MRI relies on detecting signals in the radiofrequency range that are related to very small energy transitions of the spin ensemble. While this is a blessing with regard to the harmless character of the radiation, it imposes a serious problem in terms of the low sensitivity caused by almost vanishing spin polarization at ambient temperatures. Increasing the sensitivity through artificial enhancement of the net magnetization relies on so-called hyperpolarized agents for NMR and MRI. Hyperpolarization is a powerful technique that has enabled many varied applications for molecular and cellular imaging. This tutorial will summarize the methods of hyperpolarization, probe design and optimized signal encoding.

Highlights ·        Use of MRI for rectal carcinoma staging and learn the clinical and therapeutic implications of rectal carcinoma  

Target Audience: Radiologists and MRI technicians.

Objectives: Understand the anatomical and pathological basis for MRI rectal carcinoma staging and its impact on therapeutic options.

Methods: Basic anatomy and pathology of rectal carcinoma will be introduced followed by case examples.       

Results: Participants will be able to understand the important anatomical and pathological MRI findings in rectal carcinoma.

· Basic understanding of how an MRI works can be achieved by comprehending its major functional subsystems.

· The subsystem currently experiencing the greatest innovation is RF transmission.

· Software defines the look and feel of the system and is the most important differentiator between systems.

·              EPI favors high bandwidth acquisitions to reduce susceptibility artifacts.

·              fMRI acquisition methods critically depend on the targeted spatiotemporal resolution.

·              The spatiotemporal resolution of fMRI can be optimized by a combination of k-space trajectory design, receiver coil array, and reconstruction algorithm.

·              Sequences using spin-echo or gradient-echo, the echo time, and the flip angle can tune the sensitivity of fMRI acquisitions.

·              Physiological noise is a dominant noise source in high-field fMRI experiments.

·              Care must be taken to get the best shimming and to minimize motion as well as acoustic noise/vibration.

Both contrast enhanced (CE) and non-contrast enhanced (NCE) MRA techniques are introduced. In CE-MRA, developing trends including bolus timing estimation, temporal and spatial resolution improvement, and low dose gadolinium (Gd) MRA are revisited. In NCE-MRA, recent developments, including inflow, flow-dependent, and spin labeling techniques are introduced. Clinical applications of these NCE-MRA techniques are also demonstrated.

The purpose of this presentation is to provide an overview of the possibilities and restrictions of todays MARS MR imaging techniques in patients after total knee replacement. After following this presentation, the learners will understand the major clinical problems faced by orthopedists after total knee replacement, how MR imaging can contribute in these situations and where the limitations of today’s technical possibilities are in a clinical setting.

Highlights: RF coils are an essential part of a MRI system to excite and receive MR signals. Their performance is very important for the quality of MR imaging.

· Volume coils provide relatively uniform sensitivity over a large volume.

· Surface coils are designed to maximize SNR and enable parallel imaging

· Volume coils and surface coils usually work together in the RF system to optimize the RF excitation and reception performances at the same time

· Decoupling technologies are needed in the design to minimize coupling between transmit and receive coil elements

Transmit arrays enable finer RF driving over the RF field distribution in exciting the MR signals.

In this session the following issues will be introduced.

- Transmit Arrays

- Decoupling and Matching/Tuning Techniques for Multi-element coil

- Individually Driven Coil Element

- SAR and Tissue Heating

Many methods have been proposed to address the spatio-temporal resolution tradeoff in MRI. Compressed sensing (CS) is the latest among these and holds great promise. This talk covers the basics of compressed sensing reconstruction and also touches on more advanced CS methods that incorporate parallel imaging and redundant coil information.

what happens to old when I type new

yup

In this talk, we will discuss the following aspects regarding ASL – Data acquisition.

A.     Basic principles

B.     Labeling schemes

        1.     Pulsed ASL

                a)     STAR and variants

                b)     FAIR and variants

        2.     Continuous ASL

        3.     Velocity selective ASL

C.    Background suppression

D.    Readout options

E.     Advanced methods to combine ASL with other measurements

·       The brain has a uniquely high oxygen metabolic demand, and the ability to noninvasively image brain oxygenation is critical to understand normal brain function and many cerebrovascular and neurological disorders.

·       Three classes of MRI contrast mechanisms to image oxygenation have been explored, including (1) extravascular blood oxygenation level dependent (BOLD); (2) intravascular T2-relaxation; and (3) magnetic susceptibility in cerebral veins. These methods have different abilities to localize regional oxygenation and different strengths and weaknesses.

·       Because MRI methods to image oxygenation are fairly new, additional studies are needed to validate oxygenation measurements with each other, and with the PET reference standard. Promising clinical studies in patients highlight the promise of MRI oxygenation imaging and will benefit from optimized and robust protocols to quantify oxygen metabolism.