, Stony Brook University, Stony Brook, NY, United States, 5Psychiatry, Stony Brook Medicine, Stony Brook, NY, United States |
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Recently, we developed a radiomic pipeline to non-invasively predict sentinel lymph node (SLN) metastasis in breast cancer using image features extracted from the primary tumor on the DCE-MRI. In this study, we further investigated the usefulness of the peritumoral features in the radiomic analysis and evaluated the effect of the thickness of the peritumoral regions to optimize the prediction performance. The result shows that the peritumoral features can indeed improve the prediction performance and using 4mm as the thickness of the peritumoral regions achieved the optimal prediction result in an independent validation set. |
| 876 | 15:06
|
Differentiation Idiopathic Granulomatous Mastitis and Breast Carcinoma: Value of Whole-Lesion Histogram and Texture Analysis Using Quantitative ADC Map |
1Radiology, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China, 2Radiology, Fudan University Shanghai Cancer Center, Shanghai, China, 3MR Application Development, Siemens Shenzhen Magnetic Resonance, Shenzhen, China, 4MR Application Predevelopment, Siemens Healthcare, Erlangen, Germany |
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Recently, DWI has been increasingly used in distinguishing benign inflammation lesions and breast cancers. A total of 15 patients with invasive ductal carcinoma (IDC) and 10 patients with idiopathic granulomatous mastitis (IGM) were retrospectively evaluated. We extracted the whole-lesion histogram and textural features from the ADC map. Univariate and multivariate logistic regression analysis was performed. The area under the curve (AUC) at the best cut-off point was assessed. Using the three significant features (difference entropy, difference variance and entropy of ADC), we obtained an AUC of 0.953 (95% CI: 0.787, 0.998) for the differentiation between IGM group from tumor group. |
| 881 | 13:30
|
Predicting memory impairment using resting-state brain connectomes in older adults |
1Functional MRI Laboratory, University of Michigan, Ann Arbor, MI, United States, 2Psychiatry, University of Michigan, Ann Arbor, MI, United States |
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Resting-state connectome modelling is applied to a population of older adults, including controls, subjects with amnestic MCI, and subjects with AD. Significant prediction of subjects' composite memory scores is achieved. |
| 882 | 13:42
|
Aberrant Temporal Flexibility of Visual Network in Schizophrenia: a Resting State fMRI Study |
1UC Riverside, RIVERSIDE, CA, United States |
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Schizophrenia has been associated with large-scale hypo-connectivity between brain networks. Since functional connectivity (FC) is dynamic, characterizing the temporal dynamics of FC may provide valuable insights regarding the underlying FC aberrance of patients. We present a framework to investigate the aberrant functional interaction between brain networks in schizophrenia using sliding window correlation and modularity analysis and found aberrant temporal flexibility in ROIs for visual object recognition in patients. Examination of their temporal co-activation profiles revealed higher co-activation of |
| 883 | 13:54
|
Aberrant Resting-state Functional Connectivity of Cerebellar Vermis in Parkinson’s Disease |
1University of Maryland Medical School, Baltimore, MD, United States, 2Department of Neurology, University of Maryland Medical School, Baltimore, MD, United States |
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Parkinson’s disease (PD) is one of the most common neurodegenerative disorder in the aging population1, characterized by progressive deterioration of motor function as well as non-motor symptoms2,3. To date, most of the resting-state fMRI PD studies focused on basal ganglia3,4,5, whereas few studies on cerebellum5,6, especially cerebellar vermis. In this study, we investigated the rs-FC difference in whole brain in PD patients compared with health controls and the association between FC of vermis and motor and neuropsychological measurements in PDs. Our results suggest that the cerebral vermis, visual cortex, and visual processing associated areas contribute to the development of symptoms in PD. |
| 884 | 14:06
|
Periods of discernible cognition contribute to dynamic functional connectivity during rest |
1Section on Functional Imaging Methods, National Institute of Mental Health, Bethesda, MD, United States, 2Basque Center on Cognition, Brain and Language, San Sebastian, Spain, 3Machine Learning Team, National Institute of Mental Health, Bethesda, MD, United States, 4FMRI Core Facility, National Institute of Mental Health, Bethesda, MD, United States |
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The etiology of time-varying functional connectivity (dFC) during rest is unclear. Those who hypothesize it to be neuronally relevant explore the phenomena in the context of consciousness, development and psychopathology. Yet, others have raised valid concerns regarding methodology or its significance beyond fluctuations in arousal and sleep. Here, we demonstrate how decodable covert on-going cognition contributes to dFC estimates during awake rest, suggesting that several meaningful FC configurations may be observable during rest. We also demonstrate how FC states—a common model for dFC—robustly capture periods of distinct cognition only when externally imposed, but not during rest. |
| 885 | 14:18
|
Functional Connectivity Mediates the Relationship between Regional Excitation-Inhibition Balance and Default-Mode Network Deactivation |
1Neuroimaging Research Branch, National Institue on Drug Abuse, Baltimore, MD, United States, 2Department of Psychology, Zhejiang University, Hangzhou, China, 3Harvard Medical School, Boston, MA, United States, 4Beijing Normal University, Beijing, China |
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Aberrant default mode network (DMN) activity has been related to aging and various neuropsychiatric illnesses. To better understand the neural mechanisms underlying the DMN deactivation, we investigated the triple-relationship among the task-induced deactivation, regional excitation-inhibition balance, and the interregional functional connectivity strength associated with the DMN. Using mediation analysis, we found that the network interaction between DMN and the salience network partially mediated the association between the regional excitation-inhibition balance and the DMN deactivation. This finding bridges DMN-deactivation related findings from various neuroimaging modalities and may provide new insights into the neural mechanisms of the DMN deactivation. |
| 886
|
14:30
|
Functional connectivity predicts individual longitudinal development in inhibitory control ability: a 5-year follow-up study |
1Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing, China, 2National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, China, 3University of Chinese Academy of Sciences, Beijing, China, 4CAS Center for Excellence in Brain Science and Intelligence Technology, Institute of Automation, Chinese Academy of Sciences, Beijing, China, 5The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu, China, 6The Queensland Brain Institute, University of Queensland, Brisbane, Australia |
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Inhibitory control ability (IC) is related to adolescence impulsive and risky behaviors. It will develop into adulthood, but its trajectory has great individual difference. What brain features affect the individualized development of IC? Here we use longitudinal data and predictive model to predict stop signal reaction time (SSRT) change in 5 years with 14-year-old stop signal task functional connectivity (FC). We find that 14-year-old FCs between ventral attention and subcortical networks can predict the development tendency of IC, even excluding the effect of 14-year-old SSRT. This may help to make early intervention in the development of adolescent IC. |
| 887 | 14:42
|
Increased Functional Connectivity Flexibility During Early Infancy |
1School of Data and Computer Science, Sun-Yat Sen University, Guangzhou,Guangdong, China, 2Department of Radiology and BRIC, University of North Carolina at Chapel Hill, chapel hill, NC, United States |
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Understanding the nature of dynamic neural interactions during development is a critical issue of cognitive neuroscience. However, our knowledge |
| 888 | 14:54
|
Maternal immune activation during pregnancy impacts on resting state functional connectivity in the adult offspring |
1Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich Alexander University Erlangen-Nuremberg, Erlangen, Germany, 2Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria, 3Department of Biomedical Imaging and Image-Guided Therapy, Division of Molecular and Gender Imaging, Medical University of Vienna, Vienna, Austria, 44Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria |
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The infection of the pregnant female and the ensuing induction of maternal immune activation affect fetal development with long-lasting consequences for health and disease. Specifically aberrant neural wiring may contribute in the manifestation of psychiatric disorders such as depression. Here, we investigated altered resting state functional connectivity using fMRI in adult mice after prenatal immune activation. While the overall flow of information was intact, especially the cortico-limbic connectivity was disrupted in resting state networks of adult offspring. We propose that these altered connectivity patterns may lead to behavioral and emotional abnormalities with relevance for neuropsychiatric disorders. |
| 889 | 15:06
|
Distance-enriched functional connectomics in drug-resistant temporal lobe epilepsy |
1Multimodal Imaging and Connectome Analysis Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada, 2Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China, 3Department of Radiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China, 4NeuroImaging of Epilepsy Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada |
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Temporal lobe epilepsy (TLE) is increasingly reconceptualised as a network disorder, with a growing literature suggesting concurrent structural and functional changes in large-scale network organization. In the current work, we developed a novel framework consolidating topological and spatial properties of brain networks and applied it to unveil shifts in the connectional distance distribution in TLE. Patients showed marked connectivity reductions in ipsilateral temporal, insular, and dorsomedial prefrontal networks—regions which coincide with high-degree, transmodal systems. Importantly, distance reductions occurred independently of cortical atrophy but were mediated by microstructural damage, thus emphasizing the clinical importance of physically-grounded measures of functional connectivity. |
| 890 | 15:18
|
A functional connectome-based interspecies model boosts classification in neuropsychiatric disorders |
1Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, State Key laboratory of Neuroscience, CAS Key Laboratory of Primate Neurobiology, Chinese Academy of Sciences, Shanghai, China, 2University of Chinese Academy of Sciences, Beijing, China, 3Institute of Automation, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Beijing, China, 4Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China, Kunming, China |
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Cross-species comparative connectomices based on resting-state functional MRI is a promising method to investigate large-scale brain organization. Here we leveraged a transgenic monkey model overexpressing MECP2 and developed a novel connectome-based interspecies machine learning algorithm for clinical diagnosis of individuals with neuropsychiatric disorders. This fully cross-validated algorithm based on cross-species mapping of regional features significantly boosts the diagnostic performance of ASD and OCD, but not for ADHD, in independent human cohorts, which paves a new avenue to establish a translational path to dissect the neural circuit mechanisms underlying complexity and heterogeneity of human mental disorders. |
13:30
|
An Overview of Survey Results | |
1Université de Sherbrooke, Canada |
13:40
|
A Clinical Perspective on Best Practices for Diffusion MRI | |
13:58
|
Diffusion Tensor Imaging: Your Old Good Friend | |
14:16
|
Where to Go Beyond DTI: DKI & Multi-Shell Acquisitions | |
1Department of Neurology, Medical University of South Carolina, Charleston, SC, United States |
14:34
|
Image Processing: Possible Guidelines for the Standardization & Clinical Applications | |
14:45
|
Tractography in the Clinic: Where Are We? | |
1Sackler Institute for Translational Neurodevelopment, King's College London, London, United Kingdom |
15:10
|
Panel Discussion |
13:30
|
Prologue: Resonate 2018 Recap | |
1Lawson Health Research Institute, Canada |
13:33
|
Monologue (Localizer # 1): Whistling Vivaldi: Uncovering Hidden Biases in Radiology | |
1Emory University |
13:53
|
Monologue (Localizer #2): Excellence Through Diversity: The American College of Radiology Experience. | |
1Pomona Valley Hospital Medical Center |
14:08
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Monologue (Localizer #2): A Commitment to Diversity: The UCSF Radiology & Biomedical Imaging Experience. | |
1UCSF, United States |
14:18
|
Monologue (Localizer #2): How to Engineer Diverse & Representative Study Populations for Radiology AI Applications | |
1Google, United States |
14:28
|
Dialogue (Scan): An Open-Guided Discussion on Localizers |
14:52
|
Epilogue (Recon): Summary, Resonate In-Phase |
15:45
|
MR Angiography | |
1Depts. of Medical Physics & Radiology, University of Wisconsin - Madison, Madison, WI, United States |
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Traditional clinical MR Angiography (MRA) provides volumetric datasets to characterize the vessel lumen. These MRA techniques can be generally separated into two categories: contrast-enhanced MRA, which requires the venous injection of a paramagnetic contrast agent in form of a Gadolinium (Gd) chelate and non-contrast-enhanced MRA (NCE MRA), which relies on signal properties of the blood or the motion of the blood to create signal differences between the blood pool and the surrounding tissues. The underlying contrast mechanisms of contrast-enhanced (CE MRA), time-of-flight, phase-contrast, and balanced steady state free precession (bSSFP) MRA will be discussed including recent developments in accelerated dynamic contrast-enhanced MRA (CE-MRA), the use of iron-based contrast agents, and velocity-encoded MRI. |
16:25
|
Parallel Imaging | |
1Fraunhofer Development Center for X-ray Technology (EZRT), Germany |
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In recent years, parallel imaging techniques have become essential tools for accelerating MRI exams. Nowadays, basically all modern MR systems are equipped with multi-channel coil arrays and dedicated reconstruction algorithms. After a short historical overview, this talk will describe the basic concepts of parallel imaging. Limitations due to noise amplification (i.e. g-factor) and reconstruction artifacts will be discussed and applications will be presented. Finally, future perspectives (e.g. extensions with compressed sensing or machine learning) will be outlined. |
17:05
|
Diffusion & Perfusion Weighted Imaging | |
1Dept. of Biomedical Engineering, University of Basel, Allschwil, Switzerland, 2Dept. of Radiology, Radiological Physics, University Hospital Basel, Basel, Switzerland |
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This lecture will explain the two important and popular imaging concepts of “diffusion weighted imaging (DWI)” and “perfusion weighted imaging (PWI)”. The underlying physics and fundamental properties will be explained in a pictorial way (with only a few easy mathematical equations that may be important to recognize or use). The clinical significance and potentials of the two methods are also discussed. At last, DWI and PWI are combined to establish the so-called “diffusion-perfusion-mismatch-concept” in (acute) ischemic stroke. |
17:45
|
Adjournment |
15:45
|
History & State of the Art: Simultaneous Multislice | |
1ISR-Lisboa/LARSyS and Department of Bioengineering, Instituto Superior Técnico - Universidade de Lisboa, Lisbon, Portugal |
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MRI exam times are typically much longer compared to other imaging techniques, motivating the development of methods for accelerating image acquisition. This lecture will focus on simultaneous multislice acquisitions, providing the background for the initial developments and describing some of the latest state of the art methods. |
16:05
|
Wave Encoding: The Sequence, the Reconstruction & the Trade-Offs | |
1Martinos Center for Biomedical Imaging, United States |
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Wave encoding is a controlled aliasing strategy which allows better utilization of the spatial degrees of freedom in multi-channel receive arrays. This enables high acceleration rates in parallel imaging without incurring significant g-factor penalty. Conventional spin-warp acquisitions can be augmented to utilize wave encoding using simple sequence modifications. However, this requires a dedicated image reconstruction that captures these modifications on the k-space trajectory. We will focus on wave acquisition and reconstruction techniques as well as the trade-offs in image calculation time, trajectory estimation and potential artifacts, and how these could be mitigated to enable translation of this efficient imaging technique. |
16:25
|
Spatio-Temporal Encoding | |
1EECS Department, UC Berkeley, Berkeley, CA, United States |
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Spatiotemporal Encoding MRI imposes phase modulation (quadratic phase modulation-SPEN, hyperbolic phase modulation-xSPEN) on top of the regular encoded signal, opens a new window for enhancing immunity to image distortions and accelerating the acquisition. In this presentation, I will first introduce the principle of spatiotemporal encoding MRI, and then show the state-of-art applications based on SPEN and xSPEN techniques. |
16:45
|
MRI with Non-Linear Gradients | |
1Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States |
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This course will attempt to describe general features of nonlinear gradient encoding, as well as provide an overview of the methods and applications reported in the literature. |
17:05
|
When Will Non-k-Space-Based MRI Become a Clinical Reality? | |
1Mayo Clinic, United States |
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The purpose of this presentation is to describe the various levels of efficacy or value which are faced by a new technique which is being considered for clinical implementation, including the motivation for these. Further, this general framework is expanded upon for techniques which might be considered “non-traditional.” |
17:25
|
Panel Discussion |
17:45
|
Adjournment |
| 891
|
Pitch: 15:45 Poster: 16:45 Plasma 1
|
Structural brain network properties and cognitive impairment in adolescents after radiation therapy |
1Department of Radiology & Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States, 2Department of Neurology, University of California, San Francisco, San Francisco, CA, United States |
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Cranial radiation therapy (CRT) is an effective brain cancer treatment but many patients exhibit cognitive deficits over time. We studied these deficits in adolescent and young adult survivors of pediatric brain cancer with prior CRT using white matter graph network analysis. Executive function and working memory performance were correlated with structural connectivity metrics. Global integration and segregation metrics were associated with neurocognitive deficits, as well as connectivity at domain-specific regions. Our results support past findings of CRT’s negative cognitive effects and suggest that they are driven through structural changes in brain white matter |
| 892 | Pitch: 15:45 Poster: 16:45 Plasma 2
|
Motion-Restricted Sodium Ion Pools Analysis on Glioblastoma patients with Combinatorial Therapy |
1Center for Advanced Imaging Innovation and Research (CAI2R), NYU School of Medicine, New York, NY, United States, 2Center for Biomedical Imaging, Department of Radiology, NYU School of Medicine, New York, NY, United States, 3Department of Neurosurgery, NYU School of Medicine, New York, NY, United States, 4Department of Neurology, NYU School of Medicine, New York, NY, United States |
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Differentiating treatment response from Glioblastoma progression with conventional proton magnetic resonance imaging (MRI) is challenging as it cannot unambiguously differentiate between early therapeutic response and treatment-related pseudo-progression. Based on the stability of sodium’s relaxation rate across human brains, a recent approach for separating motile and motion-restricted sodium ion pools (MRSIP) in the brain was introduced. In this study we evaluate the relationship between MRSIP concentration and the treatment evolution on a pool of glioma patients. |
| 893
|
Pitch: 15:45 Poster: 16:45 Plasma 3
|
Structural Connectivity abnormality in children treated for Medulloblastoma |
1The Hospital for Sick Children, Toronto, ON, Canada |
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Curative treatments for medulloblastoma impart significant toxicity on the developing brain. Though changes to white matter have been described, there remains a limited understanding of the effects of treatment on the structural connectome, which is thought to subserve complex and dynamic behaviors. Identifying compromise within the connectome may elucidate mechanisms of toxicity among survivors. We analyzed connectomic differences between survivors and age-matched controls. We identified two networks situated posteriorly with reduced white matter microstructure in survivors. Our findings complement studies showing long-term effects of treatment on brain structure, and localize these effects to areas around the site of the tumor. |
| 894 | Pitch: 15:45 Poster: 16:45 Plasma 4
|
Global Planar Convolutions for improved context aggregation in Brain Tumor Segmentation with MR images |
1QMENTA Inc., Barcelona, Spain, 2Computer Vision Center, Universitat Autònoma de Barcelona, Barcelona, Spain, 3SIMBIOsys, Universitat Pompeu Fabra, Barcelona, Spain |
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Brain tumors pose a significant social and economic burden worldwide. A key to |
| 895 | Pitch: 15:45 Poster: 16:45 Plasma 5
|
Feasibility study on automated white matter tract segmentation in neurosurgical pre-operative planning |
1Medical Physics Group, Inst. of Diagnostic and Interventional Radiology, Jena University Hospital, Jena, Germany, 2Section of Neuroradiology, Inst. of Diagnostic and Interv. Radiology, Jena University Hospital, Jena, Germany, 3Division of Medical Image Computing (MIC), German Cancer Research Center (DKFZ), Heidelberg, Germany, 4Department of Neurosurgery, Jena University Hospital, Jena, Germany, 5Inst. of Diagnostic and Interventional Radiology, Jena University Hospital, Jena, Germany, 6Michel-Stifel-Center-Jena for Data-Driven and Simulation Science, Friedrich-Schiller-University Jena, Jena, Germany |
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In neuro-surgical preoperative planning of extirpation of large tumors it is important to locate the paths of critical cerebral nerve fiber bundles (e.g. corticospinal-tract). Manual fiber bundle selection is elaborate, requires expert knowledge and is prone to user errors. Therefore, in this study a fully automatic pipeline for white matter bundle segmentation was setup, incorporating recently published white matter bundle segmentation based using DNN, and tested with 12 patients suffering from large brain lesions. In all cases the position of the corticospinal tracts was evaluated as plausible, although in at least one hemisphere this tract was affected by the lesion. |
| 896 | Pitch: 15:45 Poster: 16:45 Plasma 6
|
MR spectroscopy of 2-hydroxyglutarate in patients with brainstem tumors in vivo |
1UT Southwestern Medical Center, Dallas, TX, United States, 2Philips Healthcare, Andover, MA, United States |
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MRS of 2-hydroxyglutarate (2HG) has the great potential for determining the isocitrate dehydrogenase (IDH) mutational status in brain tumors noninvasively. This clinical role of 2HG MRS may be demonstrated most clearly in patients with brainstem gliomas or deep brain lesions, where surgical biopsy presents significant risk of permanent neurological deficit. We report 2HG MRS data in patients with brainstem tumors. 2HG was evaluated, using a 2HG-optimized TE 97ms PRESS at 3T, in 12 subjects with brainstem lesions in vivo. We also presents data of monitoring the tumor with serial 2HG MRS scans. |
| 897 | Pitch: 15:45 Poster: 16:45 Plasma 7
|
Quantification of regional pathophysiology in Glioblastoma Multiforme |
1Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom, 2Wellcome Centre for Integrative Neuroscience, University of Oxford, Oxford, United Kingdom, 3Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom, 4Oxford University Hospitals NHS Trust, Oxford, United Kingdom, 5Wellcome Centre for Integrative Neuroscience, university of Oxford, Oxford, United Kingdom, 6Department of Oncology, University of Oxford, Oxford, United Kingdom, 7Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, United Kingdom |
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Patients with glioblastoma multiforme (GBM) have extremely poor prognosis due to therapy resistance, aggressiveness, and poor understanding of pathophysiology. Here, we use APT-CEST and ASL MRI to noninvasively probe both pH and perfusion in ten patients with primary GBM, prior to surgical/therapeutic intervention. We observe an overall increase in APT and CBF contrast, consistent with both intracellular alkalosis and angiogenesis. Clustering analysis revealed a strong regional association between pH and CBF in 9/10 patients suggestive of similar spatial disruptions. The ability to image concomitant changes in pH and perfusion may provide a novel way to stratify patients for targeted therapeutics. |
| 898 | Pitch: 15:45 Poster: 16:45 Plasma 8
|
Brain Tumor Simulator: Creating Ground Truth for Evaluation of Complex MR Acquisition and Reconstruction Methodologies |
1Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States, 2Department of Radiology, University of Wisconsin-Madison, Madison, WI, United States, 3Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 4Department of Neurological Surgery, University of Wisconsin-Madison, Madison, WI, United States |
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New dynamic MRI methods promise to better characterize and monitor the vexing problem of brain cancer. Assessing these methods and the assumptions they rely upon is difficult as 1) no known gold standard is available for brain tumors and 2) the time window of availability for brain cancer volunteers is narrow. We present a simulator that generates realistic, heterogeneous, tumor models overlaid over normal brain tissue with user-specified permeability parameters. The simulator generates raw data for arbitrary k-space acquisition strategies. Using this simulator, new methodologies for various tumor types and sizes can be assessed before the first volunteer is ever recruited. |
| 899 | Pitch: 15:45 Poster: 16:45 Plasma 9
|
Brain Tumor Segmentation and Uncertainty Quantification Using Monte Carlo dropout sampling |
1Laboratory for Imaging Science and Technology, Department of Electrical and Computer Engineering, Seoul National University, Seoul, Korea, Republic of |
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Deep learning has made tremendous progress in many areas but it is often regarded as a black box with uncertainty in outcome. Therefore, a more reliable method is necessary to be applied in a medical field. In this work, we designed a brain tumor segmentation network that provides uncertainty quantification using Monte Carlo dropout sampling. The proposed method resulted in considerable outcomes and also provided an option for selectively maximizing precision or recall using the uncertainty quantification. |
| 900 | Pitch: 15:45 Poster: 16:45 Plasma 10
|
Basal ganglia iron deposition as a biomarker of brain tumor severity |
1Radiology, Medical College of Wisconsin, Milwaukee, WI, United States, 2Biomedical Engineering, Medical College of Wisconsin, Milwaukee, WI, United States, 3Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States |
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This study utilized quantitative susceptibility mapping (QSM) to investigate basal ganglia iron deposition in 27 patients diagnosed with gliomas. Basal ganglia QSM values of patients with glioblastomas were found to be higher than those of patients with tumors of lower grades, suggesting that iron deposition in the basal ganglia may serve as a biomarker of brain tumor severity. |
| 901 | Pitch: 15:45 Poster: 16:45 Plasma 11
|
Voxelwise correlation between vascular parameters obtained with ASL and DSC as predictor of IDH-mutation status in non-enhancing glioma |
1Department of Radiology & Nuclear Medicine, Erasmus Medical Centre, Rotterdam, Netherlands, 2Department of Neurosurgery, Erasmus Medical Centre, Rotterdam, Netherlands, 3Department of Neurology, Erasmus MC, Rotterdam, Netherlands, 4Department of Pathology, Erasmus MC, Rotterdam, Netherlands |
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Previous studies have shown good correlation between ASL and DSC vascular parameters as predictors of glioma grade, indication an option to omit DSC imaging in light of the recent finding of gadolinium deposition in the brain. However, in general these comparative studies were conducted before the recent update of the World Health Organisation classification of brain tumours. This study shows the potential of voxelwise correlations of vascular parameters obtained with ASL and DSC as predictors of IDH-mutation status in non-enhancing glioma and highlights that IDH-mutation status should be included in comparative studies of ASL and DSC vascular parameters in glioma. |
| 902 | Pitch: 15:45 Poster: 16:45 Plasma 12
|
Diffusion and quantitative MR changes in normal appearing brain following radiotherapy. |
1Institute of Radiooncology - OncoRay, Helmholtz-Zentrum Dresden-Rossendorf, Rossendorf, Germany, 2Institute of Neuroradiology, University Hospital Carl Gustav Carus and Medical Faculty of Technische Universität Dresden, Dresden, Germany, 3Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany, 4OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany, 5National Center for Tumor Diseases (NCT), Partner Site Dresden, Germany: German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany, and; Helmholtz Association / Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Dresden, Germany, 6German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany |
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Irradiation of gliomas inevitably involves irradiation of surrounding normal appearing brain. We analysed longitudinal, quantitative MR data of 24 glioma patients before and at 3, 6, 9 and 12 months after radiotherapy and found significant reductions in mean-, axial- and radial diffusivity as well as in T2* in normal appearing white matter. These changes are greater the higher the received dose and progress over time. The diffusion reductions point towards axonal swelling. T2* reductions indicate either increased tissue heterogeneity, e.g. due to microglial activation or changes in tissue oxygenation, e.g. due to vascular alterations. |
| 903 | Pitch: 15:45 Poster: 16:45 Plasma 13
|
A Brain Morphometric MRI Study on Patients with Suprasellar Tumors: Preoperative and Postoperative Assessment |
1State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China, 2Sino-Danish College, University of Chinese Academy of Sciences, Beijing, China, 3Beijing Neurosurgical Institute, Capital Medical University, Beijing, China, 4The Innovation Center of Excellence on Brain Science, Chinese Academy of Sciences, Beijing, China, 5Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China, 6Beijing Institute for Brain Disorders Brain Tumor Center, Beijing, China, 7China National Clinical Research Center for Neurological Diseases, Beijing, China |
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It has been reported that suprasellar tumors affect patients’ visual field and visual functional network. In this study, longitudinal brain morphometric assessment was performed pre- and post-operation based on 13 suprasellar tumors patients. The gray matter volume of rectus increases, but insular, caudate, and putamen decrease after |
| 904 | Pitch: 15:45 Poster: 16:45 Plasma 14
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Segmentation of Brain Metastatic Lesions in Magnetic Resonance Imaging using Deep Learning |
1Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States, 2Department of Radiology, Brigham and Women’s Hospital, Boston, MA, United States, 3Massachusetts General Hospital, Boston, MA, United States, 4Stephen E. and Catherine Pappas Center for Neuro-Oncology, Massachusetts General Hospital, Boston, MA, United States |
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Magnetic resonance imaging plays a key role in assessing the efficacy of treatment for patients with brain metastases by enabling neuroradiologists to track lesions sizes across time points. However, manual segmentation of multiple time-points is prohibitively time-consuming, thus precluding its use in current clinical workflow. In this study, we develop a deep learning approach to automatically segment metastatic lesions, and demonstrate that our predicted segmentation has high agreement with the gold-standard manual segmentation. |
| 905 | Pitch: 15:45 Poster: 16:45 Plasma 15
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Quantitative deltaT1 (qDT1) as a Replacement for Adjudicated Central ReaderAnalysis: A Sub-Analysis of the RTOG 0625/ACRIN 6677 Multi-Center Brain Tumor Trial |
1Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States, 2Medical College of Wisconsin, Milwaukee, WI, United States, 3Brown University School of Public Health, Providence, RI, United States, 4Radiology, Medical College of Wisconsin, Milwaukee, WI, United States, 5Jensen Informatics LLC, Brookfield, WI, United States, 6Duke University Medical Center, Durham, NC, United States, 7Rhode Island Hospital & Alpert Medical School of Brown University, Providence, RI, United States |
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A semi-automatic method for delineating contrast-agent enhancing brain tumor, called quantitative delta T1 (qDT1), was compared to central reader analysis of clinical trial data. The qDT1 method demonstrated equivalence with expert reads for determination of early tumor progression and proved superior for further distinguishing responders from non-responders/non-progressors at the week 8 time point. Using qDT1 provides a solution to the high percentage of intra- and inter-observer disagreements, while being easier to use and more reliable for the daily clinical assessment of tumor response to therapy, as well as for large scale clinical trials. |
| 906
|
Pitch: 15:45 Poster: 16:45 Plasma 16
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Capturing brain spatial topography reconfiguration using ultra-high-order independent component analysis (ICA) |
1The Mind Research Network, Albuquerque, NM, United States, 2School of Medicine, Yale University, New Haven, CT, United States, 3Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, NM, United States |
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The brain reorganizes its activity interactively at different temporal and spatial scales. These reconfigurations include variations within a region’s |
| 907
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Pitch: 15:45 Poster: 16:45 Plasma 17
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Characterizing Hierarchical Spatial Variations of the Brain: A Novel Analysis Framework to Study Dynamic Brain Function |
1The Mind Research Network, Albuquerque, NM, United States, 2Department of Psychiatry and Behavioral Sciences, University of New Mexico, Albuquerque, NM, United States, 3Department of Psychiatry, University of North Carolina, Chapel Hill, NC, United States, 4Department of Psychiatry, University of California San Francisco, San Francisco, CA, United States, 5San Francisco VA Medical Center, San Francisco, CA, United States, 6Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, CA, United States, 7Department of Psychiatry, University of Minnesota, Minneapolis, MN, United States, 8School of Medicine, Yale University, New Haven, CT, United States, 9Department of Psychiatry and Human Behavior, University of California Irvine, Irvine, CA, United States, 10Department of Psychology, Georgia State University, Atlanta, GA, United States, 11Department of Psychiatry, University of Iowa, Iowa, IA, United States, 12Clinical Translational Neuroscience Laboratory, Department of Psychiatry and Human Behavior, University of California Irvine, Irvine, CA, United States, 13Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, NM, United States |
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A novel, data-driven analysis framework was proposed to characterize the spatial variation of brain function. This framework utilizes the concept of a functional hierarchy and encapsulates the spatiotemporal variations of brain functional domains from its associated high-order intrinsic connectivity networks. The results show spatial fluidity behavior of functional domains, including a broad spectrum of changes in regional associations from strong coupling to complete decoupling. Interestingly, such spatial variations drive the interactions between functional domains, showing concurrent evaluation in time. Our results further highlight that the captured spatial dynamics can serve as potential biomarkers for patients with schizophrenia. |
| 908
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Pitch: 15:45 Poster: 16:45 Plasma 18
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Principal gradient of resting-state functional connectivity represents a principal propagating direction of spontaneous brain activity |
1Biomedical Engineering, Pennsylvania State University, State College, PA, United States, 2Institute for CyberScience, Pennsylvania State University, State College, PA, United States |
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Decomposing functional connectome to low-dimensional spaces revealed a principal gradient cross brain hierarchy from the primary sensorimotor areas to the default mode network. However, the physiological meaning underlying this principal gradient remains unclear. Here, we showed significant propagating activities of resting-state fMRI along this gradient direction. We further used simulation to demonstrate that the propagating activity can result in a gradient in its propagating direction with the use of the low-dimensional embedding method. Overall, the findings suggest that the principal connectivity gradient actually represents the major propagating direction of spontaneous brain activity, which is likely across brain hierarchies. |
| 909 | Pitch: 15:45 Poster: 16:45 Plasma 19
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A unified ICA framework for identifying neuro-markers in functional connectivity among multiple different brain disorders |
1The Mind Research Network, Albuquerque, NM, United States, 2School of Computer and Information Technology, Shanxi University, Taiyuan, China, 3Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, NM, USA, Albuquerque, NM, United States, 4Brainnetome Center and National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, China, 5Lawson Health Research Institute, London Health Sciences Centre, London, ON, Canada, 6Department of Psychiatry, University of Western Ontario Schulich School of Medicine and Dentistry, London, ON, Canada |
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Functional network from ICA using fMRI data has been applied to identify biomarkers of brain disorders. However, the networks from ICA might be slightly different, making the comparison of results across different studies/diseases difficult. We propose a data-driven framework to estimate functional network maps and their inter-connectivity for linking neuromarkers among different disorders and studies. Our method is capable of computing functional networks which are optimized for independence based on each coming individual-subject data, and remaining their correspondence across different subjects by using unbiased templates. The results show this approach is an effective method for studying and classifying multiple-disorders. |
| 910 | Pitch: 15:45 Poster: 16:45 Plasma 20
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Novel 4-D Algorithm for Functional MRI Image Regularization using Partial Differential Equations |
1Athena Project-Team, Inria, Université Côte d'Azur, Sophia Antipolis - Méditerranée, France |
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State-of-the-art techniques for denoising functional MRI (fMRI) images consider the problems of spatial and temporal regularization as decoupled tasks. In this work we propose a partial differential equations (PDEs) -based algorithm that acts directly on the 4-D fMRI image. Our approach is based on the idea that large image variations should be preserved as they occur during brain activation, but small variations should be smoothed to remove noise. Starting from this principle, by means of PDEs we were able to smooth the fMRI image with an anisotropic regularization, thus recovering the location of the brain activations in space and their timing and duration. |
| 911 | Pitch: 15:45 Poster: 16:45 Plasma 21
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Subject specific functional connectivity fingerprints made possible with temporal ICA |
1Donders Centre for Brain, Cognition and Behaviour, Radboud University, Nijmegen, Netherlands, 2MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, Netherlands, 3Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen, Germany |
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In the current contribution we use an ultra-fast fMRI sequence (TR=0.158s) and temporal ICA to generate subject specific fingerprints of unprecedented specificity. These "fingerprints" are generated from the mappings between common RSNs and time-series of temporal ICs. We also show that these time-series are virtually free from physiological contamination. |
| 912 | Pitch: 15:45 Poster: 16:45 Plasma 22
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Deconvolution of multi-echo functional MRI data with Multivariate Multi-Echo Sparse Paradigm Free Mapping |
1Basque Center on Cognition, Brain and Language, Donostia - San Sebastián, Spain, 2Section on Functional Imaging Methods, National Institute of Mental Health, Bethesda, MD, United States |
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This work introduces a novel multivariate deconvolution method to blindly estimate neuronal-related -signal changes in multi-echo fMRI data without prior knowledge of their timings. In contrast to current voxel-based approaches, this algorithm simultaneously deconvolves all brain’s voxel time series and uses structured spatio-temporal regularization to improve the quality of the estimates. Besides, it employs stability selection procedures to overcome the selection of regularization parameters of the deconvolution problem. We evaluate its performance in multiple realistic simulations, showing its potential to blindly detect BOLD events in paradigms when no prior information can be obtained. |
| 913 | Pitch: 15:45 Poster: 16:45 Plasma 23
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Dynamic functional connectivity and its relation to structural rich-club organisation |
1School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, Australia, 2Melbourne School of Engineering, The University of Melbourne, Melbourne, Australia, 3Melbourne Neuropsychiatry Centre, The University of Melbourne, Melbourne, Australia, 4Sydney Imaging, The University of Sydney, Sydney, Australia, 5Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, Australia |
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The relationship between static functional connectivity (FC) and structural connectivity (SC) has been long-recognised. More recently, functional connectivity has increasingly focused on the investigation of temporal variations of the BOLD fMRI signal; however, the role of SC on the observed FC fluctuations is not trivial or well understood. We show here that the structural rich-club organisation of the brain better describes the FC fluctuations than simply considering SC strength. |
| 914 | Pitch: 15:45 Poster: 16:45 Plasma 24
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Effect of physiological correction on residual motion in resting-state fMRI |
1Rotman Research Institute, University of Toronto, Toronto, ON, Canada, 2Medical biophysics, University of Toronto, Toronto, ON, Canada |
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There remain significant residual motion effects in the resting-state fMRI signal after motion correction, motion censoring, and motion regression. Due to the residual motion in the BOLD signal, use of data-driven nuisance regressors for physiological noise correction can potentially be effective in removing the residual motion. The aim of the current study is to investigate the effect of different regressors on residual motion. Our data show that the residual motion is removed by aCompCor and GSR. We recommend the output of the preprocessing pipelines be correlated against framewise motion to ensure any residual motion is removed prior to subsequent analysis. |
| 915 | Pitch: 15:45 Poster: 16:45 Plasma 25
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The Effect of Model-Based and Data-Driven Physiological Noise Correction Techniques on the Degree of Clustering in Resting-State fMRI Functional Connectivity |
1Graduate Program in Biological and Biomedical Engineering, McGill University, Montreal, QC, Canada, 2Department of Bioengineering, McGill University, Montreal, QC, Canada |
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One of the most essential steps in the analysis pipeline of fMRI studies is the correction for fluctuations due to physiological processes and head motion. This is particularly relevant for resting-state fMRI functional connectivity (FC) studies, where the SNR is lower and physiological fluctuations may introduce common variance in the signals from different areas of the brain, inflating FC. Several physiological noise correction techniques have been developed over the years. Nevertheless, an optimal preprocessing pipeline for FC has not yet been established. In this study, we examined more than 400 different pipelines using both model-based and data-driven techniques and have found that tissue-based regressors significantly improve the identifiability of well-known resting-state networks. |
| 916 | Pitch: 15:45 Poster: 16:45 Plasma 26
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Physiologic noise correction effects on seed based spontaneous co-activation pattern analysis |
1Radiology, Cleveland Clinic, Cleveland, OH, United States, 2Biomedical Engineering, Pennsylvania State University, University Park, PA, United States, 3Institute for Cyber Science, Pennsylvania State University, University Park, PA, United States |
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The Spontaneous co-activation (CAP) approach has shown the potential to investigate the dynamic change in resting state fMRI. However, dynamic rs-fMRI would be expected to be sensitive to physiologic fluctuation since dynamic changes of CAP pattern could be affected by the spatiotempolly correlated physiologic pulsation in the brain. We investigate the physiologic noise effects on seed-based CAP analysis in this study, and we find that the physiologic noise corrected data generates not only a different fraction and consistency of CAP patterns, but also different CAP patterns. |
| 917
|
Pitch: 15:45 Poster: 16:45 Plasma 27
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An automated deep neural network for denoising task-based fMRI data |
1Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV, United States, 2University of Colorado, Boulder, CO, United States |
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Deep neural networks (DNN) recently have gained increasing interest in neuroimaging research for different applications. However, it remains to be an open question whether and how artificial neural networks can be used for denoising neuroimaging data. In this study, we have designed a DNN network for denoising task-based fMRI data. The result showed that DNN can efficiently reduce physiological fluctuation and achieve more homogeneous fMRI activation maps. |
| 918 | Pitch: 15:45 Poster: 16:45 Plasma 28
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Task-fMRI: pre-whitening and hemodynamic response function modeling substantially impair specificity and sensitivity |
1Dept. of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom, 2Dept. of Pure Mathematics and Mathematical Statistics, University of Cambridge, Cambridge, United Kingdom, 3MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, United Kingdom |
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Given the recent controversies in some neuroimaging statistical methods, we investigated pre-whitening and hemodynamic response function (HRF) modeling techniques available in AFNI, FSL and SPM and used in task-fMRI studies. We found that pre-whitening often leaves much positive autocorrelated noise in the data, which leads primarily to false positives. Also, we observed that for an event-related design dataset, the use of the simple canonical HRF led to a strong sensitivity deterioration. Currently, both specificity and sensitivity could be increased in task-fMRI studies with some less popular, but widely available statistical methods. |
| 919 | Pitch: 15:45 Poster: 16:45 Plasma 29
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Towards a Standard Pipeline for the Analysis of Human Spinal Cord fMRI Data Series |
1IRCCS Fondazione Santa Lucia, Rome, Italy, 2NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada, 3Enrico Fermi Centre, Rome, Italy |
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Spinal cord functional magnetic resonance imaging (scfMRI) is still insufficiently exploited in clinical settings due to several challenging problems related to image acquisition and analysis. In the present study, we implemented and optimized a scfMRI data analysis pipeline built around the Spinal Cord Toolbox (SCT). We acquired axial and sagittal functional images at 3T from the spinal cord of forty-six healthy subjects performing an isometric motor task. Using our SCT-based pipeline, we substantially improved motion correction and image registration. Furthermore, we found task-induced activations with a high level of statistical significance. |
| 920 | Pitch: 15:45 Poster: 16:45 Plasma 30
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Computationally efficient depth-mapping scheme for human colliculi |
1Neuroscience, Rice University, Houston, TX, United States, 2Baylor College of Medicine, Houston, TX, United States, 3University of Chicago (NorthShore), Chicago, IL, United States |
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Determining depth in human colliculi is prone to errors due to its rapidly varying curvature. Thus, Euclidean definitions of depth fall short in describing the topography of deep collicular tissue. We developed a method of surface-based depth mapping that calculates a depth coordinate using an algebraic level-set method. We then generated kernels based on this level-set depth that sample functional data in a nonlinear trajectory with increasing depth. Using this method, we re-analyzed data on polar-angle representation of saccadic eye movements and were able to produce smoother laminar profiles that confirmed distinct depth-dependence of saccade-evoked activity. |
| 921
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Pitch: 15:45 Poster: 16:45 Plasma 31
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GRATER-based RF pulse predistortion improves multiband bSSFP imaging |
1Biomedical Engineering, University of Southern California, Los Angeles, CA, United States, 2Electrical Engineering, University of Southern California, Los Angeles, CA, United States |
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We present a hardware-free way to mitigate RF envelope error that has the potential to be extremely fast (<1 min), and to benefit simultaneous multislice (SMS) balanced steady-state free precession (bSSFP) imaging. This approach improves RF waveform fidelity 9-fold in a variety of multiband pulses, and correspondingly reduces bSSFP spurious side-lobe excitation 3-fold. This provides 4-fold reduction in SMS bSSFP side-lobe signal. |
| 922
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Pitch: 15:45 Poster: 16:45 Plasma 32
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Correcting Eddy Current Induced Geometric Distortion for High Resolution Multi-Band Diffusion Weighted SE-EPI with Magnetic Field Monitoring at 7T |
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 2Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, United States |
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DW-EPI suffers from geometric distortion induced by eddy current from strong diffusion gradients. Magnetic field monitoring using 19F probes followed by algebraic reconstruction incorporating higher order field perturbation has been proposed to address such issue and was applied for single-band acquisition at 3T. In this study, this approach was implemented for high resolution multiband in vivo brain DW-EPI acquisition at 7T, taking into account of scanner imposed global phase modulation for eddy-current correction. Preliminary results showed successful correction of the geometric distortion across all diffusion gradients. Further investigation needs to be made to increase the SNR of DW images. |
| 923
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Pitch: 15:45 Poster: 16:45 Plasma 33
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Frequency adjustable magnetic field probes |
1Department of Radiology - Medical Physics, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany |
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A new manufacturing method for the creation of magnetic field probes is presented. The method allows realizing field probes that can be frequency adjusted during MR acquisition. This opens up new possibilities for the use of field probes during MR experiments. In the presented proof-of-concept case, the field probe’s position in a standard gradient echo experiment was shifted within the field of view by changing its Larmor frequency using an additional micro-coil. |
| 924
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Pitch: 15:45 Poster: 16:45 Plasma 34
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Trajectory correction for ultrashort echo-time (UTE) imaging based on the measurement of the gradient impulse response function (GIRF) with a thin-slice method |
1Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany, 2Philips Research, Hamburg, Germany |
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Reconstruction of high-quality ultrashort echo-time UTE images requires precise knowledge of the dynamic gradient magnetic fields used to perform the spatial encoding during the ramp up of the gradients. System delays and eddy currents can perturb the gradient fields and significantly degrade the image quality. The present study proposes the measurement of the gradient transfer response function with standard scanner hardware to correct the UTE readout gradients and to improve UTE image quality. |
| 925
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Pitch: 15:45 Poster: 16:45 Plasma 35
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Real-time shimming in the cervical spinal cord using an 8-channel AC/DC array and a capacitive respiratory sensor |
1NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montréal, Montreal, QC, Canada, 2Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States, 3Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 4Harvard Medical School, Boston, MA, United States, 5Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, United States, 6Functional Neuroimaging Unit, CRIUGM, University of Montreal, Montreal, QC, Canada |
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Spinal cord imaging remains challenging in large part due to the temporal variations in B0 caused by respiration. This study introduces a simple circuit design for a capacitive respiratory sensor and demonstrates the utility of this device in the context of real-time shimming the neck using an 8-channel "AC/DC" (integrated RF receive + multi-coil shim) array. Using this approach, motion artifacts in a multi-echo T2*-weighted acquisition are shown to be considerably reduced. |
| 926 | Pitch: 15:45 Poster: 16:45 Plasma 36
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3D Bloch-Siegert EPI B1+-mapping |
1Institute of Medical Engineering, Graz University of Technology, Graz, Austria, 2BioTechMed Graz, Graz, Austria |
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In this work we investigate the feasibility of a double shot acquisition for 3D Bloch-Siegert B1+ mapping. Therefore, we combine the previously proposed variational reconstruction algorithm for highly subsampled Bloch-Siegert data with an EPI readout. The acquired dataset was retrospectively under-sampled and the reconstruction results are compared to the fully sampled reference, a zero padded low resolution estimate and to results acquired with a much more robust GRE readout. We can show that the results are in good accordance to the fully sampled reference and the GRE acquisition for acceleration factors of up to 100 making double shot acquisition possible. |
| 927 | Pitch: 15:45 Poster: 16:45 Plasma 37
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Accelerate GIRF measurement using an interleaved off-isocenter method |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China |
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Gradient impulse response function (GIRF) can be used to characterize gradient systems. GIRF measurements typically require multiple triangular waveforms of different durations to be played in three gradient axes. Using the traditional method, the entire measurement takes more than 10 hours. In this study, we propose an interleaved off-isocenter method to measure GIRFs. It can save nearly 50% of measurement time. The measured results are consistent with those measured using the time-consuming traditional method. |
| 928 | Pitch: 15:45 Poster: 16:45 Plasma 38
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Inter-frame phase alignment for Echo Planar Imaging calibration data acquired with opposite read-out polarities |
1Siemens Medical Solutions USA, Boston, MA, United States, 2Siemens Shenzhen Magnetic Resonance, Shenzhen, China, 3Brigham and Women's Hospital, Boston, MA, United States, 4Siemens Healthcare GmbH, Erlangen, Germany, 5Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Boston, MA, United States |
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Echo-planar imaging is subject to Nyquist ghosting due to its use of fast gradient switching. To correct for this artifact, several methods have been proposed that involve a pair of calibration imaging frames acquired with opposite readout polarities. We show that a small, relative shift in the phase-encoding direction often exists between these calibration frames that may lead to compromised image quality. A simple method is proposed to account for the shift and it is shown to be effective at correcting residual Nyquist ghost in the dual-polarity GRAPPA approach. This is demonstrated in in vivo and phantom data from 3T and 7T. |
| 929 | Pitch: 15:45 Poster: 16:45 Plasma 39
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Model-Based Single-Shot EPI Reconstruction with Sparsity Regularization |
1Department of Radiology, Mayo Clinic, Rochester, MN, United States, 2Department of Radiologic Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand |
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Echo planar imaging (EPI) is widely used clinically for its speed, but is known to be sensitive to non-idealities like B0 field inhomogeneity, eddy currents, and gradient nonlinearity. Such non-idealities are not typically managed during image reconstruction, resulting in geometrically distorted images. Post-processing corrections (e.g., image-based interpolation) usually tend to degrade resolution. In this work, a comprehensive model-based reconstruction framework that prospectively and simultaneously accounts for non-idealities in accelerated single-shot EPI acquisitions is proposed. Sparsity regularization is also incorporated to mitigate noise amplification. The proposed algorithm is demonstrated on brain MRI data acquired on a compact 3T MRI system. |
| 930 | Pitch: 15:45 Poster: 16:45 Plasma 40
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Spiral imaging using a fully automatic pre-emphasis based on the Gradient System Transfer Function (GSTF) |
1Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Würzburg, Germany, 2Comprehensive Heart Failure Center Würzburg, Würzburg, Germany |
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The Gradient System Transfer Function (GSTF) was used to implement a fully automatic gradient pre-emphasis, enabling double-oblique MR imaging for arbitrary k-space trajectories. The developed method was tested using a standard 2D FLASH spiral sequence with several orientations in a structural phantom and an exemplary in vivo cardiac study. |
| 931 | Pitch: 15:45 Poster: 16:45 Plasma 41
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Radial streak artifact reduction in multi-contrast imaging and parameter mapping using beamforming |
1Medical Imaging, University of Arizona, Tucson, AZ, United States, 2Electrical and Computer Engineering, University of Arizona, Tucson, AZ, United States |
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Streaking artifacts are a common source of image quality degradation in radial MRI even with sufficient sampling. While coil removal is popularly used to mitigate streaking artifacts, this method is known to suffer from undesirable signal loss. Recently, a streak artifact reduction method has been proposed that offers a better balance between artifact reduction and signal retention. This approach endows the channel combination maps with the ability to suppress streaking artifacts and is implemented as a post-processing step. In this work, we present a computationally efficient refinement of this approach and extend it to multi-contrast imaging and parameter mapping applications. |
| 932 | Pitch: 15:45 Poster: 16:45 Plasma 42
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Template-based field map prediction for whole-body shimming applications |
1United Imaging Healthcare, Shanghai, China, 2UIH America, Houston, TX, United States |
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For a whole-body scan, shimming are required to be carried out in multiple bed positions to provide homogeneous field for imaging different body parts. Thus, techniques to shorten the shimming time are required. This work presents a rapid B0 field prediction method for whole-body shimming based on a large field map database of different body parts. A range of applications could benefit from this technique. |
| 933 | Pitch: 15:45 Poster: 16:45 Plasma 43
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A novel method combining Dixon water-fat separation and BLADE imaging |
1Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, China, 2Siemens Medical Solutions USA, Boston, MA, United States |
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Fat suppression and motion artifacts are still challenging in clinical MRI for certain body regions. In this work a novel acquisition method combining Dixon’s method and BLADE (or PROPELLER, periodically rotated overlapping parallel lines with enhanced reconstruction) is proposed, to address fat suppression and motion artifacts simultaneously. We show that the proposed technique acquires data efficiently while avoiding the potential misalignment between echoes as well as the phase inconsistency introduced by different readout directions. |
| 934 | Pitch: 15:45 Poster: 16:45 Plasma 44
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Deep CNN for Outlier Detection: A Complementary Tool to Low-Rank based Methods for Reducing Motion Artefacts |
1Radiology, University of California Los Angeles, Los Angeles, CA, United States, 2Biomedical Physics Inter-Departmental Graduate Program, University of California Los Angeles, Los Angeles, CA, United States |
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Motion is common in MR image acquisitions. It causes artefacts in image quality that requires repeated scans, increasing the burden for patients and providers. There have been advances on hardware and software fronts in the quest to avoid such issues. The latter include data consistency methods which require no additional installation but can fail to detect high frequency outliers in k-space. We propose a Deep CNN approach to detect motion-corrupted phase encode lines, coupled with a low-rank reconstruction. This approach improves outlier detection in comparison to low-rank only methods and accelerates reconstruction time. |
| 935 | Pitch: 15:45 Poster: 16:45 Plasma 45
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Cardiac bSSFP accelerated using minimum-TR multiband RF pulse design and GIRF-correction |
1Biomedical Engineering Department, School of Biomedical Engineering & Imaging Sciences, King's College London, London, United Kingdom, 2Centre for the Developing Brain, School of Biomedical Engineering & Imaging Sciences, King's College London, London, United Kingdom |
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Cardiac balanced SSFP using simultaneous multi-slice acquisition is limited by RF pulse duration and SAR. The interplay of these constraints means that the minimum pulse duration does not usually yield the minimum TR. We show that multiband RF pulses designed using VERSE to directly minimize TR can yield a reduced TR. The result is demonstrated in a multiband-2 sequence on a 3T clinical system where the TR is only 15% longer than for single-slice excitation and the time per slice is reduced by 44%. |
| 936
|
15:45
|
DiSpect: Displacement Spectrum Imaging of Flow, Diffusion and Tissue Perfusionusing Spin-Labeling and Stimulated Echoes |
1Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, Berkeley, CA, United States |
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We present a Fourier-encoding variant of Displacement Encoding with Stimulated Echoes (DENSE). DENSE encodes bulk displacement of spins but fails to capture partial volume displacement or flow. By performing multiple scans with increasing DENSE encoding, we are able to resolve the spectrum of displaced spins within a voxel and differentiate it from static tissue. Our approach opens the possibility of quantitatively measuring complex spin dynamics, such as motion, flow, diffusion and perfusion. We present results in a flow phantom and in-vivo brain. Our results demonstrate sensitivity to slow CSF flow, blood flow, and tissue perfusion. |
| 937
|
15:57
|
MESMERISED: Super-accelerated 7T STEAM imaging for quantitative T1 and diffusion MRI |
1Cognitive Neuroscience Department, Maastricth University, Maastricht, Netherlands, 2Cognitive Neuroscience Department, Maastricht University, Maastricht, Netherlands |
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We present the MESMERISED sequence which super-accelerates 7T STEAM imaging by employing both echo-shifting and multiband/simultaneous multislice acceleration. This leads to very high multiplicative acceleration factors and time efficiency for T1w and diffusion imaging. We illustrate this with 8x to 48x accelerated T1 relaxometry data at 1.5mm isotropic and 12x accelerated 3-shell diffusion data up to b = 5000s/mm2 at 1.7mm isotropic. MESMERISED extends possibilities to efficiently probe combined T1, T2 and diffusion contrast for multi-component modeling of relaxometry, diffusion and exchange. |
| 938 | 16:09
|
Dixon-like multi-contrast GRASE imaging framework: simultaneous acquisition of two T2-weighted spin-echo images and an inverse-T1-weighted stimulated-echo image |
1Department of Biomedical Sciences and Engineering, National Central University, Taoyuan, Taiwan, 2Department of Computer Science and Information Engineering, National Cheng Kung University, Tainan, Taiwan, 3Department of Biomedical Engineering, University of Arizona, Tucson, AZ, United States |
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Our novel Dixon-like multi-contrast GRASE imaging framework can simultaneously acquire two distinct T2-weighted and an inverse-T1-weighted images with high scan efficiency. The two single-shot GRASE imaging sequences with phase difference of RF pulses generates signal with spin-echo (SE) signals and stimulated-echo (STE) signals in-phase and 180-degree out-of-phase. A Dixon-like approach can respectively acquire T2-weighted SE-only image and inverse-T1-weighted STE-only images from the data. Multi-contrast images can be efficiently acquired with the proposed framework within clinically feasible scan time. |
| 939
|
16:21
|
Direct Myelin Imaging In Human Brain Using Inversion Recovery Hybrid Encoded Ultrashort Echo Time (IR-HE-UTE) Magnetic Resonance Imaging |
1Department of Radiology, University of California San Diego, San Diego, CA, United States, 2GE Healthcare, San Diego, CA, United States, 3Department of Neurosciences, University of California San Diego, San Diego, CA, United States, 4Radiology Service, VA San Diego Healthcare System, San Diego, CA, United States |
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Multiple sclerosis (MS) is the most common immune-mediated demyelinating inflammatory disease, afflicting over 2.3 million people globally. Magnetic resonance imaging (MRI) is the gold standard non-invasive imaging modality to identify MS lesions. Clinically, both CSF-suppressed T2-weighted and T1-weighted images are used for the characterization of MS lesions (FLAIR and MP-RAGE sequences). However, these sequences are not specific for demyelinating lesions and can be challenging to interpret. In this study, we propose a direct myelin imaging technique utilizing IR-prepared hybrid encoded UTE imaging, which provides highly specific volumetric myelin images with scan time less than 7min. |
| 940
|
16:33
|
Intermittently Tagged Real-Time MRI Reveals Internal Tongue Motion during Speech Production |
1Ming Hsieh Department of Electrical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, United States, 2Department of Linguistics, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, CA, United States |
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The tongue is arguably the most important articulator enabling human speech production. Current tagged MRI methods for studying internal tongue motion evolved from CINE cardiac techniques that rely on multiple repetitions with perfect synchronization. However, speech production, unlike cardiac motion, possesses great token, type and individual variability due to its voluntary, highly context-sensitive and information-encoding nature. In this work, we demonstrate tagged RT-MRI of speech production, without requiring any repetitions or synchronization for data re-binning. We demonstrate capture of several important tongue deformation patterns and their relative timing. |
| 941
|
16:45
|
Efficient whole-brain tract-specific T1 mapping with slice-shuffled inversion-recovery diffusion-weighted imaging at 3T |
1McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada, 2Department of Biomedical Engineering, McGill University, Montreal, QC, Canada, 3Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 4Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada, 5Department of Radiology and Department of Clinical Neuroscience, University of Calgary, Calgary, AB, Canada, 6Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States, 7Department of Radiology, Harvard Medical School, Harvard University, Boston, MA, United States, 8Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada |
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The majority of voxels in magnetic resonance images of human white matter contain crossing tracts. Conventional T1 mapping techniques are sensitive to the myelin content of the entire voxel and are thus non-specific to individual tract myelination. We recently proposed an efficient slice-shuffled, multiband accelerated inversion-recovery diffusion-weighted MRI (IR-DWI) sequence at 3 Tesla. Here we demonstrate that IR-DWI can be used to estimate tract-specific T1 in voxels with crossing fibres in a phantom and in a healthy subject in a reasonable scan time. |
| 942 | 16:57
|
A Novel Phase Based T2 Mapping Technique Using Gradient Echo Imaging |
1Biomedical Engineering, University of Wisconsin-Madison, madison, WI, United States, 2Radiology, University of Wisconsin-Madison, madison, WI, United States, 3Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 4Medical Physics, University of Wisconsin-Madison, madison, WI, United States, 5Medicine, University of Wisconsin-Madison, madison, WI, United States, 6Emergency Medicine, University of Wisconsin-Madison, madison, WI, United States |
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Quantitative T2-MRI with has a plethora of clinical applications. Current quantitative T2-MRI techniques encode T2-information into the signal magnitude. In this work, a novel method encoding T2 information into the gradient echo signal phase is proposed. With certain RF phase, a heavily T2-weighted signal phase is created. The signal phase has a mild T1 dependence that can be corrected using a spoiled gradient echo magnitude signal. Feasibility in phantoms was demonstrated, as well as in vivo 3D T2 mapping of the abdomen. The proposed method has the potential to be developed into an accurate and robust T2 mapping technique. |
| 943 | 17:09
|
HYFI: Hybrid filling of the dead-time gap for faster zero echo time imaging |
1ETH Zurich and University of Zurich, Zürich, Switzerland |
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MRI of tissues with short transverse relaxation times can be performed efficiently with zero echo time sequences. However, in situation involving large dead time gaps, current established techniques such as algebraic ZTE, PETRA or WASPI are not optimal because of either point spread function-related artifacts or low SNR efficiency. In this work, a novel ZTE-based MRI technique is proposed. It employs a hybrid encoding scheme with both Cartesian and radial acquisitions. In this way, SNR efficiency is improved while preserving image quality as compared to existing methods. |
| 944 | 17:21
|
3D-EPTI for Ultra-fast Multi-contrast and Quantitative Imaging |
1Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, United States, 2Harvard-MIT Health Sciences and Technology, MIT, Cambridge, MA, United States, 3Department of Electrical Engineering and Computer Science, MIT, Cambridge, MA, United States |
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A new technique, 3D-EPTI with inversion-recovery-prepared gradient- and spin-echo readouts, was developed to rapidly acquire a time-series of distortion- and blurring-free multi-contrast images. The technique relies on a new ‘time-resolved’ multi-shot 3D-EPI readout with a hybrid spatio-temporal CAIPI and golden-angle radial-blade sampling scheme. With just about 2 minutes of 3D-EPTI acquisition, thousands of brain volume data at 1.1 mm isotropic resolution can be generated at different TIs and TEs, capturing signal evolution of T1 inversion recovery interspersed with T2/T2* decay, enabling rapid simultaneous quantitative parameters estimation. |
| 945 | 17:33
|
A prototype of a fully integrated environment for a collaborative work in MR sequence development for a reproducible research |
1MR Physics, Fraunhofer MEVIS, Bremen, Germany, 2MR-Imaging and Spectroscopy, Faculty 01 (Physics/Electrical Engineering), University of Bremen, Bremen, Germany |
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We present a prototype exemplifying conceptual web-based workflow with services and applications which allow MR sequence developers to collaboratively create and work on MR sequences. By automating various error-prone tasks that usually overwhelm new and existing users and focusing on an interplay of web-services and applications, we introduce a novel developer experience. That might help the MR community to establish a sequence development workflow that can greatly benefit from collaborative efforts and make MR sequence developments more transparent and reproducible. |
| 946
|
15:45
|
Rapid High-Resolution Simultaneous Acquisition of Metabolites, Myelin Water Fractions, and Tissue Susceptibility of the Whole Brain Using "SPICY" 1H-MRSI |
1Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 2Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 3Department of Radiology, The Fifth People's Hospital of Shanghai, Shanghai, China, 4School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China, 5Med-X Research Institute, Shanghai Jiao Tong University, Shanghai, China |
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We report further advances on ultrahigh-resolution 1H-MRSI without water suppression to enable rapid simultaneous acquisition of brain metabolites, myelin water fractions (MWF) and tissue susceptibility in high spatial resolution. Building on the SPICE (SPectroscopic Imaging by exploiting spatiospectral CorrElation) subspace imaging framework, we extend the SPICE data acquisition scheme with several novel features, including the use of ultrashort-TE (~1.6 ms), very-short-TR (~160 ms), and variable density sampling of (k, t)-space. We reconstruct the spatial distributions of brain metabolites, MWF, and tissue susceptibility using model-based reconstruction methods that incorporate learned spatiospectral features. Experimental results have been obtained which demonstrate that in a single 5-min scan, we can obtain metabolites in a nominal resolution of 2.0×2.4×3.0 mm3 and QSM/MWF in a nominal resolution of 1.8×1.8×1.8 mm3. |
| 947
|
15:57
|
Learning Nonlinear Low-Dimensional Models for MR Spectroscopic Imaging Using Neural Networks |
1Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 2Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States |
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Low-dimensional subspace models have recently been developed for fast, high-SNR MRSI, by effectively reducing the degrees-of-freedom for the imaging problem. However, low-dimensional linear subspace models may be inadequate in capturing more complicated spectral variations across a general population. This work presents a new approach to model general spectroscopic signals, by learning a nonlinear low-dimensional representation. Specifically, we integrated the well-defined spectral fitting model and a deep autoencoder network to learn the low-dimensional manifold where the high-dimensional spectroscopic signals reside, and applied this learned model for denoising and reconstructing MRSI data. Promising results have been obtained demonstrating the potential of the proposed method. |
| 948
|
16:09
|
Using an AC/DC Coil to Improve the Line Width and Lipid Suppression for measuring 2HG in Glioma Patients at 3T |
1Department of Radiology, A. A. Martinos Center for Biomedical Imaging, Boston, MA, United States, 2Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States, 3Harvard Medical School, Boston, MA, United States, 4Fetal Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Boston, MA, United States, 5Department of Radiology, Harvard Medical School, Boston, MA, United States, 6Department of Radiology, Medical University of Vienna, Vienna, Austria, 7Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, United States, 8Department Neurology, Division of Neuro-Oncology, Massachusetts General Hospital, Boston, MA, United States, 9Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, United States |
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An AC/DC 32-channel coil, which can detect signal while simultaneously alter the B0-field, was used to improve lipid inversion and the spectral linewidth for measuring 2HG. Two patients and two volunteers were measured with a spiral-based 3D sequence once with the standard scanner shim only, and once with the additional shimming of the integrated B0/Rx coil. Data quality was strongly improved, leading to improved 2HG-detection in one patient, and a decreased variability of 2HG in tumor-void areas. This can reduce the likelihood of false-positive 2HG detection. Quantification of other metabolites was additionally improved by the AC/DC shim. |
| 949 | 16:21
|
Dephasing Optimization Through Coherence Order Pathway Selection (DOTCOPS): Validation and Inclusion of Phase Cycling |
1Biomedical Engineering, Columbia University, New York, NY, United States, 2Radiology, Columbia University, New York, NY, United States |
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Modern magnetic resonance spectroscopic (MRS) pulse sequences frequently overlook the issue of unwanted coherence pathways as source of numerous spectral artifacts. A novel and robust algorithm which only requires the input of the desired coherence pathway was developed to efficiently dephase all unwanted coherence pathways for any MRS pulse sequence. Experiments were performed on phantoms and healthy volunteers comparing crusher schemes obtained from the literature with those obtained from the optimization algorithm for sLASER and MEGA-sLASER. The results demonstrate that the effects of unwanted coherences can be drastically reduced through the implementation of an optimized crusher and phase cycling scheme. |
| 950 | 16:33
|
Next generation Crusher Coil for suppressing extra cranial lipid signals at 7 Tesla |
1Imaging Division, University Medical Center Utrecht, Utrecht, Netherlands, 2WaveTronica, WaveTronica B.V., Utrecht, Netherlands |
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We previously presented a crusher coil for suppression of extra-cranial lipids in brain Magnetic Resonance Spectroscopic Imaging (MRSI). To improve crushing performance and the reproducibility of the production of crusher coils, a new crusher coil was designed, created and tested. By doubling the amount of wires and improving their spatial distribution around the coil (consistent meandering), we could achieve efficient lipid suppression with as little as 30% of the power, used with the proof of principle coil. The presented design is easy to reproduce, repair and modify due to a modular build. |
| 951
|
16:45
|
Preliminary detailed in-vivo brain atlas of metabolic and macromolecular distributions in humans using 7T 1H Magnetic Resonance Spectroscopic Imaging |
1University Medical Center Utrecht, Utrecht, Netherlands, 2Max Planck Institute for Biological Cybernetics, Tübingen, Germany, 3IMPRS for Cognitive and Systems Neuroscience, Eberhard Karls University of Tübingen, Tübingen, Germany, 4Amsterdam University Medical Center, Amsterdam, Netherlands |
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This study amalgamated current state-of-the-art MRSI developments to create a detailed and reliable in vivo metabolic atlas of the healthy human brain. We used an ultra-high field 7T MR scanner to acquire high resolution, short echo-time (TE) MRSI data along with an external crusher coil for hardware based extra-cranial lipid signal suppression. Advanced post-processing and data reconstruction techniques were used in conjunction with stringent data filtering based on several quality assurance metrics, while registration to the MNI152 standard atlas allowed us to generate high-resolution metabolite/macromolecule ratio maps. |
| 952 | 16:57
|
Ultra-high-resolution brain MRSI at 7T and 9.4T – A direct comparison |
1MRCE, Medical University of Vienna, Vienna, Austria, 2Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States, 3Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 4F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States, 5Department of Cognitive Neuroscience, Maastricht University, Maastricht, Netherlands, 6Scannexus BV, Maastricht, Netherlands, 7MRShim GmbH, Reutlingen, Germany, 8Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria |
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Despite the successful demonstration of fast ultra-high resolution MRSI at 7T and 9.4T, a direct comparison has been lacking. This study fills this gap by measuring the same FID-MRSI protocol in the same volunteer group at both field strengths within a short time frame. Our results show overall similar quality measures across field strengths, with more quantifiable metabolites but also more prevalent spectral artefacts at 9.4T. |
| 953 | 17:09
|
Whole-slice mapping of GABA and GABA+ at 7T via adiabatic MEGA-editing, real-time instability correction, and concentric circle readout |
1High Field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria, 2Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States, 3Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 4Christian Doppler Laboratory for Clinical Molecular MRI, Vienna, Austria |
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In vivo detection of γ-aminobutyric acid (GABA) and glutamate (Glu), both major neurotransmitters in the human brain, benefits from the higher sensitivity at ultra-high field (7T) compared to lower field strengths. However, strong B0/B1+ inhomogeneities and chemical shift displacement errors as well as subject motion and frequency drifts can significantly impair the experiment. An adiabatic MEGA-editing scheme was developed and incorporated into a real-time corrected B1+-insensitive MRSI sequence, which enabled whole-slice metabolic imaging of neurotransmitters in the human brain with unprecedented high-resolution at 7T and allowed a comprehensive assessment of regional GABA levels without co-edited macromolecule contamination. |
| 954 | 17:21
|
Accelerated Spectral-Editing MRSI using Subspace Modeling, Multi-Slab Acquisition and 3D CAIPIRINHA Undersampling |
1Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States, 2Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, China, 3Department of Biomedical Engineering, Tsinghua University, Beijing, China, 4Department of Engineering Physics, Tsinghua University, Beijing, China |
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Spectral-editing MRSI allows reliable and selective detection of many important metabolites, e.g., GABA and 2-HG, by eliminating all uncoupled resonances in the J-difference spectrum. Despite significant advances in fast MRSI sequences and constrained image reconstruction, spectral-editing MRSI is still limited by its long acquisition time and low spatial resolution. Recently, a subspace-based approach has been proposed to accelerate spectral-editing MRSI, reporting encouraging phantom and in vivo results. In this work, we propose to further accelerate the subspace-based spectral editing MRSI using (i) multi-slab acquisition to maximize the time efficiency of long-TR spin-echo acquisition and (ii) a 3D (2D spatial + 1D spectral) CAIPIRINHA (Controlled Aliasing in Parallel Imaging Results in Higher Acceleration) scheme for sparse sampling of the (k,t)-space. We evaluate the performance of the proposed method using simulation, phantom, and in vivo studies. |
| 955
|
17:33
|
Density-Weighted Concentric Ring Trajectory using simultaneous multi-slice (SMS) acceleration: 3D Metabolite-cycled Magnetic Resonance Spectroscopy Imaging at 3 T |
1School of Health Sciences, Purdue University, West Lafayette, IN, United States, 2Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States, 3Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, United Kingdom, 4Department of Radiological Sciences, University of California, Los Angeles, Los Angeles, CA, United States, 5Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States |
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In this study, we proposed a novel simultaneous multi-slice (SMS) density weighted (DW) concentric ring trajectory (CRT) metabolite-cycling Magnetic Resonance Spectroscopy Imaging (MRSI) sequence to alleviate some conventional MRSI drawbacks, e.g. long acquisition time, eddy current artifacts, and side lobe artifacts. The sequence was tested on 5 healthy subjects, showing the feasibility of acquiring three slices of high-quality water-only and metabolite spectra simultaneously with a resolution of 5mm X 5mm X 10mm within 20 minutes. |
| 956 | 15:45
|
Unique Structural Backbone Topological Organization in Early Stage Parkinson’s Disease |
1Imaging Research, Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV, United States, 2Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV, United States, 3Feinstein Institute for Medical Research, Northwell Research, Manhasset, NY, United States, 4Barrow Neurological Institute, Phoenix, AZ, United States |
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This study shows the presence of a distinctive anatomical backbone network in early Parkinson’s Disease (PD) involving cortical and subcortical regions that are known to be involved in various stages of PD, including early PD. Impaired network segregation and rich-club measures were further found within this backbone network in PD which were associated with disease duration. We hope that by identifying a set of core abnormalities in PD structural connectivity, this will permit improved ability to understand structural-network related disease progression and also to understand changes in these core structural connectivity measures with disease-modifying therapies as they emerge. |
| 957 | 15:57
|
Braak model investigation in Parkinson disease using multimodal MRI biomarkers |
1CENIR, ICM, Paris, France, 2Neuroradiology, APHP, Pitie Salpêtrière, Paris, France, 3Sorbonne Universite, Univ Paris 06, UMR S 1127, CNRS UMR 7225, ICM, Paris, France, 4ICM team Movement Investigation and Therapeutics, ICM, Paris, France, 5Clinique des mouvements anormaux, Département des Maladies du Système Nerveux, Hôpital Pitié-Salpêtrière, PARIS, France |
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The aim of this study was to test using multimodal MRI biomarkers if the pattern of neurodegeneration in the brain of patients with Parkinson disease (PD) fits the model of disease progression proposed by Braak and al. (2003). Partial Least Squares Path-Modeling of multi-modal imaging data was in-line with the Braak pathology model confirming the gradual lesions in PD brain. While substantia nigra damage was observed in all PD patients, Braak’s model of disease progression was better followed by PD patients with idiopathic rapid eye movement sleep behavior disorders (RBD) than without RBD as demonstrated by model goodness of fit. |
| 958 | 16:09
|
The alteration of white matter tract of patients with Parkinson's disease combined with the changes in tract-connected gray matter : a longitudinal report |
1Department of Medical Imaging and Radiological Sciences, Chang Gung University, Taoyuan City, Taiwan, 2Neurology, Chang Gung Memorial Hospital, Taoyuan City, Taiwan, 3Radiology, Keelung Chang Gung Memorial Hospital, Keelung City, Taiwan |
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Parkinson's disease (PD) is a progressive nervous system disorder as a result from the loss of cell in basal ganglia. Fixel-Based Analysis can qualify the fibre density and fibre-bundle cross-section in the nerve fibre. Further, gray matter degeneration was determined by using ROI-based Analysis to investigate Mean Diffusivity (MD) changes. Therefore, the current study proposed to investigate the structural connectivity of atrophy cortical regions in the PD patients with axonal injury over a period of 2 years. |
| 959 | 16:21
|
White matter changes in the perforant path in patients with amyotrophic lateral sclerosis |
1Department of Anatomy, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, Netherlands, 2Wellcome Centre for Integrative Neuroimaging, FMRIB, University of Oxford, Oxford, United Kingdom, 33Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom |
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Patients with amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) share clinical overlap in terms of cognitive decline and are both characterised by the deposition of pathological TDP-43 inclusions in the brain. Here, we hypothesize that white matter degeneration of the perforant path in the hippocampus is a key feature of ALS patients developing FTD-like symptoms. Using diffusion MRI, polarized light imaging (PLI) and immunohistochemical (IHC) analysis we analysed white matter in the perforant path. dMRI and PLI measures suggest white matter degeneration in this pathway; however, densitometric analysis of IHC did not support this interpretation. |
| 960
|
16:33
|
Advanced brain aging in patients with right mesial temporal lobe epilepsy: A machine learning approach based on white matter tract integrity |
1Institute of Medical Device and Imaging, College of Medicine, National Taiwan University, Taipei, Taiwan, 2Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan, 3Department of Neurology, National Taiwan University Hospital and College of Medicine, Taipei, Taiwan, 4Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei, Taiwan, 5AcroViz Technology Inc., Taipei, Taiwan, 6Molecular Imaging Center, National Taiwan University, Taipei, Taiwan |
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It is unclear whether left and/or right side lesions of mesial temporal lobe epilepsy (MTLE) exhibit different degrees of brain aging. Therefore, we developed machine-learning-based brain age models to quantify the brain aging of patients with unilateral MTLE and of healthy controls. The significantly overestimated brain age was found in the right but not left MTLE patients. Also, the degree of overestimated brain age was correlated with the clinical factors. Moreover, the right uncinate fasciculus was the most contributing feature to the overestimated brain age. This study uncovered the underpinning of advanced brain aging in right MTLE patients. |
| 961 | 16:45
|
Microstructural Changes of Normal-Appearing White Matter in Vascular Parkinsonism |
1Neuroscience Research Center, University Magna Graecia of Catanzaro, Catanzaro, Italy, 2Neuroimaging Unit, Institute of Molecular Bioimaging and Physiology, National Research Council (IBFM-CNR), Catanzaro, Italy, 3Institute of Neurology, University Magna Graecia of Catanzaro, Catanzaro, Italy, 4Masaryk University, Central European Institute of Technology (CEITEC), Brno, Czech Republic |
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White matter hyperintensities (WMH) play a crucial role in the pathogenesis of Vascular Parkinsonism (VP), a clinical entity characterized by parkinsonism, postural instability, marked gait difficulty and poor levodopa response. However, involvement of normal-appearing white matter (NAWM) in VP still remains unknown. Here we analyzed NAWM microstructure in VP compared to Parkinson’s disease (PD) and controls using MRI and DTI. We found extensive DTI alterations in VP, but not in PD nor in controls. NAWM damage in the genu of corpus callosum correlated with clinical core features such as postural instability, freezing-of-gait and symmetry of parkinsonism. |
| 962 | 16:57
|
Distinctive structural connectivity between cognitively impaired and nonimpaired active professional fighters |
1Imaging Research, Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV, United States, 2University of California, San Diego, San Diego, CA, United States, 3Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV, United States |
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Using neuropsychological scores from the Professional Fighters Brain Health Study (PFBHS), this study first identified 70 cognitively impaired active professional |
| 963
|
17:09
|
Improving strain diagnosis of prion disease by diffusion MRI and biophysical modelling |
1Centre for Medical Image Computing, Department of Computer Science, University College London, London, United Kingdom, 2Neuroradiology, Fondazione IRCCS Istituto Neurologico “Carlo Besta”, Milano, Italy, 3Neurology, Fondazione IRCCS Istituto Neurologico “Carlo Besta”, Milano, Italy, 4Philips United Kingdom, Guildford, United Kingdom, 5Queen Square MS Centre, UCL Institute of Neurology, Faculty of Brain Sciences, University College London, London, United Kingdom, 6Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy, 7Brain MRI 3T Research Center, IRCCS Mondino Foundation, Pavia, Italy |
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Sporadic Creutzfeldt–Jakob disease (sCJD) is the most common form of prion disease, characterized by five different strains, presenting intracellular vacuoles with different diameter/distribution. Unfortunately, no reliable non-invasive method for strain identification currently exists. Here we provide the first quantitative maps of MR-measured vacuolar diameter/density in five sCJD patients, using multishell diffusion MRI and biophysical modelling. Results show distribution of small and larger vacuoles in the brain lesions of each patient, presumably corresponding to different sCJD strains, and absence of vacuoles in five age-matched healthy controls. If validated, this method would be extremely valuable for non-invasive diagnosis of sCJD strain |
| 964
|
17:21
|
Structural and functional organization of the brain connectome in patients with different motor neuron diseases: a multicenter study |
1Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 2Department of Medical, Surgical, Neurological, Metabolic and Aging Sciences, University of Campania "Luigi Vanvitelli", Naples, Italy, 3Department of Neurology, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 4ALS Center, ‘Rita Levi Montalcini’ Department of Neuroscience, University of Torino, Torino, Italy, 5Department of Neuroradiology and CERMAC, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy |
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We investigated structural and functional brain network topology in amyotrophic (ALS), primary lateral sclerosis (PLS) and progressive muscular atrophy (PMA) patients and in healthy controls (HC), using graph analysis and connectomics. ALS and PLS patients showed widespread microstructural alterations in sensorimotor network, basal ganglia area and prefrontal cortex and posterior brain regions compared to HC, while PMA subjects did not show significant brain damages. All groups had a relatively preserved global and local functional connectome properties compared to each other. Graph analysis and connectomics might represent a powerful approach to understand the pathophysiological process associated with motor neuron diseases. |
| 965 | 17:33
|
Ex vivo Correlations of MRI Parametrics and Histological Measures in Parkinson’s Disease Midbrain |
1Neurosurgery, The Pennsylvania State University - College of Medicine, Hershey, PA, United States, 2Radiology, The Pennsylvania State University - College of Medicine, Hershey, PA, United States, 3Pathology, The Pennsylvania State University - College of Medicine, Hershey, PA, United States, 4Neurology, The Pennsylvania State University - College of Medicine, Hershey, PA, United States |
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Parkinson’s disease is neurodegenerative disease characterized by the loss of dopaminergic neurons in the substantia nigra resulting in a range of motor deficits. There is uncertainty in how MRI metrics relate to disease pathology, especially in regard to cellular changes, iron, and the presence of neuromelanin. This work aims to analyzing MRI parametrics on ex vivo PD midbrains to determine how image contrast, relaxation, and susceptibility changes are related to cellularity and integrity in this brain region. Changes in MRI parametrics were found in the substantia nigra of PD subjects in relation to histological markers. |
| 966 | 15:45
|
Comparing imaging changes and pain response in patients with intra- or extra-osseous bone metastases treated palliatively with magnetic resonance guided high intensity focused ultrasound (MRgHIFU) |
1CRUK Cancer Imaging Centre, The Institute of Cancer Research and Royal Marsden Hospital, London, United Kingdom, 2Targeted Approaches to Cancer Pain, The Institute of Cancer Research, London, United Kingdom, 3Pain Medicine Department, Royal Marsden Hospital, London, United Kingdom, 4Therapeutic Ultrasound, The Institute of Cancer Research, London, United Kingdom, 5Philips MR Therapy, Vantaa, Finland, 6University Medical Center Utrecht, Utrecht, Netherlands, 7Samsung Medical Center, Seoul, Korea, Republic of |
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Imaging changes and pain relief were compared in 21 patients with intra- versus extra-osseous bone metastases treated palliatively with magnetic resonance guided high intensity focused ultrasound (MRgHIFU). Thermal dose volumes measured on proton resonance frequency shift (PRFS) thermometry were significantly larger in the extra-osseous group. Intra-osseous lesions showed focal non-enhancement by Day 30, and patients had better pain response to MRgHIFU than those with extra-osseous lesions. By Day 30, 67% (6/9) patients with intra-osseous lesions were responders, compared with 33% (4/12) of patients with extra-osseous lesions. In neither group was pain response indicated by non-enhancement on Gd-T1W imaging. |
| 967 | 15:57
|
Real-time in-vivo tissue temperature and displacement measurements in the brain for MR-guided HIFU treatment and comparison to in-silico focused ultrasound simulation. |
1IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Bordeaux, France, 2Univ. Bordeaux, Centre de recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France, 3INSERM, Centre de recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France, 4Institut Langevin Ondes et Images, ESPCI ParisTech, CNRS 7587, UMRS 979 INSERM, Paris, France, 5ICM, Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, Paris, France, 6UPMC Université Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, Paris, France |
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MR-guided High Intensity Focus Ultrasound is an appealing technology in neurosurgery. For such application, accurate targeting and monitoring are crucial. A recent sequence allowing simultaneous measurements of temperature and displacement measurements is used to identify in real-time both the focal point by Acoustic Radiation Force Intensity (ARFI) and verify the absence of heating during ARFI sonication. The method has been evaluated in vivo in a non-human primate under anesthesia with a single-element transducer. A comparison with in-silico focused ultrasound simulation is also provided. |
| 968 | 16:09
|
Combining MR and ultrasound imaging, through sensor-based probe tracking |
1Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States |
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Sensors attached to the skin can ‘spy’ on product ultrasound scanners, allowing the position and orientation of the ultrasound probe to be inferred. These MR-compatible sensors can emit and/or receive ultrasound waves, they are small in size (about 3x3x1cm) and are easily fixed to the torso. In transmit-receive mode they can monitor physiological motion, and in receive-only mode they can monitor the motion of an ultrasound probe. The sensors can accompany subjects to serial MRI and ultrasound imaging exams and act as a common denominator between the two, allowing ultrasound images to be placed in the spatial context of MRI. |
| 969 | 16:21
|
A Variable Flip Angle Golden-Angle-Ordered 3D Stack-of-Radial Sequence for Combined PRF/T1 Monitoring of MR-Guided HIFU Ablation |
1Radiological Sciences, University of California, Los Angeles, Los Angeles, CA, United States, 2Physics and Biology in Medicine Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA, United States, 3Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, United States |
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Proton resonance frequency (PRF) shift is widely used for MR temperature mapping, but fails in adipose tissues. T1 measurement offers an alternative temperature mapping method in adipose tissues. Combined PRF-T1 temperature mapping has been evaluated for Cartesian MRI, but there is a lack of research for non-Cartesian techniques. In this work, we propose a new 3D stack-of-radial technique for combined PRF-T1 MR temperature mapping. Results from non-heating in vivo scans demonstrate good stability of T1 and PRF measurements. Data from ex vivo high-intensity focused ultrasound (HIFU) ablations demonstrate good agreement between both PRF and T1 mapping compared to temperature probes. |
| 970
|
16:33
|
Real-Time T1/PRF-Based MR Thermometry Using Deep Learning and VFA-mFFE for Guidance of HIFU Treatment |
1Department of Electronics and Information, Korea University, Seoul, Korea, Republic of, 2Korea Artificial Organ Center, Korea University, Seoul, Korea, Republic of, 3ICT Convergence Technology for Health and Safety, Korea University, Sejong, Korea, Republic of, 4Research Institute for Advanced Industrial Technology, Korea University, Sejong, Korea, Republic of, 5Bioimaging Research Team, Korea Basic Science Institute, Chungcheongbuk-do, Korea, Republic of, 6Correspoding author, ohch@korea.ac.kr, Seoul, Korea, Republic of |
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MR temperature mapping of adipose and aqueous tissues is crucial in ensuring the safety and efficacy of HIFU treatment in regions of the body where the adipose and aqueous tissues are treated. We suggest a simultaneous and real-time temperature mapping method for adipose and aqueous tissues by using deep learning and multi-echo fast field echo with |
| 971
|
16:45
|
Simultaneous fat-referenced PRFS thermometry and MR Elastography for the monitoring of thermal ablation |
1ICube, UMR7357, Université de Strasbourg, CNRS, FMTS, Strasbourg, France, 2Imagerie Interventionnelle, Hôpitaux Universitaires de Strasbourg, Strasbourg, France |
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Coupled MR Elastography (MRE) and Proton Resonance Frequency Shift (PRFS) thermometry have been proposed for the monitoring of thermal ablations. Fat-referenced PRFS thermometry based on water-fat separation allows correcting for errors caused by field drift. We propose a new approach for combined MRE and fat-referenced PRFS thermometry, allowing for improved thermometry while keeping the acquisition time unchanged. This is obtained by varying simultaneously TE and MRE phase offsets for water-fat separation and MRE, respectively. Feasibility of the method was demonstrated in a water/fat phantom during a High Intensity Focused Ultrasound ablation experiment, in which elasticity and temperature changes were monitored. |
| 972
|
16:57
|
Real-Time Needle Detection and Segmentation using Mask R-CNN for MRI-Guided Interventions. |
1Radiological Sciences, University of California, Los Angeles, Los Angeles, CA, United States, 2Bioengineering, University of California, Los Angeles, Los Angeles, CA, United States, 3Mechanical and Aerospace Engineering, University of California, Los Angeles, Los Angeles, CA, United States |
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Real-time needle tracking for MRI-guided interventions is challenging due to variations in the needle features and the contrast between the needle and surrounding tissue. Mask region-based convolutional neural network (R-CNN) is a powerful deep-learning technique for object detection and segmentation in natural images, which has the potential to overcome these challenges. In this study, we train the Mask R-CNN model using annotated intra-procedural images from MRI-guided prostate biopsy cases and real-time images from MRI-guided needle insertion in a phantom. Mask R-CNN achieved accurate needle detection and segmentation in real time (~80 ms/image), which has the potential to improve MRI-guided interventions. |
| 973
|
17:09
|
Deep Learning Based Needle Localization on Real-Time MR Images of Patients Acquired During MR-guided Percutaneous Interventions |
1Siemens Healthcare, Erlangen, Germany, 2TU Dortmund, Dortmund, Germany, 3ICube UMR7357, University of Strasbourg, CNRS, FMTS, Strasbourg, France, 4Imagerie Interventionnelle, Hôpitaux Universitaires de Strasbourg, Strasbourg, France |
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Automatic localization of needles in real-time images can facilitate MR-guided percutaneous interventions. It enables automatic slice repositioning and targeting support and, thus, allows for faster workflows. Systematic acquisition of training data for deep learning tasks in the context of interventional MRI can be difficult due to the fact, that treatment quality must not be impaired. Therefore, we investigated whether images of porcine animal experiments can be used to train deep learning algorithms for needle artifact segmentation in human datasets. Results show that transfer is feasible at 1.5T. Additional fine tuning using small amounts of human data further reduces the error. |
| 974 | 17:21
|
Real-time catheter tracking for cardiac MR-Thermometry during RF-ablation |
1IHU-LIRYC, Pessac, France, 2Univ. Bordeaux, Centre de recherche Cardio-Thoracique de Bordeaux, Bordeaux, France, 3INSERM U1045, Bordeaux, France, 4Siemens Healthcare, Saint-Denis, France, 5Imricor, Brunsville, MN, United States, 6Siemens Healthcare, Erlangen, Germany, 7Bordeaux University Hospital (CHU), Pessac, France |
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| 975 | 17:33
|
Cervical-Cancer Imaging for brachytherapy planning employing an endo-vaginal array that includes an enhanced forward-looking coil |
1School of Medicine, Johns Hopkins University, Baltimore, MD, United States |
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Advanced cervical-cancer spreads from the cervix to the posterior-endometrium and vaginal walls. Improving imaging SNR in this region shortens scan-times required for precisely localizing live-tumor locations before high-dose-rate (HDR) interstitial radiation-therapy. Current endo-vaginal coils focus on vaginal-wall imaging and are in-effective for posterior-endometrium/cervix imaging. This study designs and builds an endo-vaginal array which contains sideways-looking vaginal-wall, and forward-looking cervix/posterior-endometrium elements. The forward-looking “spiral”-coil is metallic-backed, pushing the RF-lobe upwards, enlarging its FOV. The array was designed with electromagnetic simulation and tested in phantoms and swine. Forward-looking SNR over a 3x3x3 cm3 FOV was ~4-8 times that of the spine-array. |
| 976 | 15:45
|
Sub-millimeter, Non-contrast 3D Coronary MRA for Assessment of Arterial Stenosis: Initial Clinical Experience and Comparison with Coronary CT Angiography |
1School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 2Department of Cardiology, Guy's and St Thomas' Hospital, London, United Kingdom, 3MR Research Collaborations, Siemens Healthcare Limited, Frimley, United Kingdom |
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Coronary CT angiography (CCTA) is an established diagnostic imaging modality for the assessment of patients with suspected coronary disease, where high resolution (sub-millimeter) imaging is required for the accurate detection and quantification of stenosis. To date, achieving such resolutions using coronary MRA (CMRA) has not been possible due to prohibitively long scan times. However, accelerated imaging using image-based navigators and non-rigid motion compensated patch-based undersampled reconstruction techniques have enabled sub-millimeter coronary MR imaging in acceptable acquisition times. In this feasibility study, we demonstrate that accelerated sub-millimeter CMRA holds promise for the detection and exclusion of significant coronary artery stenosis. |
| 977 | 15:57
|
Clinical Evaluation of Cine Fast Interrupted Steady-State (FISS) Arterial Spin Labeling for Dynamic MR Angiography of the Heart and Great Vessels |
1Radiology, NorthShore University HealthSystem, Evanston, IL, United States, 2Feinberg School of Medicine, Northwestern University, Chicago, IL, United States, 3Medicine, NorthShore University HealthSystem, Evanston, IL, United States, 4Medicine, University of Chicago Pritzker School of Medicine, Chicago, IL, United States, 5Siemens Medical Solutions USA Inc, Chicago, IL, United States, 6Radiology, University of Chicago Pritzker School of Medicine, Chicago, IL, United States |
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Evaluation of hemodynamic patterns is often an essential component of the cardiac MRI exam. We hypothesized that cine fast interrupted steady-state (FISS) ASL could prove advantageous for demonstrating flow patterns in the heart and great vessels and tested this technique in 19 patients undergoing cardiac MRI for standard indications. We found that cine FISS ASL is a robust, efficient imaging technique that is easily incorporated into cardiac MRI protocols and shows promise for depicting abnormal blood flow patterns in patients with a variety of cardiovascular disorders, including aortic stenosis, hypertrophic cardiomyopathy, and congenital shunts. |
| 978
|
16:09
|
Highly Accelerated 3D Whole-Heart Isotropic Sub-Millimeter CMRA with Non-Rigid Motion Correction |
1School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 2MR Research Collaborations, Siemens Healthcare Limited, Frimley, United Kingdom |
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Whole-heart sub-millimeter isotropic coronary magnetic resonance angiography (CMRA) provides detailed information of the coronary arteries and surrounding vessels. Recently, a patch-based reconstruction technique (3D PROST) has been proposed to achieve sub-millimeter isotropic resolution CMRA in a predictable scan time. However, this approach only corrects for 2D translational respiratory motion of the heart and image quality can be affected by residual non-rigid motion. Here we propose to integrate 3D PROST into a highly accelerated non-rigid motion correction framework to achieve high quality whole-heart free-breathing isotropic sub-millimeter Cartesian CMRA in a clinically feasible scan time. The feasibility of the proposed method was tested in seven healthy subjects and two patients with suspected coronary artery disease. |
| 979
|
16:21
|
“3D-Stars” Cine MRI for the Coronary Arteries: Feasibility of Volumetric Endothelial Function Assessment |
1Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2Division of MR Research, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 3Advanced Clinical Imaging Technology, Siemens Healthcare AG, Lausanne, Switzerland, 4Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, 5Center for Biomedical Imaging (CIBM), Lausanne, Switzerland, 6Siemens Healthineers, Baltimore, MD, United States, 7Siemens Healthineers, Los Angeles, CA, United States |
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2D coronary cine MRI has been shown to noninvasively assess coronary endothelial dysfunction, which is an early manifestation of atherosclerosis and a predictor of future acute events. However, atherosclerosis is a diffuse process and a 2D approach can only provide local measures. Recently, we introduced “3D-Stars”, a free-breathing golden-angle 3D stack-of-stars cine sequence with isotropic spatial resolution to image the proximal and mid segments of the right coronary artery. Here, we show excellent image quality at rest and during isometric-handgrip stress acquisitions and feasibility for assessing normal coronary endothelial function along the vessel in a small cohort of healthy subjects. |
| 980 | 16:33
|
A comparison of Enhanced Acceleration-Selective Arterial Spin Labeling (eAccASL) and Background Suppressed Single shot TFE-TRANCE (BASS TRANCE) for the peripheral arteries |
1Department of Radiology, Tokai University Hospital, Isehara, Kanagawa, Japan, 2Philips Japan, Shinagawa, Tokyo, Japan, 3Department of Diagnostic Radiology, Tokai University School of Medicine, Isehara, Kanagawa, Japan |
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We evaluated the peripheral MR angiography (MRA) of 8 healthy volunteers using conventional and enhanced acceleration-selective arterial spin labeling (cAccASL, eAccASL), and Background suppressed single shot TFE-TRANCE (BASS TRANCE). In eAccASL, additional 180°refocusing pulses and motion sensitized gradients (MSGs) will compensate for B1 inhomogeneity and eddy current effects at 3.0 Tesla. Contrast ratios for BASS TRANCE was the highest values, compared to cAccASL and eAccASL. However, qualitative assessment showed eAccASL could provide more robust visualization than cAccASL and similar visualization to BASS TRANCE. Therefore, eAccASL can provide the more robust peripheral MRA without any gating. |
| 981 | 16:45
|
Contrast Free Methods for Vascular Assessment in Lower Extremities of Diabetes |
1Washington University in St. Louis, Saint Louis, MO, United States, 2Radiology, Wayne State University, Detroit, MI, United States, 3The MRI Institute for Biomedical Research, Bingham, MI, United States |
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The purpose of this study is to develop a new contrast-free MR angiography technique without using any ECG triggering for the vascular assessment of lower extremities in patients with diabetes. Healthy volunteers and diabetes underwent both MR angiography and skeletal muscle perfusion imaging at rest and during an isometric contraction exercise. The angiography, perfusion, and even possible calcification of vessels can be assessed in one imaging session in patients with diabetes. |
| 982 | 16:57
|
Associations between carotid intraplaque hemorrhage and new ipsilateral ischemic lesions after carotid artery stenting: A quantitative study with multi-contrast MRI |
1Diagnostic Radiology, Shanghai zhongshan hospital of Fudan University, Shanghai, China |
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The risk of cerebral embolism after carotid artery stenting (CAS) in patients with carotid intraplaque hemorrhage (IPH) is still controversial. This study further investigated the relationship between IPH and new ipsilateral ischemic lesions (NIIL) after CAS, and performed a volumetric MRI analysis of IPH for predicting the risk of NIIL following CAS. We confirm that carotid IPH is associated with the incidence of NIIL following CAS. Quantification of IPH volume with MRI can be useful for predicting the risk of NIIL after CAS. |
| 983
|
17:09
|
Automatic AHA Classification of Carotid Atherosclerotic Lesions in Multicontrast MR Images using Deep Learning |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, People's Republic of China, Beijing, China, 2Vascular Imaging Laboratory, Department of Radiology, University of Washington, Seattle, WA, United States, Seattle, WA, United States |
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In this study, we aimed to develop a convolutional neural network (CNN) to classify carotid atherosclerotic lesions in high-resolution multicontrast MR images automatically using the modified American Heart Association (AHA) classification scheme as criteria. The network was trained on a large number of plaque images combined with lesion type labeled by experienced radiologists. Transfer learning was utilized to take the advantage of state-of-the-art CNN pre-trained on ImageNet dataset. The accuracy of lesion type classification achieved 85.1% with preprocessing and fine-tuning of the network. |
| 984
|
17:21
|
ECG- and Navigator-Free 3D Multi-Contrast Aortic Vessel Imaging with MR Multitasking |
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 2Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 3Department of Bioengineering, UCLA, Los Angeles, CA, United States, 4Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 5Department of Imaging, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 6Department of Radiology, Fujian Medical University Union Hospital, Fuzhou, China, 7Siemens Healthineers, Los Angeles, CA, United States, 8Department of Medicine, UCLA, Los Angeles, CA, United States |
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MR imaging has the potential to provide a comprehensive assessment of atherosclerotic disease of the aortic arch with both luminal and vessel wall imaging approaches, but typically have long scan times. MR Multitasking is useful for expediting acquisitions that have otherwise been complicated by navigator gating or ECG triggering. In this work, we present an MR multitasking technique that simultaneously produces MRA and multi-contrast vessel wall images with a single ECG- and navigator-free 3D acquisition. Four healthy control subjects and four patients with neurovascular disorders and suspected aortic atherosclerosis were scanned. The 3D, free-breathing, non-ECG sequence provided images at time points for MRA, dark blood, and gray blood contrasts. |
| 985 | 17:33
|
MRI-based Analysis of Morphologic, Inflammatory, and Mechanical Stress Factors that Govern Abdominal Aortic Aneurysm Progression Rates |
1Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States |
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Clinical management of abdominal aortic aneurysm (AAA) disease is based on the maximal aneurysm diameter. Novel markers including vascular inflammation, intraluminal thrombus (ILT) composition and mechanical vessel wall stress have been correlated to AAA risk. Prior studies have typically focused on a single marker. We have developed a comprehensive AAA assessment based on high-resolution black-blood MRI and followed 41 patients for 1.9±0.6 years. Our results showed that both active ILT change and inflammation (identified by USPIO uptake) were strongly associated with AAA growth and/or intervention, and wall stress varied in a sub-group of patients. Such comprehensive assessment may improve AAA patient risk stratification. |
| 986
|
15:45
|
Validation of prostate tissue composition measurement using Hybrid Multidimensional MRI: Correlation with quantitative histology |
1Department Of Radiology, University of Chicago, Chicago, IL, United States, 2Faculty of Health Sciences, University of Sydney, Sydney, Australia, 3Human Tissue Resource Center, University of Chicago, Chicago, IL, United States, 4Department Of Pathology, University of Chicago, Chicago, IL, United States |
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This study validates prostate tissue composition measured non-invasively using Hybrid Multidimensional MRI (HM-MRI) with ground truth reference standard quantitative histology results from whole mount prostatectomy. There was no significant difference in prostate tissue composition measured using HM-MRI and quantitative histology with excellent correlation (0.89) and agreement on Bland-Altman analysis (bias <5%). There is significant difference in epithelium and lumen volume between cancer and normal tissue with high area under the ROC curve (0.87-0.95). This study demonstrates that the tissue composition measured using HM-MRI matches very closely with ground truth quantitative histology measures and can be used for non-invasive prostate cancer diagnosis. |
| 987
|
15:57
|
Prospective multi-institutional validation of IMPROD biparametric MRI in men with a clinical suspicion of prostate cancer (MULTI-IMPROD trial) |
1University of Turku, Turku, Finland, 2Icahn School of Medicine at Mount Sinai, New York, NY, United States, 3Turku University Hospital, Turku, Finland, 4Satakunta Central Hospital, Pori, Finland, 5Helsinki University Hospital, Helsinki, Finland, 6Tampere University Hospital, Tampere, Finland, 7University of Helsinki, Helsinki, Finland |
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In this prospective multicenter trial, a prior developed unique MRI acquisition and reporting protocol, IMPROD bpMRI (NCT01864135), enabled the detection of 97% (143/146) of men with Gleason score ≥3+4. IMPROD bpMRI consists of T2-weighted imaging and three separate diffusion weighted imaging acquisitions with acquisition time <15 minutes. IMPROD bpMRI appears to be a powerful tool for improved prostate cancer risk stratification in men with a clinical suspicion of prostate cancer based on elevated PSA and/or digital rectal examination. Public access to all data is provided at the following addresses: http://petiv.utu.fi/improd and http://petiv.utu.fi/multiimprod |
| 988 | 16:09
|
Preliminary application of Three-Dimensional Multifrequency MR Elastography for the Prostate Disease |
1Department of Radiology, The third affiliated hospital of Sun Yat-sen University, Guangzhou, China, 2MR Research China, GE Healthcare, Beijing, China, 3Department of Radiology, Mayo Clinic, Rochester, Armenia |
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Prostate cancer (PCa) is the second leading cause of cancer deaths among males in the in the United States. Early detection of clinically significant PCa is a major challenge. MR elastography (MRE) is a noninvasive technique capable of quantifying the mechanical properties of tissue and has shown promising results in the detection and localization of PCa. Our results show that transpelvic three-dimensional (3D) MRE using a pelvic wall driver could be successful performed in the prostate at the frequencies of 60 Hz and 90 Hz and can provide a potential quantitative biomarker to evaluate prostate diseases. |
| 989
|
16:21
|
Post-treatment diffusion weighted imaging predicts ablation zone margins following MRI-guided high intensity focused ultrasound of the prostate. |
1Department of Radiology, Stanford University, Palo Alto, CA, United States, 2Department of Urology, Stanford University, Palo Alto, CA, United States |
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The efficacy and safety of magnetic resonance imaging-guided high intensity focused ultrasound (MRg-HIFU) treatment of intermediate risk prostate cancer is being assessed as part of a clinical trial. Non-perfused volume (NPV) on post-treatment contrast-enhanced imaging defines the zone of ablation, however contrast administration precludes further treatment due to concern for gadolinium dissociation. Thus, pre-contrast imaging tools which can predict NPV are of value. From a cohort of 19 men who underwent MFg-HIFU for treatment of prostate cancer, we show that post-treatment DWI can predict NPV, with the potential to increase confidence in predicting the ablation zone prior to contrast administration. |
| 990 | 16:33
|
High Resolution T2W imaging using Multi-shot Reduced Field-of-View PROPELLER |
1Global MR Applications & Workflow, GE Healthcare, Houston, TX, United States, 2Global MR Applications & Workflow, GE Healthcare, New York, NY, United States, 3Global MR Applications & Workflow, GE Healthcare, Menlo Park, CA, United States, 4Global MR Applications & Workflow, GE Healthcare, Madison, WI, United States, 5Global MR Applications & Workflow, GE Healthcare, Boston, MA, United States, 6M. D. Anderson Cancer Center, Houston, TX, United States |
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Multi-shot fast-spin-echo based PROPELLER (FSE-PROPELLER) combines the robustness to off-resonance and bulk motion and has been increasingly used in body imaging. However, FSE-PROPELLER methods require longer acquisition times compared with conventional FSE methods, especially in high resolution imaging with small FOV, since the oversampling is not confined to a single axis. Outer volume suppression alone can provide a modest reduction in scan time. In this work, we optimized the rotating outer volume suppression method and combined it with variable refocusing flip angles to further reduce scan time for high resolution T2W imaging. |
| 991
|
16:45
|
Clinical-genomic Risk Group Classification of Suspicions Lesions on Prostate mpMRI |
1University of Miami, Miami, FL, United States |
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The applications of prostate mpMRI in clinical decisions, related to the need for prostate biopsy and which areas to biopsy, have rapidly increased over the past few years. After the biopsy, clinicians also have series of methods to determine the aggressiveness of the prostate cancer. The National Comprehensive Cancer Network [NCCN]1 risk groups is one of the most commonly used system. The primary intent of the NCCN is to predict biochemical recurrance rather than survival outcomes such as distant metastasis (DM). Recently, NCCN was integrated with a genomic classifier, Decipher,2 optimized to predict the risk of DM. The resultant new 3-tier risk clinical-genomic classification (CGC) system grouped the patients in low-, intermidiate- and high-risk.3 Here we present radiomics-based approach to predict the low risk group based on the novel CGC. |
| 992
|
16:57
|
Utility of Quantitative Exam with MR Fingerprinting and Diffusion Mapping for Characterization of Cancer Suspicious Lesions in the Transition Zone of Prostate |
1Radiology, Mayo Clinic, Rochester, MN, United States, 2Case Western Reserve University, Cleveland, OH, United States, 3University Hospitals Cleveland Medical Center, Cleveland, OH, United States |
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This study presents the utility and two-reader reliability of a quantitative protocol comprising of MRF-relaxometry and diffusion-based ADC mapping in differentiating transition zone (TZ) prostate cancers from non- cancers. Two-reader agreement was good to excellent for T1, T2 and ADC. T1, T2 and ADC values were significantly lower in targeted biopsy-proven cancers versus non-cancers. T1+ADC combination could differentiate all cancers from non-cancers with an AUC of 0.95. For indeterminate PIRADS category 3 TZ lesions, non-cancers had significantly higher T1 and ADC than cancers and T1 may be the best property for further characterization of indeterminate TZ lesions (AUCT: 0.87 versus AUCADC: 0.84). |
| 993 | 17:09
|
Feasibility of Using Combined PI-RADS Version 2 and Three-Dimensional Multifrequency Prostate MRE in Diagnosing Clinically Significant Prostate Cancer. |
1Department of Radiology, The third affiliated hospital of Sun Yat-sen University, Guangzhou, China, 2MR Research China, GE Healthcare, Beijing, China, 3Department of Radiology, Mayo Clinic, Rochester, MN, United States |
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PI-RADS v2 can be used as a valuable scoring system in clinically significant PCa detection. MRE is expected to add a new method to routine clinical practice. In this study, we combined PI-RADS v2 and MRE at 60, 90 and 120Hz and compared the diagnostic performance for differentiating PCa from prostatitis lesions. Our results showed that the diagnostic accuracy of combined PI-RADS v2+MRE approach at 90 and 120Hz were improved compared with PI-RADS v2. In conclusion, the combined PI-RADS v2+MRE approach, especially at 90 and 120Hz, may have the potential to improve PCa diagnosis. |
| 994 | 17:21
|
Simultaneous T1, T2 and ADC Mapping in Prostate Cancer and BPH using STimulated-Echo based Mapping (STEM) |
1Medical Physics, University of Wisconsin Madison, Madison, WI, United States, 2Radiology, University of Wisconsin Madison, Madison, WI, United States, 3Mechanical Engineering, University of Wisconsin Madison, Madison, WI, United States, 4Biomedical Engineering, University of Wisconsin Madison, Madison, WI, United States |
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A method for simultaneous T1, T2 and Apparent Diffusion Coefficient (ADC) mapping, STimulated-Echo based Mapping (STEM), has been proposed to achieve rapid and co-registered multi-slice T1, T2 and ADC maps within a moderate scan time. In this study, the STEM method is optimized for prostate imaging and evaluated in 16 patients with suspected prostate cancer (PCa) or benign prostatic hyperplasia (BPH). T1, T2 and ADC maps were successfully estimated and compared among BPH, PCa and healthy prostate tissues. |
| 995 | 15:45
|
A novel 11.7T ultra-high field dMRI connectivity atlas of the Japanese quail |
1CEA (Commissariat à l'Energie Atomique et aux Energies Alternatives), NeuroSpin, Gif-sur-Yvette, France, 2Université Paris-Saclay, Orsay, France, 3FLI/Noeud Paris-Sud, Orsay, France, 4CNRS IFCE Université François Rabelais Tours, INRA (Institut national de la recherche agronomique), Nouzilly, France, 5Université Grenoble Alpes, GIN (Grenoble Institut des Neurosciences), Grenoble, France, 6Beauval Nature, ZooParc de Beauval, Saint-Aignan, France |
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Despite the existence of several structural atlases of avian brains, few of them address the bird structural connectivity. In this study, a novel atlas of the structural connectivity is proposed for the Japanese quail, aiming at investigating two lines: the short and the long tonic immobility lines. Using high resolution T2-weighted MRI and ultra-high field diffusion MRI, the connectivity of both lines was investigated, showing the existence of structural differences between the connectivity patterns characterizing the two lines. Thus, the link between their specific behaviors facing fear and their underlying anatomical substrates reached a better understanding. |
| 996 | 15:57
|
In-vivo diffusion imaging of hippocampal network with 600 μm isotropic resolution at 7T |
1Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States, 2School of Information Technology and Electrical Engineering, University of Queensland, Brisbane, Australia, 3Siemens Medical Solutions USA, Inc., Los Angeles, CA, United States, 4Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, CA, United States |
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Neuroimaging findings indicate that neurological disorders differentially target distinct subregions of the hippocampal circuit 1. Therefore, the ability to image hippocampal network is essential to study the mechanism of the disease pathophysiology. Here we propose a novel framework that enables high-resolution intra-hippocampal macro-structural and network diffusion imaging. |
| 997
|
16:09
|
High Resolution Diffusion MRI of the Hippocampus Reveals Heterogenous Development across the Head, Body, and Tail Through Childhood and Adolescence |
1Biomedical Engineering, University of Alberta, Edmonton, AB, Canada |
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High resolution diffusion tensor imaging reveals regional-specificity in microstructural development of the healthy human hippocampus over 6-20 years. The whole structure, head, body, and tail were visualized and segmented directly on mean diffusion-weighted images. Whole-structure analyses showed age-related higher FA and lower MD, and substructure analysis revealed that these associations were strongest in the head – a finding corroborated by prior shape analyses showing greater expansion in the hippocampal head during development. This regional-specificity may reflect hippocampal neurogenesis and myelination in coherence with the high concentration of connections that form at the head from childhood into adulthood. |
| 998 | 16:21
|
Assessing Human Optic Nerve Function using Diffusion Basis Spectrum Imaging (DBSI) |
1Radiology, Washington University School of Medicine, St Louis, MO, United States, 2Hope Center for Neurological Disorders, Washington University School of Medicine, St Louis, MO, United States, 3Biostatistics, Washington University School of Medicine, St Louis, MO, United States, 4Neurology, Washington University School of Medicine, St Louis, MO, United States, 5Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 6Biomedical Engineering, Washington University in St. Louis, ST. LOUIS, MO, United States |
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Previously, we employed diffusion fMRI to assess mouse optic nerve activation in response to flashing-light visual stimulation. Perpendicular apparent diffusion coefficient (ADC⊥) decreased independent of vascular effects. In the current study, we applied DTI and diffusion basis spectrum imaginig (DBSI) to assess human optic nerve activation with flashing checkerboard stimulation. We observed 43% and 13% decrease of DBSI λ⊥ and λǁ, respectively, but not in DTI. |
| 999 | 16:33
|
Joint evidences for a posterior parieto-motor cortex pathway in humans using diffusion MRI tractography and direct cortical stimulation |
1CNRS/ISC, Bron, France, 2CNRS/INCIA, Bordeaux, France, 3Department of Pediatric Neurosurgery, Hôpital Mère Enfant, Bron, France |
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This study aims to identify projections from the posterior parietal "reach area" to the primary motor cortex, in healthy humans, using diffusion MRI tractography and direct cortical stimulation information. We analyzed multiple-shell data from 20 subjects of the Human Connectome Project and found significant ipsilateral projections connecting the identified region to the primary motor cortex, especially the hand-knob area which shows the highest streamlines density on both hemispheres. Strikingly, we also identified a density peak in the left (language-related) hemisphere, within the dorsolateral part of the precentral gyrus related to mouth control. |
| 1000
|
16:45
|
A Multiparametric DTI analysis for Stratification of CSVD Subgroups |
1The Mind Research Network, Albuquerque, NM, United States, 2University of New Mexico Health Sciences Center, Albuquerque, NM, United States, 3University of New Mexico, Albuquerque, NM, United States |
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Vascular cognitive impairment and dementia (VCID) which includes all forms of small vessel diseases is associated with white matter (WM) damages. Diffusion tensor imaging (DTI) has been used widely in several studies in characterizing these WM changes in VCID. The aim of this study is to evaluate the classification accuracy of diffusion measures to distinguish cerebral small vessel disease (CSVD) subjects from healthy controls (HC) and be further able to discriminate CSVD subgroups consisting of subcortical ischemic vascular disease , mixed dementia , leukoaraiosis , and Alzheimer’s disease. The proposed classification framework includes feature extraction followed by multiclass random forest classification with leave one out cross validation. The classification features were defined based on histogram measures calculated on 4 WM regions from four DTI modalities (FA, MD, AD, and RD). Multiple classification tasks were performed owing to the different subject groups. We have shown that DTI combined with FLAIR and cognitive score can give up to 78% classification accuracy for the 5-group and the 4-group classification without the need of the harder to measure cerebrospinal fluid biomarkers. |
| 1001 | 16:57
|
Fluid intelligence is associated with gray matter volume and white matter tract integrity within multiple-demand network across adult lifespan |
1Molecular Imaging Center, National Taiwan University, Taipei, Taiwan, Taipei City, Taiwan, 2Institute of Medical Device and Imaging, National Taiwan University College of Medicine, Taipei, Taiwan, Taipei, Taiwan, 3AcroViz Technology Inc., Taipei, Taiwan, Taipei, Taiwan, 4Cambridge Center for Ageing and Neuroscience (Cam-CAN),University of Cambridge and MRC Cognition and Brain Sciences Unit, Cambridge CB2 3EB, UK., Cambridge, United Kingdom, 5Department of Neurology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan, Taipei, Taiwan |
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In human brain, there are many cognitive demands sharing similar brain regions including working memory, attention, mathematical calculation and reasoning, and problem solving. These multiple-demand (MD) brain regions mainly involve the frontal and parietal lobes including the posterior-lateral frontal, dorso-medial frontal, and mid-parietal cortices. Previous studies with limited age ranges of the participant population reported the total brain volume was highly correlated with Gf and inconsistent findings of white matter tracts related with Gf. Fewer research explores the life-span patterns of Gf with gray and white matter and no previous study investigated the relationship of left and right hemispheres with Gf. The present study aimed to probe the life-span relationship between gray matter volume and white matter tracts connecting the MD regions and Gf in an adult life span large cohort of 603 normal participants from 18 to 88 years old. We also further compared the contributions of the left and right hemispheres to Gf. We hypothesized that gray matter volume and white matter tracts connecting the MD network may reflect age-related changes of Gf, and that Gf is a lateralized complex function. The novelty of our findings is that we examined larger normal adult population across 18 to 88 years old and found that both gray matter volume and white matter tract integrity in the MD regions are the neural substrates of Gf, reflecting the life-span aging patterns of Gf. We further examined the relationship of left and right hemispheres with Gf and found that left and right MD regions showed similar patterns of correlations with Gf scores. The age-related decrease of gray matter volume and tract integrity in the MD network is associated with the reduced functions of multiple-demand cognitive abilities reflected by Gf scores. |
| 1002
|
17:09
|
B-tensor encoding in meningiomas: Comparisons with histology, microimaging and tumor consistency |
1Medical Radiation Physics, Lund University, Lund, Sweden, 2Laboratory of Mathematics in Imaging, Harvard Medical School, Boston, MA, United States, 3Radiology, Brigham and Women's Hospital, Boston, MA, United States, 4Oncology and Pathology, Clinical Sciences, Lund University, Skåne University Hospital, Lund, Sweden, 5Neurosurgery, Clinical Sciences, Lund University, Skåne University Hospital, Lund, Sweden, 6Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 7Diagnostic Radiology, Clinical Sciences, Lund University, Lund, Sweden, 8Lund University Bioimaging Center, Lund University, Lund, Sweden |
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B-tensor encoding enables a mapping of novel dMRI parameters such as microscopic anisotropy and tissue heterogeneity which are sensitive to elongated cell structures and heterogeneity in cell density, respectively. We applied b-tensor encoding to patients with meningioma tumors and compared the imaging findings to the histological type and grade as well as to the tumor consistency determined during surgery. Results show that microcystic/angiomatous meningiomas could be differentiated, and tumor consistency linked both to tissue heterogeneity and microscopic anisotropy and that tumor heterogeneity could provide additional contrast. |
| 1003 | 17:21
|
Whole lesion IVIM analysis in the diagnosis of thyroid tumor: Comparison with Conventional Diffusion-Weighted Imaging |
1MR Department, Beijing Shijitan Hospital of Capital Medical University, Beijing, China, 2Philips Healthcare, Hong Kong, China, 3Beijing Friendship Hospital, Capital Medical University, Beijing, China |
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To compare the diagnostic efficiency of IVIM parameters and conventional DWI (b=600 and b=990) derived from 3D whole-lesion (W-L ROI) delineation. Forty-three patients with 46 pathologically confirmed thyroid nodules were involved. According to ROC curve, D, f, ADC600 and ADC990 values showed diagnostic significance with the AUC values of 0.962, 0.756, 0.970 and 0.939 respectively. Furthermore, the Youden index of D value (0.871) was higher than that of ADC600 (0.826). IVIM is a more promising tool in the differentiation of benign and malignant thyroid nodules using W-L ROI delineation than conventional DWI. |
| 1004 | 17:33
|
The performance of intravoxel-incoherent motion diffusion-weighted imaging (IVIM) derived hypoxia for the risk stratification of prostate cancer |
1The Department of Radiology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China |
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Prostate cancer (PCa) is one of the most common malignant cancers in man. A recently work derived the information of hypoxia from intravoxel-incoherent motion diffusion-weighted imaging (IVIM) and demonstrated strong correlation between IVIM derived hypoxia and immunohistological hypoxia marker. In our work, IVIM derived hypoxia demonstrated better discrimination ability for the risk of PCa than apparent diffusion coefficient (ADC) and pure tissue diffusion (Ds). It might further improve the risk stratification of PCa and can be used as a prognostic factor. |
15:45
|
Past, Present & Future of Clinical IVIM | |
16:09
|
The Merits of IVIM Perfusion Imaging | |
1ETH, Zürich, Switzerland |
16:33
|
Advanced IVIM Metrics: Boldly Going Beyond Perfusion | |
1New York University Langone Health, United States |
16:57
|
Strategies for Optimal Acquisition & Analysis | |
1Institute for Circulation and Medical Imaging, Norwegian University of Science and Technology (NTNU), Trondheim, Norway |
17:21
|
Confounding Factors to Consider When Estimating Perfusion-Related IVIM Parameters | |
1CEA Neurospin, Gif-sur-Yvette, France |
15:45
|
Deep Learning for Medical Imaging / MRI | |
1MGH/Harvard Medical School, United States |
15:57
|
Brief Overview of QSM | |
1University College London, United Kingdom |
16:09
|
QSM Using Deep Neural Network: QSMnet | |
1Seoul National University, Seoul, Korea, Republic of |
16:21
|
DeepQSM: Using Deep Learning to Solve the Dipole Inversion for MRI Susceptibility | |
1The University of Queensland |
16:33
|
Brief Overview of EPT | |
1Engineering Product Development, Singapore University of Technology and Design, Singapore, Singapore |
16:45
|
Dictionary‐Based Electric Properties Tomography | |
1Philips Research Europe, Hambrug, Germany |
16:57
|
Opening a New Window on EPT With Deep Learning | |
1Imaging Division, UMC Utrecht, Utrecht, Netherlands |
17:09
|
A Clinician's View on DL-EPT | |
1Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Japan |
17:21
|
A Clinician's View on DL-QSM | |
1Stanford University, United States |
| 7:00 | Perfusion: ASL Basics & Analysis |
| Yang Li |
| 7:30 | Perfusion: DSC & DCE Basics & Analysis |
| James Ewing |
| 8:00 | Adjournment |
| 7:00 | Synthetic MRI Technique |
| Dan Ma |
| 7:30 | Clinical Applications of Synthetic MRI |
| Suraj Serai |
| 8:00 | Adjournment |
| 7:00 | The Role of 19F in Cell Tracking |
| Paula Foster |
| 7:30 | Measuring Metabolic Rate with 17O: MR vs. PET |
| Michael Bock |
| 8:00 | Adjournment |
| 7:00 | Dielectric Tissue Properties & the MRI Methods for Its Quantification |
| Dong-Hyun Kim |
| 7:30 | Electrical Property Mapping: Practical Considerations and Strategies |
| Rosalind Sadleir |
| 8:00 | Adjournment |
| 7:00 | Quantitative Imaging: MR Fingerprinting: Research Perspective |
| Young Han Lee |
| 7:30 | Quantitative Imaging: MR Fingerprinting: Clinical Perspective |
| Riccardo Lattanzi |
| 8:00 | Adjournment |
| 7:00 | Cardiovascular MR: Technical Promises |
| Matthias Stuber |
| 7:30 | Cardiovascular MR: Challenges of the Future |
| David Bluemke |
| 8:00 | Adjournment |
8:15
|
Structural & Functional Connectivity in the Developing Brain: State of the Field & Effects of Premature Birth | |
1Murdoch Childrens Research Institute, Melbourne, Australia |
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Recent advances in neuroimaging have allowed unprecedented insight into the structural and functional organisation of the newborn brain. Advanced image analysis methods allow the modelling and interrogation of brain development through the lens of network analysis, fostering an understanding of the emergence and advancement of connectivity in the neonatal brain. Premature birth, and subsequent early exposure to the extra-uterine environment, can be viewed as an extreme stressor to the developing brain. The long-term adverse impact of premature birth is well established, with lower gestational age at birth correlated to poor motor, cognitive and health outcomes. In this talk, I will outline the current approaches for investigating structural and functional connectivity in the newborn brain and describe the impact of preterm birth on brain network organisation. |
8:45
|
Stress & the Developing Brain: Lessons from the Lab | |
1University of California - Irvine, Irvine, CA, United States |
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There is compelling evidence from human studies and experimental models that stress or adversity during developmental sensitive periods influences brain maturation, with major cognitive and emotional consequences. However, what exactly stress is, how the developing brain senses it, and how the 'stress-signals' act to influence brain circuit maturation has remained unclear. We will employ neurobiological principles and combined neuroimaging, molecular and behavioral approaches to address these critical questions: we need the answers in order to intervene and prevent aberrant circuit developement and function that promotes vulnerabilities to mental and cognitive disorders. |
9:15
|
Stress & the Developing Brain: Lessons from the Clinic | |
1Oregon Health Sciences University, Portland, United States |
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This session addresses the use of structural and functional MRI to study the mechanisms through which the early environment influences risk for psychiatric disorders. Learning objectives are as follows: (1) Understand the concept of developmental programming; (2) Identify mechanisms through which prenatal conditions can influence the developing brain; (3) Learn how functional and structural MRI with infants has been used to advance understanding of developmental programming; and (4) Understand the potential for clinical intervention research to lend an experimental framework to the study of early human brain development. |
9:45
|
Stress & the Developing Brain: Connecting Environmental & Genetic Risk | |
1University of Denver, Denver, CO |
10:15
|
Adjournment |
| 1005 | Pitch: 8:15 Poster: 9:15 Plasma 1
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The relationship between diffusion MRI-derived axon diameters and conduction velocities in human peripheral nerves |
1National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, United States, 2National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States, 3National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States, 4Biomedical Engineering, University of Arizona, Tucson, AZ, United States, 5Clinical Center, National Institutes of Health, Bethesda, MD, United States, 6Center for Information Technology, National Institutes of Health, Bethesda, MD, United States, 7National Institute of Mental Health, National Institutes of Health, Bethesda, MD, United States |
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From diffusion-weighted MRIs with large |
| 1006 | Pitch: 8:15 Poster: 9:15 Plasma 2
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Exploring diffusion properties in neocortical grey matter using inversion recovery diffusion weighted imaging |
1Neurophysics, Max Planck Institute for Human cognitive and Brain Sciences, Leipzig, Germany, 2International Max Planck Research School on Neuroscience of Communication: Function, Structure, and Plasticity, Leipzig, Germany, 3Medical Center, Faculty of Medicine, University Freiburg, Freiburg, Germany, 4Department of Medical Physics, University Freiburg, Freiburg, Germany, 5Felix Bloch Institute for Solid State Physics, Faculty of Physics and Earth Sciences, Leipzig University, Leipzig, Germany |
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We measured inversion recovery prepared diffusion signal for grey matter. We found that the mean diffusivity (MD) in grey matter drops significantly for TIs higher than the nulling TI. MD in GM dropped from around 0.8×10-3 mm2/s before the null point to around 0.6×10-3 mm2/s immediately after the null point. Our findings suggest that the neocortical gray matter could be characterized using a two dimensional T1-diffusion correlation measurement. |
| 1007 | Pitch: 8:15 Poster: 9:15 Plasma 3
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Joint RElaxation-Diffusion Imaging Moments (REDIM) to probe tissue microstructure |
1Harvard Medical School, Boston, MA, United States, 2Brigham and Women's Hospital, Boston, MA, United States, 3Boston Children's Hospital, Boston, MA, United States, 4Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States |
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The joint probability distribution of diffusivity and T2-relaxation coefficient provides useful information to characterize tissue microstructure. A standard approach for estimating this joint distribution relies on estimating the inverse Laplace transform from a large number of measurements which is not only infeasible in clinical settings but also numerically unstable. In this work, we introduce a novel approach, termed REDIM, to probe tissue microstructure using the statistical properties of a family of scaled distribution functions. In particular, we use specific functions to zoom into the joint probability function to robustly estimate different features of the underlying diffusion-relaxation processes. We show that this approach can be reliably implemented for use with in-vivo diffusion MRI (dMRI) data. |
| 1008 | Pitch: 8:15 Poster: 9:15 Plasma 4
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Biophysical modeling of the white matter: from theory towards clinical practice |
1Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, Portugal, 2CUBRIC, School of Psychology, Cardiff University, Cardiff, United Kingdom, 3Champalimaud Centre for the Unknown, Lisbon, Portugal, 4iMinds - Vision Lab, University of Antwerp, Antwerp, Belgium |
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We address the degeneracy of the diffusion standard model and improve the precision and accuracy in parameter estimation, thus promoting clinical applicability. Acquisition of additional data is not required; instead, we introduce a more robust and accurate estimator by fitting the standard model directly to diffusion-weighted data rather than its rotational invariants. We are able to overcome the implicit assumption of data being shelled in terms of b-values. This enables the correction of gradient nonlinearities to avoid biases in model parameter estimation, whereas revising the optimal experimental design demonstrates that non-shelled encoding schemes are favorable in terms of achievable precision. |
| 1009 | Pitch: 8:15 Poster: 9:15 Plasma 5
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Effective medium theory of multiple diffusion encoding |
1Center for Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark, 2Radiology, NYU School of Medicine, New York, NY, United States |
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We consider the effect of tissue heterogeneity on diffusion acquisitions with multiple encodings. Previously, these signals were analyzed in Gaussian compartments, or disconnected pores. Here we assume a more realistic situation where a compartment cannot be considered Gaussian (uniform) at finite diffusion times, and derive the 4th-order contributions in the diffusion weightings, that distinguish the double-diffusion-encoding (DDE) signal from its single-encoding counterpart. We specifically identify terms odd in the DDE diffusion wave-vectors, which emerge due to local tissue heterogeneity but absent when compartments are Gaussian. Our results are expressed via the dynamical exponent related to the disorder universality class, and agree with Monte Carlo simulations. |
| 1010 | Pitch: 8:15 Poster: 9:15 Plasma 6
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Deep learning 3D white matter fiber orientation from 2D histology: pulling 3D rabbits out of 2D hats |
1Vanderbilt University Institute of Imaging Science, Nashville, TN, United States, 2Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN, United States, 3Computer Science, Vanderbilt University, Nashville, TN, United States, 4Electrical Engineering, Vanderbilt University, Nashville, TN, United States, 5Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, 6Vanderbilt University Institue of Imaging Science, Nashville, TN, United States |
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Most histological analysis of tissue microstructure is inherently 2D. In this work, we implement a deep learning approach to extract 3D microstructural measures from 2D microscopy images. Specifically, we train a neural network to estimate 3D fiber orientation distributions from myelin-stained micrographs. We apply this technique to an entirely unseen brain, which suggests the potential to use this methodology on consecutive 2D slices to investigate 3D structural connectivity using “myelin-stained-tractography” at resolutions much higher than possible with current diffusion MRI practices. There is potential to use similar techniques to estimate a number of 3D metrics from common 2D histological contrasts. |
| 1011
|
Pitch: 8:15 Poster: 9:15 Plasma 7
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Multi-diffusion time DWI to detect altered microvessel structure in a rat model of hypertension |
1Division of Neuroscience and Experimental Psychology, University of Manchester, Manchester, United Kingdom, 2Henry Moseley X-ray Imaging Facility, School of Materials, University of Manchester, Manchester, United Kingdom, 3Bioxydyn Limited, Manchester, United Kingdom |
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The role of microvascular pathology in the development and progression of dementia is currently unclear. Non-invasive methods for imaging microvessel structure are needed to study cerebrovascular alterations in-vivo. The time for water molecules to change direction relative to the diffusion time alters the measured pseudo-diffusion coefficient of intra-voxel incoherent motion (IVIM). Using multi-diffusion time multi-b-value data and a velocity autocorrelation model, the capillary segment length (l) can estimated. In this study we validate hippocampal l against vascular corrosion casts, then apply the method to study vascular structure and function in a rat model of hypertension in comparison with age-matched controls. |
| 1012
|
Pitch: 8:15 Poster: 9:15 Plasma 8
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Revisiting double diffusion encoding MRS in the mouse brain at 11.7 T: what microstructural features is metabolite diffusion sensitive to? |
1Molecular Imaging Research Center (MIRCen), Commissariat à l'Energie Atomique (CEA), Fontenay-aux-Roses, France |
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Double diffusion encoding MRS (DDE-MRS) was shown to be highly sensitive to cell microstructure, in particular cell fiber diameter. Here we revisit the ability of DDE-MRS to probe microstructure by quantifying DDE-MRS signal for six metabolites with high accuracy. We show that signal modulation differs for neuronal and glial metabolites, yielding larger fiber diameters for glia when using a model of isotropically oriented cylinders, as previously reported. However, fiber diameters appear overestimated. Further data acquisition and modeling suggests DDE-MRS is not only sensitive to fiber diameter but also to other microstructural features, such as cell body diameter or fiber length. |
| 1013 | Pitch: 8:15 Poster: 9:15 Plasma 9
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Validating the single fODF and single microstructure kernel assumption in vivo using local SHARD features |
1Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 2Biomedical Engineering Department, School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 3Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, Portugal, 4iMinds - Vision Lab, University of Antwerp, Antwerp, Belgium |
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Most biophysical models of diffusion in the white matter assume that the diffusion MRI signal can be written as the convolution of a single fibre orientation distribution function and a single microstructural kernel, thereby ignoring microstructural differences between fascicles being captured in the same voxel. Here, we validate this assumption by various model selection approaches, i.e., Relative variance explained, F-test of 1- and 2-component models, and Component noise likelihood, and conclude that biologically more realistic, but mathematically more complex versions of the Diffusion Standard Model do not significantly improve the goodness-of-fit, even in case of rich diffusion MR data. |
| 1014
|
Pitch: 8:15 Poster: 9:15 Plasma 10
|
Effect of cell complexity and size on diffusion MRI signal: a simulation study |
1Centre for Medical Image Computing, Department of Computer Science, University College London, London, United Kingdom |
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Mapping tissue microstructure in gray matter is becoming an important field of research in diffusion MRI. Previous studies have focused on characterizing different features separately, such as neurite density, branching order or soma size. However, the combined effect of different cell morphologies and sizes on the diffusion MRI signal has not yet been investigated. This work employs numerical simulations in more realistic cell configurations to investigate the effect of soma diameter, branch diameter and branching order, on the dMRI signal and its time dependence. |
| 1015 | Pitch: 8:15 Poster: 9:15 Plasma 11
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Quantitative characterization of a capillary-network MRI phantom using restricted diffusion analysis |
1Department of Radiology, LMU University of Munich, Munich, Germany, 2German Center for Vertigo and Balance Disorders, LMU University of Munich, Munich, Germany, 3Comprehensive Pneumology Center, German Center for Lung Research, Munich, Germany, 4Experimental Physics - Medical Physics, LMU University of Munich, Garching, Germany |
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An artificial 3D capillary-network phantom (made out of melt-spun sugar fibers) was characterized with diffusion-time-dependent diffusion-weighted MRI. Restricted diffusion was analyzed based on a two-compartment (cylinders and spheres) model; diffusion coefficients were simulated with a simple random-walk model of spins in 2D and 3D spherical geometries. The best model fit agreed very well with the measured diffusion-time-dependent diffusion coefficients and resulted in a mean diameter of 142±2 µm of the spheres and a mean diameter of 9.7±0.7 µm of the capillary tubes (cylinders) with a capillary fraction of fcyl=35±1%. |
| 1016 | Pitch: 8:15 Poster: 9:15 Plasma 12
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High Gradient Amplitude and High Slew Rate Oscillating Gradient Diffusion-Encoding for Human Brain Imaging |
1GE Global Research, Niskayuna, NY, United States, 2GE Healthcare, Stockholm, Sweden, 3Department of Radiology, Mayo Clinic, Rochester, MN, United States, 4Walter Reed National Military Medical Center and Uniformed Services University of the Health Sciences, Bethesda, MD, United States |
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Two high amplitude and slew rate head-gradient MRI systems (C3T: 80mT/m, 700T/m/s, and MAGNUS: 200 mT/m, 500 T/m/s) with significantly better performance than clinical whole-body MRI have been developed. These allow for microstructure-sensitive, oscillating-gradient-spin-echo (OGSE) diffusion-encoding to be feasibly applied for human brain imaging. An analysis of waveforms at varying gradient performances reveals that peripheral nerve stimulation and gradient slew rates limit OGSE frequencies, while gradient strength limits b-values and echo times. In vivo human imaging was performed at 3T, demonstrating significantly increased measured diffusivity in OGSE diffusion tensor imaging (DTI) as compared to standard DTI. |
| 1017 | Pitch: 8:15 Poster: 9:15 Plasma 13
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Mapping tumour response to radiotherapy using diffusion model comparison |
1Quantitative Biomedical Imaging Laboratory, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom, 2Division of Cancer Sciences, The University of Manchester, Manchester, United Kingdom, 3Division of Pharmacy & Optometry, The University of Manchester, Manchester, United Kingdom, 4Division of Cardiovascular Sciences, The University of Manchester, Manchester, United Kingdom, 5Bioxydyn Ltd., Manchester, United Kingdom |
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This work evaluates how the suitability of two diffusion MRI models varies spatially within tumours at the voxel level and in response to radiotherapy, potentially allowing inference of qualitatively different tumour microenvironments. Models of restricted and free diffusion were compared, with regions well-described by the former hypothesised to reflect cellular tissue, and those well-described by the latter expected to reflect necrosis or oedema. Results suggest spatial and radiotherapy-related variation in the models’ suitability for describing diffusion in tumours, with a post-therapy decrease in the proportion of tissue characterised by restricted diffusion. Within restricted diffusion regions, microstructural parameters were sensitive to radiotherapy-induced changes. |
| 1018 | Pitch: 8:15 Poster: 9:15 Plasma 14
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Comparison of Tumor Water Exchange Rate and Intracellular Water Lifetime Measured by Diffusion MRI |
1Radiology, New York University School of Medicine, New York, NY, United States |
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In vivo measurement of cellular-interstitial water exchange rate remains non-trivial. Its development is also hampered by the lack of a gold standard method for validation. In this study, we have used two complementary diffusion MRI methods to measure the water exchange rates. Time-dependent diffusional kurtosis imaging was used to measure the water exchange rate ($$$\tau_{ex}$$$) between the intra- and extra-cellular spaces, while a constant gradient diffusion MRI experiment was used to measure the intracellular water lifetime ($$$\tau_i$$$). These two measurements were conducted using GL261, a mouse glioma tumor model. |
| 1019 | Pitch: 8:15 Poster: 9:15 Plasma 15
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Characterization of Prostate Microstructure Using Diffusion-Relaxation Correlation Spectrum Imaging and Comparison to Digital Histopathology |
1Department of Radiological Sciences, University of California, Los Angeles, Los Angeles, CA, United States, 2Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, United States, 3Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 4Department of Urology, University of California, Los Angeles, Los Angeles, CA, United States |
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Prostate microstructural MRI has the potential to improve prostate cancer (PCa) detection and characterization by resolving the signal signatures of sub-voxel microscopic tissue compartments. Recently, a new model, Diffusion-Relaxation Correlation Spectrum Imaging (DR-CSI), was developed but has not been applied to prostate imaging. In this work, we investigated Prostate DR-CSI and compared DR-CSI features (signal component fractions) to histopathology features (microscopic tissue compartments) derived from digital pathology, to evaluate this new multi-component signal model for prostate microstructure characterization. |
| 1020 | Pitch: 8:15 Poster: 9:15 Plasma 16
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Repeatability and Reproducibility of Confounder-Corrected R2* as a Biomarker of Liver Iron Concentration: Interim Results from a Multi-Center, Multi-Vendor Study at 1.5T and 3T |
1Radiology, University of Wisconsin-Madison, Madison, WI, United States, 2Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 3Global MR Applications & Workflow, GE Healthcare, Menlo Park, CA, United States, 4Radiology, The Johns Hopkins University, Baltimore, MD, United States, 5Siemens Healthineers, Baltimore, MD, United States, 6Radiology, University of Texas Southwestern Medical Center, Dallas, TX, United States, 7Radiology, Technical University of Munich, Munich, Germany, 8Siemens Healthineers, Los Angeles, CA, United States, 9Medicine, University of Wisconsin-Madison, Madison, WI, United States, 10Radiology, Stanford University, Palo Alto, CA, United States, 11Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States |
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R2* mapping has the potential to provide rapid and reliable quantification of liver iron concentration. Importantly, previous studies have demonstrated that by correcting for relevant confounding factors (eg: noise floor effects and fat) R2* mapping is highly insensitive to the presence of these confounders. However, the repeatability and reproducibility of confounder-corrected R2* across multiple sites and vendors remains unknown. This abstract reports interim results from a multi-center, prospective, NIH-sponsored liver iron quantification study. Our results suggest excellent repeatability and reproducibility of confounder-corrected R2* for liver iron quantification in patients, across four centers, three vendors and at both 1.5T and 3T. |
| 1021
|
Pitch: 8:15 Poster: 9:15 Plasma 17
|
Triglyceride Saturation Estimation using Phase- and Amplitude-Modulated Bipolar MRI |
1Pattern Recognition Lab, Department of Computer Science, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany, 2MR Application Predevelopment, Siemens Healthcare GmbH, Erlangen, Germany, 3Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, United States, 4Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, United States, 5Radiology, Duke University Medical Center, Durham, NC, United States, 6Center for Advanced Magnetic Resonance Development, Duke University Medical Center, Durham, NC, United States, 7Division of Gastroenterology, Department of Medicine, Duke University Medical Center, Durham, NC, United States |
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Our purpose was to develop a robust method to estimate triglyceride saturation from bipolar multi-gradient-echo MRI data. Discrepancies in amplitude and phase between even and odd echoes were addressed analytically. The method was demonstrated in abdominal (n=5 patients) and breast (n=1 volunteer) MRI data. Compared to calculating fatty acid composition parameters without modeling amplitude modulations, the proposed method reduced the intensity shift in the readout direction in the estimated parameter maps, but also led to artifacts at water/fat borders. |
| 1022
|
Pitch: 8:15 Poster: 9:15 Plasma 18
|
Direct Radiologic-Pathologic Correlation of Liver Lesions with an MR-Compatible Sectioning and Localization Device |
1Department of Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States, 2Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States, 3Department of Pathology, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States, 4Departments of Radiology, Medical Physics, Biomedical Engineering, Medicine, and Emergency Medicine., University of Wisconsin School of Medicine and Public Health, Madison, WI, United States |
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The purpose of this study was to demonstrate the feasibility of a novel method for precise radiologic-pathologic correlation of liver metastases, in patients undergoing curative resection. Intraoperative gadoxetic acid was administered to patients at the time of partial hepatectomy prior to vascular inflow ligation. Ex vivo MRI was then performed using an MR-compatible sectioning device to identify lesion coordinates to inform pathologic processing. Results from resection specimens in 6 patients with a total of 25 liver lesions are presented. The study’s novel radiologic-pathologic correlation method combines intraoperative gadoxetic acid administration and ex vivo MR imaging to perform accurate lesion localization. |
| 1023 | Pitch: 8:15 Poster: 9:15 Plasma 19
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Multi-Site, Multi-Vendor, and Multi-Platform Reproducibility and Accuracy of Quantitative Proton-Density Fat Fraction (PDFF) at 1.5 and 3 Tesla with a Standardized Spherical Phantom: Preliminary Results from a Study by the RSNA QIBA PDFF Committee |
1Radiology, Nationwide Children's Hospital, Columbus, OH, United States, 2Radiology, UT Southwestern Medical Center, Dallas, TX, United States, 3Medical Physics, Radiology, and Biomedical Engineering, University of Wisconsin Madison, Madison, WI, United States, 4Calimetrix, LLC, Madison, WI, United States, 5Radiology, Division of Gastroenterology, and Center for Advanced Magnetic Resonance Development, Duke University Medical Center, Durham, NC, United States, 6Liver Imaging Group, Radiology, UC San Diego, San Diego, CA, United States, 7Radiology, Children's Hospital of Philadelphia, Philadelphia, PA, United States, 8Radiology, University of Michigan, Ann Arbor, MI, United States, 9Radiology, Mayo Clinic, Rochester, MN, United States, 10Radiology, Cinncinati Children's Hospital Medical Center, Cinncinati, OH, United States, 11Radiology, University of Wisconsin Madison, Madison, WI, United States, 12RSNA, Oak Brook, IL, United States |
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Proton Density Fat Fraction (PDFF) is a widely-accepted quantitative MRI biomarker of hepatic steatosis. Formed in 2015, the PDFF Committee of the RSNA QIBA initiative promotes standardized usage of PDFF for clinical care and research. In this work, the committee describes preliminary results from a multi-center, multi-vendor, multi-platform, and multi-protocol study to characterize the accuracy and reproducibility of PDFF as measured by commercially-available 2D and 3D spoiled-gradient-recalled-echo sequences in a standardized phantom with known PDFF reference targets ranging from 0-100%. Results show that confounder-corrected PDFF reconstructed from multi-fat-spectral peak modeling is an accurate and precise quantitative measurement of PDFF, with minimal bias and strong linearity. |
| 1024
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Pitch: 8:15 Poster: 9:15 Plasma 20
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Feasibility of Rapid Automated Liver Quantitative Susceptibility Mapping in a Patient Population |
1Cornell University, New York, NY, United States, 2Weill Cornell Medicine, New York, NY, United States, 3Southern Medical University, Guangzhou, China, 4Columbia University Medical Center, New York, NY, United States |
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Accurate measurement of the liver iron concentration (LIC) is needed to guide iron-chelating therapy for patients with transfusional iron overload. In this work, we investigate the feasibility of automated quantitative susceptibility mapping (QSM) to measure the LIC in clinical practice. We propose to incorporate In-phase echo acquisition for rapid, robust initialization of the field in water-fat separation problem (T2*-IDEAL). |
| 1025
|
Pitch: 8:15 Poster: 9:15 Plasma 21
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Imaging Diamagnetic Susceptibility of Collagen in Hepatic Fibrosis using Susceptibility Tensor Imaging |
1University of California, Berkeley, Berkeley, CA, United States |
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We propose to quantify susceptibility anisotropy of collagen in the liver using susceptibility tensor imaging (STI). Magnetic susceptibility anisotropy measured by STI differentiates the anisotropic collagen fibers which |
| 1026
|
Pitch: 8:15 Poster: 9:15 Plasma 22
|
Liver glycogen concentration and body hydration status are predictors of liver shMOLLI T1 measurements |
1Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom, 2Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia, 3Perspectum Diagnostics, Oxford, United Kingdom |
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Liver T1 measurements can be used to characterise liver disease but are also sensitive to physiologically normal liver changes. In this work, a set of metabolic interventions were performed to assess the effect of liver glycogen concentration and body hydration status on liver shMOLLI T1 measurements in healthy volunteers. Glycogen showed an in vivo relaxivity in keeping with literature phantom data and hydration status showed a smaller effect. Our results will impact the way T1 measurements of participants with impaired glycogen storage are interpreted, as well as instructions given to participants before their scans. |
| 1027 | Pitch: 8:15 Poster: 9:15 Plasma 23
|
Detection of Early Hepatic Inflammation in Obese Patients with MR Elastography (MRE) |
1Radiology, Mayo Clinic, Rochester, MN, United States, 2Gastroenterology, Mayo Clinic, Rochester, MN, United States, 3Anatomic Pathology, Mayo Clinic, Rochester, MN, United States |
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We performed multifrequency MRE in 10 controls and 88 patients underwent bariatric surgeries. A total of 38 patients were reassessed one year later with MRE and biopsy. At the initial exam, MRE-assessed loss modulus (imaginary component of the complex shear modulus) at 30Hz was significantly higher in obese patients compared with controls, even those without elevated liver fat. The elevation in loss modulus became normalized after treatment. In summary, MRE-assessed loss modulus shows promise as a sensitive indicator of early hepatic inflammation or cell injury in obese patients, pointing to a potential role in selection of patients for bariatric surgery. |
| 1028
|
Pitch: 8:15 Poster: 9:15 Plasma 24
|
Free-Breathing Liver Fat Quantification in Adults with NAFLD using a 3D Stack-Of-Radial MRI Technique |
1Radiological Sciences, University of California Los Angeles, Los Angeles, CA, United States, 2Siemens Healthineers, Siemens, Los Angeles, CA, United States |
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Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide and can lead to liver failure. Conventional Cartesian MRI techniques can quantify liver fat. However, Cartesian MRI requires breath-holding to avoid respiratory motion artifacts in the liver, which may be challenging for many patients. Therefore, we evaluated the accuracy and repeatability of a recently developed free-breathing 3D stack-of-radial liver fat quantification technique in adults with NAFLD at 3 T. The new free-breathing technique demonstrated good repeatability and accuracy compared to conventional breath-holding Cartesian MRI and breath-holding MR spectroscopy. |
| 1029 | Pitch: 8:15 Poster: 9:15 Plasma 25
|
3D Arterial Spin Labeling Imaging of Arterial and Portal-Venous Perfusion in Human Liver at 3 Tesla under Free Breathing: Preliminary Results |
1Section on Experimental Radiology, University Hospital of Tübingen, Tübingen, Germany, 2Siemens Healthcare GmbH, Erlangen, Germany, 3Department of Diagnostic and Interventional Radiology, University Hospital of Tübingen, Tübingen, Germany, 4Institute of Signal Processing and System Theory, University of Stuttgart, Stuttgart, Germany |
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Measurement of hepatic arterial perfusion is important for assessment of chronic liver diseases and characterization of liver lesions. The aim of this study was to investigate the capability of a 3D-PCASL sequence for measurement of arterial, portal-venous and global perfusion of the liver under free respiration. It is demonstrated that the presented method provides high quality ASL perfusion images of the liver under free breathing conditions. Results in a patient with hepatocellular carcinoma clearly indicate high and quantitatively measurable arterial perfusion of lesions, although direct measurement of the clearly lower ASL signal of arterial perfusion in normal liver tissue is usually limited by background noise. |
| 1030 | Pitch: 8:15 Poster: 9:15 Plasma 26
|
Low Flow Continuous Oxygen Inhalation May Avoid the Incidence of “Transient Severe Motion” (TSM) after Administration of Gadoxetate Disodium |
1Ridiology, The First Affiliated Hospital of Xi'an Jiao Tong University, xi'an, China, 2Radiology, The First Affiliated Hospital of Xi'an Jiao Tong University, xi'an, China, 3GE Healthcare China, xi'an, China, 4Radiology, Changan Hospital Affiliated to the First Affiliated Hospital of Xi'an Jiao Tong University, xi'an, China |
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In this study, we try to provide patients with continuous low flow oxygen inhalation during dynamic contrast-enhanced MR liver imaging to reduce “Transient Severe Motion” (TSM) after administration of gadoxetate disodium. The image quality was quantitatively assessed regarding to motion artifacts for each dynamic phases. The incidences of TSM were also compared between experimental and control groups. The results show that continuous oxygen inhalation at low flow rate can significantly reduce motion artifact and may avoid the occurrence of TSM. |
| 1031 | Pitch: 8:15 Poster: 9:15 Plasma 27
|
Gadoxetic acid-enhanced MRI: assessment of arterial phase artifacts and hepatobiliary uptake in a large series. |
1Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 2Radiology, Lausanne University Hospital, Lausanne, Switzerland, 3Radiology, Icahn School of Medicine at Mount Sinai, new York, NY, United States, 4Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 5Icahn School of Medicine at Mount Sinai, New York, NY, United States |
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In this study, we retrospectively evaluated the prevalence of artifacts during the arterial phase presumed to be related to transient severe motion during liver MRI with gadoxetic acid as well as the quality of contrast uptake during hepatobiliary phase in a single large center study. While we found a relatively high rate of motion artifacts on a single arterial phase (9.8%), it was rarely present in both arterial phases (2.3%). We also observed poor contrast uptake during hepatobiliary phase in 1.6% of cases. TSM and poor contrast uptake during HBP was found in only 0.7% of patients. |
| 1032 | Pitch: 8:15 Poster: 9:15 Plasma 28
|
Characterization of Abdominal Neoplasms using a Fast Inversion Recovery Radial SSFP T1 Mapping Technique |
1Medical Imaging, University of Arizona, Tucson, AZ, United States, 2Biomedical Engineering, University of Arizona, Tucson, AZ, United States, 3Electrical and Computer Engineering, University of Arizona, Tucson, AZ, United States |
||
We present a rapid technique for high-resolution multi-slice T1 mapping of the abdomen using the inversion recovery radial steady-state free-precision (IR-radSSFP) pulse sequence. We propose a joint two-component fit to estimate accurate T1 maps in the presence of partial volume. The utility of the sequence has been demonstrated for the characterization of abdominal neoplasms using data acquired on 22 clinical patients. |
| 1033 | Pitch: 8:15 Poster: 9:15 Plasma 29
|
Comparison of FerriScan- versus R2*-Derived Liver Iron Concentration (LIC) for Clinical Decision Making in Patients with Liver Iron Overload Disease |
1Medical Imaging, University Health Network, Toronto, ON, Canada, 2Division of Medical Oncology & Hematology, University Health Network, Toronto, ON, Canada, 3University Health Network, Toronto, ON, Canada |
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This study compared clinical decision making between FerriScan and an R2*-based method in patients with iron overload disease. FerriScan is the current gold standard. However, it is expensive, and data must be transferred offsite. FerriScan and R2* techniques were both used to manage (simulated) patient chelator dosing. The agreement between different reviewers assessing the same FerriScan data was the same as the agreement when the same reviewer used R2*- compared to FerriScan-derived LIC values. Thus, switching to R2*-based decision making from FerriScan is no more likely to cause a difference in patient management than switching from one hematologist to another. |
| 1034 | Pitch: 8:15 Poster: 9:15 Plasma 30
|
Alternative linear post-processing method for calculating viscoelastic parameters of the liver from multi-frequency MR elastograms. |
1Radiology, Shinshu University School of Medicine, Matsumoto, Japan, 2Shinshu University Hospital, Matsumoto, Japan |
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An alternative linear post-processing method that enables fast and precise calculation of viscoelastic parameters (viscosity, η and elasticity, μ) of the liver from multi-frequency MR elastograms has been shown in this study. Correlation of viscoelastic parameters between linear and non-linear calculation methods was significantly high in phantom (r = 0.980 for μ, r = 0.983 for η) and patients study (r = 0.932 for μ, r = 0.935 for η). Calculation speed by linear method (0.42 s) was significantly faster than that by non-linear method (47.14 s). The proposed method will promote clinical application of viscoelastic analysis of liver diseases using MR elastography. |
8:15
|
Rapid Electrodynamic/Analytic Simulations for Coil Design Optimization | |
1Center for Advanced Imaging Innovation and Research (CAI2R) and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine |
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Ultimate intrinsic SNR, SAR and TXE can be computed analytically in simple anatomy-mimicking geometries by using a complete set of surface current modes. The performance of RF coil designs with respect to the corresponding ultimate limits can be rapidly calculated within the same analytical simulation framework. Ideal current patterns associated with optimal performance can be also derived and can provide fundamental physical insight into what features are most important in constructing the best possible coil for magnetic resonance. |
8:45
|
Efficient & Effective Numerical Simulations for RF Coil Modeling & Safety Prediction | |
1C.J. Gorter Center for High-Field MRI, Radiology, Leiden University Medical Center, Leiden, Netherlands |
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This educational talk is tailored to the efficient and effective use of numerical simulation techniques for the assessment of safety and effectiveness of RF coil designs. Proper modeling practices will be identified, and recently developed methodologies will be discussed. |
| 1035
|
9:15
|
Fast field analysis for complex coils and metal implants in MARIE 2.0 |
1Dept of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States, 2CDISE, Skolkovo Institute of Science and Technology, Moscow, Russian Federation, 3Q Bio, Redwood City, CA, United States, 4Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, United States, 5Harvard-MIT Division of Health Sciences Technology, Cambridge, MA, United States, 6Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States, 7Harvard Medical School, Boston, MA, United States |
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When multicoil transmit arrays are used in high field scanners, patient-specific optimization can improve image quality and increase safety margins, particularly for patients with implants. The feasibility of performing such optimizations in real-time was demonstrated recently[5], using a combination of fast tissue mapping and voxel-based field simulation[4], but only for a single-port coil and an implant-free patient. In this abstract we describe new techniques for simulating complex coils that accelerates MARIE simulation as much as an order of magnitude, and an efficient approach to including metal implants. We demonstrate field analysis in minutes using the open-source simulator MARIE2.0. |
| 1036 | 9:27
|
Ideal current patterns for optimal SNR in realistic heterogeneous head models |
1Center for Computational and Data-Intensive Science and Engineering (CDISE), Skolkovo Institute of Science and Technology, Moscow, Russian Federation, 2Q Bio, Redwood City, CA, United States, 3Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, United States, 4Bernard and Irene Schwartz Center for Biomedical Imaging (CBI), Department of Radiology, New York University School of Medicine, New York, NY, United States, 5Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, NY, United States |
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We describe a method to calculate, for the first time, ideal current patterns (ICP) associated with optimal signal-to-noise ratio (SNR) in heterogeneous head models for arbitrary current-bearing substrates. We show ICP for different voxel positions in the brain and neck, magnetic field strengths, and realistic head coil substrates. Even though the optimal SNR distribution is similar for different substrates, we show that the ICP depend instead on the topology of the substrate on which they are restricted. ICP can inform non-convex radiofrequency (RF) coil optimization problems by providing an intuitive initial guess and could lead to task-optimal RF arrays designs. |
| 1037 | 9:39
|
Improvement of the Transmit Efficiency Using a Miniaturized Artificial Magnetic Conductor Surface for RF shield at 9.4T |
1ITEE, The University of Queensland, Brisbane, Australia |
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A novel structure for size-reduction of artificial magnetic conductor surface was designed for 9.4T MRI, aiming to improve the transmit efficiency of RF coils. This design achieved great miniaturization of the EBG unit cell size, which has been reduced to 4.48% of free-space wavelength. The reflection phase coefficient and the dispersion diagram are employed to characterize the EBG structure performance. Compared with a conventional metallic RF shielding plate, full-wave simulation results suggest that the proposed structure can achieve improved transmit efficiency. |
| 1038
|
9:51
|
Experimental Validation of Subject-Specific Local SAR Assessment by Deep Learning |
1Center for Image Sciences, University Medical Center Utrecht, Utrecht, Netherlands, 2MR Code BV, Zaltbommel, Netherlands, 3Biomedical Image Analysis, Eindhoven University of Technology, Eindhoven, Netherlands |
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Subject-specific local SAR assessment is one of the outstanding challenges of ultra-high field MRI. In this work, we present experimental, in-vivo results on four healthy subjects of a novel deep learning approach which provides online subject-specific local SAR distributions based on measured B1+ maps. Results are validated by creating a subject-specific model of each subject and calculate a reference local SAR distribution off-line by FDTD simulations. The results show that a Convolutional Neural Network (CNN) trained with synthetic MR data enables accurate subject-specific local SAR prediction during an MRI examination. |
| 1039
|
10:03
|
Peripheral Nerve Stimulation (PNS) constrained gradient coil design within a Boundary Element Method Stream Function (BEM-SF) optimization |
1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany, 2A.A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States, 3Harvard Medical School, Boston, MA, United States, 4Harvard-MIT Division of Health Sciences Technology, Cambridge, MA, United States |
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Gradient system performance is increasingly constrained by Peripheral Nerve Stimulation (PNS). Nonetheless, gradient coil windings are optimized using the boundary element stream function method (BEM-SF) incorporating only non-biological metrics. We introduce direct incorporation of PNS constraints into a BEM-SF optimization in addition to the usual constraints. We pre-compute a novel PNS “oracle” matrix of each nerve segment’s likelihood to be excited by a given stream-function basis. The constraint is linear in current, so stimulation likelihood is a simple sum over all stream function bases. This allows convex optimization with a PNS constraint and examination of tradeoffs with linearity, inductance, torque and efficiency. |
10:15
|
Adjournment |
| 1040
|
8:15
|
STrategically Acquired Gradient Echo (STAGE) Imaging for Standardized Multi-Contrast and Quantitative Brain Data Acquisition: Validating T1 mapping and Preliminary Clinical Results |
1Department of Radiology, Wayne State University, Detroit, MI, United States, 2The MRI Institute for Biomedical Research, Bingham Farms, MI, United States, 3IRCCS, Fondazione Don Carlo Gnocchi ONLUS, Milano, Italy, 4Tianjin First Central Hospital, Tianjin, China |
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One major thrust in radiology today is imaging standardization with rapidly acquired quantitative multi-contrast information. This is critical for multi-center trials, for the collection of big data and the use of artificial intelligence in evaluating the data. STAGE is one such method that can provide more than ten qualitative and quantitative pieces of information in roughly 5 minutes or less at 3T. In this work, we introduce several new image contrasts derived from STAGE and validate STAGE T1 mapping using the ISMRM/NIST phantom as well as in vivo data. We also present some preliminary pathological results. |
| 1041
|
8:27
|
OneforAll: Improving the Quality of Multi-contrast Synthesized MRI Using a Multi-Task Generative Model |
1Biomedical Engineering, Tsinghua University, Beijing, China, 2Electrical Engineering, Stanford University, Stanford, CA, United States, 3Subtle Medical, Menlo Park, CA, United States, 4Global Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States, 5Radiology, Stanford University, Stanford, CA, United States |
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To improve the quality and efficiency of multi-contrast MR neuroimaging, a new Multi-Task Generative Adversarial Network (GAN) is proposed to synthesize multiple contrasts using a uniformed network. The cohort of 104 subjects consisting of both healthy and pathological cases is used for training and evaluation. For both the subjective and non-subjective evaluation, the proposed method achieved improved diagnostic quality compared with state-of-the-art synthetic MRI image reconstruction methods based on model-fitting and also previously shown deep learning methods. |
| 1042 | 8:39
|
White matter microstructure changes as a function of time-of-day: a biomarker of accumulating sleep pressure? |
1Department of Diagnostic Physics, Oslo University Hospital, Oslo, Norway, 2Norwegian Centre for Mental Disorders Research, Oslo University Hospital, Oslo, Norway |
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There is an increasing awareness of time-of-day (TOD) effects in MRI. The underlying causes of these fluctuations may be related to diurnal physiological variations, reflecting the processes that govern transition between sleep and wake. We probed TOD effects in a prospective manner, scanning 47 healthy individuals in the morning and the same evening using a five-shell diffusion-weighted imaging protocol at 3T, where a number of important Zeitgeber signals were rigorously controlled. We found significant changes in an number of derived DWI parameters (FA, MD, AWF, MK), and speculate that these changes are pointing towards underlying mechanisms of sleep-wake homeostasis. |
| 1043
|
8:51
|
Whole Brain Mapping of Subcortical U-fibers in the Human Connectome Project Data |
1Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, China, 2New York University School of Medicine, New York, NY, United States |
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Although reconstruction of subcortical U-fibers from diffusion MRI data has been demonstrated before, systematic examination of U-fibers |
| 1044 | 9:03
|
T2 Weighted Whole-Brain Intracranial Vessel Wall Imaging at 3 Tesla with Cerebrospinal Fluid suppression |
1Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China, 2Siemens Healthcare Pte. Ltd, Singapore, Singapore, Singapore, 3Department of Neurology, Shenzhen No.2 People’s Hospital, Shenzhen, China |
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T2 weighting intracranial vessel wall MR imaging provides good contrast to discriminate various important plaque components and is a good tool to differentiate intracranial vasculopathy. However, the strong CSF signal in T2-weighted images interfere the depiction of the vessel wall. In this study, we proposed to use T2IR preparation module combined with T2-weighted SPACE for whole brain intracranial vessel wall imaging, the T2IR pulses were used to suppress CSF while minimizing its effect on the signal reduction from T2w SPACE. This new technique was first evaluated in healthy volunteers and then tested on some stroke patients. |
| 1045 | 9:15
|
Stirred CSF Measured by Low b-value DTI |
1Healthcare Business Unit, Hitachi, Ltd., Tokyo, Japan, 2Research and Development Group, Hitachi, Ltd., Tokyo, Japan, 3Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Japan |
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Cerebrospinal fluid (CSF) plays an important role in clearance systems of the brain. There have been many studies on bulk flow of CSF; however, there have been few studies on complex flow like pseudo-random movement of CSF. In this paper, we investigate locally “stirred” CSF by using low b-value diffusion tensor imaging (DTI). Measured DTI shows inhomogeneous physiology of CSF, including extremely high and anisotropic diffusion tensors around the middle-cerebral artery. It demonstrates that the low b-value DTI will be useful in estimating local drainage of CSF. |
| 1046 | 9:27
|
Integration of field monitoring for neuroscientific applications - SNR, acceleration and image integrity |
1Institute for Bio Engineeringmedical, ETH Zurich and University of Zurich, Zurich, Switzerland, 2Skope MRT, Zurich, Switzerland, 3Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland |
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Full integration of field monitoring capability in an MRI system’s hard- and software by co-designing the two subsystems for neuroscientific applications is demonstrated along with its benefits in cutting edge fast imaging. The system entails a custom brain receiver array with integrated field-probes monitoring k-space during readout as well as the subsequent data processing pipeline for image reconstruction. All data is aggregated in an ISMRMRD data container for open access. |
| 1047
|
9:39
|
A Joint Recommendation for Optimized Preprocessing of Connectom Diffusion MRI Data |
1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, 2Martinos Center for Biomedical Imaging, MGH, Boston, MA, United States, 3CUBRIC, Cardiff University Brain Research Imaging Centre, Cadiff, United Kingdom |
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The possibility of acquiring diffusion MRI data with extremely high resolution and strong diffusion weighting imposes new challenges on the preprocessing. In a joint effort, all research institutions with the availability of a human MRI system with 300 |
| 1048
|
9:51
|
Myeloarchitectonic mapping of cortical gray matter with 3D inhomogeneous magnetization transfer (ihMT) |
1Division of MRI research, Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States, 2CRMBM, Aix Marseille Univ, CNRS, Marseille, France, 3Global MR Applications and Workflow, GE Healthcare, Boston, MA, United States |
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Advances in inhomogeneous magnetization transfer (ihMT) imaging have enabled improved volumetric imaging of gray matter. We performed a cortical surface-based analysis of the ihMT ratio (ihMTR) and the inverse ihMT ratio (ihMTRinv) to investigate the distribution of myelin in cortical gray matter. IhMT MRI, and especially ihMTRinv, displayed regional differences in cortical myelination, in agreement with postmortem studies. These findings support the myelin sensitivity and specificity of ihMTRinv and its use for gray matter characterization. |
| 1049 | 10:03
|
Submillimeter whole brain diffusion MRI at 7 Tesla using simultaneous multislice imaging |
1Center for Magnetic Resonance Research, Radiology, Medical School of the University of Minnesota, Minneapolis, MN, United States |
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Acquisition of whole-brain diffusion MRI at submillimeter resolutions has proven to be highly beneficial for probing the brain’s structure and connectivity. Here, we investigate how simultaneous multislice (SMS) imaging, a single-shot acquisition that has great success in large-scale cohort studies such as the Human Connectome Projects (HCP), can be used to achieve submillimeter whole-brain diffusion at 7 Tesla. We acquired SMS diffusion at 0.7-mm isotropic resolution using a standard body gradient. Our results show that these submillimeter data can be used to generate a whole-brain tractogram and a connectome comparable to those of the 1.05-mm HCP-style acquisition using denoising approaches. |
| 1050
|
8:15
|
Awake and behaving mouse fMRI in Go/No-go task. |
1Institute of Neuroscience, Chinese Academy of Sciences, Shanghai, China |
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The current study describes a novel awake and behaving mouse fMRI paradigm, which enables the functional imaging of mice brain during an olfaction based go/no-go (GNG) task. This novel paradigm incorporates a MR compatible behavioral apparatus (olfactometer, licking detection and water delivery) and awake head fixation mechanism, all specifically designed to be used with a cryogenic coil at high field. High-resolution functional images uncovered the large-scale networks that are differentially recruited in the hit vs. correct-rejection trials, with greatly limited motion artefacts. This method paved the way for future whole-brain, systematic mapping of cognitive processes in mice. |
| 1051
|
8:27
|
Triple network activity regulation mediated by the insular cortex in the mouse brain. |
1Singapore Bioimaging Consortium, Agency for Science, Technology and Research, Singapore, Singapore, 2Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom, 3University College London, London, United Kingdom |
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The triple-network model is a contemporary theoretical framework derived from empirical neuroimaging data to explain a wide range of observations stemming from multiple psychopathologies. Central to the model are interactions between the salience, default-mode, and central executive networks. The insula area is a central node of the salience network. Using acute photostimulation, we report evidence to support the existence of a triple-network system within the mouse brain. Further, by using sustained optogenetic neuromodulation, we show that inhibition of the insular area acts on homotopic functional connectivity but fails to affect wider interactions within triple-network system in a resting-state setting. |
| 1052
|
8:39
|
Thalamic low frequency activity contributes to resting-state cortical interhemispheric MRI functional connectivity |
1Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, Hong Kong, 2Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, Hong Kong |
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The brain consists of numerous interconnected parallel and hierarchical networks subserving sensory, behavioral and cognitive functions. Resting-state functional MRI (rsfMRI) connectivity has helped study the complex brain-wide functional networks. Yet, less is known about the role of |
| 1053
|
8:51
|
Ultrahigh spatial and temporal resolution fMRI with implanted CMOS-based planar microcoil at 14.1T |
1High-Field MR Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany, 2Graduate Training Centre of Neuroscience, IMPRS for Cognitive and Systems Neuroscience, University of Tübingen, Tübingen, Germany, 3Institute of Theory of Electrical Engineering, University of Stuttgart, Stuttgart, Germany, 4Institute of Microelectronics, University of Ulm, Ulm, Germany, 5Department Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Tübingen, Germany, 6Department for Biomedical Magnetic Resonance, University of Tübingen, Tübingen, Germany |
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Compared to electrophysiological or optical recording of brain activity, fMRI has a rather low spatial and temporal resolution. Here, we propose the use of implanted microcoils for studying animal brain activity in-vivo with ultra high sensitivity compared to conventional coils. A fully integrated CMOS NMR transceiver containing an on-chip-microcoil, integrated amplifiers and a demodulator is used to acquire ultra-localized signal (10nl) at ultrahigh temporal resolution (5ms) showing unprecedented high speeds and spatial resolutions of the BOLD response. |
| 1054 | 9:03
|
MR-Guided Pharmacological Intervention: Creating Causal Capabilities for fMRI |
1Radiology, University of Wisconsin - Madison, Madison, WI, United States, 2Medical Physics, University of Wisconsin - Madison, Madison, WI, United States, 3Biomedical Engineering, University of Wisconsin - Madison, Madison, WI, United States, 4Psychiatry, University of Wisconsin - Madison, Madison, WI, United States, 5Neuroscience, University of Wisconsin - Madison, Madison, WI, United States |
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Neuroscience is in need of precise interventional tools that alter local neural dynamics while monitoring whole brain network activity. We demonstrate methods to guide catheters to deliver and monitor pharmacologic alteration of a local brain region in anaesthetized Rhesus monkeys while monitoring changes in resting state functional connectivity MRI (rs-fcMRI) throughout all brain networks. Expected and unexpected alterations in rs-fcMRI after unilateral and bilateral infusions of inhibitory agents in the limbic system are provided. The approach shows promise for using the alterations to compute effective connectivity through fMRI. |
| 1055 | 9:15
|
Temporal dynamics of mouse BOLD fMRI in the sensory pathway |
1Cener for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon, Korea, Republic of, 2Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Korea, Republic of, 3Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Sungkyunkwan University, Seoul, Korea, Republic of |
||
Ultra-high field fMRI allows us to detect the functional sensory pathway including thalamic nuclei. Although hemodynamic response function is determined spatially by the vascular architecture and temporally by the evolution of hemodynamic changes, fMRI signals may provide insight into tracking sequential neural processing. Here, we investigated the spatiotemporal evolution of functional sensory pathways during forepaw stimulation in anesthetized mice using ultra-high field BOLD fMRI. |
| 1056
|
9:27
|
Line-scanning diffusion fMRI reveals a rapid-onset (<200 ms) component |
1Champalimaud Research, Champalimaud Foundation, Lisbon, Portugal |
||
Diffusion fMRI (dfMRI) has been proposed as a more direct means for mapping neural activity more accurately than BOLD fMRI. However, the origin of dfMRI signals is still an ongoing debate. Here, we developed a line-scanning dfMRI technique achieving very high temporal resolution (100 ms), and measured activity in the forelimb S1 upon rat forepaw stimulation. Our results show a rapid-onset (<200ms) dfMRI component that was not found in BOLD fMRI. Upon inducing hypercapnia, the fast dfMRI component was nearly unaffected while the slower dfMRI component was substantially modulated, suggesting a potentially neural origin for the former. |
| 1057
|
9:39
|
Using BOLD fMRI to map anesthesia-induced burst suppression in humans and non-human primates |
1Functional Imaging Laboratory, German Primate Center, Göttingen, Germany, 2Georg-August University of Göttingen, Göttingen, Germany, 3Klinikum Rechts der Isar der Technischen Universität München, Munich, Germany |
||
Deeply anesthetized and comatose states are often accompanied by a distinctive pattern of electroencephalographic activity, called “burst suppression”. This pattern’s underlying mechanism and functional significance remain largely unknown. In this work we demonstrated that burst suppression can be detected in fMRI data, without the need for accompanying measures of neural activity. We then used this fMRI approach to perform whole-brain mapping of burst suppression in anesthetized human volunteers and non-human primates. We found that burst suppression involves the same set of brain areas across primate species, and is mostly absent in primary visual and somatosensory areas. |
| 1058 | 9:51
|
Multilevel functional organization of the mouse lemur primate brain |
1Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), Direction de la Recherche Fondamentale (DRF), Institut François Jacob, MIRCen, Fontenay-aux-Roses, France, 2Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay UMR 9199, Neurodegenerative Diseases Laboratory, Fontenay-aux-Roses, France |
||
Resting state networks have been characterized in numerous mammals covering human, non-human primates, dogs, rabbits and rodents, though only ever at single semi-arbitrary levels of complexity. In humans, resting state networks analyses have been extended to extracting networks of varying complexity, representing different levels of a possible “functional hierarchy”. We performed the first study of “functional hierarchy” in animals. We focused on the gray mouse lemur (Microcebus murinus), a small primate attracting increased attention as a model for cerebral and age-related disorders. |
| 1059 | 10:03
|
Subcortico-centric view of macaque neocortical organization investigated using resting-state fMRI |
1Center for Biosystems Dynamics, RIKEN, Kobe, Japan, 2Sumitomo Dainippon Pharma Co., Ltd, Osaka, Japan, 3Department of Neuroscience, Washington University in St. Louis, St. Louis, MO, United States, 4Department of Radiology, Washington University in St. Louis, St. Louis, MT, United States |
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An important aspect to understand evolutionary differences across primate species is through conserved subcortical circuitry and diversification of neocortical inputs. Here, we explore neocortical profiles of major subcortical structures using ‘Human Connectome Project-style’ resting-state functional MRI (rfMRI) connectivity in alert and anesthetized macaque monkeys. Our results reveal that the major subcortical “limbic and associative” structures have largely overlapping neocortical rfMRI connectivity profiles. These findings suggest important differences relative to previous reports of functional connectivity profiles in humans, and may provide a valuable clue to the evolution of human brain function and behavior in the primate lineage. |
| 1060
|
8:15
|
Parallel Transmit Optimized Spiral Composite Adiabatic Pulses for 3D Spatial-Spectral Selectivity in Spectroscopy |
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States |
||
In this abstract we demonstrated by simulation and phantom experiments the feasibility of designing composite refocusing pulse for spectroscopy using parallel transmission, featuring inherent 2D spatial and spectral selectivity along with improved immunity to B0 non-uniformity and B1+ heterogeneity while simultaneously providing lipid and water suppression and short echo times of ~18ms. |
| 1061
|
8:27
|
Double-Shot Semi-Adiabatic Localization for Ultra Short Echo Time Magnetic Resonance Spectroscopy |
1Biomedical Engineering, Columbia University, New York, NY, United States, 2Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, MN, United States, 3GE Healthcare, Berlin, Germany, 4Radiology, Columbia University, New York, NY, United States |
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Modern magnetic resonance spectroscopic (MRS) pulse sequences which employ localization through adiabatic pulses suffer from long minimum echo times ($$$\ge$$$ 19 ms). Here we developed a novel MRS pulse sequence which allows for an echo time of 8 ms with adiabatic localization in two of the three spatial dimensions, at the cost of two-shot volume localization. The sequence is highly robust to B1 inhomogeneity and does not have any anomalous J-modulation since no slice-selective refocusing pulses are used. High spectral quality was obtained in phantom experiments, although strong lipid contamination was observed, consistent with previously reported two-shot localization methods. |
| 1062
|
8:39
|
Optimization of 1H Single Voxel Multi-Parametric Spectroscopic Fingerprinting (MRSF) |
1Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel |
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Brain metabolite T1 and T2 have diagnostic value and per-subject knowledge of both metabolite and water reference T1, T2 is necessary for accurate metabolite absolute quantification. Here we optimize the excitation schedules of our recently-proposed magnetic resonance spectroscopic fingerprinting (MRSF) sequence to accurately estimate metabolite T1 and T2. We computationally evaluate the optimized schedules using Monte-Carlo simulations, as well as phantom and in-vivo experiments. |
| 1063 | 8:51
|
Localized pure shift proton MRS for measurements on biological samples |
1Department of Electronic Science, Xiamen University, Xiamen, China |
||
Localized proton magnetic resonance spectroscopy (MRS) provides a non-invasive tool for metabolic studies on biological systems by revealing valuable biochemical information, complementary to anatomical information delivered by MRI. However, due to limited proton chemical shift range and extensive J coupling splittings, spectral congestion is generally encountered in the resulting 1D spectra acquired by conventional proton MRS techniques, such as PRESS (Point resolved spectroscopy) and STEAM (STimulated Echo Acquisition Mode). In this abstract, we present a previously-unreported proton MAS approach to obtain localized 1D pure shift spectra with spectral simplification, potentially useful for studies on biological samples. |
| 1064
|
9:03
|
In vivo Detection of Metabolic Turnover of GABA and Glutamate in Human Brain using Dynamically Acquired MEGA-PRESS MRS During 13C-Labeled Glucose Infusion |
1Department of Psychiatry, Mcgill university, Montreal, QC, Canada, 2Centre d'Imagerie Cérébrale, Douglas Mental Health University, Montreal, QC, Canada, 3Clinical Research Division, Douglas Institute Psychiatrist, Montreal, QC, Canada |
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Glucose, the main substrate for cerebral energy metabolism, serves as a metabolic precursor for both glutamate and GABA synthesis. In the current study, we employ a novel approach to investigate 13C-labeling of both glutamate and GABA in the human brain. Specifically, localized homonuclear (1H) J-difference edited (MEGA-PRESS) MRS spectra were acquired dynamically (without heteronuclear decoupling or editing pulses) to detect glutamate and GABA labelling following an infusion of 13C labeled glucose. Despite excellent spectral quality and temporal stability, little or no GABA labeling was observed, raising some questions as to the functional status of the GABA pools detected by MEGA-PRESS. |
| 1065
|
9:15
|
Cardiac creatine quantified by cycled water-suppressed 1H-MRS at 3T |
1University of Cambridge, Cambridge, United Kingdom, 2Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, Oxford, United Kingdom, 3Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom, 4Oxford Heart Centre, John Radcliffe Hospital, Oxford, United Kingdom, 5Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Science, Bratislava, Slovakia |
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This work aimed to use cardiac 3T 1H-MRS to quantify creatine concentration (“[Cr]”) in the human heart, because creatine plays a key role in cardiac energy metabolism. We implemented a cycled water-suppression scheme (WC) into the PRESS and STEAM pulse sequences on a Siemens 3T Prisma MRI scanner. Compared to the vendor’s product PRESS sequence, we found that PRESS-WC was able to measure [Cr] more than 2 times more reproducibly and in a shorter scan. Using PRESS WC in a 10-breathhold protocol, we were able to detect a decrease in creatine concentration in 5 patients suffering from aortic stenosis. |
| 1066
|
9:27
|
SENSE-based reconstruction for removal of spurious echo artifacts in MRS |
1Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States |
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Spurious echo artifacts appear in MRS spectra and originate from regions of unsuppressed and insufficiently crushed signal. We propose a reconstruction method to remove such artifacts using the sensitivity weighting of the receive channels at each spatial location. Data from phantom and simulations show that spurious echoes can be separated from underlying signal. The spatial distribution of unwanted signal was estimated in vivo using B0 maps. Artifactual components of the signal were identified in sinus regions, however not entirely removed from the spectrum. Further work will aim to improve the conditioning of the SENSE reconstruction to remove spurious echo artifacts from MRS data. |
| 1067
|
9:39
|
Functional Magnetic Resonance Spectroscopy in the mouse brain |
1Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown, Lisbon PT, Portugal |
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Functional magnetic resonance spectroscopy (fMRS) can provide insights on brain metabolism under activation, as has already been shown in humans. Assessing fMRS in mice would open interesting perspectives for understanding neural activity given mouse transgenics. We report preliminary encouraging results of fMRS in the mouse superior colliculus, during visual stimulation at 9.4 T (using a cryocoil for reception). Time courses of different metabolites concentrations notably reveal metabolite signal modulations during activation. |
| 1068
|
9:51
|
Towards a Fitting Model of Macromolecular Spectra: Amino Acids |
1Biological Cybernetics, Max Planck Institute, Tübingen, Germany, 2Faculty of Science, University of Tübingen, Tübingen, Germany |
||
Broad signals underlying in vivo 1H MRS spectra are referred to in |
| 1069
|
10:03
|
About the need for a comprehensive description of the macromolecular baseline signal for MR fingerprinting and multidimensional fitting of MR spectra |
1University of Bern, Departments of Radiology and Biomedical Research, Bern, Switzerland, 2NIH, NIMH, Magnetic Resonance Spectroscopy Core, Bethesda, MD, United States |
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The purpose of this study was to evaluate the need for a comprehensive description of the macromolecular baseline signal (MMBL), e.g. for MR fingerprinting and multidimensional fitting of MR spectra. Inherent J-evolution for certain signals as well as multi-component T2-decays can cause variance of the signal shape as function of TE that is not described in a mono-exponential decay model. Two methods are described to accommodate this signal behavior when fitting a 2DJ-Inversion-Recovery dataset. In addition, the MMBLs for different TEs, as well as resulting metabolite contents, T1s and T2s with the conventional and alternative methods are reported. |
| 1070 | 8:15
|
Fetal Brain Automatic Segmentation Using 3D Deep Convolutional Neural Network |
1Diagnostic Imaging and Radiology, Childrens National Medical Center, Washington, DC, United States, 2Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, 3Fetal Medicine, Childrens National Medical Center, Washington, DC, United States |
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Fetal brain MR image segmentation is necessary for brain development research. Currently, this task mainly relies on labor-intensive manually contouring or correction, because automatic segmentation often fails due to the low image quality. In this work, we apply a convolutional neural network, 3D U-Net, to segment the fetal brain regions. The proposed method was validated on 209 fetal brain MRI scans, including healthy fetal controls and high-risk fetuses with congenital heart disease. The proposed method showed high consistency with the manual correction results and may facilitate the identification of aberrant fetal brain development by providing quantitative morphological information. |
| 1071
|
8:27
|
Quantifying T1 and T2* Relaxation Times of Fetal Fat, Fetal Liver, Fetal Kidney, and Amniotic Fluid at 1.5T |
1Medical Biophysics, Western University, London, ON, Canada, 2Obstetrics and Gynaecology, Western University, London, ON, Canada, 3Division of Maternal, Fetal and Newborn Health, Children’s Health Research Institute, London, ON, Canada |
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T1 and T2* relaxation times of fetal tissues as a function of gestational age have not been previously published. We acquired fetal MRI data from pregnant women with a gestational age between 29 and 38 weeks. Using DESPOT1 and Quantitative IDEAL, the T1 and T2* relaxation times, respectively, of fetal fat, fetal liver, fetal kidney, and amniotic fluid were quantified as a function of gestational age. Only fetal fat T1 and T2* relaxation times, and fetal liver T2* relaxation times changed during this gestational period. |
| 1072
|
8:39
|
The Utility of MRI for Measuring Hematocrit in Fetal Anemia |
1Department of Physiology, University of Toronto, Toronto, ON, Canada, 2Institute of Medical Science, University of Toronto, Toronto, ON, Canada, 3Division of Cardiology, Hospital for Sick Children, Toronto, ON, Canada, 4Division of Maternal-Fetal Medicine, Mount Sinai Hospital, Toronto, ON, Canada, 5Division of Translational Medicine, Hospital for Sick Children, Toronto, ON, Canada, 6Mouse Imaging Centre, Hospital for Sick Children, Toronto, ON, Canada, 7Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada |
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To determine the accuracy of MRI for estimating hematocrit in anemic fetuses, the current study compared MRI-estimated hematocrit against the gold-standard fetal blood sampling and Doppler assessment of the middle cerebral artery for peak systolic velocity (MCA-PSV). MRI-estimated hematocrit was calculated from T1 and T2 measurements of intrahepatic umbilical vein blood. MRI results correlated well with fetal blood sampling and had a higher specificity for predicting anemia than Doppler MCA-PSV. In conclusion, MRI is feasible and accurate for the detection of fetal anemia and may be used to confirm the need for blood transfusion when MCA-PSV is suggestive of anemia. |
| 1073 | 8:51
|
Dual-Imaging Modality Approach to Evaluate Cerebral Hemodynamics in Growth-Restricted Fetuses: Oxygenation and Perfusion |
1Department of Biomedical Engineering, Wayne State University, Detroit, MI, United States, 2Department of Radiology, Wayne State University, Detroit, MI, United States, 3Department of Obstetrics and Gynecology, Wayne State University, Detroit, MI, United States, 4Institute for Biomedical Research, Waterloo, ON, Canada, 5Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, United States |
||
Cerebral blood perfusion has shown to be a sensitive biomarker of brain sparing at early stages of fetal growth restriction (FGR) compared to conventional Doppler estimates. Blood perfusion along with cerebral blood oxygenation may provide a holistic view of the fetal brain metabolism during FGR. Fractional moving blood volume, an ultrasound-based; and susceptibility weighted imaging, an MRI-based technique were used to estimate fetal cerebral blood perfusion and oxygenation, respectively. A significantly negative and positive correlation was found between cerebral blood perfusion and oxygenation, in normal growth and FGR fetuses, respectively. This dual modality based model will improve assessment of fetal well-being. |
| 1074 | 9:03
|
Using 3D Radial VIBE MR to Evaluate the Normal and Abnormal Gastrointestinal Tract in Fetuses |
1Department of Radiology, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China, 2Diagnostic Imaging, SIEMENS Healthcare, Shanghai, China, 3R&D, Diagnostic Imaging, SIEMENS Healthcare, Erlangen, Germany |
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Images obtained with the radial VIBE sequence were reported to have less motion artifacts [MB1] than Cartesian sampled 3D VIBE T1W images in various pediatric regions. In this study, all cases with GI anomalies were diagnosed with acceptable image quality, including dilatation, narrowing, and herniation of the intestine. All parts of the colon were visualized and measurable after 24 weeks’ gestation. The results also indicate that an increasing trend of colon calibers with advancing gestational age, and a GA-specific caliber pattern that may improve the diagnosis of GI tract abnormalities. [MB1]There is no quantification & no image comparison proving this, |
| 1075 | 9:15
|
A Longitudinal Multisite Study of Endogenous BOLD MRI In Human Pregnancies |
1Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States, 2Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, UT, United States, 3Division of Reproductive and Developmental Sciences, ONPRC, Portland, OR, United States, 4Department of Obstetrics & Gynecology, OHSU, Portland, OR, United States, 5Department of Obstetrics & Gynecology, University of Utah, Salt Lake City, UT, United States, 6Department of Radiology, University of Utah, Salt Lake City, UT, United States, 7Advanced Imaging Research Center, OHSU, Portland, OR, United States |
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The spatial distribution of placental T2* determined via BOLD MRI has been shown to correlate with maternal blood flow and corresponding blood oxygen levels within individual placental lobules. Here, we report data from a longitudinal multisite study aimed at assessing placental T2* across multiple gestational time points in human pregnancy and correlating it with pregnancy outcomes. |
| 1076 | 9:27
|
BOLD MR Imaging of Placenta in Congenital Heart Disease: Correlation with Maternal Risk Factors, Placental Pathology, and Maternal Serum Hormones |
1Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA, United States, 2Radiology, Children's Hospital of Pittsburgh, Pittsburgh, PA, United States, 3Radiology, Children's Hospital of Los Angeles, Los Angeles, CA, United States, 4Bioinformatics, University of Pittsburgh, Pittsburgh, PA, United States, 5Epidemiology, University of PIttsburgh, Pittsburgh, PA, United States |
||
Intrinsic placental BOLD (pBOLD) was analyzed in mothers of congenital heart disease patients (CHD) and controls. The relationship between pBOLD temporal variance (primary outcome measure), CHD status and resting state fetal brain BOLD (rsBOLD) was specifically examined with secondary analyses exploring the relationship between pBOLD, placental histopathology, maternal risk factors (MRFs) and serum hormones (estriol, PAPP-A, β-hCG). We found that CHD patients demonstrated increased pBOLD temporal variance vs controls (p<0.001). When including the presence of MRFs (HTN, DM2, and Drug Use) as a covariate, a positive correlation between pBOLD and rsBOLD was identified (p=0.003). |
| 1077 | 9:39
|
Studying human placental function ex-vivo using perfusion methods in MRI |
1Sagol Brain Institute, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel, 2Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel, 3Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel, 4Pediatric Radiology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel, 5Pediatric Neurology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel, 6Obstetrics and Gynecology, Lis Maternity Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel, 7Department of Medical Engineering, Tel Aviv Academic College of Engineering, Tel Aviv, Tel Aviv, Israel |
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The aim of this study was to investigate the functional characteristics of the human placenta ex-vivo using a novel MR compatible perfusion system. Fifteen normal human placentas were scanned ex-vivo; bolus arrival time (BAT) and flow were extracted from TWIST data. Higher BAT and lower flow values were found in placentas with peripheral cord insertion. Significant correlations were obtained between BAT and the linear distance of the blood vessel from cord insertion location. This is the first work that studied the perfusion of human placentas with MRI and provides information regarding the relation between placental structure and function. |
| 1078 | 9:51
|
Feasibility of quantitative susceptibility mapping in the human placenta |
1Division of Diagnostic Imaging and Radiology, Children's National Medical Center, Washington, DC, United States, 2Division of Fetal and Transitional Medicine, Children's National Medical Center, Washington, DC, United States, 3Department of Pediatrics, George Washington University, Washington, DC, United States, 4Department of Radiology, George Washington University, Washington, DC, United States, 5Department of Obstetrics and Gynecology, George Washington University, Washington, DC, United States, 6Division of Neonatology, Children's National Medical Center, Washington, DC, United States |
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Quantitative susceptibility mapping (QSM) is an emerging tool for measuring magnetic susceptibility of tissue, which is used to identify hypoxia, hemorrhage, and calcifications. In this study we demonstrated the feasibility of performing QSM in the in-vivo human placenta. The measurement differences in R2* and susceptibility between 1.5 T and 3 T were consistent with our expectations and previous studies, and susceptibility was significantly reduced in response to maternal hyperoxia due to reduced deoxyhemoglobin. These results suggest that placental QSM may have the potential to assess placental function such as oxygenation. |
| 1079 | 10:03
|
Prediction of Ischemic Placental Disease during Early Gestation using Pseudo-Continuous Arterial Spin Labeling MRI |
1Radiological Sciences, University of California, Los Angeles, Los Angeles, CA, United States, 2Mark & Mary Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, United States, 3Department of Pediatrics, University of California, Los Angeles, Los Angeles, CA, United States, 4Department of Obstetrics and Gynecology, University of California, Los Angeles, Los Angeles, CA, United States |
||
A real-time and non-invasive way to assess placental development would have great potential to help diagnose various conditions of placental insufficiency. Arterial spin labeling (ASL) MRI has great potential to serve as |
| 1080
|
8:15
|
Fetal Cardiac MRI using Self-gating with a Cartesian K-space Trajectory |
1Department of Cardiology, Boston Children's Hospital, Boston, MA, United States, 2Department of Pediatrics, Harvard Medical School, Boston, MA, United States, 3Department of Informatics, Technical University of Munich, Garching, Germany, 4Department of Medicine, Fetal Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Boston, MA, United States, 5Department of Radiology, Boston Children's Hospital, Boston, MA, United States, 6Department of Radiology, Harvard Medical School, Boston, MA, United States |
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Fetal cardiac MRI may be a useful compliment to echocardiography given its ability to measure blood flow and produce quality images independent of body habitus. Fetal cardiac MRI is, however, technically challenging since the fetal electrocardiogram signal cannot be sampled for cardiac gating. Self-gating is a method to extract the cardiac gating signal directly from MRI data, and its performance has been validated on adults. In this work, we investigated the feasibility of using self-gating for fetal cardiac MRI and show the results from three pregnant volunteers. |
| 1081 | 8:27
|
Regional Power Ratio: a noninvasive index of regional myocardial function |
1University of Oslo, OSLO, Norway |
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Detailed understanding of the regional mechanical response to myocardial infarction (MI) is currently incomplete. Strain, which is most widely used for evaluating regional function, does not account for differences in loading conditions. Regional work and power, however, take load into account, but requires pressure measurement or estimation. Here, we present a noninvasive index of regional function, Regional Power Ratio (RPR), which allows comparison of the instantaneous power generated by different regions in the myocardium. We use RPR to investigate the regional dispersion of function in the MI heart, and compare to analysis of regional work. |
| 1082 | 8:39
|
Balanced SSFP Highly Accelerated Cine ‘Watermark’ Quantifies 2D Myocardial Strain with comparison to 2D Spiral Cine DENSE |
1MRI Research Center, Auburn University, Auburn University, AL, United States |
||
Cardiac MRI (CMR) myocardial tagging enables quantification of myocardial strain. However, tagging remains limited to a research context due to the time-intensive analysis and need to run multiple sequences. CMR sequences must be fast and efficient. We previously developed low-acceleration FLASH and Balanced-SSFP versions of Cine ‘Watermark’ (CWM) that acquire normal cine magnitude images plus ‘hidden’ (via phase) cardiac strain data for calculating myocardial strain. Here we present a highly x4 accelerated bSSFP CWM with improved performance and scan efficiency. The bSSFP CWM is demonstrated in human subjects at 3T and its performance is compared to 2D Spiral Cine DENSE. |
| 1083 | 8:51
|
Shear wave MR elastography using intrinsic cardiac motion for the non-invasive evaluation of myocardial stiffness: initial results in volunteers and HCM patients. |
1Department of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 2Department of Radiology and Nuclear Medicine, Amsterdam UMC, Amsterdam, Netherlands, 3Department of Chemical Engineering, IQS School of Engineering, Universitat Ramon Llull, Barcelona, Spain, 4Philips Healthcare, Guildford, United Kingdom, 5Department of Biomedical Engineering and Cardiac Surgery, University of Michigan, Ann Arbor, MI, United States, 6Laboratory for Vascular Translational Science, INSERM, Paris, France |
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Imaging myocardial stiffness provides useful clinical information in various cardiac conditions and diseases. We developed an intrinsic shear wave MRE method for determining shear wave speed in the interventricular septum using an adapted motion-sensitised pencil beam respiratory navigator sequence (cRNAV). Time of flight between two imaged locations in the basal and apical septum was used to estimate flexural shear wave velocity. Initial testing provided promising results in healthy volunteers and two patients with hypertrophic cardiomyopathy (HCM). |
| 1084 | 9:03
|
Long TR bSSFP Cardiac Cine Imaging at Low Field (0.55T) using EPI and Spiral Sequences for Improved Sampling Efficiency |
1National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States |
||
One key benefit of low field MRI (0.55T) is a more homogeneous B0 field due to the scaling of susceptibility with field strength. For cardiac imaging, where balanced steady-state free precession (bSSFP) is the dominate sequence, bSSFP banding artifacts are directly related to off-resonance phase accrual over each TR. We exploit the improved homogeneity by extending the TR of the clinical bSSFP cardiac cine sequence to improve sampling efficiency and thus SNR. Using fast, efficient acquisition strategies such as EPI and spiral, we can extend the TR from 3.1 to 8 ms to improve SNR without additional banding. |
| 1085
|
9:15
|
Changes in myocardial stiffness and damping ratio due to cardiac amyloidosis: Evaluation with magnetic resonance elastography and a novel neural network inversion |
1Radiology, Mayo Clinic, Rochester, MN, United States |
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Myocardial viscoelasticity plays an important role in cardiac function. The objective of this study is to evaluate if magnetic resonance elastography (MRE) can detect differences in myocardial stiffness (µ) and damping ratio (ζ) in cardiac amyloidosis patients. Twenty-six patients with cardiac amyloidosis and 96 healthy volunteers were enrolled. The mean left ventricular µ was significantly higher (p < 0.01) and ζ was significantly lower (p<0.01) in cardiac amyloidosis patients (median µ: 19.5 kPa, median ζ: 0.15) compared to normal controls (median µ: 15.7 kPa, median ζ: 0.18). These results motivate future investigation of cardiac MRE in different patient cohorts. |
| 1086 | 9:27
|
Predictive Value of Cardiac Magnetic Resonance Feature Tracking for Clinical Cardiac Events in Asymptomatic Aortic Stenosis Patients with Normal Ejection Fraction |
1Boramae Medical center, seoul, Korea, Republic of, 2Seoul National University Hospital, Seoul, Korea, Republic of |
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Using cardiac magnetic resonance feature tracking, Global longitudinal and radial peak strains (PS) are correlated with degree of aortic stenosis (AS) and can reflect cardiac dysfunction. Furthermore, global longitudinal PS may be one of the most potent predictive factor for clinical cardiac event in asymptomatic AS patients with normal ejection fraction. |
| 1087 | 9:39
|
Comparing Myocardial Stiffness using MRE with Ex-vivo histopathology results in Heart Failure with Preserved Ejection Fraction Porcine Model |
1Radiology, Ohio State University Wexner Medical Center, Columbus, OH, United States, 2Davis Heart and Lung Research Institute, Ohio State University Wexner Medical Center, Columbus, OH, United States, 3Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus, OH, United States |
||
Cardiovascular abnormalities that induce heart failure with preserved ejection fraction(HFpEF) eventually increases left ventricular(LV) myocardial stiffness(MS). Currently, MS is measured using LV catheterization. However, this procedure is invasive and only gives global measurements. Previous study has shown feasibility of cardiac Magnetic Resonance Elastography(MRE) in determining MS and validated against LV catheterization. Histopathology of ex-vivo samples can provide fibrosis content. Aim of this study is to estimate MS using cardiac MRE in HFpEF porcine model and validate against histopathology results. Preliminary study demonstrate increased LV stiffness correlates well with increase in fibrosis from histopathology in diseased samples when compared to healthy. |
| 1088 | 9:51
|
The antibiotic doxycycline compromises cardiac mitochondrial and contractile function in diabetic mice |
1Preclinical & Translational MRI, Biomedical Engineering and Physics, Amsterdam UMC, Amsterdam, Netherlands, 2Lab Genetic Metabolic Diseases, Amsterdam UMC, Amsterdam, Netherlands |
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Given the evolutionary similarities between the bacterial and mitochondrial protein synthesis machinery, we tested the hypothesis that the widely used antibiotic doxycycline reduces mitochondrial function, and results in cardiac contractile dysfunction. Indeed, doxycycline exposure resulted in a dose-dependent reduction in maximal uncoupled mitochondrial respiration in cultured H9C2 cells. Maximal mitochondrial respiration was also reduced in mice treated with doxycycline. MRI of treated mice revealed contractile dysfunction as evidenced by marked diastolic and a mild systolic dysfunction. Moreover, doxycycline exacerbated mitochondrial and contractile dysfunction in animals with type 2 diabetes mellitus. |
| 1089 | 10:03
|
DAS-Net: A Generative Adversarial Net to Suppress Artifact-Generating Echoes in DENSE MRI |
1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, 2Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, United States |
||
In DENSE, displacement-encoded stimulated echoes are acquired with an artifact-generating signal due to T1 relaxation. Phase-cycling acquisitions are generally used to suppress the artifact-generating echoes which can result in imperfect artifact suppression when there is motion between the two acquisitions. To avoid this problem, a generative adversarial convolutional neural network (DAS-Net) is proposed to suppress the artifacts from a single acquisition. DAS-Net was trained on a DENSE dataset acquired from healthy volunteers. Results show that DAS-Net can effectively suppress the artifact-generating echoes and has the potential to obviate the need for phase-cycling acquisitions |
| 1090
|
8:15
|
AUTOmated pulse SEQuence generation (AUTOSEQ) and neural network decoding for fast quantitative MR parameter measurement using continuous and simultaneous RF transmit and receive |
1Radiology, MGH Martinos Center for Biomedical Imaging, Charlestown, MA, United States, 2Radiology, Harvard Medical School, Boston, MA, United States, 3Physics, Harvard University, Cambridge, MA, United States, 4Biostatistics, Harvard University, CAMBRIDGE, MA, United States |
||
Limited human intuition of the Bloch equations’ nonlinear dynamics, particularly over long periods of non-steady-state time evolution or in regimes such as off-resonance excitation, is an obstacle to fully exploiting the vast parameter space of potential MR pulse sequences. Our previous work introduced a computational graph approach to modeling the Bloch equations. In this work, we show the AUTOSEQ framework extended with a multilayer fully-connected neural network to perform fast quantitative MR parameter measurement. By employing continuous off-resonant excitation with simultaneous continuous receive, we demonstrate in simulated experiments the ability to quantify T1 and T2 parameters in a single TR. |
| 1091 | 8:27
|
Contrast-free MRI Contrast Enhancement with Deep Attention Generative Adversarial Network |
1Tsinghua University, Beijing, China, 2Stanford University, Stanford, CA, United States, 3Subtle Medical Inc., Menlo Park, CA, United States, 4Grenoble Institute of Neurosciences, Grenoble, France |
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While gadolinium-based contrast agents (GBCAs) have been dispensable for magnetic resonance imaging in clinic practice, recently there are rising concerns about the safety of GBCAs. In previous studies, we tested the feasibility of predicting contrast agents from pre-contrast images via deep convolutional neural networks. In this study, we further improved the results with deep attention generative adversarial network. The image similarity metrics show that the model can synthesize post-contrast T1w images with superior image quality and great resemblance to the ground truth images. Restoration of contrast uptake is clearly noted on the synthesized images even in small vessels and lesions. |
| 1092
|
8:39
|
Reinforcement Learning for Online Undersampling Pattern Optimization |
1Electrical Engineering, Stanford University, Stanford, CA, United States, 2Radiology, Stanford University, Stanford, CA, United States |
||
Magnetic resonance imaging (MRI) is an important but relatively slow imaging modality. MRI scan time can be reduced by undersampling the data and reconstructing the image using techniques such as compressed sensing or deep learning. However, the optimal undersampling pattern with respect to image quality and image reconstruction technique remains an open question. To approach this problem, our goal is to use reinforcement learning to train an agent to learn an optimal sampling policy. The image reconstruction technique is the environment and the reward is based upon an image metric. |
| 1093 | 8:51
|
Active acquisition for MRI reconstruction |
1University of Florida, Gainesville, FL, United States, 2Facebook AI Research, Montreal, QC, Canada, 3NYU School of Medicine, New York, NY, United States |
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In this abstract, we introduce a novel pipeline for MRI reconstruction, which actively selects sampling trajectories in order to ensure high fidelity images, while speeding up the acquisition time. The pipeline is based on recent advances in deep learning and is composed of two networks interacting with each other in order to perform active acquisition. Results on a large scale knee dataset highlight the potential of the method when compared to standard acquisition heuristics. Moreover, we show that the learnt acquisition strategy efficiently reduces the reconstruction uncertainty and paves the way towards more applicable solutions for accelerating MRI. |
| 1094
|
9:03
|
Estimating Model and Data Dependant Uncertainty for Synthetic-CTs obtained using Generative Adversarial Networks |
1Medical Biophysics, University of Toronto, Toronto, ON, Canada, 2Physical Sciences Platform, Sunnybrook Research Institute, Toronto, ON, Canada, 3Medical Physics, Sunnybrook Health Sciences Centre, Toronto, ON, Canada, 4Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto, ON, Canada |
||
The feasibility of using a neural network model to place uncertainty estimates on synthetic-CTs created with a generative adversarial network was investigated. Dropout-based variational inference was employed to account for the uncertainty on the trained model. The standard GAN loss function was also combined with an additional log-likelihood term, designed such that the network learns which regions of input data lead to highly variable output. On a dataset of n=105 brain patients, our results demonstrate that the predicted uncertainty can be interpreted as an upper bound on the true error with a confidence of approximately 95%. |
| 1095
|
9:15
|
Deep learning-based uncertainty estimation: application in PET/MRI joint estimation of attenuation and activity for patients with metal implants |
1University of California San Francisco, San Francisco, CA, United States, 2UC Berkeley - UC San Francisco Joint Graduate Program in Bioengineering, Berkeley and San Francisco, CA, United States, 3GE Global Research, Niskayuna, NY, United States, 4GE Global Research, Munich, Germany |
||
PET image reconstruction requires accurate estimates of attenuation coefficients. Metal implants corrupt both the MRI and CT images and thus are not suitable for use in image reconstruction. In particular, the metal implant appears as a large signal void in the MRI and is incorrectly estimated as having the attenuation coefficients of air. We proposed to use Bayesian deep learning to identify the location of the metal implant and use it to guide PET joint estimation of attenuation and activity. We found that the metal implant is recovered and lesion uptake near the implant agree well with our reference data. |
| 1096 | 9:27
|
Predicting 10-Year Risk of Type 2 Diabetes Onset Using Lifestyle, Genomics, and Whole Body DIXON MR Imaging |
1Human Longevity, Inc, San Diego, CA, United States |
||
Diabetes Mellitus is an important factor in the onset and progression of many related serious conditions. It is also very actionable and preventable thus the need for improved risk assessment to identify high-risk individuals early.
In this study we use lifestyle, genomic, MRI features and Cox Proportional Hazard models1 to improve DM risk assessment. To our knowledge, this is the first demonstration of integrating these features for assessing type 2 DM risk. Our final cross-validated concordance index is 84%, 4% of which is due to MRI features. On average our models can predict up to ten years into the future. |
| 1097
|
9:39
|
Convolutional neural network-based image reconstruction and image classification: atomization or amalgamation? |
1Weill Cornell Medicine, New York, NY, United States, 2Memorial Sloan Kettering Cancer Center, New York, NY, United States, 3Cornell University, Ithaca, NY, United States |
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Convolutional neural networks have emerged as a powerful tool for image reconstruction and image analysis. In this abstract, we evaluate whether image reconstruction and image classification tasks are best performed separately, or whether a combined CNN, performing image reconstruction and clinical diagnosis steps in tandem, delivers synergistic effects. |
| 1098 | 9:51
|
Relax-MANTIS: REference-free LAtent map-eXtracting MANTIS for efficient MR parametric mapping with unsupervised deep learning |
1Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 2Radiology, University of Wisconsin-Madison, Madison, WI, United States, 3Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States |
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The purpose of this work was to develop and evaluate a novel deep learning-based framework termed Reference-free Latent map-eXtracting MANTIS (Relax-MANTIS) for efficient MR parameter mapping. Our approach incorporated end-to-end CNN mapping, the concept of cyclic loss to enforce data fidelity and without the need of explicit training references. Our results demonstrated that the proposed framework produced accurate and robust T1 mapping in knee and low-SNR lung UTE MRI. The good quantitative agreement to the reference method suggests that Relax-MANTIS allows potentially accelerated quantitative mapping without modifications of scan protocol and sequence for high-resolution knee and whole lung T1 quantification. |
| 1099 | 10:03
|
Deep Learning with Attention to Predict Gestational Age of the Fetal Brain Using MRI |
1Electrical Engineering, Stanford University, Stanford, CA, United States, 2Radiology, Stanford University, Stanford, CA, United States, 3Philips Healthcare North America, Gainesville, FL, United States |
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Fetal brain imaging is a cornerstone of prenatal screening and early diagnosis of congenital anomalies. Knowledge of fetal gestational age is the key to the accurate assessment of brain development. This study develops an attention-based deep learning model to predict gestational age of fetal brain. The proposed model is an end-to-end framework that combines key insights from multi-view MRI including axial, coronal, and sagittal views. The model uses age-activated weakly-supervised attention maps to enable rotation-invariant localization of fetal brain among background noise. We evaluate our method on a collected fetal brain MRI cohort and achieve promising age prediction performance. |
| 1100
|
8:15
|
Dixon-cMRF: cardiac tissue characterization using three-point Dixon MR fingerprinting |
1School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 2Philips Healthcare, Guilford, United Kingdom |
||
Cardiac Magnetic Resonance Fingerprinting (cMRF) has been recently proposed to reduce scan time by estimating simultaneously T1, T2 and M0 in a single breath-hold acquisition. Additionally, cardiac fat images may carry additional diagnostic information and promising results have been shown for epicardial fat volume quantification, characterisation of cardiac masses and detection of fibro-fatty infiltrations. Here we extend cMRF with a three-point Dixon encoding (Dixon-cMRF) for enhanced myocardium tissue characterisation by providing T1, T2, M0 for both water and fat, from which an additional fat fraction map can be computed. The feasibility of Dixon-cMRF was evaluated in 5 healthy subjects. |
| 1101 | 8:27
|
Accelerating Quantitative Chemical Exchange Saturation Transfer MRI using MR Fingerprinting and Synthetic CEST Analysis |
1Radiology, Johns Hopkins University, Baltimore, MD, United States, 2Kennedy Krieger Institute, Baltimore, MD, United States |
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Current CEST-MRI approaches are qualitative in nature, producing contrast that has |
| 1102
|
8:39
|
Deep Learning-enabled Diffusion Tensor MR Fingerprinting |
1Computer Science, Technical University of Munich, Garching, Germany, 2GE Healthcare, Munich, Germany, 3Cardiff University Brain Research Imaging Centre (CUBRIC), Cardiff University School of Psychology, Cardiff, United Kingdom, 4Division of Psychological Medicine and Clinical Neurosciences, Cardiff University School of Medicine, Cardiff, United Kingdom, 5Imago7 Foundation, Pisa, Italy, 6Department of Neuroradiology, Klinikum rechts der Isar, Munich, Germany, 7Department of Physics, Technical University of Munich, Garching, Germany |
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MR Fingerprinting enables the quantification of multiple tissue properties from a single, time-efficient scan. Here we present a novel Diffusion Tensor MR Fingerprinting acquisition scheme that is simultaneously sensitive to T1, T2 and the full diffusion tensor. We circumvent the long-standing issue of phase errors in diffusion encoding and expensive dictionary matching by using a neural network architecture capable of learning the non-linear relation between fingerprints and multiparametric maps, robustly mitigating motion, undersampling and phase artifacts. As such, our framework enables the simultaneous quantification of relaxation parameters together with the diffusion tensor from a single, highly accelerated acquisition. |
| 1103 | 8:51
|
Flow-Encoded Magnetic Resonance Fingerprinting: Simultaneous Measurement of Flow, T1, & T2 with Whole Brain Coverage |
1Translational Medicine, Hospital for Sick Children, Toronto, ON, Canada, 2Pediatrics, Hospital for Sick Children, Toronto, ON, Canada, 3Neuroscience and Mental Health, Hospital for Sick Children, Toronto, ON, Canada, 4Medical Biophysics, University of Toronto, Toronto, ON, Canada |
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Incorporating bipolar, flow sensitizing gradients into a magnetic resonance fingerprinting (MRF) pulse sequence permits quantification of vessel flow along with static tissue T1 and T2 relaxation times. This abstract demonstrates quantification of T1, T2 and multi-directional flow with a single, volumetric, flow-encoded MRF acquisition with whole brain coverage. Comparison of T1, T2, and flow measurements with inversion recovery, spin-echo, and phase contrast techniques revealed good agreement between flow-encoded MRF and gold-standard methods. The capacity to obtain volumetric relaxometry and flow measurements with a single acquisition can support efficient, comprehensive assessments of cerebral blood flow and tissue integrity. |
| 1104 | 9:03
|
Quantitative Magnetization Transfer Imaging in the Hybrid State |
1Center for Biomedical Imaging, Dept. of Radiology, New York University School of Medicine, New York, NY, United States, 2Center for Advanced Imaging Innovation and Research, New York University School of Medicine, New York, NY, United States |
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This work extends the hybrid-state model, recently introduced to explain and optimize the dynamics of complex non-steady-state pulse sequences such as MR Fingerprinting, to magnetization transfer. We numerically optimize a hybrid-state pulse sequence for SNR efficiency and demonstrate the potential of the extended hybrid-state framework for quantification of MT effects in vivo in the human brain. Our preliminary results show good agreement with literature and demonstrate the feasibility of quantifying the fractional semi-solid pool size, as well as T1 and T2 relaxation times of the free pool, in under 10 minutes. |
| 1105
|
9:15
|
Independent Component Analysis of Complex Magnetic Resonance Fingerprinting Data |
1Radiology, Case Western Reserve University, Cleveland, OH, United States |
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Magnetic Resonance Fingerprinting (MRF) sequences have variable flip angles and TRs that generate unique signal evolutions based on selected tissue properties. To obtain quantitative maps with accurate values in the dictionary matching step it is important to minimize various noise sources or simulate them into the dictionary. We propose to explore systematic artifacts or features that are not in the dictionary with independent component analysis of complex MRF time series. In vivo brain results with 3D MRF revealed global sequence related features (bias from B0 and B1 associated with phase of MRF data) and subject specific reconstruction artifacts. |
| 1106
|
9:27
|
MR Fingerprinting multi-component analysis using a fast joint sparsity algorithm |
1TU Berlin, Berlin, Germany, 2Philips Research Europe, Hamburg, Germany |
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A new method to perform a multi-component analysis in MR Fingerprinting is proposed, which is faster and less sensitive to noise than previous methods. The algorithm finds a small number of components throughout the region of interest without assumptions about the number or relaxation times of the components. The proposed method is compared to previously published methods in numerical simulations and in vivo experiments. |
| 1107
|
9:39
|
Hybrid-State Free Precession for Measuring Magnetic Resonance Relaxation Times in the Presence of B0 Inhomogeneities |
1New York University Center for Data Science, New York University, New York, NY, United States, 2Courant Institute of Mathematical Sciences and New York University Center for Data Science, New York University, New York, NY, United States, 3Center for Biomedical Imaging, Dept. of Radiology, and Center for Advanced Imaging Innovation and Research, New York University, New York, NY, United States |
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Magnetic resonance fingerprinting is a methodology for the quantitative estimation of the relaxation times T1,2. An important challenge is to make estimation robust to inhomogeneities of the main magnetic field B0. Free precession sequences with smoothly varying parameters, such as balanced hybrid-state free precession (bHSFP) sequence, can be optimized for T1,2-encoding performance. Previously, magnetic field deviations were assumed to be determined by a separate experiment. Here we develop a numerically optimized bHSFP sequence that takes into account variations in B0 with the aim of mitigating bias due to B0 inhomogeneities. Our numerical results indicate that this approach yields accurate T1,2 estimates when B0 inhomogeneities are unknown. |
| 1108
|
9:51
|
Fast 3D MR Fingerprinting with Pseudorandom Cartesian Sampling |
1Radiology, Case Western Reserve University, Cleveland, OH, United States, 2Siemens Healthcare GmbH, Erlangen, Germany, 3Friedrich‐Alexander‐Universität Erlangen‐Nürnberg, Erlangen, Germany, 4Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 5Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States |
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A 3D Magnetic Resonance Fingerprinting method based on the pseudorandom Cartesian sampling was proposed to achieve isotropic high-resolution T1, T2 and off-resonance quantification. Compared to existing MRF methods based on non-Cartesian sampling patterns, the proposed method demonstrates a flexible sampling framework that is less susceptible to imperfections of the imaging gradients and off-resonance effects. It provides a step forward to a robust and high-resolution isotropic MRF method in brain, musculoskeletal and abdominal imaging. |
| 1109
|
10:03
|
Sub-millimeter MR Fingerprinting using deep-learning-based spatially-constrained tissue quantification |
1Radiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, 2Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, 3Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States |
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MRF is a relatively new quantitative MR imaging technique which can provide rapid and simultaneous quantification of multiple tissue properties. However, high-resolution MRF, particularly at sub-millimeter levels, is technically challenging and often requires extended scan time. In this study, a rapid high-resolution MRF technique was developed using a deep-learning-based spatially-constrained tissue quantification method. The experimental results from in vivo brain data demonstrate that high-quality T1 and T2 quantification with 0.8-mm resolution can be achieved in 15 sec per slice. |
8:15
|
Bayesian Inference for (Neuro-) Imaging | |
1University of Oxford, United Kingdom |
8:35
|
Bayesian Heteroscedastic Regression for Analysis of fMRI Data | |
8:55
|
Altered Connectivity in the Large-Scale Brain Networks in Patients With Schizophrenia | |
9:15
|
The Use of Bayesian-Probability-Based Algorithms for Intra-Voxel Incoherent Motion (IVIM) Model Fitting of Diffusion-Weighted MRI (DWI) | |
1The Institute of Cancer Research, London, United Kingdom |
9:35
|
A Bayesian Approach to the Partial Volume Problem in MR Fingerprinting | |
1Radiology, Case Western Reserve University, Cleveland, OH, United States |
9:55
|
Bayesian Inference & DKI | |
1School of Health Sciences, Fujita Health University, Nagoya, Japan |
8:15
|
Modelling of BBB Permeability to Contrast Agents & Water | |
1University of Manchester, United Kingdom |
8:39
|
Overview of Clinical Applications of DCE MRI | |
1Monash Biomedical Imaging, Australia |
9:03
|
DCE MRI Methods in Cerebral Small Vessel Disease (SVD) & Dementia | |
9:27
|
Non-Contrast Assessment of BBB Permeability to Water | |
9:51
|
Diffusion-Weighted Arterial Spin Labeling (DW ASL) for Water Permeability Mapping | |
| 10:45 | Standardization of Machines & Acquisition Schemes |
| 11:05 | Standardization of Data Formats & Post-Processing Methods |
1The Mind Research Network, United States |
| 11:25 | Standardization of Clinical Interpretations: Psychoradiology Perspective |
| 11:45 | 1110First-in-human trial of Gd-based theranostic nanoparticles: MRI assessment of uptake and biodistribution in patients with multiple brain metastases |
1NHTherAguix, Crolles, France, 2CHU Grenoble Alpes, Grenoble, France, 3GIN, Inserm, Université de Grenoble, Grenoble, France, 4Institut des Sciences Moléculaires, CNRS, Université de Bordeaux, Bordeaux, France, 5Institut Lumière Matière, CNRS, Université de Lyon, Villeurbanne, France, 6Neurospin, CEA, Gif-sur-Yvette, France |
| 11:51 | 1111Objective lung-density quantification in neonatal bronchopulmonary dysplasia via ultrashort echo-time MRI, with comparison to clinical severity and reader scoring |
1Center for Pulmonary Imaging Research, Cincinnati Children's Hospital, Cincinnati, OH, United States, 2Pulmonary Medicine, Cincinnati Children's Hospital, Cincinnati, OH, United States, 3BPD Center, Cincinnati Children's Hospital, Cincinnati, OH, United States, 4Radiology, Cincinnati Children's Hospital, Cincinnati, OH, United States, 5Pediatrics, University of Cincinnati, Cincinnati, OH, United States, 6Medical Physics, University of Wisconsin - Madison, Madison, WI, United States, 7Radiology, University of Wisconsin - Madison, Madison, WI, United States, 8Neonatology and Pulmonary Biology, Cincinnati Children's Hospital, Cincinnati, OH, United States |
| 11:57 | 1112Longitudinal multimodal MRI monitoring of a novel combination therapy using radiosurgery and checkpoint inhibitor immunotherapy in glioblastoma multiforme |
1Radiology, Stony Brook University, Stony brook, NY, United States, 2Radiation Oncology, Stony Brook University, Stony brook, NY, United States |
| 12:03 | 1113Intact Metabolite Spectrum Mining by Deep Learning in Proton Magnetic Resonance Spectroscopy of the Brain |
1Department of Biomedical Sciences, Seoul National University, Seoul, Korea, Republic of, 2Department of Radiology, Seoul National University Hospital, Seoul, Korea, Republic of |
| 12:09 | 1114Liquid metal in stretchable tubes: A wearable 4-channel knee array |
1Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland, 2Institute for Electronics, ETH Zurich, Zurich, Switzerland |
13:45
|
Future of Breast MRI | |
1University Aachen, RWTH, Germany |
14:15
|
MRI-Derived Parameters for Hormone Receptors | |
1Radiology, Memorial Sloan Kettering Cancer Center |
14:45
|
Radiomics for Breast Cancer | |
1Memorial Sloan-Kettering Cancer Center, United States |
15:15
|
Screening Breast MRI for High Risk Patients | |
1Radiology, University of Michigan, Ann Arbor, MI, United States |
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Well-established indications for supplemental screening breast MRI include: 1) hereditary predisposition that renders a lifetime risk of >20% for developing breast cancer (genetic mutation or pedigree assessment); 2) chest radiation therapy between the ages of 10-30 (when breasts are developing and radiosensitive). Emerging data suggest adjunct MRI screening should be considered for women with LCIS/ALH/ADH and that it may benefit women with a personal history of breast cancer, particularly if initially diagnosed before age 50. |
15:45
|
Adjournment |
13:45
|
Diffusion Goes Multi-Modal: Myelin Mapping | |
1Vanderbilt University, United States |
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Myelin plays a central role in determining MRI contrast in neuronal tissues, and, consequently, there are many MRI approaches measuring myelin content. This presentation will review several common approaches as well as some recent and developing approaches. |
14:15
|
g-Ratio Mapping: Challenges & Validation | |
1McGill University, Montreal, QC, Canada, 2University of Calgary, Calgary, AB, Canada |
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The fiber g-ratio is the ratio of the inner to the outer diameter of the myelin sheath of a myelinated axon. In healthy neural tissue, it is optimized for speed of signal conduction, cellular energetics, and spatial constraints. The g-ratio is a fundamental contributor to functionally relevant neuronal properties such as conduction velocity. g-Ratio imaging has the potential to allow us to investigate in vivo g-ratio changes in health and disease. This lecture details the methodology for imaging the g-ratio with MRI, describes the known challenges in doing so, presents validation work to date, and discusses challenges in validating the technique. |
| 1115 | 14:45
|
Characterizing diffusion of myelin water in the living human brain using ultra-strong gradients and spiral readout |
1CUBRIC, School of Psychology, Cardiff University, Cardiff, United Kingdom |
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Myelin is a key white matter compartment, but myelin water is beyond the detection of conventional diffusion MRI methods because of its short T2. Here we combine ultra-strong gradients and spiral readout to achieve very short echo times (TE=30ms) at very high diffusion weighting (b=6000s/mm^2), with the aim of achieving significant sensitivity to the diffusion of myelin water in the living human brain. We investigated the challenge of disentangling 3 distinct compartments – including the short T2 component from myelin. |
| 1116 | 14:57
|
A Novel MRI technique for quantifying myelin in mice brain white matter |
1Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel, 2School of Chemistry, Tel Aviv University, Tel Aviv, Israel, 3Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel |
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In vivo myelin imaging in MS could provide a tracking tool for demyelination and facilitating the development of new therapeutic agents that may promote remyelination. We propose to use a recently reported MRI sequence, MEX, which measures a signal linearly dependent on the myelin protons fraction in the tissue, F. The sequence was used on cuprizone fed (n=7) and control mice (n=4). The cuprizone mice exhibit significant decrease of F by 25% in the Corpus Callosum (WM), and no change in GM. This study provides a proof of usefulness of this method, for demonstrating quantification of brain white matter demyelination. |
| 1117 | 15:09
|
Simple scheme for correcting bias in axonal water fraction due to differences in compartmental transverse relaxation times |
1Department of Neurology, Medical University of South Carolina, Charleston, SC, United States, 2Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States, 3Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, United States |
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Neglecting differences in compartmental transverse relaxation times when modeling diffusion MRI data may affect the accuracy of estimates for microstructural parameters. Here we propose a straightforward method for correcting the bias in the axonal water fraction (AWF), as calculated from the fiber ball white matter (FBWM) model, due to T2 differences between the intra-axonal and extra-axonal compartments. This correction scheme simply requires that one additional high b-value shell be acquired at a different echo time than for the standard dataset needed for FBWM. AWF values were found to be 16% lower, on average, after the T2 correction. |
| 1118 | 15:21
|
Advances in direct myelin imaging |
1Institute for Biomedical Engineering, ETH and University of Zurich, Zurich, Switzerland |
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Direct imaging of myelin is of great interest for improved diagnosis of neurodegenerative diseases. However, MR signals from myelin exhibit ultra-short T2 values in a range of 8 μs - 1 ms with a large fraction below 100 μs. Due to restrictions in sequence timing, current short-T2 imaging approaches cannot sufficiently capture these very short signals. In the present work, advanced short-T2 methodology and hardware are employed to actually image the majority of the ultra-short-T2 components in the brain. The abilities of the approach are proven in excised brain tissue and applied in vivo. |
| 1119 | 15:33
|
Uncovering 3D Axonal Morphologies with Synchrotron Imaging: Impact on Microstructure Imaging with Diffusion MRI |
1Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark, 2Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kongens Lyngby, Denmark, 3Signal Processing Lab (LTS5), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 4European Synchrotron Research Facility, Grenoble, France, 5Radiology Department, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland, 6Department of Medical Radiation Physics, Clinical Science, Lund University, Lund, Sweden |
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In this study, we segmented large axons from high resolution 3D synchrotron images of the monkey splenium. We simulate the intra-axonal MRI diffusion signal of both the segmented geometry and a simplified, corresponding cylindrical geometry, and calculate the corresponding axon diameter indices. The axon diameter index is well estimated in the simplified geometry, but is overestimated in the more complex segmented geometry, potentially due to variations in axon diameter and non-uniform trajectories. Lastly, we present the observation that segmented axons, which all have average diameters >2 µm, seem to experience similar absolute diameter variations. |
15:45
|
Adjournment |
13:45
|
How to Assess Accuracy & Reproducibility in qMRI | |
1NIST, Boulder, CO, United States |
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In this talk, we'll discuss the design of repeatability and reproducibility studies in home-built phantoms, standard phantoms and in vivo on our quest for ground truth. |
14:15
|
Magnetic Susceptibility in Tissue: What It Is & How to Measure | |
1University of Nottingham, Nottingham, United Kingdom |
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This talk will describe: what magnetic susceptibility is; how we measure magnetic susceptibility using MRI; and some ways of validating methods for measuring magnetic susceptibility. |
| 1120
|
14:45
|
Evaluating the influence of contrast weighting, resolution, and parallel imaging on the reproducibility and tissue specificity of radiomic features |
1Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States |
||
Computer-extracted (radiomic) features can provide a wealth of quantitative information that is useful for quantitative characterization of disease. However, routine image acquisition parameters can vary substantially across patients with the potential to confound or degrade results obtained by analysis of radiomic features. The extent to which the variation in routine image acquisition parameters can affect radiomic features in vivo is not well known. In this work, we evaluate the influence of varied contrast weighting (TR, TE), varied resolution, and the use of parallel imaging on intensity and textural radiomic features in T2-weighted images. |
| 1121
|
14:57
|
A multiparametric (1H, 23Na, diffusion, flow) anthropomorphic abdominal phantom for multimodal MR and CT imaging |
1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany, 2Fraunhofer Institute for Manufacturing Engineering and Automation, Project Group for Automation in Medicine and Biotechnology, Mannheim, Germany, 3Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany |
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Anthropomorphic phantoms are essential for the evaluation of image registration algorithms in multimodal imaging, quantification experiments in multinuclear MR imaging, and verification of diffusion and flow measurements. A human-like abdominal phantom incorporating a liver with lesions, a rib cage, vessels, and a lung was developed. Its tissue-mimicking characteristics were evaluated with 1H and 23Na MR and CT imaging as well as functional flow and diffusion MR imaging. The phantom exhibited morphological and functional parameters comparable to corresponding human values. It is suitable for a quantitative evaluation of a clinical workflow ranging from diagnostics to interventional procedures. |
| 1122 | 15:09
|
Towards QSM Challenge 2.0: Creation and Evaluation of a Realistic Magnetic Susceptibility Phantom |
1Donders Institute for Brain Cognition and Behaviour, Radboud University, Nijmegen, Netherlands, 2Athinoula A. Martinos Centre for Biomedical Imaging, Charlestown, MA, United States, 3Department of Radiology, Harvard Medical School, Boston, MA, United States, 4Harvard-MIT Health Sciences and Technology, MIT, Cambridge, MA, United States, 5Philips Research, Hamburg, Germany, 6Department of Electrical Engineering, Pontificia Universidad Catolica de Chile, Santiago, Chile, 7Biomedical Imaging Center, Pontificia Universidad Catolica de Chile, Santiago, Chile, 8Spinoza Centre for Neuroimaging, Amsterdam, Netherlands, 9Department of Neurology, Medical University of Graz, Graz, Austria, 10Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States, 11Center for Biomedical Imaging, Clinical and Translational Science Institute, University at Buffalo, The State University of New York, Buffalo, NY, United States |
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We present the creation of a modular and realistic digital phantom to serve as a ground-truth to assess the quality of different reconstruction algorithms for Quantitative Susceptibility Mapping (QSM). The phantom is derived from high-resolution, quantitative MRI data of a healthy volunteer, features a realistic morphology including a non piece-wise constant susceptibility distribution. Varying degrees of complexity can be realized, for example by adding the effects of tissue microstructure, down sampling or adding background-fields. The freely available phantom will be used in the upcoming QSM Reconstruction challenge. |
| 1123
|
15:21
|
QSM and R2* measurements from cortical and subcortical regions of the human brain at 7T: a Multi-Centre Reproducibility Study |
1Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom, 2Welcome Centre for Integrative Neuroimaging (FMRIB), University of Oxford, Oxford, United Kingdom, 3Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Cardiff, United Kingdom, 4Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom, 5Imaging Centre of Excellence, University of Glasgow, Glasgow, United Kingdom |
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Multi-site studies allow for cost-effective research at high-field by increasing the size of the healthy and patient pool. For T2*-weighted imaging, the variability in the scanners’ shimming conditions may contribute to inconsistent numerical results.In this study we present a multi-site, multi-vendor ‘travelling-heads’ study with harmonized protocols for QSM and R2*-mapping. Average values across cortical and subcortical ROIs are in agreement with literature, show low variance and high correlation values when comparing measurements across different scanners. R2*-mapping is more stable than QSM due to shimming differences across scanners that affect the background field. |
| 1124 | 15:33
|
Separating chemical shift/exchange from magnetic susceptibility in a phantom |
1Department of Electrical and Computer Engineering, Seoul National University, Seoul, Korea, Republic of |
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We proposed a new method that separates susceptibility-induced frequency shift from chemical shift/exchange-induced frequency shift in a phantom using three axes scanned datasets. The method was successfully validated in numerical simulation and phantoms and reported susceptibility and chemical shift/exchange in vegetable oil (susceptibility: 0.66±0.02 ppm; chemical shift: 3.58±0.01 ppm) and iron oxide (concentration: 0.025%; susceptibility: 0.30±0.02 ppm; chemical exchange: 0.039±0.003 ppm). |
15:45
|
Adjournment |
| 1125
|
13:45
|
Monitoring treatment response in a murine lymphoma with Deuterium Metabolic Imaging and Spectroscopy |
1Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, United Kingdom, 2Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom |
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We investigated whether Deuterium Metabolic Imaging (DMI) with 2H-labeled glucose can be used to monitor treatment response in a pre-clinical murine lymphoma model (EL4). Localized 2H spectra were acquired from tumors, with a time resolution of ~1min, following a bolus injection of labeled glucose. These showed inhibition of lactate labeling following treatment of the tumors with etoposide. 2D chemical shift images (2D CSI) were acquired from the tumors, but imaging treatment response may need faster image acquisition. Studies with a respiratory chain inhibitor in vitro suggested that labeling of water in EL4 tumor cells may be due, at least in part, to TCA cycle activity. |
| 1126
|
13:57
|
Novel Fluorine-18 Labeled Fe3O4@Al(OH)3 Nanoparticles as Dual Contrast Agents for Simultaneous PET/MRI |
1Biomedical MRI, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium, 2MoSAIC, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium, 3NANOMAG Group, Department of Applied Physics, Research Technological Institute, Universidade de Santiago de Compostela, Santiago de Compostela, Spain, 4Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium, 5Nanohealth and Optical Imaging Group, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium, 6Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium |
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The emergence of (pre)clinical PET/MRI scanners is accompanied by the development of novel contrast agents. Aluminum hydroxide magnetic nanoparticles (Fe3O4@Al(OH)3 NPs) can overcome limitations of iron oxide NPs after labeling with Na18F, allowing visualization with PET (high sensitivity, low background) and MRI (high resolution, longitudinal NP follow-up). In this study, labeling of novel Fe3O4@Al(OH)3 nanostructures with Na18F was rapid. In vivo, radiolabeled NPs accumulated in liver of healthy mice, while cells labeled with radiolabeled NPs were also seen in lungs. Our results indicate the potential of these novel nanostructures for cell tracking with high sensitivity, specificity and resolution using PET/MRI. |
| 1127 | 14:09
|
Longitudinal & quantitative 3D-R2* MRI validates methimazole-enhanced intranasal delivery of labeled neural stems cells for treatment of glioblastoma. |
1Radiology & Biomedical Engineering, Northwestern University, Chicago, IL, United States, 2Radiology, Northwestern University, Chicago, IL, United States, 3Neurosurgery, Northwestern University, Chicago, IL, United States |
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Longitudinal and quantitative 3D-R*2 MRI provides a unique platform for tracking labeled cells in vivo, across subjects and time-points following treatment. In this study we use this approach to demonstrate how FDA approved methimazole can enhance intranasal delivery and accumulation of labeled and therapeutically enhanced neural stem cells in glioma xenografts. 3D rendering of the high resolution quantitative maps across different sessions enhances visualization of the NSC accumulation and provides a unique tool to track the homing-pathway of the stem cells. Results were confirmed by survival data for different groups with the Met+NSC treated group exhibiting increased survival trends. |
| 1128 | 14:21
|
Transfer Learning of an Ultra-low-dose Amyloid PET/MRI U-Net Across Scanner Models |
1Stanford University, Stanford, CA, United States, 2University of Leipzig, Leipzig, Germany |
||
Reducing the radiotracer dose of amyloid PET/MRI will increase utility of this modality for early diagnosis and for multi-center trials on amyloid-clearing drugs. To do so networks trained on data from one site will have to be applied to data acquired on other sites. In this project we have shown that after fine-tuning, a network trained on PET/MRI data acquired from one scanner is able to produce diagnostic-quality images while achieving noise reduction and image quality improvement for data acquired on another scanner. |
| 1129 | 14:33
|
Synthesis of standard dose FDG PET images from low dose acquisition using a combination of atlas and CNN based method |
1Electrical and Computer Systems Engineering, Monash University, Monash, Australia, 2Computer Science and Engineering, Indian Institute of Technology, Bombay, Mumbai, India, 3IITB-Monash Research Academy, Mumbai, India, 4Monash Biomedical Imaging, Monash, Australia |
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Radiation exposure in positron emission tomography (PET) examination is a major issue for patient safety. PET image quality is severely degraded if low dose of radioactive tracer is administered. With a simultaneous magnetic resonance (MR)-PET scanner, MR anatomical priors can potentially improve PET image reconstruction. In this work, we introduce a framework to synthesize high quality standard dose PET images from the low dose PET and T1 MR images using an atlas guided convolutional neural network (CNN) approach. Compared with the conventional methods, the introduced method demonstrates improved PET image quality for datasets acquired with ten-fold PET dose reduction. |
| 1130 | 14:45
|
Tumor-Specific Self-Assembly of DiaCEST Nanoparticles as Theranostic Agents |
1Johns Hopkins University, Baltimore, MD, United States, 2Chinese Academy of Sciences, Beijing, China, 3Kennedy Krieger Institute, Baltimore, MD, United States |
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We employed a tumor-specific enzyme (furin)-mediated conversion of the anti-cancer and CEST MRI-visible drug olsalazine (Olsa), which resulted in the formation of self-assembled intracellular nanoparticles in tumor cells. In vivo studies using high-furin and low-furin expressing human xenografts showed that the OlsaCEST signal and anti-tumor therapeutic effect were 5 to 6-fold increased compared to single olsalazine molecules. An excellent “theranostic correlation” (R2 = 0.97) could be observed between the magnitude of the CEST MRI signal and therapeutic response (normalized tumor size). |
| 1131 | 14:57
|
A fluorine-19 MR characterization of ABL-101 - a novel tracer with high biocompatibility and MR sensitivity |
1Radiology, Lausanne University Hospital (CHUV), Lausanne, Switzerland, 2Institute of Neurological Sciences, Queen Elizabeth University Hospital, Glasgow, United Kingdom, 3Aurum Biosciences Ltd, Glasgow, United Kingdom, 4Center for BioMedical Imaging (CIBM), Lausanne and Geneva, Switzerland |
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A major challenge that slows down the translation of fluorine-19 (19F) MRI for inflammation monitoring and cell tracking into clinical practice is the need for perfluorocarbons (PFCs) that have good biocompatibility while also being suitable for 19F MRI. We therefore characterized ABL-101, a perfluoro(t-butylcyclohexane) emulsion, as a 19F MRI tracer. ABL-101 had T2/T1 ratios and detection limits similar to PFCs developed specifically for MRI. This combined with the short clearance half-life of this intravenous emulsion make ABL-101 a very promising candidate as a tracer in future clinical trials that use 19F MRI. |
| 1132
|
15:09
|
Detection of γ-glutamyl-transferase activity up-regulation in orthotopic glioma using hyperpolarized γ-glutamyl-[1-13C]glycine |
1Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States, 2Chemistry and Biotechnology, University of Tokyo, Tokyo, Japan, 3Laboratory of functional and metabolic imaging, EPFL, Lausanne, Switzerland |
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γ-glutamyl-transferase (GGT) is a key enzyme in the γ-glutamyl cycle, which regulates glutathione homeostasis. Previous studies reported that the enzyme is upregulated in many human malignancies including glioblastoma, but remains low in normal brain. Here, we demonstrate the potential of hyperpolarized γ-glutamyl-[1-13C]glycine as a probe for GGT activity in the brain by demonstrating that its conversion to [1-13C]glycine is significantly higher in animals with orthotopic glioblastoma tumors when compared to healthy animal brains. |
| 1133 | 15:21
|
Hyperpolarized [1-13C]pyruvate spectroscopy assessment of the metabolic reserve in a porcine model of compensated cardiac overload |
1The Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Aarhus, Denmark, 2The MR Research Center, Aarhus University, Aarhus, Denmark, 3Comparative Medicine Lab, Aarhus University, Aarhus, Denmark |
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Mitochondrial dysfunction is a hallmark of heart failure undetectable by current clinical techniques. We examined pigs with cardiac overload using hyperpolarized [1-13C]pyruvate magnetic resonance spectroscopy at rest and under stress. Mitochondrial function was determined in-vitro. Pyruvate oxidation rates were decreased in overloaded hearts, especially under stress. In-vitro mitochondrial respiration rates were decreased in tissue from overloaded hearts. In one group, we pharmacologically increased pyruvate oxidation, which led to decreased hypertrophy, increased contractile reserve and better mitochondrial respiration. Our work underlines the importance of metabolism in heart failure and suggests that stress hyperpolarized imaging may be a marker of mitochondrial dysfunction. |
| 1134 | 15:33
|
Imaging Post-Transplant Allogeneic Rats with Acquired Immune Tolerance Using Hyperpolarized [1-13C] Pyruvate MRI |
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Surgery, University of Pennsylvania, Philadelphia, PA, United States |
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Post-transplant, lungs are clinically monitored using regular radiography and/or CT scans to detect rejection. We previously demonstrated that lactate-to-pyruvate ratio derived via hyperpolarized (HP) [1-13C]-pyruvate MRI is an earlier predictor of lung rejection than microCT in an orthotopic rat lung transplantation model. In this study, we imaged transplanted allogeneic lungs in a recipient rats with acquired immune tolerance to resolve the signal contribution of ischemia-reperfusion injury from that of tissue rejection. Transplanted rat lungs with acquired immune tolerance exhibit similar behavior to that of syngeneic lung transplants before abolishing their acquired tolerance. |
| 1135 | 13:45
|
DOSMA: A deep-learning, open-source framework for musculoskeletal MRI analysis |
1Radiology, Stanford University, Stanford, CA, United States, 2Physics and Astronomy, University of Bologna, Bologna, Italy, 3Mechanical Engineering, Stanford University, Stanford, CA, United States, 4Bioengineering, Stanford University, Stanford, CA, United States, 5Orthopedic Surgery, Stanford University, Stanford, CA, United States, 6Electrical Engineering, Stanford University, Stanford, CA, United States |
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With the onset of deep learning, many novel post-processing networks are emerging. However, these algorithms are decentralized, and thus are difficult to consolidate and implement in a clinical setting. To this end, we have developed a Python-based deep-learning, open-source musculoskeletal MR analysis framework termed DOSMA to reduce the complexity of tissue segmentation, registration, and quantitative analysis. We hope that by encouraging contributions from many researchers, this pipeline will facilitate automating traditionally laborious, manual, decentralized MR image processing tasks and will provide a standardized comparison framework for different quantitative estimation techniques. |
| 1136 | 13:57
|
Fully automatic segmentation of wrist cartilage on MR images by convolutional neural network |
1The International Research Center Nanophotonics and Metamaterials, University of Information Technology Mechanics and Optics, Saint-Petersburg, Russian Federation, 2Federal Almazov North-West Medical Research Center, Saint-Petersburg, Russian Federation, 3APHM, Service de Radiologie, Hôpital de la Conception, Marseille, France, 4CRMBM, Aix-Marseille Universite, Marseille, France |
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A fully automatic, wrist cartilage segmentation method on magnetic resonance images is developed and validated. The method is based on convolutional neural networks (CNN). Cartilage segmentations obtained with the CNN showed a substantial agreement with manual segmentations for the full 3D wrist images and a good agreement for central coronal slices. The proposed method provided cartilage masks having a high concordance with manually obtained ones. |
| 1137
|
14:09
|
Automatic Segmentation of Knee Cartilage and Menisci from MRI Data: Efficient Multiclass Solution Based on Deep Learning |
1Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland, 2Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland |
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Manual segmentation of articular cartilage and menisci from magnetic resonance data is time-consuming and can be challenging. Recently, deep learning has shown promising results in medical image segmentation. The aim of this study was to develop a method for automatic segmentation of articular cartilage and menisci that performs more accurately and efficiently than the previously published methods. On OAI/iMorphics dataset the method achieves Dice score of 90.7±1.9 for femoral cartilage, 89.7±2.8 for tibial, 87.1±4.7 for patellar, and 86.3±3.4 for menisci. The presented results could facilitate the osteoarthritis research and enhance clinical practice. Source codes and pretrained models will be open-sourced. |
| 1138 | 14:21
|
MRI-Based Multi-Task Deep Learning for Cartilage Lesion Severity Staging in Knee Osteoarthritis |
1Department of Radiology and Biomedical Imaging, University of California San Francisco - UCSF, San Francisco, CA, United States, 2Lawrence Livermore National Lab, San Francisco, CA, United States, 3Center for Digital Health Innovation, UCSF, San Francisco, CA, United States |
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The automation of the grading task for the knee MRI scoring is appealing. The goal of this study is to leverage recent developments in Deep Learning (DL) applied to medical imaging in order to (i) identify cartilage lesions and assess severity (ii) identify the presence of BMELs, (ii)combine the two models in a multi-task automated and scalable fashion. We were able to boost performance of our final classifiers by not simply focusing on what the fine tuning of a single purpose model could offer, but rather broadly considering related tasks that could bring additional information to our classification problem. |
| 1139 | 14:33
|
Variational Networks for Accelerating Biexponential 3D-T1rho Mapping of Knee Cartilage |
1School of Medicine, New York University, New York, NY, United States, 2Institute of Computer Graphics and Vision, Graz University of Technology, Graz, Austria |
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Quantitative T1ρ imaging using biexponential models usually requires multiple spin-lock times, which makes the acquisition time demanding. Recently, Compressed Sensing (CS) has demonstrated significant reduction in data acquisition time in MRI applications in general, and T1ρ relaxation mapping of knee cartilage in particular. However, biexponential T1ρ mapping error using CS is much higher than that of monoexponential T1ρ mapping error for the same acceleration factor. One possible approach to reduce artifacts, improving image and mapping quality, is to learn a Variational Network (VN) for image reconstruction. Here, we compare a VN, trained with real knee cartilage images, against the best CS approaches known for biexponential T1ρ mapping. Our results show that the VN produced biexponential maps superior to CS, with lower T1ρ mapping error. |
| 1140
|
14:45
|
Evaluating the Use of Deep-Learning Super-Resolution for Obtaining Osteoarthritis Biomarkers |
1Radiology, Stanford University, Palo Alto, CA, United States, 2Austin Radiological Association, Austin, TX, United States, 3LVIS Corporation, Palo Alto, CA, United States, 4Neurology, Stanford University, Palo Alto, CA, United States |
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The use high-resolution magnetic resolution imaging (MRI) is beneficial for acquiring quantitative biomarkers corresponding to osteoarthritis (OA) severity and progression. However, the long scan times of high-resolution sequences, such as double-echo steady-state (DESS) that was included in the Osteoarthritis Initiative, precludes their widespread adoption. Deep-learning-based super-resolution has the potential to transform low-resolution MRI that can be acquired faster, into high-resolution images. Using qualitative cartilage image quality, and quantitative cartilage morphometry and osteophyte detection, we have shown that deep-learning-based super-resolution can enhance DESS slice-resolution threefold and offer the same utility as the original high-resolution acquisition for obtaining OA biomarkers. |
| 1141
|
14:57
|
Large-scale Knee Osteoarthritis Prediction from Spherical Coordinate Encoding of Bone Shape with Deep Learning Classifier |
1Department of Radiology, University of California, San Francisco, San Francisco, CA, United States |
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Osteoarthritis (OA) is a degenerative joint disease which affects 27 million U.S. adults. Previous studies have shown a relationship between bone shape and OA. In this study, the femur, tibia, and patella from the Osteoarthritis (OA) Initiative data set were segmented and converted into a spherical coordinate plane. The 2D spherical images for each bone were combined into RGB images and used to train a knee OA diagnosis and a knee OA progression binary classifier, while taking into account demographic data such as age, gender, and BMI. The model achieved an OA diagnosis average accuracy of 78.15%. |
| 1142 | 15:09
|
BoneMRI of the cervical spine: Deep learning-based radiodensity contrast generation for selective visualization of osseous structures |
1Center for Image Sciences, UMC Utrecht, Utrecht, Netherlands, 2MRIguidance BV, Utrecht, Netherlands, 3Dept. of Emergency Medicine, Isala, Zwolle, Netherlands, 4Image Sciences & Linguistics, MRIguidance BV, Utrecht, Netherlands, 5University of Twente, Enschede, Netherlands, 6Dept. of Medical Physics, Isala, Zwolle, Netherlands, 7Dept. of Neurosurgery, Isala, Zwolle, Netherlands, 8Dept of Radiology, UMC Utrecht, Utrecht, Netherlands, 9Dept of Orthopedics, UMC Utrecht, Utrecht, Netherlands, 10Dept of Radiology and Nuclear Medicine, Academic Medical Center, Amsterdam, Netherlands, 11Dept of Radiology and Nuclear Medicine, Isala, Zwolle, Netherlands |
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In this work BoneMRI is presented, a deep learning approach aiming at visualisation of radiodensity contrast by learning a mapping from MRI to CT data from 25 patients. Normal as well as pathological osseous structures in the cervical spine were clearly depicted. Quantitatively, radiodensity contrast similarity and high geometrical accuracy of vertebral dimensions was demonstrated. As BoneMRI is a 3D method it facilitates multiplanar reformatting in any desired direction. As such, BoneMRI is a promising tool for efficient morphological assessment of osseous structures without the need for ionizing radiation, simultaneously providing soft tissue contrasts in a single examination. |
| 1143 | 15:21
|
Computer-aided classification of intervertebral disc degeneration based on fractal dimension |
1The affiliated hospital of Chinese traditional medical university, Xian Yang, China, 2Siemens Healthcare, Scientific marketing, Xi'an, China |
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Magnetic resonance imaging (MRI) is considered to be the best imaging method to evaluate the IVD degeneration. However, grading systems for degeneration severity evaluation are based on qualitative descriptions of disc image, which impairs the detection of small changes in intervertebral discs. In order to obtain a tool for objective and continuous grading of IVD degeneration. Fractal method was used to analyze the spatial distribution of intervertebral disc signals. We found that fractal dimension value displayed the strongest association with the clinical grading of disc degeneration severity, suggesting that IVD fractal analysis is a suitable tool for objective and continuous IVD degeneration classification. |
| 1144 | 15:33
|
Comparison of Radiomics and Deep Learning for Differentiation of Spinal Metastases Coming from Lung Cancer and Other Primary Cancers |
1Department of Radiological Sciences, University of California, Irvine, CA, United States, 2Department of Radiology, Peking University Third Hospital, Beijing, China |
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For patients found to have spinal metastasis, a confirmed pathological diagnosis is needed to proceed with appropriate treatment. This study compared ROI analysis, radiomics, and deep learning for differentiation of primary cancer coming from 30 lung and 31 other tumors. Radiomics using GLCM texture and histogram parameters from the segmented 3D tumor achieved accuracy of 0.71, while the deep learning using recurrent CLSTM network with the entire 12 sets of DCE images reached an accuracy of 0.81. The wash-out slope in DCE kinetics measured from hot-spot was the best diagnostic parameter, which could be easily performed in a clinical setting. |
| 1145 | 13:45
|
Longitudinal multimodal MRI monitoring of a combination therapy using hydrogen enriched water and minocycline in ischemic stroke |
1Radiology, Stony Brook University, Stony brook, NY, United States, 2Neurology, Stony Brook University, Stony brook, NY, United States |
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Hydrogen or minocycline individually has been shown to be neuroprotective in experimental ischemic stroke. This study evaluated the efficacy of combined hydrogen enriched water with minocycline in an ischemic stroke rat stroke model using longitudinal MRI and behavioral tests using a double-blinded design. We found that the combination therapy reduced lesion volumes, white-matter damage, and behavioral deficits, compared to individual or vehicle treatment alone. These findings suggest that combination of hydrogen water with minocycline has positive therapeutic effects in ischemic stroke. |
| 1146
|
13:57
|
Whole-brain functional magnetic resonance imaging of serotonergic neuron optogenetic activation |
1Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, Portugal |
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Serotonin (5-HT) has been implicated in a variety of brain processes and is a main target of psychoactive drugs, yet we know little about where and how 5-HT acts to ultimately shape behaviour. Here, we optogenetically stimulated serotonergic neurons in the mouse dorsal raphe nucleus (DRN), and mapped the ensuing downstream activity using BOLD fMRI. Furthermore, by pairing 5-HT stimulation with sensory stimuli, we revealed how 5-HT stimulation affects sensory-evoked activity. Our findings highlight the feasibility of using opto-fMRI, with and without concurrent manipulations, to study 5-HT modulation on downstream circuitry in the global brain in-vivo. |
| 1147 | 14:09
|
Molecular profiles underlying the fluid-solid transition of brain tissue during maturation: High-resolution multifrequency MR elastography of the mouse brain paired with proteomics mass spectrometry. |
1Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany, 2Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany, 3Max Planck Institute for Molecular Genetics, Berlin, Germany, 4Department for Medical Immunology, Charité - Universitätsmedizin Berlin, Berlin, Germany, 5Department of Medical Informaticsy, Charité - Universitätsmedizin Berlin, Berlin, Germany |
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We have investigated the mechanical development of the mouse brain from 4 weeks to 20 weeks by multifrequency MR elastography and performed proteomics analysis with mass spectrometry. Highly resolved elastographic atlases of brain maturation were generated and regional analysis was performed to identify areas with age-dependent changes in viscoelasticity. In hippocampus, molecular signatures associated with macroscopically observed mechanical profile were identified, suggesting a transition from a soft-fluid to a more elastic-solid state during maturation. Combining MRE and proteomic analysis, we provide structural and functional information related to brain maturation from the molecular level up to whole-organ mechanical scale. |
| 1148 | 14:21
|
Heritability of the mouse connectome |
1Center for In Vivo Microscopy, Department of Radiology, Duke University, Durham, NC, United States, 2Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United States, 3Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD, United States |
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The human connectome project has demonstrated the enormous potential of functional and structural connectomics in understanding the brain. Extension of connectomics to mouse models has analogous potential, particularly where genetic variation can be controlled and manipulated. But the methods developed for human are not immediately extensible to the mouse models. We have developed a long term strategy, methods and infrastructure to make mouse connectomics routine with validation against tracer techniques. This project represents our first effort to deploy the methods in a study of heritability in a controlled collection of 4 genetically different strains. |
| 1149
|
14:33
|
Learning-induced microstructural changes in specific layers of primary motor cortex revealed by diffusion kurtosis tensor imaging |
1Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown, Lisbon, Portugal, 2Johns Hopkins University, Baltimore, MD, United States |
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Motor skill acquisition is known to induce microstructural changes in the motor cortex grey matter, which yield the encoding of new motor memories. Whether such alterations can be measured with diffusion magnetic resonance imaging (dMRI) is still an open question. Here, diffusion kurtosis tensor imaging is used to detect specific layer changes ex-vivo in mice after learning a new lateralized motor prehension task. Mean Kurtosis (MK) was found to increase with learning in M1 layers 5b and 6. Such changes were not observed in non-task-related regions. Moreover, single subject MK distributions appear to correspond with behaviour performance. |
| 1150
|
14:45
|
Triple Quantum Filtered Sodium Imaging at 21.1 T Reveals Dynamic Progression in a Preclinical Migraine Model |
1Chemical and Biomedical Engineering, Florida State University, Tallahassee, FL, United States, 2National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, United States, 3Physics, Florida State University, Tallahassee, FL, United States, 4Neurosciences, Huntington Medical Research Institutes, Pasadena, CA, United States |
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The brain allocates >50% of its energy reserves to the regulation of sodium homeostasis, indicating the critical importance of sodium and its fluxes in normal brain as well as neurological disorders. With the goal of localizing specific changes within intra- vs. extracellular compartments, this study utilizes Triple Quantum (TQ) coherence to evaluate 23Na fluxes in a preclinical rodent analogue of migraine. At a high spatial and temporal resolution, longitudinal scanning was performed at 21.1 T to quantify alterations in bulk and bound sodium during and following the onset of central sensitization. |
| 1151 | 14:57
|
Chronic hepatic encephalopathy in early developing brain, neurometabolic changes differ depending on the age of disease onset, in vivo longitudinal 1H MRS study |
1CIBM, EPFL, Lausanne, Switzerland, 2Service of Biomedicine, Neurometabolic Unit, Lausanne University Hospital, Lausanne, Switzerland, 3Swiss Center for Liver Disease in Children, University Hospitals Geneva, Geneva, Switzerland |
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Chronic hepatic encephalopathy (CHE) due to chronic liver disease (CLD) causes irreversible cognitive deficits in children. We aimed to study possible differences in neurometabolic changes in rat model of CLD&CHE depending on the age of the disease onset (post-natal day 15 vs 21), using in-vivo 1H-MRS. We showed differences in Gln, tCho, Lac, Asc, GSH and neurotransmitter concentrations between p15 and p21 pups during the evolution of the disease. These differences suggest that age of disease onset and its coincidence with neurodevelopmental processes play an important role and may result in different vulnerability to the disease depending on the age. |
| 1152
|
15:09
|
A longitudinal neuroimaging study of the effects of early versus late anti-inflammatory treatment in the TgF344-AD rat model of Alzheimer’s disease |
1Biological and Biomedical Engineering, McGill University, Douglas Mental Health University Institute, Montreal, QC, Canada, 2Douglas Mental Health University Institute, Montréal, QC, Canada, 3Psychiatry, McGill University, Douglas Mental Health University Institute, Montréal, QC, Canada |
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Alzheimer’s disease (AD) is a progressive neurodegenerative disorder with no effective treatments or known biomarkers for definitive diagnosis, substantiating the need for early detection and intervention. This project employs Magnetic Resonance Spectroscopy to measure neurochemical changes in the TgF344-AD rat model of AD in response to treatment with a common non-steroidal anti-inflammatory drug. Progression of neurochemical changes over time and in response to treatment are compared to behavioural measures of cognition and histopathology. Preliminary results suggest neurochemical changes are present before onset of cognitive impairment, and treatment response depends on whether treatment is administered early or late into disease progression. |
| 1153 | 15:21
|
The Effects of Genetic Risk Factors for Glaucoma on the Visual Pathway using Diffusion Tensor MRI |
1Department of Ophthalmology, New York University School of Medicine, New York, NY, United States, 2Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, United States, 3Department of Ophthalmology and Visual Sciences, University of Wisconsin - Madison, Madison, WI, United States, 4McPherson Eye Research Institute, University of Wisconsin - Madison, Madison, WI, United States, 5Department of Medical Physics, University of Wisconsin - Madison, Madison, WI, United States, 6Department of Ophthalmology and Visual Sciences, University of Iowa College of Medicine, Iowa City, IA, United States, 7Department of Radiology, New York University School of Medicine, New York, NY, United States |
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Glaucoma is the second leading cause of blindness worldwide. To date, the cause of the disease is still unknown, yet a number of candidate genes for glaucoma have been recently identified. In this study, we evaluated the effects of some of these genetic risk factors on the visual pathway using diffusion tensor MRI in experimental animal models. We found that LTBP2 mutants in cats and DBA/2J mice had decreased fractional anisotropy and increased radial diffusivity in the visual pathway. DBA/2J mice also exhibited reduced axial diffusivity, whereas TBK1-transgenic mice did not show detectable DTI changes along the visual pathway. |
| 1154 | 15:33
|
Rapid and Accurate CEST and NOE MRI of Injured Spinal Cord Using Multi-Pool Fitting |
1Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States, 2Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States, 3Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States |
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This study aims to evaluate the accuracy of estimates of the amplitudes of specific CEST and NOE effects in Z-spectra derived from multi-pool fitting using down sampled data, and their sensitivity for assessing injury-associated changes in spinal cords of squirrel monkeys. An inverse subtraction analysis corrected for changes in the apparent water longitudinal relaxation rate R1obs (AREXmfit) was used to quantify regional spectra around lesion sites. The results provide an optimized rapid, sensitive, and accurate protocol for deriving both NOE and CEST effects in spinal cord imaging at high field. |
| 1155
|
13:45
|
Motion-Robust, High-SNR Fat Quantification using a Variable Flip Angle Approach |
1Radiology, University of Wisconsin-Madison, Madison, WI, United States, 2Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 3Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States, 4Emergency Medicine, University of Wisconsin-Madison, Madison, WI, United States, 5Medicine, University of Wisconsin-Madison, Madison, WI, United States |
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Current chemical shift encoded (CSE)-MRI techniques enable quantification of liver fat using 3D breath-hold methods. However, many patients are unable to sustain breath-holds, leading to motion artifacts that cause variability and bias in fat quantification. A recently developed 2D sequential CSE-MRI technique is motion-robust with short temporal footprint but suffers from low SNR due to the small flip angles used to avoid T1 bias. To overcome this limitation, we propose a novel centric encoding variable flip angle (CEVFA) technique that minimizes T1 bias in fat quantification while achieving higher SNR performance and validate this technique in phantoms and in-vivo scans. |
| 1156 | 13:57
|
Multimodal MRI Combined with Liver Volume for Quantitative Assessment of Liver Function in Patients With Cirrhosis |
1Department of Medical Imaging, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China, 2Department of Biomedical Engineering, School of Life Science and Technology of Xi’an Jiaotong University, Xi'an, China, 3The Third Hospital of HeBei Medical University, Shi jiazhuang, China |
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This study aim to combine multimodal MRI with liver volume for quantitative assessment of liver function in patients with cirrhosis. Eighty-five subjects underwent GD-EOB-DTPA enhanced MR and IVIM-DWI.Through statistical analysis, RE, D* and Vliver/Vspleen from modeling group were selected as optimal indicators. Using multiple regression to establish a multi-parametric model for liver function assessing: F(x). The ROC analysis of the validation group showed that it had an AUC of 0.973 in distinguishing Child-Pugh A group and Child-Pugh B and C group. The results showed it could evaluate the overall liver function and expected to be a method for preoperative local liver function assessment. |
| 1157
|
14:09
|
Improved robustness of R2* mapping using spin-density projection for liver iron quantification at 3 Tesla |
1Department of Radiology, UT Southwestern Medical Center, Dallas, TX, United States, 2Department of Radiology, University of Wisconsin at Madison, Madison, WI, United States |
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In patients with iron overload, liver iron concentration can be measured by R2- or R2*-MRI. While gradient-recalled-echo (GRE) based R2*-MRI holds practical advantages over spin-echo based R2-MRI, the R2* technique is more challenging in patients with severe iron overload with rapid signal decay. We introduce a technique known as spin density projection (SDP), which uses liver-to-subcutaneous fat spin density ratios as an internal reference to improve robustness of R2* fitting. We performed a computer simulation and retrospective analysis of GRE imaging data in 45 patients with suspected iron overload and compared R2* fitting without and with SPD. We found that SPD increased robustness by reducing standard deviation of R2* estimation. |
| 1158 | 14:21
|
Flow quantification in portal hypertension with 4D flow: comparison of a free breathing k-t accelerated sequence to a respiratory-navigated sequence |
1Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 2Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 3Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 4Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 5Radiology, Northwestern University, Chicago, IL, United States, 6Laboratoire d'Imagerie Biomedicale, INSERM, Paris, France, 7Department of Interventional Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 8Biomedical Engineering, Northwestern University McCormick School of Engineering, Evanston, IL, United States |
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The purpose of our prospective study was to compare a free-breathing k-t GRAPPA accelerated 4D flow sequence with a standard navigator-gated sequence, and to correlate hemodynamic parameters to the hepatic venous pressure gradient (HVPG) in patients with chronic liver disease. The k-t accelerated sequence had significant (three-fold) reduction in acquisition time, while obtaining equivalent image quality and quantitative parameters in the large vessels as the standard sequence. However, there was systematic under-estimation of velocities in small arteries. Time-average velocity in the superior mesenteric vein measured with the k-t sequence was positively correlated with HVPG. |
| 1159 | 14:33
|
Simultaneous Fat, T1 and Stiffness Quantification Using Multi-Echo, Variable Flip Angle, Spoiled-Gradient-Echo, Magnetic Resonance Elastography |
1Radiology, Mayo Clinic Arizona, Scottsdale, AZ, United States, 2Radiology, Mayo Clinic, Rochester, MN, United States, 3Siemens Healthcare, Salt Lake City, UT, United States |
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Hepatic fat fraction measurements using Dixon MRI and stiffness measurements using MRE provide important liver fat and fibrosis biomarkers for evaluating liver diseases. We have developed Dixon MR Elastography to measure fat fraction and stiffness in a single acquisition. In addition, by also using variable flip angles this new technique can simultaneously measure stiffness, T1, and fat fraction, thus providing even more clinically useful information in one scan. Promising results were obtained in a fat/water/gel phantom and six healthy volunteers. |
| 1160 | 14:45
|
Early analysis of hepatic PDFF and liver stiffness results in the Strong Heart Study, investigating possible factors affecting nonalcoholic fatty liver disease in an American Indian population |
1Liver Imaging Group, Department of Radiology, UC San Diego, La Jolla, CA, United States, 2Department of Biostatistics & Epidemiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States, 3Norman Regional Health System, Norman Regional Moore, Moore, OK, United States, 4Department of Radiology, Mayo Clinic, Scottsdale, AZ, United States, 5Computational and Applied Statistics Laboratory, San Diego Supercomputer Center, UC San Diego, La Jolla, CA, United States, 6Medstar Health Research Institute, Hyattsville, MD, United States, 7Department of Medicine (Cardiology), Weill Cornell Medicine, New York, NY, United States, 8Georgetown-Howard Universities Center for Clinical and Translational Science, Washington, DC, United States, 9NAFLD Research Center, Division of Gastroenterology, Department of Medicine, UC San Diego, La Jolla, CA, United States, 10Texas Biomedical Research Institute, San Antonio, TX, United States |
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In this analysis of early data from the Strong Heart Study, we show that advanced MRI estimates of proton-density fat fraction (PDFF) and liver stiffness can be acquired successfully in a population of American Indians. Diagnosis of diabetes, and whether participants self-report binge-drinking are collected. Too few cases have been enrolled to permit significance testing, but PDFF values are higher for diagnosed diabetes, and stiffness values are higher for self-reported binge drinking. This study offers a unique opportunity to study the possible roles of diabetes and binge drinking in nonalcoholic fatty liver disease for an at-risk population of American Indians. |
| 1161 | 14:57
|
Highly Accelerated Prospectively Gated Free Breathing Dynamic Abdominal Imaging with Cartesian Sampling |
1Diagnostic Radiology, University of Texas MD Anderson Cancer Center, Houston, TX, United States, 2Global MR Applications & Workflow, GE Healthcare, Madison, WI, United States, 3Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, TX, United States, 4Global MR Applications & Workflow, GE Healthcare, Houston, TX, United States |
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Dynamic abdominal imaging has the requirements of high spatial-temporal resolution, large spatial coverage, and acquisition timing with the contrast injection. Golden angle radial sampling in combination with compressed sensing and parallel imaging has been reported for free breathing dynamic volumetric imaging. However, radial sampling suffers from streaking artifacts, inflexible FOV prescription, and long reconstruction time. In this study, we report a Cartesian sampling technique that combines compressed sensing, parallel imaging, temporal view sharing, and navigator for prospective gating. The potential of the technique for free breathing dynamic abdominal imaging is demonstrated in both volunteers and patients. |
| 1162 | 15:09
|
In Vivo Multicomponent 3D-T1ρ Relaxation Mapping of Human Liver under Free-breathing |
1Radiology, NYU Langone Health, New York, NY, United States, 2Medicine, NYU Langone Health, New York, NY, United States |
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| 1163 | 15:21
|
Radiomics analysis of peritumoral tissue on gadoxetic acid-enhanced MR imaging for prediction of early recurrence in hepatocellular carcinoma |
1Department of Radiology, West China Hospital,Sichuan University, Chengdu, China |
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Postoperative recurrence has become the main obstacle in prognosis of HCC patients, even after successful curative therapy. Our study analyzed the radiomics features derived from peritumoral tissue on gadoxetic acid-enhanced MR images, combined with clinical characteristics and subjective imaging findings, to evaluate their ability to preoperatively predict early recurrence of HCC after surgical resection. An AUC of 0.882 for the radiomics signature and an improved AUC of 0.926 for integrated radiomics nomogram were obtained. These results suggest that radiomics features can accurately and objectively predict early recurrence of HCCs after curative resection from preoperative MR images. |
| 1164 | 15:33
|
Gadoxetate acid disodium-enhanced MRI: Multiple arterial phases using differential sub-sampling with cartesian ordering (DISCO) may achieve more optimal late arterial phases than the single arterial phase imaging |
1West China Hospital, Sichuan University, Chengdu, China, 2GE Healthcare China, MR Research, Beijing, China |
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Differential sub-sampling with cartesian ordering (DISCO) is a high spatial-temporal resolution MR technique that combines multiple features: a dual echo SPGR echo acquisition for DIXON water-fat separation, a pseudo-random variable density k-spacesegmentation, parallel imaging and a view sharing reconstruction. Gadoxetate acid disodium is a specific hepatobiliary contrast agent, however, the high frequency happening of transient severer motion can impair arterial phase (AP) images. In this study, we prospectively determine multiple AP imaging using DISCO can improve the capturing rate of well-timed late AP with less motion artifact in in comparison to single AP imaging using LAVA-Flex. |
| 1165
|
13:45
|
Accelerated spin-echo fMRI using Multisection Excitation by Simultaneous Spin-echo Interleaving (MESSI) with ‘complex-basis’ RF-encoded generalized SLIce Dithered Enhanced Resolution Simultaneous Multi-Slice (MESSI-gSlider-SMS) |
1Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 2Department of Radiology, Harvard Medical School, Boston, MA, United States, 3Harvard-MIT Division of Health Science and Technology, Cambridge, MA, United States |
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High spatiotemporal resolution spin-echo fMRI is challenging as it requires a long echo time to generate BOLD-contrast, resulting in longer repetition times. We propose a new technique, Multisection Excitation by Simultaneous Spin-echo Interleaving (MESSI), which utilizes the dead time in long TE acquisitions to improve the slice-coverage of SE-fMRI. For further accelerations, we combine the MESSI with both ‘complex-basis’ RF-encoded gSlider and conventional-SMS. Compared with standard SE-EPI acquisition with the same TR, the proposed MESSI-gSlider acquisition shows comparable tSNR but with eight-fold increase in slice-coverage. This method should be beneficial for applications requiring high spatiotemporal resolution SE-fMRI with whole-brain coverage. |
| 1166 | 13:57
|
Novel alpha-180 SE based LINE-scanning method (SELINE) for laminar-specific fMRI |
1Max Planck Institute for Biological Cybernetics, Tuebingen, Germany, 2Graduate Training Centre of Neuroscience, Tuebingen, Germany, 3Department of Biomedical Magnetic Resonance, University of Tuebingen, Tuebingen, Germany, 4MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, United States |
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Laminar-specific functional magnetic resonance imaging (fMRI) opens new possibility for studying the neuronal circuitry and functional connectivity of cortex. FLASH based line-scanning method was proposed with high temporal and spatial resolution to better characterize the fMRI onset time across the cortical layers by combining 2 saturation RF pulses. However, the imperfect RF saturation performance led to poor boundary definition of the ROI from the cortex. In this work, we propose an α-180˚ SE based line-scanning (SELINE) method, solving this problem. We will improve this method to better understand the distinct laminar-specific neuronal circuitry and functional connectivity. |
| 1167 | 14:09
|
Full-FOV, Whole-brain, Half-millimetre Resolution fMRI at 7T using Accelerated multi-band EPIK with TR-external Phase Correction |
1Institute of Neuroscience and Medicine 4, INM-4, Forschungszentrum Juelich, Juelich, Germany, 2Institute of Neuroscience and Medicine 11, INM-11, JARA, Forschungszentrum Juelich, Juelich, Germany, 3JARA - BRAIN - Translational Medicine, Aachen, Germany, 4Department of Neurology, RWTH Aachen University, Aachen, Germany |
||
Ultra-high spatial resolution fMRI can identify brain activations with precise spatial localisation. There have been numerous attempts to achieve a sub-millimetre resolution in fMRI by using reduced- or full-FOV imaging. Although the reduced-FOV scheme can achieve more enhanced resolution than the full-FOV scheme, the restricted FOV often limits its use for more general functional studies. This work aims to present a novel half-millimetre resolution fMRI method which can also provide full-FOV and whole-brain coverage. The method was developed based on EPIK and a TR-external EPI phase correction scheme. Here, the above configuration was employed for exemplary finger-tapping fMRI at 7T. |
| 1168 | 14:21
|
Ultra-high spatial resolution TURBINE fMRI at 7T |
1Wellcome Centre for Human Neuroimaging, UCL Institute of Neurology, London, United Kingdom, 2Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, United Kingdom |
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Ultra-high spatial resolution fMRI often uses 3D-EPI for data acquisition. However, 3D-EPI can be susceptible to artefacts from inter-shot variability, such as motion and physiological noise. Here, we present an improved hybrid radial-Cartesian 3D EPI sampling strategy, TURBINE, to generate ultra-high spatial resolution fMRI data at conventional scan times at 7T. TURBINE enables intrinsic correction of global and z-dependent shot-to-shot phase variations, and self-navigated motion correction. Using these features, along with a temporally regularized reconstruction, we demonstrate robust BOLD activation in 0.67mm isotropic resolution (16mm slab, TRvol = 2.32s) and 0.8x0.8x2.0mm (whole-brain, TRvol = 2.4s) acquisitions. |
| 1169 | 14:33
|
High-resolution segmented-accelerated EPI using Variable Flip Angle FLEET with tailored slice profiles |
1Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, United States, 2Department of Radiology, Harvard Medical School, Boston, MA, United States, 3Vanderbilt University Institute of Imaging Science, Nashville, TN, United States, 4Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, 5Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States |
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New evidence suggests that fMRI has spatial specificity at scales far below current voxel sizes, but encoding limits preclude single-shot EPI at sufficient spatial resolution. Segmented EPI can help overcome these limits, but is well-known to be temporally unstable. Here we propose a reordering of the EPI segments, known as FLEET, combined with |
| 1170 | 14:45
|
Comparison of Oscillating Steady State to GRE BOLD for fMRI |
1Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Ann Arbor, MI, United States, 2Biomedical Engineering, University of Michigan, Ann Arbor, Ann Arbor, MI, United States |
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The combination of a quadratic phase sequence with balanced gradients leads to an oscillating steady state (OSS) MRI signal with an average signal amplitude that is 2-3 times the Ernst angle GRE imaging. With signal phase varies with off-resonance making the resultant signal T2*-weighted and thus, suitable for BOLD fMRI. In this work, simulations of changes to the tissue T2*, as seen in fMRI, are carried out for OSS and compared to GRE. The OSS method is compared to GRE for high-resolution fMRI studies, demonstrating substantially higher activation counts as well as temporal SNR (tSNR). |
| 1171 | 14:57
|
Task-based High Angular Resolution Functional Imaging (tHARFI) shows directional contrast of BOLD signal |
1Vanderbilt University Institute of Imaging Science, Nashville, TN, United States, 2Vanderbilt Brain Institute, Nashville, TN, United States, 3Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, United States, 4Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States, 5Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, 6Peabody College of Education and Human Development, Nashville, TN, United States, 7BIomedical Engineering, Vanderbilt University, Nashville, TN, United States, 8Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN, United States |
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We present a method to detect and quantify correlated BOLD signals in brain white matter using task-based high angular resolution functional imaging (tHARFI). This technique measures the anisotropic component of these signals, highlighting directional differences between two different task states. The ability to quantify these correlated functional signals in white matter may improve our ability to delineate functional circuits in the brain, and complement other modalities to better understand structural and functional relationships in the brain. |
| 1172 | 15:09
|
Geometric Distortions and Signal-To-Noise Ratio of Conventional and Inner Fields-of-View for T2*-Weighted Echo-Planar Imaging of the Spinal Cord |
1Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany |
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Geometric distortions and signal-to-noise ratios (SNR) of T2*-weighted echo-planar imaging (EPI) of the spinal cord are compared for conventional and inner-FOV acquisitions based on 2D-selective RF (2DRF) excitations. For conventional acquisitions, the required FOV increases with the in-plane object size yielding more pronounced distortions, prolonged echo times (TEs), and reduced SNR. For inner-FOV acquisitions, the FOV is small and independent of the object size yielding only minor distortions. The 2DRF pulse duration must be adapted for larger object sizes resulting in slightly prolonged TEs but overall TEs remain shorter and SNR values are larger than for conventional acquisitions. |
| 1173 | 15:21
|
Resting-state fMRI at UHF: Optimizing BOLD sensitivity by using plug-and-play parallel transmission at 7T |
1Neurospin, CEA, Gif-sur-Yvette, France, 2Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands, 3Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States |
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The 7T Human Connectome Project (HCP) resting-state fMRI (RS-fMRI) protocol employs slice-accelerated multiband (MB) EPI with a total of 10-fold acceleration (MB 5 and in-plane 2). Such highly accelerated acquisitions provide exquisite temporal resolution at good sensitivity in most cortical regions, but quickly become very SNR starved in transmit field (B1+) deprived regions. This can be mitigated using parallel RF transmission (pTX), which however usually comes at the expense of time-consuming calibrations and pulse computations. This work shows experimentally with HCP-style RS-fMRI scans that a plug-and-play alternative for B1+ mitigation using pTX is possible with multiband Universal Pulses. |
| 1174 | 15:33
|
DANTE Prepared EPI for Fast Whole Brain VASO Detection at 3T |
1National Institutes of Mental Health, National Institutes of Health, Bethesda, MD, United States |
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Vascular space occupancy (VASO) fMRI may provide more quantifiable and localized hemodynamic measures of brain activitythan conventional BOLD measurements. Due to application of inversion recovery pulse, conventional approach for VASO measurements suffers from low imaging efficiency, high SAR and interference of inflow and CBF effect. We demonstrated that DANTE prepared single echo or multi-echo EPI can be used to acquire robust full brain multi-slice VASO activation with benefit of high image efficiency, low SAR without complication of inflow and CBF effect. |
| 1175 | 13:45
|
Respiratory motion compensated Multitasking for 3D myocardial perfusion without breath-holds, ECG, or multiple boluses |
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 2Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, United States, 3Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 4Siemens Healthineers, Los Angeles, CA, United States, 5Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States |
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Quantitative myocardial perfusion MRI is potentially powerful for diagnosing coronary artery disease. However, It is challenging to accurately measure dynamic contrast enhancement throughout the whole moving heart. Most perfusion methods employ some combination of ECG-triggering, breath-holds, dual-bolus acquisition, and multislice 2D acquisition, leading to difficult workflows and limited spatial coverage. Here we describe a non-ECG, free-breathing, single-bolus, 3D alternative which employs the MR Multitasking framework to perform low-rank tensor imaging. We add 3D respiratory motion compensation to this framework to eliminate the need for breath-holds. This new method is demonstrated and evaluated in healthy volunteers. |
| 1176
|
13:57
|
Extreme MRI: Super-High-Res Dynamic Volumetric MRI from Continuous Non-Gated Acquisition |
1University of California, Berkeley, Berkeley, CA, United States, 2University of California, San Francisco, San Francisco, CA, United States, 3Stanford University, Stanford, CA, United States |
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The goal of this work is to recover transient dynamics in 3D dynamic MRI by reconstructing images with near-millimeter spatial resolution and sub-second temporal resolution without gating. This setting poses two major challenges: extreme undersampling and extreme computational/memory cost. To achieve this “extreme MRI”, we propose two innovations: explicit multi-scale low rank matrix factorization to regularize the problem and reduce memory usage, and stochastic optimization to reduce computation. We demonstrate the feasibility of the proposed method in DCE imaging acquired with 3D cones trajectory and lung imaging acquired with 3D UTE radial trajectory. |
| 1177 | 14:09
|
A kinetic-guided compressed sensing approach for DCE-MRI reconstruction |
1Department of Information Engineering, University of Pisa, Pisa, Italy, 2School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 3Athinoula A. Martinos Center for Biomedical Imaging, Boston, MA, United States, 4Department of Radiology, Massachusetts General Hospital, Boston, MA, United States |
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In this work, we propose a reconstruction method for free-breathing DCE-MRI, that combines golden-angle radial sampling, parallel imaging and tracer kinetic (TK) modeling in an iterative reconstruction approach. We introduce a new model in which information coming from TK modeling are treated as a priori knowledge, assisting image reconstruction. The proposed approach is compared with Total Variation Compressed Sensing reconstruction achieving comparable denoising effect in the spatial domain, but improved temporal fidelity and TK modeling. |
| 1178 | 14:21
|
High Resolution DSC Perfusion Imaging Using Low Rank Reconstruction with Progressive Learning |
1Medical Physics, University of Wisconsin - Madison, Madison, WI, United States, 2Radiology, University of Wisconsin - Madison, Madison, WI, United States |
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Single shot echo-planar imaging, traditionally used for dynamic susceptibility contrast (DSC) perfusion-weighted MRI (PWI), is not efficient for high resolution imaging due to T2* signal decay and poor compatibility with advanced reconstruction techniques. Spiral acquisition samples k-space more efficiently and is amenable to advanced reconstructions necessary for imaging at higher resolution and for multi-echo imaging. However, for high accelerations, spirals lack necessary k-space center training data. We enable low-rank-based reconstruction for multi-echo spiral acquisition by introducing progressive learning of temporal models. Our approach is demonstrated for multi-echo spiral DSC PWI with high spatial/temporal resolution (1.1x1.1mm/1.1s). |
| 1179
|
14:33
|
Multi-Point 5D Flow MRI - Accelerated Cardiac- and Respiratory-Motion Resolved Mapping of Mean and Turbulent Velocities in 4 Minutes |
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland |
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This work presents a framework for respiratory motion-resolved multi-point 4D Flow MRI (MP 5D Flow MRI) of mean and turbulent velocities in 4 minutes using a combination of Cartesian Golden angle undersampling, data-driven motion detection and locally low-rank imaging reconstruction. In an imaging study with 9 volunteers, 7-point 5D Flow MRI was compared to a standard, navigator-gated 4-point 4D Flow MRI parallel imaging protocol. Results demonstrate that flow fields from MP 5D Flow MRI in end-expiration agree well with 4D Flow MRI data while scan time was reduced by a factor of 4.5. In addition, MP 5D Flow MRI provides higher accuracy for low velocities and allows assessing TKE over a larger dynamic range compared to 4D Flow MRI. |
| 1180
|
14:45
|
Prospective 3D+t non-rigid motion estimation at high frame-rate from highly undersampled k-space data: validation and preliminary in-vivo results |
1Center for image sciences, University Medical Center Utrecht, Utrecht, Netherlands, 2Utrecht University, Utrecht, Netherlands |
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We previously presented a framework to reconstruct 3D non-rigid motion-fields from highly undersampled k-space data by exploiting the lower-dimensional nature of motion-fields. Here, a quantitative comparison with a well-established image-based motion estimation is performed on 3D abdomen images. To also exploit temporal compressibility the framework is extended to reconstructions of spatio-temporal non-rigid motion-fields at high frame-rate, and validation is performed on 2D+t abdomen cine-acquisitions. Additionally, a dedicated non-Cartesian 3D trajectory was employed to prospectively acquire highly undersampled k-space data, and reconstruct 3D+t head motion at 16Hz. High quality respiratory/head motion-fields are obtained and the framework outperforms the fully-sampled image-based motion estimation even for undersampling up to 8x. |
| 1181
|
14:57
|
High-Dimensionality Undersampled Patch-Based Reconstruction (HD-PROST) for Accelerated Multi-Contrast Magnetic Resonance Imaging |
1School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom |
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In magnetic resonance imaging, multiple contrasts are exploited to extract clinically relevant tissue parameters and pathological tissue changes. Multi-contrast acquisitions find important applications in parameter mapping (e.g. T1 and T2 mapping) and magnetic resonance fingerprinting. However, these acquisitions lead to long scan times since multiple images with different contrasts need to be acquired. In this study, we present a new reconstruction technique, termed as High-Dimensionality undersampled Patch-based RecOnSTruction (HD-PROST), for highly accelerated 2D and 3D multi-channel multi-contrast MRI. |
| 1182
|
15:09
|
Rapid, Time-Resolved Brain Imaging with Multiple Clinical Contrasts using Wave-Shuffling. |
1Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States, 2Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States, 3Department of Physics and Astronomy, Heidelberg University, Heidelberg, Germany, 4Siemens Healthcare GmbH, Erlangen, Germany |
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Previously, we presented Wave-Shuffling: a technique that combines random-sampling and the temporal low-rank priors of T2-shuffling with the sinusoidal gradients of Wave-CAIPI to achieve highly-accelerated, time-resolved acquisitions. In this work, we optimize and apply Wave-Shuffling to T2-SPACE and MPRAGE to achieve rapid, 1 mm-isotropic resolution, time-resolved imaging of the brain where we recover a time-series of clinical contrast. We also present preliminary explorations into Joint-Contrast Wave-Shuffling to boost signal-to-noise ratio and reconstruction-conditioning at high accelerations. |
| 1183
|
15:21
|
Autocalibrated multiband CAIPIRINHA with k-t-acceleration: Towards the complete spatio-temporal coverage of the heart motion in one single breath-hold |
1Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany, 2Working Group on Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max-Delbrück Center for Molecular Medicine, Berlin, Germany, 3Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States, 4Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, IL, United States |
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Recent developments in cardiac multiband CAIPIRINHA with autocalibration allow the simultaneous acquisition and reconstruction of multiple slices in one breathhold. Nevertheless, applications such as high resolution multi-slice cine imaging, and multi-slice three-directional velocity encoding of the myocardium, are still hindered by excessive breathhold duration.
In this study, we combine autocalibrated multiband CAIPIRINHA with k-t-acceleration to substantially accelerate data acquisition. When applied to gradient-echo and phase-contrast imaging, our technique allowed cardiac cine acquisitions at high spatial resolution (1.1mm), and three-directional velocity encoding of the myocardium, to be acquired in one breath-hold of 18 heart-beats at 2 or 3 slices, simultaneously. |
| 1184
|
15:33
|
Self-calibrating through-time spiral GRAPPA for flexible real-time imaging |
1Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 2Case Western Reserve University, Cleveland, OH, United States |
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A self-calibrating through-time spiral GRAPPA method is presented that uses the same undersampled scan for both the accelerated data and the calibration data. This method can be used to capture at least one heartbeat worth of data at 12 slice positions in less than one minute, in a free-breathing and ungated scan. |
13:45
|
MR Biomarkers of Drug Safety: A Drug Developer’s Perspective | |
14:05
|
Hyperpolarized MR to Identify Markers of Cardiotoxicity | |
1Physiology Anatomy and Genetics, University of Oxford, Oxford, United Kingdom |
14:25
|
MR Biomarkers to Detect Transporter-Mediated Liver Toxicity | |
14:45
|
New Preclinical Studies With MR Biomarkers of Neurotoxicity | |
1Neurotoxicology, NCTR, Jefferson, AR, United States |
15:05
|
Neuroimaging Markers of Metal Toxicity in Career Welders | |
1Purdue University, United States |
15:25
|
New Studies in MR Biomarkers of Drug-Induced & Radiation-Induced Lung Injury | |
13:45
|
Open Questions for Diffusion & Relaxometry MRI | |
1University of Oxford |
14:00
|
Theoretical Approaches for Combined Diffusion-Relaxometry | |
1BWH Radiology, Harvard Medical School, Boston, MA, United States |
14:10
|
Exploiting B0 Field Strength as an Additional Dimension in Multi-Dimensional Diffusion MRI | |
14:20
|
Multidimensional Diffusion-Relaxation Correlation Spectroscopic Imaging | |
1University of Southern California, Los Angeles, CA, United States |
14:30
|
Use of Spectral Constraints in Multidimensional Diffusion-Relaxation Correlation MRI: Mapping Tissue | |
14:40
|
Characterization of Prostate Microstructure Using Water Diffusion & NMR Relaxation | |
14:50
|
Multidimensional Correlation of Nuclear Relaxation Rates & Diffusion Tensors | |
1Physical Chemistry, Lund University, Lund, Sweden |
15:00
|
Panel Discussion |
16:00
|
Contrast Agents | |
1INSELSPITAL, Universitätsspital Bern, Switzerland |
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The gadolinium chelates (the GBCAs) are critical to disease diagnosis by MR, indeed to clinical medicine worldwide, and have proven to be overall a very safe class of contrast media. This review focuses on the current knowledge regarding accumulation of gadolinium in the brain (dentate nucleus and other structures) and body, with clinical recommendations based on that and other safety data, including in depth discussion of the European Medicines Agency (EMA) ruling. Also, it is important to recognize that the discussion of dechelation and long term deposition in the brain and body of insoluble Gd and Gd bound to macromolecules (not as the injected chelate) involves only the linear Gd chelates. |
16:40
|
High Field Imaging | |
1High-Field and Hybrid MR Imaging, Erwin L. Hahn Institute for MRI, University Essen-Duisburg, Essen, Germany |
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With more than 80 installed MRI systems worldwide operating at a magnetic field strength of 7 Tesla or higher, ultra-high field (UHF) MRI has been established as a platform for clinically oriented research in recent years. Profound technical and methodological developments have helped to overcome the inherent physical challenges of UHF radiofrequency (RF) signal homogenization in the human body. The ongoing development of dedicated transmit/receive RF coil arrays was pivotal in realizing UHF body MRI, beyond mere brain imaging applications. Against this backdrop, UHF MRI recently has demonstrated capabilities and potentials for clinical diagnostics in a variety of studies. |
17:20
|
Artifacts to Artefacts | |
1Radiology, Case Western Reserve University, Cleveland, OH, United States |
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The appearance, causes and pathways to avoidance or alleviation of various commonly encountered MR imaging artifacts will be discussed. |
18:00
|
Adjournment |
16:00
|
Artifacts Game Show | |
1Siemens Healthineers, Rochester, MN, United States |
16:30
|
Adjournment |
16:00
|
Reimbursement Models & Their Impact on Imaging | |
1Mayo Clinic, United States |
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Reimbursement Models & Their Impact on Imaging |
16:20
|
Cost-Effectiveness Analysis: An Introduction | |
1Harvard Medical School/MGH, Boston, MA, United States |
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Overview of talk 1. Effectiveness 2. Utility, Quality-Adjusted Life Year (QALY) 3. Cost-Effectiveness 4. Willingness-to-pay (WTP) threshold |
16:40
|
Cost Effectiveness Principles in MRI: Optimizing MRI from the Cost Effectiveness Perspective | |
1NYU, New York, New York, United States |
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This educational presentation will describe the importance of studying MRI cost effectiveness as it relates to population-level health outcomes, patient-centered care, and costs to the healthcare system. Examples of work in MRI, spanning innovation and common clinical practice, will serve to illustrate applications of cost effectiveness analysis. Cost effectiveness analysis, a standardized means of comparing medical interventions and tests, quantifies the clinical effectiveness relative to cumulative costs. Furthermore, research goals can be prioritized based on targets for maximized value.
|
| 1185
|
17:00
|
5-Minute Quantitative Double-Echo in Steady-State for High-Value Diagnostic Knee MRI: Combining an Efficient Multi-Contrast Acquisition with Quantitative Imaging and Artificial Intelligence |
1Radiology, Stanford University, Palo Alto, CA, United States, 2Radiology, Santa Clara Valley Medical Center, San Jose, CA, United States, 3LVIS Corporation, Palo Alto, CA, United States, 4Neurology, Stanford University, Palo Alto, CA, United States |
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There exists interest in rapid diagnostic knee magnetic resonance imaging (MRI) protocols in a push towards ‘high-value radiology’. Recent efforts for expediting knee MRI involve accelerating 2D fast spin echo (FSE) sequences, which precludes multiplanar reformations, or using 3D FSE sequences, which can cause image blurring. To overcome these limitations, we show how a 5-minute quantitative double-echo steady-state (qDESS) sequence generates high-resolution and multi-contrast images using deep-learning-based super-resolution, along with automatic T2 relaxation time measurements. In a preliminary study with 25 patients, we demonstrate how qDESS can perform rapid and accurate diagnostic knee MRI using rich structural and quantitative information. |
| 1186
|
17:04
|
Introduction of Targeted Rapid Knee MRI exam using T2 Shuffling into Clinical Practice: Retrospective Analysis on Image Quality, Charges, and Scan Time |
1Electrical Engineering and Computer Sciences, University of California, Berkeley, Berkeley, CA, United States, 2MR Applications & Workflow, GE Healthcare, Menlo Park, CA, United States, 3Radiology, Stanford University, Stanford, CA, United States, 4Radiology, Lucile Packard Children’s Hospital, Palo Alto, CA, United States, 5Intel Labs, Santa Clara, CA, United States, 6Intel Labs, Hillsboro, OR, United States |
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Volumetric fast spin echo (FSE) of the knee using T2 Shuffling (T2Sh) has previously been described as comparable to traditional 2D imaging. T2Sh has the added advantage of being a rapid single-scan 4D multi-plane reformattable sequence for pediatric knee examinations. This study investigates the feasibility and effectiveness of a targeted rapid pediatric knee MRI exam after introduction into clinical practice, with the goal of reducing cost and enabling same-day MRI access. |
| 1187 | 17:08
|
Pulmonary High-Resolution ZTE MR Imaging: Comparison with Low-Dose Computed Tomography for the Assessment of Pulmonary Nodules |
1Department of Diagnostic Radiology, National Cancer Center/ National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academ, Beijing, China, 2Department of Diagnostic Radiology, National Cancer Center/ National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China, 3National Cancer Center/ National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China, 4GE healthcare MR research China, Beijing, China |
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We evaluated the capability of pulmonary MR imaging of zero echo time (zTE) in assessing patients with pulmonary nodules detected by low-dose computed tomography (LDCT). Consequently, pulmonary thin-section MR imaging with zTE was useful in nodule detection and was considered at least as effective as low-dose thin-section CT. This excellent acquisition method of zTE-MRI is turned out to be radiation-free, quiet and relatively insensitive to cardio-respiratory motion, which is important for the detection and follow-up of pulmonary nodules. |
| 1188
|
17:12
|
Comprehensive stroke protocol of less than six minutes: using Compressed-SENSE with valued addition of SWIp and Non-Contrast-3D-MRA |
1Philips Health Systems, Philips India Limited, Gurugram, India, 2Philips Health Systems, Philips India Limited, Chennai, India, 3Department of Radiology, Fortis Memorial Research Institute, Gurugram, India |
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Acute-stroke-management needs intervention to be done within certain time-window-period. A stroke-MRI-protocol should preferably be within six minutes as reported in previous studies. |
| 1189
|
17:16
|
Combined T1, T2, and T2* mapping using a multi-inversion multi-echo spin and gradient echo EPI sequence |
1A.A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States, 2Department of Radiology, Harvard Medical School, Boston, MA, United States, 3Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, United States |
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Rapid EPI acquisitions are limited by geometric distortion and blurring due to long readouts. Here we incorporate several recent advances in reconstruction approaches and hardware technology to mitigate some of these errors, and implement a multi-echo multi-inversion EPI-based sequence that can be used to find quantitative proton density, T1, T2, and T2* maps. In addition, high quality clinical contrasts can be generated from these maps including T2-, T2*-, T1-, and FLAIR-weighted images. Our protocol provides high-quality, whole-brain, multi-contrast maps with minimal distortion in scan times of 1-3 minutes. |
| 1190 | 17:20
|
EPIMix 3.0 |
1Neuroradiology, MR Applied Science Laboratory Europe, GE Healthcare, Stockholm, Sweden, 2Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden, 3Karolinska University Hospital, Stockholm, Sweden, 4Karolinska Institutet, Stockholm, Sweden |
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EPIMix is a multi-contrast MRI sequence that can produce T1-FLAIR, T2w, T2*w, T2-FLAIR, DWI, ADC images of the brain in about 70 s. To make EPIMix closer to a single-scan brain MRI exam, we propose optional supplemental sequence modules. The add-on sequences include T2w SMS FSE Propeller (distortion free), 3D SWI-EPI, and 3D T1w SPGR-EPI (isotropic resolution), which all have higher resolution and less distortions compared to EPIMix. With this extension to EPIMix, nine images series can be produced in 3 min total scan time. |
| 1191 | 17:24
|
Increasing the Value of Legacy MRI Scanners with Magnetic Resonance Fingerprinting |
1Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 2Siemens Healthineers, Cleveland, OH, United States, 3Radiology, University Hospitals of Cleveland, Cleveland, OH, United States |
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Few of the 32,000 MRI scanners around the world are equipped with the latest hardware and software required for advanced imaging. Magnetic Resonance Fingerprinting (MRF) presents an opportunity to expand the value of the existing MRI install base as it is rapid, quantitative, and does not require the latest gradient systems or multi-channel receiver coils. In this work, we demonstrate repeatable and reproducible T1 and T2 MRF maps on a 16-year-old MRI scanner as a proof of principle towards implementing MRF on cheap, legacy MRI scanners. |
| 1192 | 17:28
|
Spin-echo imaging at 0.55T using a spiral trajectory |
1National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States |
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Low field MRI combined with modern system engineering is attractive for high quality imaging with reduced production and operation costs. Moreover, there are potential clinical opportunities afforded by the reduced SAR and reduced local susceptibility. However, for a low field system to be clinically useful, neuroimaging must be feasible. Here we explore the potential of spiral neuroimaging at 0.55T to regain SNR that is sacrificed by moving to low field. We show that we can use a 30 ms spiral readout at 0.55T without the need for off-resonance correction and generate a 2.6x gain in SNR compared to Cartesian imaging protocols. |
| 1193 | 17:32
|
High-Performance Diffusion Imaging on a 0.5T System |
1Research and Development, Synaptive Medical, Toronto, ON, Canada |
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Diffusion imaging is a valuable tool in the identification of neurological diseases, especially in an acute setting. Large high-field systems can be challenging to site in an acute setting. Mid-field systems have various siting advantages but historically can suffer from sub-par imaging performance. In this work we compare diffusion weighted imaging performance on a 0.5 T system with a high-performance gradient system to a typical 1.5 T clinical scanner. We demonstrate the ability to achieve comparable imaging performance both analytically as well as through imaging examples. |
| 1194 | 17:36
|
Imaging at 0.5 T with high-performance system components |
1Research and Development, Synaptive Medical, Toronto, ON, Canada, 2Physics & Astronomy, University of Western Ontario, London, ON, Canada |
||
While the predominant MR market share is taken up with high-field systems (1.0T and above), there are benefits to imaging at mid-field. Mid-field systems can have a compact fringe field, low weight, compact design facilitating siting, low susceptibility-based geometric distortion and reduced RF heating with or without the presence of implants. Mid-field systems have historically been associated with sub-par image quality due to lower signal-to-noise behavior coupled with an absence of state-of-the-art hardware. Here we present a head-only, superconducting mid-field system designed with high-performance system components aimed at achieving comparable image quality to typical 1.5T systems in comparable scan times. |
| 1195 | 17:40
|
On the value of high-performance gradients for clinical MR imaging |
1Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany, 2Department of Radiology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany |
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High-performance imaging remains to be one of the hot topics in scientific and clinical development over the recent decades. High-performance gradients are also commonly believed to promise several good image quality and rapid acquisition times. In this project we question the hypothesis that strong gradient systems are advantageous for standard clinical imaging and diagnostics. More specifically we aim to analyse the impact of distinct reduced gradient performance parameters on imaging quality of stroke, cardiac and liver protocols compared to the state-of-the-art high-performance gradient systems at 1.5T, while keeping parameters and measurement time as close as possible. |
| 1196 | 17:44
|
Feasibility of brain pathology assessment with diffusion imaging on a portable scanner using a fixed encoding field |
1A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 2Harvard Medical School, Boston, MA, United States, 3Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States, 4A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 02129, MA, United States, 5Harvard Medical School, Cambridge, MA, United States |
||
Diffusion-weighted MRI is widely used for diagnosing brain pathology, but is typically not available close to the site of acute brain injury due to size, weight, power, and exclusion-zone constraints. Recently-developed lightweight brain scanners have achieved portability by using inhomogeneous B0 fields and by correcting for field imperfections during image reconstruction. Building on work done by the petroleum industry with single-sided borehole magnets, we use the built-in spatial encoding field of a portable brain scanner for both diffusion-encoding and spatial-encoding. We also introduce a method for using dummy refocusing pulses to vary the b-value without changing TEeff and T2-contrast. |
| 1197 | 17:48
|
Self-administered exam using Autonomous Magnetic Resonance Imaging (AMRI) |
1Electrical Engineering, New York University, New York, NY, United States, 2Columbia Magnetic Resonance Research Center, Columbia University, New York, NY, United States |
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Scanner density expressed as number of scanners per million people could be used to quantify access to MRI. Globally, scanner density distribution is heterogenous and shortage of skilled manpower to operate systems is one of the barriers in delivering MR. The imr-framework software library transforms a standard MR system into an autonomous scanner (“AMRI”). This work demonstrates self-administering an MR exam leveraging the AMRI implementation. Self-administered exams could alleviate some of the challenges associated with delivering MR imaging to financially constrained geographies. Current and future work involves deployment of AMRI in Kolkata, India. |
| 1198 | 17:52
|
How MRI as a Micro-Service Architecture can Accelerate Research and Commercialization |
1Engineering, Synaptive Medical, Toronto, ON, Canada, 2Research and Development, Synaptive Medical, Toronto, ON, Canada, 3System Test, Synaptive Medical, Toronto, ON, Canada |
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We have developed an MRI system having a modern micro-service style distributed software architecture, with the intent of building a flexible, sustainable platform. To describe the architecture, we provide two demonstrations: 1) fully scripted, perform a phantom experiment, extract the images, and upload them to a cloud server for analysis, and 2) update a protocol, append to the queue of scans to be acquired at the simplified operator console, all remotely from another user interface. Through these demonstrations and discussion of its current uses, we aim to illustrate how it could help accelerate collaborative research and commercialization efforts. |
17:56
|
Adjournment |
| 1199
|
16:00
|
The multi-centre iBEAt study: A comprehensive multi-parametric MR imaging biomarker panel for Diabetic Kidney Disease |
1Leeds Imaging Biomarkers Group, Biomedical Imaging Science Department, LICAMM, University of Leeds, Leeds, United Kingdom, 2Biomedical Imaging Science Department, LICAMM, University of Leeds, Leeds, United Kingdom, 3University of Leeds, Leeds, United Kingdom, 4University of Turku, Turku, Finland, 5Swiss Institute of Bioinformatics, Lausanne, Switzerland, 6Novo Nordisk, Bagsværd, Denmark, 7University of Exeter, Exeter, United Kingdom, 8University of Bari, Bari, Italy, 9Siemens Healthcare GmbH, Erlangen, Germany, 10University of Bordeaux, Bordeaux, France |
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There is a major clinical need for better biomarkers to identify Diabetic Kidney Disease (DKD) patients at risk of progression. iBEAt is a prospective multi-centre cohort study in 500 patients aiming to determine if MRI biomarkers can provide prediction of progression. We have developed a dedicated MRI biomarker panel for iBEAt interrogating body composition, renal morphology and tissue structure, hemodynamics and filtration. Here we present the details as well as example data and preliminary results on the ISMRM/NIST phantom, and on healthy volunteers. |
| 1200 | 16:12
|
Intravoxel-Incoherent-Motion Diffusion Weighted MR Imaging for Early Assessment of Graft Function in Kidney Transplant |
1Department of Education, Taichung Veterans General Hospital, Taichung, Taiwan, 2Department of Radiology, Taichung Veterans General Hospital, Taichung, Taiwan, 33Department of Electrical Engineering, National Chung Hsing University, Taichung, Taiwan, 4Division of Nephrology, Taichung Veterans General Hospital, Taichung, Taiwan, 5Division of Urology, Taichung Veterans General Hospital, Taichung, Taiwan |
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There are currently many different criteria for defining delayed graft function in patients with renal transplant, some of which require subjective decision-making, others require observation over time. We propose the intravoxel incoherent motion MR sequence as a method to acquire objective, sensitive biomarkers early after transplantation. The proposed method is shown to provide information of rapid-moving fluid in addition to conventional slow diffusion from the renal parenchema, and have the potential to assess the renal graft condition from both diffusion-based and perfusion-based view. |
| 1201 | 16:24
|
Lower ADC Values are Associated with Annual Loss of Renal Function in Individuals with Advanced CKD |
1Northwestern University, Chicago, IL, United States, 2NorthShore University HealthSystem, Evanston, IL, United States, 3NIDDK, Bethesda, MD, United States |
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We present data from a multi-center trial involving patients with advanced CKD (stage 3B & 4) with multiple etiologies. BOLD and Diffusion MRI data was acquired at baseline and repeated 1 year later. Renal function was monitored on a quarterly basis to evaluate progression. Our data show for the first time a strong association of ADC with annual loss of renal function. Further ADC values showed differences when individuals were stratified by diabetes and progression status. BOLD MRI did not demonstrate similar association. |
| 1202 | 16:36
|
Unbiased MRI Assessment of Renal Tubular Volume Fraction with Data-Driven IVIM |
1Max Delbrueck Center for Molecular Medicine, Berlin, Germany, 2Institute for Vegetative Physiology, Charité – Universitaetsmedizin Berlin, Berlin, Germany, 3Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany, 4Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany |
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T2* mapping does not fully represent renal tissue oxygenation. Tubular volume fraction changes should be considered to correct T2*. Diffusion weighted imaging provides information about in-vivo evaluation of water mobility which can be linked to three sources: tissue water diffusion, blood flow, and tubular flow. In this work we explore the feasibility of assessing tubular volume fraction changes using the non-negative least squares (NNLS) approach that is data-driven and requires no a priori knowledge |
| 1203 | 16:48
|
Fast hybrid IVIM-DK imaging in the kidney |
1Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan, 2Department of Urology, National Taiwan University Hospital, Taipei, Taiwan, 3Graduate Institute of Medical Device and Imaging, National Taiwan University, Taipei, Taiwan, 4Graduate Institute of Clinical Medicine, National Taiwan University, Taipei, Taiwan |
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The application of intravoxel incoherent motion (IVIM) and diffusion kurtosis (DK) MRI has been hindered largely by the long scan time required to sample over multiple b-values and/or diffusion-encoding directions. In this study, a novel method is described to expedite hybrid IVIM-DK imaging in the kidneys. Scan time is reduced by acquiring minimally-required non-zero b-values, while index calculation is made more time-efficient by using closed-form solution to replace nonlinear fitting. Experimental data demonstrated feasibility with b = 0/400/800/1600 s/mm2. Measurement variability was found greater among diffusion-encoding directions than between repeats, suggesting non-trivial structural anisotropy in the kidneys. |
| 1204 | 17:00
|
Renal multi-parametric MRI: Ready to launch? A reproducibility study |
1Radiology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands, 2Nephrology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands, 3Radiology, C.J. Gorter Center for high field MRI, Leiden University Medical Center, Leiden, Netherlands |
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Functional MRI of the kidneys is a promising tool for diagnosis, prognosis and treatment monitoring in kidney disease, but there is urgent need for technical validation of renal MRI parameters, including reproducibility. We performed repeated measurements of a multi-parametric renal MRI protocol, including oxygenation, diffusion, perfusion and relaxometry, in healthy volunteers at 3T. This allows for mutual comparison of parameters in terms of reproducibility. As a first step to large scale studies, we have determined reproducibility and shown feasibility of renal quantitative, multi-parametric MRI within a clinically acceptable scan time. |
| 1205 | 17:12
|
Recombinant expression and synthesis of a targeted human contrast agent for quantitative renal MRI |
1Biology, University of Hawaii at Manoa, Honolulu, HI, United States, 2Physics, University of Hawaii at Manoa, Honolulu, HI, United States, 3Martinos Center for Biomedical Imaging, Harvard University, Charlestown, MA, United States, 4Pediatrics, University of Virginia, Charlottesville, VA, United States, 5Bioengineering, University of Hawaii at Manoa, Honolulu, HI, United States, 6Washington University in St. Louis, Clayton, MO, United States |
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This study demonstrates the synthesis and use of a human recombinant cationic ferritin nanoparticle, synthesized in ecoli, as contrast agent for targeted renal imaging. Injected nanoparticles accumulated in the glomerular basement membrane in a mouse, allowing measurement of nephron endowment using gradient echo imaging and automated segmentation. Use of human recombinant contrast agents may allow improved biocompatibility for clinical translation. |
| 1206
|
17:24
|
Radiomic analysis of MRI in Clear Cell Renal Carcinoma: Non-invasive prediction of High Grade Histology |
1Radiology, UT Southwestern Medical Center, Dallas, TX, United States, 2Clinical Science, UT Southwestern Medical Center, Dallas, TX, United States, 3Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States, 4Urology, UT Southwestern Medical Center, Dallas, TX, United States, 5Pathology, UT Southwestern Medical Center, Dallas, TX, United States, 6Kidney Cancer Program, UT Southwestern Medical Center, Dallas, TX, United States |
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Clear cell RCC (ccRCC), the most common and aggressive subtype of kidney cancer is a very |
| 1207 | 17:36
|
Value of Whole-lesion MR T2WI Texture Analysis in Diagnosis of Renal Oncocytoma from Localized RCC Subtypes: Comparison with Characteristic Imaging Signs |
1Radiology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China, 2National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China |
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Accurate imaging diagnosis of renal oncocytomas remains a challenge for radiologists. Our study retrospectively collected MR imaging of 37 renal oncocytomas and 131 Stage I renal cell carcinoma, compared the diagnostic efficacy between whole-lesion MRI texture analysis and traditional imaging features. Tumor central scar or segmental enhancement inversion showed low sensitivity with high specificity. While whole-lesion MRI texture analysis showed better performance in diagnosis of renal oncocytomas, especially in differentiating oncocytomas with chrommphobe RCC. Whole-lesion MR T2WI texture analysis can be an applicable method in diagnosis of renal oncocytomas. |
| 1208 | 17:48
|
Non-Invasive Assessment of Intratumor Heterogeneity in Clear Cell Renal Cell Carcinoma using Quantitative MRI-Derived Texture Features |
1Radiology, UT Southwestern Medical Center, Dallas, TX, United States, 2Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States, 3Clinical Science, UT Southwestern Medical Center, Dallas, TX, United States, 4Pathology, UT Southwestern Medical Center, Dallas, TX, United States, 5Urology, UT Southwestern Medical Center, Dallas, TX, United States, 6Kidney Cancer Program, UT Southwestern Medical Center, Dallas, TX, United States, 7Internal Medicine, UT Southwestern Medical Center, Dallas, TX, United States |
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Intra and inter-tumor heterogeneity pose a challenging task for predicting tumor behavior due to the limited understanding of the molecular mechanism of clear cell renal cell carcinoma (ccRCC) development. The purpose of the present study was to correlate non-invasive quantitative measures of heterogeneity on MR imaging with histopathologic signatures of aggressiveness and gene expression heterogeneity in ccRCC. MRI derived Haralick texture features offer objective, quantitative measures of ccRCC aggressiveness, which can help compensate for the limitations of percutaneous biopsies in the tissue characterization of larger, heterogeneous tumors and assist in the implementation of active surveillance and neoadjuvant therapy protocols. |
| 1209
|
16:00
|
Multi-Vendor Validation of Controlled Saturation Magnetization Transfer (CSMT) for VFA T1 and T2 mapping |
1Centre for the Developing Brain,School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 2Biomedical Engineering Department, School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 3MR Research Collaborations, Siemens Healthcare Limited, Frimley, United Kingdom, 4Neuroimaging, King's College London, London, United Kingdom |
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White matter T1 values have been reported to range from 699ms-1735ms1. The recently introduced Controlled Saturation Magnetization Transfer (CSMT)2 qMRI approach suggests this might be due to MT effects. In this work employ the CSMT framework on 3 major MR manufacturers and demonstrate it allows a decrease in variability of T1/T2 estimation both in phantom and in-vivo. |
| 1210 | 16:12
|
Repeatability Measurements of Magnetic Resonance Fingerprinting Metrics using ACR and ISMRM/NIST Phantoms: A Multi-Center Study |
1Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, United States, 2Imago7 Foundation, Pisa, Italy, 3Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, United States, 4GE Healthcare, New York, NY, United States, 5Computer Science, Technical University of Munich, Munich, Germany, 6Global Research, GE Healthcare, Munich, Germany, 7GE Healthcare MR Workflow & Application Team, GE Healthcare, New York, NY, United States, 8Applied Physics and Applied Mathematics, Columbia University Medical Center, New York, NY, United States, 9Department of Radiology, Columbia University Medical Center, New York, NY, United States, 10Columbia Magnetic Resonance Research Program, Columbia University Medical Center, New York, NY, United States |
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Magnetic Resonance Fingerprinting (MRF) provides multiple quantitative imaging (QI) metrics within a single MR acquisition. The quantitative images must be standardized to generate MR protocols for acquisition of biomarkers. In this study both qualitative and quantitative repeatability experiments have been performed using ACR and ISMRM/NIST system phantoms at three collaborative centers (2 USA, 1 Europe) to evaluate imaging data consistency and the inherent reliability (Coefficient of Variation) of MRF. Results of both qualitative and quantitative study has shown reliability of MRF method. |
| 1211 | 16:24
|
Iron-Induced MR Contrast in Human Locus Coeruleus: A Cautionary Tale of Misleading Post Mortem MRI Results |
1Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, 2Neurocomputation and Neuroimaging Unit, Department of Education and Psychology, Free University Berlin, Berlin, Germany, 3Felix Bloch Institute for Solid State Physics, Faculty of Physics and Earth Sciences, Leipzig University, Leipzig, Germany, 4Berlin Joint EPR Lab, Institute for Nanospectroscopy, Helmholtz-Zentrum Berlin fuer Materialien und Energie, Berlin, Germany, 5Department of Systems Neurosciences, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, 6Integrative Model-Based Neuroscience Research Unit, University of Amsterdam, Amsterdam, Netherlands, 7Department of Anatomy and Embryology, Faculty of Health, Medicine and Life Science, Maastricht University, Maastricht, Netherlands, 8EPR Research Group, Max Planck Institute for Chemical Energy Conversion, Mülheim, Germany, 9Paul Flechsig Institute of Brain Research, Leipzig University, Leipzig, Germany |
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MR contrast mechanisms in human locus coeruleus were studied combining high-resolution post mortem MRI, histology, ion-beam microscopy, and electron paramagnetic resonance. We demonstrate that the main source of MR contrast in formalin fixed LC is paramagnetic iron accumulated in noradrinergic neurons. However, we show that MR contrast in LC drastically changes during the first six months of tissue fixation. We assign these changes to iron been scavenged by neuromelanin and the change of its paramagnetic state. The results have major consequences for MRI of the locus coeruleus, demonstrating a fundamental change rather than the commonly known gradual changes in contrast due to formalin fixation. |
| 1212
|
16:36
|
Longitudinal assessment of relaxation and magnetization transfer saturation rates during formalin fixation across fiber pathways of the human brain |
1Department of Systems Neurosciences, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, 2Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, 3Department of Legal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany |
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We longitudinally investigated the effect of brain tissue fixation, using 4% paraformaldehyde, on three potential quantitative myelin MRI markers across different white matter fiber pathways of the human brain: longitudinal (R1) and apparent transverse (R2*) relaxation rates and magnetization transfer (MT) using the quantitative multi-parameter mapping (MPM) protocol. To better understand the temporal evolution of the fixation process within the whole brain and its influence on MRI parameters, we monitored the temporal evolution of the fixation process of a whole human post-mortem brain using the same MPM protocol at 15 time-points (one unfixed, in-situ MRI scan and 14 ex-vivo MRI scans) at different stages of the fixation process (days 1-93). |
| 1213
|
16:48
|
A Biophysical Model of Iron-Induced Relaxation in Human Substantia Nigra for Early Stage Parkinson Diagnostic |
1Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, 2Faculty of Physics and Earth Sciences, Leipzig University, Leipzig, Germany, 3Paul Flechsig Institute of Brain Research, Leipzig, Germany, 4Center for Cognitive Neuroscience Berlin, Freie Universität Berlin, Berlin, Germany |
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We present a biophysical model that quantitatively describes gradient and spin echo relaxation in substantia nigra induced by iron accumulated the neuromelanin of dopaminergic neurons. This model was informed by 3D quantitative microscopic iron distributions obtained from classical histology and Proton-Induced X-ray Emission. It was validated by comparison to quantitative MRI on post mortem human brain tissue. We demonstrate that the total iron content of DN can be extracted analytically from relaxometry in nigrosomes. This results provides an important step toward a highly desired early stage biomarker for detecting dopaminergic neurons depletion in Parkinson's disease. |
| 1214 | 17:00
|
Image contrast at 0.55T |
1Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States, 2Systems Biology Center, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States, 3Laboratory of Functional Molecular Imaging, Division of Intramural Research, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States |
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In addition to having cost advantages, low-field MRI may offer new imaging opportunities by virtue of the physical attributes. Here we report T1, T2 and T2* tissue parameters and contrast agent relaxivities for a custom high performance 0.55T MRI system. We found that T1 was 29% shorter at 0.55T compared 1.5T, whereas T2 was lengthened by 33% and T2* was lengthened by 54% at 0.55T. Marketed small molecular weight gadolinium-based contrast agents demonstrate similar relaxivity at 0.55T and 1.5T, indicating similar dosing requirements, and larger molecular complex agents had increased T1 relaxivity at 0.55T, indicating potential advantages at low-field. |
| 1215
|
17:12
|
A totally balanced spin lock preparation module for accurate and artifact-free T1ρ-mapping |
1Department of Internal Medicine I, University Hospital Würzburg, Würzburg, Germany, 2Experimental Physics V, University of Würzburg, Würzburg, Germany, 3Comprehensive Heart Failure Center (CHFC), University Hospital Würzburg, Würzburg, Germany |
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To date, one of the main challenges of accurate and artifact-free T1ρ-mapping is the sensitivity of the required spin lock preparation module against field imperfections. Already established methods are sensitive to B0 and B1 field inhomogeneities. In this work, we present a novel spin lock preparation module that aims to be totally balanced, meaning that every pulse is being compensated by a correspondent pulse with opposite phase. Our new method proves to be highly robust to both types of field inhomogeneities. The superiority over common methods is demonstrated by Bloch simulations and measurements of a glucose phantom at 7.0T. |
| 1216 | 17:24
|
Free Breathing R2* Mapping Using Three-Dimensional Self-Gating Motion-Compensated Stack-of-Radial MRI |
1MR R&D Collaborations, Siemens Healthineers, Los Angeles, CA, United States, 2Department of Radiological Sciences, University of California Los Angeles, Los Angeles, CA, United States, 3Department of Physics and Biology in Medicine, University of California Los Angeles, Los Angeles, CA, United States, 4MR Application Predevelopment, Siemens Healthcare GmbH, Erlangen, Germany, 5MR R&D Collaborations, Siemens Healthineers, Baltimore, MD, United States, 6MR R&D Collaborations, Siemens Healthineers, Austin, TX, United States |
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R2* mapping is an emerging biomarker to evaluate iron overload. Due to its relative insensitivity to motion, free-breathing 3D stack-of-radial imaging is a useful technique in patient populations with breath-hold difficulties. However, its performance for R2* quantification is still under investigation. This study proposes a new 3D self-gating motion-compensated free-breathing stack-of-radial MRI method for R2* quantification. Preliminary in vivo results demonstrated good agreement of R2* mapping in the liver with the proposed method compared to the reference results of breath-hold Cartesian MRI. |
| 1217
|
17:36
|
Free-Breathing Water, Fat, and Iron Quantification in the Abdomen Using Radial Multi-Echo Acquisition and Respiratory-Resolved Model-Based Reconstruction |
1Pattern Recognition Lab, Department of Computer Science, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany, 2MR Application Predevelopment, Siemens Healthcare GmbH, Erlangen, Germany, 3Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, United States, 4Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, United States, 5MR R&D Collaborations, Siemens Medical Solutions, New York, NY, United States |
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A novel method for free-breathing fat/iron quantification with integrated R2* correction is presented, which is based on radial stack-of-stars 3D GRE acquisition with multiple echoes. An iterative model-based approach with TV as sparsifying transformation is used for the reconstruction. Results from full k-space data, retrospectively undersampled data, and motion-resolved processing are compared to a Cartesian reference technique in 5 clinical patients. The proposed method provides comparable results while eliminating the requirement to perform acquisitions during breath-holding, which poses a significant advantage for patients with reduced breath-hold capability such as pediatric, sick, or elderly patients. |
| 1218
|
17:48
|
Click Your Fat Away: Rapid Synthetic Knee MR Imaging with Switchable Fat and Magnetization-Transfer Contrast |
1Advanced Clinical Imaging Technology, Siemens Healthcare AG, Lausanne, Switzerland, 2Department of Radiology, University Hospital (CHUV), Lausanne, Switzerland, 3LTS5, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 4Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 5Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, Netherlands |
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Synthetic MRI is increasingly used in clinical practice to supplement or replace conventional MRI, due to the ability to generate both a multitude of MR images with weighted contrasts and quantitative T1, PD and T2 maps, which is of high interest in musculoskeletal imaging. To further broaden the application of synthetic image contrasts, we developed a method which allows switching between images with and without fat signal as well as magnetization-transfer weighting. The method includes three pulse sequences to estimate quantitative maps for the calculation of a variety of contrasts and requires a total acquisition time of 6:46 min. |
| 1219 | 16:00
|
Quantitative 129Xe MRI detects early impairment of gas-exchange in a rat model of pulmonary arterial hypertension |
1Biomedical Engineering, Duke University, Durham, NC, United States, 2Radiology, Duke University Medical Center, Durham, NC, United States, 3Department of Medicine, Duke University Medical Center, Durham, NC, United States |
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Hyperpolarized 129Xe MRI is capable of regional mapping of gas-exchange and has found application in a wide range of lung disorders. Here, we apply 129Xe gas exchange MRI and dynamic spectroscopy at 7 Tesla to study a rat model of pulmonary arterial hypertension. 129Xe spectroscopy and gas-exchange imaging showed reduced uptake by RBCs early in the progression of the disease, and at later time points was accompanied with increased uptake by barrier tissues, structural abnormalities, edema, and ventilation defects. Imaging results were compared to H&E histology, which showed evidence of vascular remodeling. |
| 1220 | 16:12
|
Retrospectively Gated UTE MRI with Deep-Learning Segmentation to Quantify Preclinical Lung Fibrosis Severity |
1Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, United States, 2Center for Pulmonary Imaging, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States, 3Molecular & Developmental Biology Graduate Program, Cincinnati, OH, United States, 4Division of Neonatology and Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States, 5Division of Pulmonary and Critical Care, University of Kansas Medical Center, Kansas City, KS, United States |
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Fibrosis contributes to morbidity and mortality in an array of pulmonary diseases, and no therapies exist to halt or reverse its progression. This paucity of treatment strategies results from poorly understood etiology, making it essential to develop animal models that fully mimic human disease and identify noninvasive, quantitative markers for fibrosis severity for use in animal models and patients. Here we report an image reconstruction and analysis pipeline, combining retrospectively gated ultrashort echo time (UTE) MRI and deep-learning segmentation to quantify lung fibrosis progression in Surfactant Protein C (SP-C) knock-in models based on mutations that predispose humans to lung fibrosis. |
| 1221
|
16:24
|
Dynamic BOLD Responses of Renal Tissues to interleaved Hypoxia and Hyperoxia in Healthy Rats as Measured by MRI at 7T |
1School of Biomedical Engineering, Guangdong Provincial Key Laborary of Medical Image Processing, Southern Medical University, Guang Zhou, China, 2Philips Healthcare, Guang Zhou, China, 3State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Nanfang Hospital, Southern Medical University, Guangzhou, China, Guang Zhou, China, 4Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong,Pokfulam,Hong Kong SAR,China, Hong Kong, China |
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Renal oxygen status is tightly correlated with renal (patho)physiology. How the renal oxygen is regulated in response to interleaved hypoxia and hyperoxia has not been well investigated. In this work we utilized dynamic BOLD MRI with temporal resolution of 9 seconds to track the renal tissues oxygen responses in healthy rats, thereafter, characterizing the renal oxygen changes by a mathematic model. In the experiment, significant T2* overshot was observed in outer medulla at the initial stage of re-oxygenation. Significant difference of model parameters compared among renal cortex, outer medulla and inner medulla was observed. |
| 1222 | 16:36
|
Spin-lock Relaxation Rate Dispersion Reveals Spatiotemporal Changes Associated with Tubulointerstitial Fibrosis in Murine Kidney |
1Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States, 2Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, TN, United States |
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Currently there are no reliable non-invasive means for assessing the severity and progression of fibrosis in kidneys. Here we evaluate spin-lock MR imaging with different locking fields for detecting progressive renal fibrosis in an hHB-EGFTg/Tg mouse model. We fit the dispersion of spin-lock relaxation rates R1ρ at different locking fields (frequencies) to a model of exchanging water pools and assessed the value of the derived quantities for detecting tubulointerstitial fibrosis in kidney, including the transverse relaxation rate (R2), the asymptotic value of R1ρ at high locking frequency (R1ρinf), an exchange rate-weighted parameter Sρ, and the inflection frequencies ωinfl in the dispersion. |
| 1223
|
16:48
|
Magnetization Transfer Imaging is Insensitive to Decrease in Renal Perfusion: A Graded Ischemia Study on Swine |
1Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, United States |
||
The impact of renal perfusion on magnetization transfer imaging (MTI) was evaluated on seven pigs that underwent consecutive MRI at baseline, 50%, 75%, and 100% acute renal artery stenosis as well as reperfusion. Renal perfusion, R2*, apparent diffusion coefficient (ADC), stiffness, and MT ratio (MTR) were measured. During graded ischemia, decline in renal perfusion was accompanied with elevated R2*, decreased ADC and stiffness. In contrast, no change was observed in the MTR. In conclusion, MTI is insensitive to decrease in renal perfusion and may offer a relatively reliable technique for measurement of renal structural changes. |
| 1224
|
17:00
|
Contrast-enhanced MRI reveals differential effects of afferent and efferent vagus nerve stimulation on gastric motility |
1Electrical and Computer Engineering, Purdue University, West Lafayette, IN, United States, 2Biomedical Engineering, Purdue University, West Lafayette, IN, United States, 3Psychological Sciences, Purdue University, West Lafayette, IN, United States |
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We used in vivo contrast-enhanced MRI to evaluate how vagus nerve stimulation (VNS) could modulate and coordinate the motility of the antrum and pylorus. We tested cervical VNS with different settings (afferent or efferent) and parameters (amplitude, duration, and frequency) and found differential effects on the motility. Our results suggest that selective stimulation of vagal afferent using a monophasic pulse train is a more effective strategy to facilitate and coordinate the antro-pyloric motility than selective stimulation of the vagal efferent. These results could shed lights on the selection of VNS settings for modulating gastric functions. |
| 1225 | 17:12
|
Fetal Hepatic Flow in Sheep Assessed using 4D flow MRI |
1Translational Medicine, The Hospital for Sick Children, Toronto, ON, Canada, 2Heart Centre, The Hospital for Sick Children, Toronto, ON, Canada, 3Faculty of Medicine, University of Toronto, Toronto, ON, Canada, 4Pharmacy and Medical Sciences, University of South Australia, Adelaide, Australia, 5Preclinical Imaging and Research Laboratories, South Australian Health and Medical Research Institute, Adelaide, Australia, 6Cardiology, The Hospital for Sick Children, Toronto, ON, Canada, 7Paediatrics, University of Toronto, Toronto, ON, Canada, 8Medical Biophysics, University of Toronto, Toronto, ON, Canada |
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Assessment of fetal hepatic flow poses difficult technical problems due to the small nature of vessels, slow blood flow within the liver, and sources of motion present in utero. Here, 4D flow MRI is coupled with specialized animal preparation to capture 3D fetal hepatic hemodynamics in a late gestation sheep model of human pregnancy. Full vasculature segmentation, fetal liver shunt visualization, and comprehensive measurement of hepatic circulation is demonstrated. |
| 1226 | 17:24
|
Metabolic Imaging of Pancreas in a High Fat Diet Fed Obese Rodent Model |
1Laboratory of Molecular Imaging, Singapore Bioimaging Consortium, Singapore, Singapore |
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Onset of hyperglycemia and lipotoxicity are associated with reduced β-cell mass and function compromising insulin secretion leading to insulin resistance. It is technically challenging to image pancreas in rodents by conventional imaging approaches. In this study we have utilized GdDOTA-diBPEN to image the pancreas in control and high fat diet (HFD) fed rat model. HFD fed rodent model shows increase in pancreatic fat and functional βcell volume during compensatory phase which is due to the adaptive response to HFD. Longitudinal assessment of pancreatic fat accumulation and βcell mass and function will provide better insights associated with β-cell dysfunction. |
| 1227 | 17:36
|
Multi-Parametric MRI of Liver Fibrosis and Treatment Response in a Rat Model of Nonalcoholic Steatohepatitis (NASH) |
1Athinoula A. Martinos Center for Biomedical Imaging, Institute for Innovation in Imaging (i3), Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, United States, 2Division of Surgical Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States |
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Noninvasive MR quantification of |
| 1228 | 17:48
|
Magnetic resonance temperature imaging in activated brown adipose tissue of rat |
1Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, GuangDong, China, 2University of Chinese Academy of Sciences, Beijing, China, 3Shenzhen Hospital of Guangzhou University of Chinese Medicine, Shenzhen, GuangDong, China |
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Brown adipose tissue (BAT) is a special adipose tissue which burns fat and dissipates energy in heat. As a result, it is considered to be the next potential therapeutic target for treating obesity and other metabolic diseases. The ability of heat dissipation of BAT is thought to be highly related to the BAT activity. In this study, we intended to use MR thermometry to map the temperature change distribution in BAT after activated by Norepinephrine. The preliminary results show the PRFS based thermometry can observe the temperature change in BAT after activation, implying that MR thermometry might be a useful tool to characterize the BAT activity. |
| 1229
|
16:00
|
Initial Clinical Evaluation of Quantitative Ultra-high Resolution First-pass Spiral Perfusion Imaging with Whole Heart Coverage in Patients with Ischemic Heart Disease at 3T |
1Medicine, University of Virginia, Charlottesville, VA, United States, 2Radiology, University of Virginia, Charlottesville, VA, United States, 3Biomedical Engineering, University of Virginia, Charlottesville, VA, United States |
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First-pass contrast-enhanced myocardial perfusion imaging is a useful noninvasive tool to evaluate patients with coronary artery disease, but current techniques are still limited in spatial-temporal resolution, ventricular coverage and absolute quantification which reduces the sensitivity to detect perfusion differences between the endocardium and epicardium and quantify ischemic burden. In this study, we designed a dual-density dual-contrast spiral pulse sequence to achieve quantitative ultra-high resolution first-pass spiral perfusion imaging with whole heart coverage at 3T and further tested in 9 patients with suspected CAD undergoing cardiac catheterization. |
| 1230 | 16:12
|
Rapid Automatic Quantification of Myocardial Blood Flow in Free-breathing Myocardial Perfusion MRI without the Need for Motion Correction: A Novel Spatio-temporal Deep Learning Approach |
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 2UCLA David Geffen School of Medicine, Los Angeles, CA, United States |
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It can be argued that the most significant technical impediment for wider clinical adoption of fully-quantitative cardiac perfusion MRI is the lack of a fully-automatic post-processing workflow across all scanner platforms. In this work, we present an initial proof-of-concept based on a deep-learning approach for quantification of myocardial blood flow that eliminates the need for motion correction, hence enabling a rapid and platform-independent post-processing framework. This is achieved by optimizing/training a cascade of deep convolutional neural networks to learn the common spatio-temporal features in a dynamic perfusion image series and use it to jointly detect the myocardial contours across all dynamic frames in the dataset. |
| 1231
|
16:24
|
On Probing Intravoxel Incoherent Motion in the Heart using Spin Echo versus Stimulated Echo Diffusion Weighted Imaging |
1Institute for Biomedical Engineering, ETH Zurich, Zurich, Switzerland |
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Intravoxel Incoherent Motion (IVIM) imaging in the heart remains challenging resulting in large variation of the perfusion surrogates in practice. In the present work, IVIM sensitivity of standard and motion-compensated Spin Echo (SE) and Stimulated Echo Acquisition Mode (STEAM) diffusion-weighted imaging approaches are analyzed using Monte Carlo simulations and perfused porcine heart experiments. An extended IVIM model is proposed to account for the microstructural properties of the myocardium. It is demonstrated that motion-compensated SE sequences provide insufficient perfusion sensitivity. In contrast, STEAM allows delineating hypoperfused myocardium using experimental imaging data. |
| 1232
|
16:36
|
Hierarchical Bayesian myocardial perfusion quantification |
1Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 2Philips Healthcare, Best, Netherlands, 3Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands |
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Myocardial perfusion can be quantified from dynamic contrast-enhanced MRI. This facilitates a non-invasive, automated, fast and user-independent evaluation of myocardial blood flow. However, due to the relatively low SNR, low temporal resolution and short scanning time the model fitting can yield unreliable parameter estimates. To counter-act this, simplified models and segmental averaging are used. In this work, Bayesian inference is employed. The inclusion of both spatial prior knowledge and prior knowledge of the kinetic parameters improves the reliability of the parameter estimation. This allows the generation of accurate high-resolution voxel-wise quantitative perfusion maps that clearly delineate areas of ischaemia. |
| 1233 | 16:48
|
Improving the accuracy of Blood Oxygen Level Dependent Imaging using FLASH normalised T2 prepared SSFP acquisition |
1Radcliffe Department of Medicine, Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, Oxfordshire, United Kingdom |
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T2-prepared |
| 1234
|
17:00
|
Whole heart ungated myocardial perfusion imaging with steady-state radial SMS readout and without magnetization preparation |
1UCAIR, University of Utah, Salt Lake City, UT, United States, 2Physics, University of Utah, Salt Lake City, UT, United States, 3Cardiovascular, University of Utah, Salt Lake City, UT, United States |
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Here we propose a framework for dynamic contrast enhanced myocardial perfusion MRI using an interleaved slice-group radial simultaneous multi-slice acquisition without magnetization preparation or ECG gating. The unique acquisition and reconstruction framework can provide 9 image slices with high spatial resolution cover the whole heart, and have comparable normal-ischemic tissue contrast with saturation recovery prepared radial readout, but is more efficient and robust. Also bright-blood cine images at the same slice positions can be reconstructed that can improve the cardiac MRI efficiency. |
| 1235
|
17:12
|
Compressed Sensing Accelerated Wideband Myocardial Perfusion Pulse Sequence for Patients with a Cardiac Implantable Electronic Device |
1Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States, 2Biomedical Engineering, Northwestern University, Evanston, IL, United States, 3Radiology, Mayo Clinic, Rochester, MN, United States, 4Cardiology, Internal Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States |
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We have recently developed a 2-fold accelerated wideband myocardial perfusion MRI pulse sequence using TGRPPA for imaging patients with a cardiac implantable electronic device (CIED). In patients with rapid heart rates and/or during stress, it may be necessary to further accelerate the perfusion scans to adequately sample the heart. This study describes a 5-fold accelerated wideband myocardial perfusion pulse sequence using compressed sensing and how repeatable it is for quantification of resting myocardial blood flow (MBF) measurement in patients with and without a CIED. |
| 1236
|
17:24
|
High-resolution quantification of myocardial perfusion using spatial correlations |
1Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany, 2King’s College London, School of Biomedical Engineering and Imaging Sciences, London, United Kingdom |
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Pixel-wise quantification of myocardial perfusion by dynamic contrast-enhanced magnetic resonance imaging allows for a non-invasive, observer independent and reproducible evaluation of the perfusion with high spatial resolution. The method suggested here, exploits the spatial smoothness of the perfusion using a spatial Tikhonov regularization to cope with the low signal-to-noise ratio of the data. This allows us to obtain quantitative perfusion values with high spatial resolution to detect small ischemic regions. The parameter regulating the strength of regularization is determined from the L-curve criterion and does not require any manual adjustments. The feasibility of the method is demonstrated in three patients. |
| 1237 | 17:36
|
Simultaneous 13N-Ammonia and gadolinium first-pass myocardial perfusion with hybrid PET-MR imaging: a clinical feasibility study. |
1Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 2Siemens Healthcare, Camberley, United Kingdom, 3National Heart, Lung and Blood Institute, Bethesda, MD, United States, 4Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom |
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Hybrid PET-MR imaging allows simultaneous measurement of myocardial blood flow (MBF) under identical physiological conditions. We sought to determine feasibility of simultaneous 13N-Ammonia PET and dynamic contrast-enhanced cardiovascular magnetic resonance (CMR) in healthy volunteers. 13N-Ammonia and gadolinium contrast were administered simultaneously during adenosine stress. Mean global stress MBF values for PET and CMR were 2.58 ± 0.11ml/g/min and 2.60 ± 0.47ml/g/min respectively. On a per territory basis, there was a moderate correlation (r = 0.63, p=0.03) and CMR underestimated PET MBF by 0.34ml/g/min (95% limits of agreement -0.49 to +1.18). Future studies in patients with CAD is warranted. |
| 1238 | 17:48
|
High-Resolution motion-corrected 2D Myocardial Perfusion MRI using Locally Low Rank and Wavelet Sparsity Constraints |
1Division MR Clinical Science, Philips, Best, Netherlands, 2Dept. of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands, 3Philips Health Systems, London, United Kingdom, 4School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 5Philips Healthcare, Guildford, United Kingdom, 6Philips Healthcare Iberia, Madrid, Spain, 7University of Leeds, Leeds, United Kingdom |
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First-pass perfusion cardiac MR (FPP-CMR) allows the assessment of ischemic heart disease. However, conventional FPP-CMR has limited spatial resolution and requires breath-holding. Moreover, diagnostic accuracy may be compromised due to dark-rim artifacts. Here, we propose a free-breathing quantitative high-resolution FPP-CMR framework that combines dynamically variable undersampling with a motion-corrected reconstruction approach that uses spatial and temporal constraints. The proposed motion-corrected strategy improves image sharpness and quantification of myocardial blood flow from free-breathing acquisitions. The highly undersampled acquisitions allow short acquisition windows and facilitate higher spatial resolution images, which are less sensitive to dark-rim artifacts, thus improving the diagnostic accuracy of FPP-CMR. |
| 1239 | 16:00
|
Investigation of blood flow causing pulsatile tinnitus in a patient-specific benchtop flow model |
1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, 2Neurology, University of California San Francisco, San Francisco, CA, United States |
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We created 3D printed patient-specific cerebral venous flow models of a patient with pulsatile tinnitus (PT) caused by idiopathic intracranial hypertension whose PT was resolved by CSF removal via lumbar puncture (LP). Prior to and almost immediately after the LP, she underwent MR imaging consisting of anatomic and flow evaluation sequences. Benchtop flow models were generated from both the pre and post LP data sets. We performed sound measurements and flow analysis of these models to identify flow features that correlate with sound production. Very similar features were seen both in vitro and in vivo in the pre-LP (PT) state that were absent in the post-LP (no PT) state. Patient-specific flow models may be an appropriate in vitro surrogate for venous causes of PT that could enable concrete determination of the links between geometry, blood flow, and PT. |
| 1240
|
16:12
|
Brain and head-and-neck MRI in immobilization masks: a novel and practical setup for radiotherapy |
1University Medical Center Utrecht, Utrecht, Netherlands, 2Utrecht University, Utrecht, Netherlands, 3University of Turin, Turin, Italy |
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For radiotherapy treatment planning, it is essential to perform the MRI/CT exams in treatment position. For this purpose, thermoplastic immobilization masks are used for brain and head-and-neck radiotherapy. However, since standard immobilization masks do not fit in the diagnostic MR head/neck coils, suboptimal surface-loop coils leading to poor image quality are used in clinical practice. Here, we present a new immobilization setup. This setup has several advantages compared to state-of-the-art setups: it fits in the diagnostic head/neck MR coils, it allows diagnostic image quality in treatment position, high SNR, homogenous signal, restricted motion (about 1 mm) and accurate inter-fraction repositioning. |
| 1241
|
16:24
|
A 12-channel flexible receive coil for accelerated tongue imaging |
1Department of Head and Neck Surery and Oncology, Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Amsterdam, Netherlands, 2Department of Radiology and Nuclear Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands, 3Department of Oral and Maxillofacial Surgery, Academic Centre for Dentistry Amsterdam and Academic Medical Center, Amsterdam, Netherlands, 4MR Coils BV, Zaltbommel, Netherlands, 5Department of Oral and Maxillofacial Surgery, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands, 6Department of Robotics and Mechatronics, MIRA Institute, University of Twente, Enschede, Netherlands, 7Biomedical Engineering and Physics, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands |
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Acceleration techniques necessary for real-time MRI of swallowing and diffusion imaging of the tongue require multiple coil elements and decrease SNR. Therefore, we designed a 12-channel flexible tongue coil with a higher density of elements compared to the conventional head and neck coil. The SNR in the tongue coil is better, while the G-factor is lower compared to the conventional coil. Real-time MRI displayed better image quality with fewer radial streaking artefacts using the tongue coil. A multiband-SENSE factor of 2 was feasible for diffusion-weighted imaging with the tongue coil. |
| 1242 | 16:36
|
Baseline Multiparametric Volumetric T2RT Histogram Analysis: Can It Be Used to Predict Therapy Response in Patients with Thyroid Associated Ophthalmopathy (TAO) Undergoing Intravenous Methylprednisolone |
1radiology, The Affliated Tongji Hospital, Tongji Medical College, Huazhong University of Science & Technology, WuHan, China, 2The Affliated Tongji Hospital, Tongji Medical College, Huazhong University of Science & Technology, WuHan, China |
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Prompt recognition the characteristics of extraocular muscles (EOMs) representing responding to intravenous methylprednisolone pulses (ivMP) is crucial for identifying optimal, patient-tailored treatment options in the era of personalized, precision medicine for thyroid-associated ophthalmopathy (TAO). This study attempts to predict the therapy response using the baseline histogram features of EOMs from volumetric T2 relaxion time (T2RT) texture analysis. Multivariate logistic regression analysis suggested that 90th and 95th percentile T2RT, skewness, entropy and inhomogeneity were significant predictors of ivMP response. Volumetric T2RT histogram analysis is a feasible and promising tool for predicting the response of ivMP therapy in patients with TAO. |
| 1243 | 16:48
|
Diffusion Weighted Imaging to differentiate human papillomavirus positive from human papilloma virus negative head and neck squamous cell carcinoma: how do b-values influence results? |
1Radiology department, Geneva University Hospital, Geneva, Switzerland |
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This study investigates whether and how the choice of b-values influences ADC ability to differentiate between human papillomavirus (HPV) positive (HPV+) from HPV negative (HPV-) head and neck squamous cell carcinoma (HNSCC) using quantitative histogram parameters of tumor ADC maps obtained with different combinations of b-values and with monoexponential and bi-exponential models (IVIM). Results show that ADC calculated with 2 b-values, b0 and b1000, are sufficient and that ADC calculated only with high b-values (combination excluding b0) are not able to differentiate both tumor types. |
| 1244 | 17:00
|
MRI-based radiomics nomogram in differentiating sinonasal mucosal melanoma from sinonasal lymphoma |
1EENT Hospital of Fudan University, Shanghai, China, 2East China Normal University, Shanghai, China, 3SIEMENS Healthcare, Diagnostic Imaging, Shanghai, China |
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Differentiating sinonasal mucosal melanoma (SNMM) from sinonasal lymphoma before surgery is important. However, it is a challenge to perform preoperative diagnosis through either histological biopsy or conventional MRI. In this study, an MRI-based individualized 3D nomogram through radiomics was constructed, and its value was explored in the differentiation between the two entities. The nomogram shows satisfactory efficiency in the diagnosis, and its performance was better than that of human radiologists. This study demonstrates that noninvasive MRI-based radiomics could be helpful in the preoperative differentiation of SNMM from sinonasal lymphoma. |
| 1245 | 17:12
|
Differentiation of Malignant and Benign Parotid Tumors with Amide Proton Transfer-Weighted MR Imaging |
1Peking Union Medical College Hospital, Beijing, China, 2Philips Healthcare, Beijing, China |
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This retrospective study evaluated the diagnostic efficacy of diffusion-weighted imaging (DWI) and amide proton transfer-weighted (APTw), for differentiating between malignant, pleomophic adenomas and Warthin’s tumours. APTw imaging can differentiate Warthin’s tumors and malignant tumors of parotid. ADC can differentiate Warthin’s tumors and pleomorphic adenomas. APT combined with ADC had the better performance to differentiate the three common kinds of parotid tumours. |
| 1246
|
17:24
|
Detection of malignant parotid gland tumors using multi-modality MRI and deep learning: diffusion versus T1 contrast-enhanced imaging |
1National Taiwan University of Science and Technology, Taipei, Taiwan, 2Chinese Medical University Hsinchu Hospital, Hsinchu, Taiwan, 3Feng Chia University, Taichung, Taiwan |
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The study presents an automatic recognition method for parotid gland tumor. We used a convolution neural network to conduct the segmentation of parotid gland tumor and classifications of tumor types. We also designed eight combinations of various MRI contrasts to compare the results of recognition for parotid gland tumor. We compared results obtained using various combinations of MR images as the input of the convolutional neural network and found that diffusion-related parameters and contrast-enhanced T1 images played the primary role of the prediction accuracy. |
| 1247
|
17:36
|
Probabilistic structural atlas of human lateral parabrachial nucleus, medial parabrachial nucleus and vestibular nuclei complex using in vivo 7 Tesla MRI. |
1Brainstem Imaging Lab, Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, United States, 2Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy, 3Centre of Space BioMedicine, University of Rome Tor Vergata, Rome, Italy, 4Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN, United States, 5Department of Otorhinolaryngology - Head and Neck Surgery, Mayo Clinic, Rochester, MN, United States |
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Parabrachial and vestibular nuclei are anatomically and functionally connected brainstem gray-matter structures involved in autonomic and vestibular functions. Their assessment in research and clinical investigations is difficult due to limited image-resolution/contrast of clinical scanners and the absence of probabilistic atlas of these structures. We delineated these nuclei in single-subject multi-contrast 1.1mm-resolution 7Tesla MRI of healthy humans and generated a validated in-vivo probabilistic atlas of these nuclei in stereotaxic space. Upon coregistration to clinical-MRI, this atlas might improve the evaluation of lesions and assessment of connectivity-pathways underlying autonomic and vestibular mechanisms in a broad-set of clinical conditions relating to these nuclei. |
| 1248 | 17:48
|
Nasopharyngeal Irradiation can Increase Signal Intensity on T1-Weighted MRI of the Dentate Nucleus in Patients with Nasopharyngeal Malignancies |
1Department of radiology, Rui Jin Hospital, Shanghai, China, 2Department of radiology, Wayne State University, Detroit, MI, United States |
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Patients with nasopharyngeal malignancies (NPM) are generally treated by nasopharyngeal irradiation. In order to evaluate curative effect, gadolinium-based contrast agents (GBCAs)-based MRI examinations are always performed repeatedly. Whether the nasopharyngeal irradiation affects the T1 signal intensity (SI) in DN remains unclear. 68 NPM patients and 68 suitable control patients were enrolled. We found that the uptake rate of gadolinium from the NPM was significantly higher than that from control patients. We speculated that the nasopharyngeal irradiation increases the T1 SI by the damage to the blood–brain barrier (BBB). |
| 1249 | 16:00
|
Multi-Channel Image Reconstruction with Latent Coils and Adversarial Loss |
1Radiology, Stanford University, Stanford, CA, United States, 2Electrical Engineering, Stanford University, Stanford, CA, United States |
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Model-based accelerated imaging techniques enable high scan time reductions while maintaining high image quality. These techniques rely on the ability to accurately estimate the imaging model. This model can be extended to include information beyond physical limits, such as high-resolution phase information to promote conjugate symmetry or information of voxels without signal for a stronger image prior. Thus, we propose a deep learning approach to estimate the imaging model with latent coil maps. Furthermore, we jointly train this latent map estimator with a deep-learning-based reconstruction using adversarial loss, and we demonstrate the effectiveness of this approach in volumetric knee datasets. |
| 1250 | 16:12
|
Robust high-quality multi-shot EPI with low-rank prior and machine learning |
1Martinos Center for Biomedical Imaging, Charlestown, MA, United States, 2National Nanotechnology Center, Pathum Thani, Thailand, 3Siemens Healthcare, Erlangen, Germany, 4Siemens Healthcare, Charlestown, MA, United States, 5Department of Electrical Engineering, Stanford University, Stanford, CA, United States |
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We introduce acquisition and reconstruction strategies for robust, high-quality multi-shot EPI (msEPI) without phase navigators. We extend the MUSSELS low-rank constrained parallel imaging technique to perform Virtual Coil (VC) reconstruction, and demonstrate diffusion imaging with sub-millimeter in-plane resolution using 55% partial-Fourier (PF) sampling. We propose Blip Up-Down Acquisition (BUDA) using interleaved blip-up and -down phase encoding, and incorporate B0 forward-modeling into MUSSELS to enable distortion- and navigator-free msEPI. We improve the acquisition efficiency by developing Simultaneous MultiSlice (SMS-)MUSSELS, and combine it with machine learning (ML) to provide Rtotal=16-fold acceleration with 3-shots. Deploying this in a spin-and-gradient-echo (SAGE) scan with signal modeling allows for whole-brain T2 and T2* mapping with high geometric fidelity in 12.5 seconds. |
| 1251 | 16:24
|
Multicontrast Distortion-free MRI Using PSF-EPI |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, 2Philips Healthcare, Beijing, China, 3School of Computer Science and Technology, Beijing Institute of Technology, Beijing, China, 4A. A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, United States, 5Harvard-MIT Health Sciences and Technology, MIT, Cambridge, MA, United States, 6Vascular Imaging Laboratory, Department of Radiology, University of Washington, Seattle, WA, United States |
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Fast multimodal exams are required in many situations such as acute ischemic stroke and brain trauma. Recently a multicontrast full brain protocol was proposed based on single shot echo-planar imaging (SS-EPI). However, the SS-EPI images suffer from distortion artifacts. In this work, we provide a speedy multi-contrast distortion-free imaging protocol including T2w, DWI, T2*w, T1 FLAIR and T2 FLAIR based on point spread function encoded echo-planar imaging (PSF-EPI). |
| 1252
|
16:36
|
Pushing fMRI spatial and temporal resolution further: high density receive arrays combined with shot-selective 2D CAIPIRINHA for 3D EPI scans at 7T |
1Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 2Department of Radiotherapy, University Medical Center Utrecht, Utrecht, Netherlands, 3Department of Neuroscience, University of Turin, Turin, Italy, 4Philips Healthcare, Best, Netherlands |
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There is an overall drive to high resolution brain MRI with a short scan time. In this study, it was investigated whether 3D EPI fMRI scans acquired with high density receive arrays, can still benefit from a CAIPI sampling pattern, in terms of (temporal) SNR. A 2D CAIPIRINHA acceleration scheme for multi-shot 3D EPI scans was implemented. When combining this implementation with high density receive coil arrays at 7T, it allowed substantial reduction of the scan time for sub-millimeter fMRI scans of the visual cortex. |
| 1253
|
16:48
|
Dictionary-Based Oscillating Steady State fMRI Reconstruction |
1Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, United States, 2Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States |
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Oscillating steady state (OSS) imaging is a new fMRI acquisition method that substantially improves SNR by exploiting a large and oscillating signal. However, the oscillation nature of the signal leads to an increased number of acquisitions. To improve the temporal resolution and address the nonlinearity of the OSS signal, we propose a novel dictionary-based regularization method for OSS reconstruction to reconstruct dramatically undersampled (e.g. R = 12) data. The proposed method leads to better image quality than CG-SENSE and does not require any temporal filtering like low-rank methods, therefore the undersampling directly leads to an improved fMRI temporal resolution. The high SNR advantage of OSS is also well preserved. |
| 1254
|
17:00
|
Compressed-sensing 1mm-isotropic 3D Whole-Heart Water/Fat Coronary MR Angiography in ~10 minutes |
1School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, 2Cardiovascular MR Predevelopment, Siemens Healthcare GmbH, Erlangen, Germany, 3MR Research Collaborations, Siemens Healthcare GmbH, Frimley, United Kingdom |
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Prolonged acquisition time and robust fat suppression remain a challenge for coronary MR angiography. Here we present a highly efficient undersampled whole-heart water/fat CMRA acquisition and reconstruction approach, for improved fat suppression at 3Twithin an overall short scan time. The proposed approach is integrated with 2D translational motion correction, to enable 100% respiratory scan efficiency, which in combination with an undersampled acquisition trajectory allows the acquisition of high-resolution water/fat datasets in ~10 minutes. The feasibility of the proposed approach was tested in healthy subjects, and results show improved depiction of the coronary arteries compared to conventional fat suppression. |
| 1255 | 17:12
|
Multi-Regularization Reconstruction of One-Dimensional $$$ T_2$$$ Distributions |
1Department of Mathematical Sciences, Uiversity of Delaware, Newark, DE, United States, 2National Institute on Aging, National Institutes of Health, Baltimore, MD, United States |
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Tikhonov regularization and related methods are widely used in recovering relaxation time distributions in magnetic resonance relaxometry. Regularization optimization methods such as the L-curve and generalized cross-validation (GCV) identify a single optimized solution as the best approximation to the underlying distribution. In contrast, we propose a new reconstruction method, Multi-Reg, incorporating a range of regularized solutions. Multi-Reg is based on a dictionary of noise-corrupted regularized reconstructions of distribution basis functions. We demonstrate that Multi-Reg can out-perform L-curve or GCV analyses in simulation analyses of Gaussian distribution components, and with experimental results on mouse spinal cord and human muscle. |
| 1256
|
17:24
|
High-resolution Isotropic Whole Brain T2 Mapping with Model-based Super-resolution Reconstruction |
1School of Engineering, Institute for Digital Communications,University of Edinburgh, Edinburgh, United Kingdom, 2Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom, 3Advanced Clinical Imaging Technology, Siemens Healthcare AG, Lausanne, Switzerland, 4LTS5, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 5Department of Radiology, University Hospital Lausanne (CHUV), Lausanne, Switzerland, 6Computer Science Department, University of Bath, Bath, United Kingdom |
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We propose a method to reconstruct 1-mm3 isotropic T2 maps based on multiple 2D multi-echo spin-echo (MESE) acquisitions. To compensate for the prolonged scan time due to multiple acquisitions, data were highly (10-fold) undersampled. The data was reconstructed by combining a classical super-resolution approach with an iterative model-based reconstruction. The method was tested on a phantom and four healthy volunteers. T2 values were compared against fully sampled MESE data. The proposed technique allows the assessment of T2 values in brain structures at high isotropic resolution. |
| 1257 | 17:36
|
Efficient Intravoxel B0 Inhomogeneity Corrected Reconstruction of Multi-Gradient-Echo Images Using A Low-Rank Encoding Operator |
1Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 2Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States |
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Intravoxel macroscopic B0 field inhomogeneity is common source for image artifacts, and can cause significant errors in quantitative analysis of the imaging data, particularly for gradient-echo-based acquisitions. This work presents a new method for intravoxel B0 inhomogeneity corrected reconstruction. Specifically, we derived a signal model that incorporates intravoxel B0 variations, and introduced a low-rank approximation to the encoding operator. This approximation allows for very efficient computation of the forward model, which can be integrated into any regularized reconstruction formulation. Effective correction for multi-gradient-echo data were demonstrated. We expect the proposed method to be useful for a range of applications involving T2* contrast. |
| 1258 | 17:48
|
Implementation of an MRI Reconstruction Framework with a System-Integrated Acquisition Database |
1Research and Development, Synaptive Medical, Toronto, ON, Canada |
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A reconstruction framework is introduced that adds an acquisition database between the system receive chain and the reconstruction processors. This additional system service opens up a number of dataflow possibilities. The framework is demonstrated on a mid-field superconducting head-only MRI system by simultaneously running three reconstruction programs on the system reconstruction platform and comparing the resulting images. |
16:00
|
Iron in the Alzheimer’s Brain: Characterization by Electron Paramagnetic Resonance | |
| TBD |
16:30
|
Pathologic Bases of Imaging Changes in Dementia | |
17:00
|
Preclinical Functional Neuroscience Techniques: Potentials for Alzheimer’s Disease | |
1UCL, London, United Kingdom |
17:30
|
From Mice to Men: Imaging Molecules & Function in Dementia With Novel Probes | |
16:00
|
Psychoradiology in Clinical Practice | |
1University of Amsterdam's Faculty of Medicine, Amsterdam, Netherlands |
16:20
|
Psychoradiology of Schizophrenia | |
16:40
|
Distinct & Shared Abnormalities in Structural MRI Across Psychiatric Disorders | |
17:00
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Prediction of Mental Illness at the Individual Level Based on Resting-State Brain Connectivity | |
1New Jersey Institute of Technology, Newark, New Jersey, United States |
17:20
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Brain Connectivity Signatures for Early Dementia | |
17:40
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Neuroimaging as a Biomarker for Mental Illness & Monitoring Treatment Response | |
1MGH Martinos, United States |
| 18:15 | Predict – Then Act! Moving Towards Tailored Prevention |
1University Aachen, RWTH, Germany |