Keywords: Bone, Head & Neck/ENT, craniosynostosis, skull, ultrashort echo time, dual-echo

Motivation: Reduction of ionizing radiation for repeat CT imaging of pediatric patients with craniosynostosis.

Goal(s): Develop an MRI method for rapid, high-resolution skull imaging with CT-like contrast. 

Approach: A dual-echo UTE sequence acquires 2 image echoes (proton density-weighted and T₁-weighted) in 3 minutes at a voxel size of 0.65x0.65x0.65 mm. A new joint ℓ₀-wavelet regularizer and an improved method for calculating the third image with CT-like contrast are developed.

Results: In 3 minutes of scan time, 3 co-registered high-resolution images with 3 different contrasts are simultaneously acquired. Image quality is not hindered by the aggressive acceleration factor. Short-T₂ specific images strongly resemble CT images.

Impact: We present a bone-specific dual-echo UTE MRI method that facilitates unimodal, single-session radiology for pediatric patients with craniosynostosis. The method does not involve ionizing radiation and may reduce the lifetime risk of cancer for patients indicated for repeat CT scans.

Keywords: Skeletal, Quantitative Imaging, Musculoskeletal

Motivation: The development of ankylosing spondylitis(AS) is associated with alterations in bone marrow microenvironment.

Goal(s): To quantitatively analyze changes and correlations of the lumbar and sacroiliac joints bone marrow microenvironment in AS using MRI mDixon-Quant. 

Approach:  Fat fraction (FF) and T2* were measured in the lumbar, bone marrow edema (BME), fat metaplasia (FM) of sacroiliac joints. 

Results: FF value in the lumbar of the AS group demonstrated a significant increase compared to the normal control group, positively correlating with FF value in FM of sacroiliac joints. FF and T2* showed significant differences between BME and FM in sacroiliac joints.

Impact: FF and T2* values help to quantitatively analyze variations in the bone marrow microenvironment of lumbar and sacroiliac joints in AS, providing MRI evidence for the mechanism of osteoporosis in AS, while also guiding clinical treatment for inflammation-associated osteopenia.

Keywords: Bone, Bone, Fat

Motivation: The relationship between vertebral bone mineral density (BMD) and fat composition of adjacent vertebral body and paraspinal muscle in patients with low back pain (LBP) remains unclear.

Goal(s): To investigate the association between vertebral BMD and the fat fractions of vertebral bone marrow and paraspinal muscle in LBP patients.

Approach: A retrospective study was conducted on LBP patients who underwent both quantitative computed tomography (QCT) and chemical shift-encoded MRI examinations.

Results: Age, fat fractions of bone marrow and psoas major are independent factors that influence vertebral bone mineral density.

Impact: The fat fraction of vertebral bone marrow and paraspinal muscles independently influences bone mineral density. The MR-based fat fractions may potentially predict osteoporosis and osteoporotic fractures without radiation, providing a safer way to diagnose osteoporotic vertebral fractures and associated complications.

Keywords: Vascular, DSC & DCE Perfusion

Motivation: By investigating changes in bone marrow microvascular permeability and bone microstructure, we can explore the key pathological and physiological mechanisms underlying impaired vascular repair in diabetes

Goal(s): To assess the functional changes in endothelial progenitor cells (EPCs) and alterations in bone microstructure in rabbits with severe limb ischemia complicated by diabetes mellitus using DCE-MRI and micro Micro-CT

Approach: 30 healthy male New Zealand white rabbits  underwent sagittal MR imaging of the femoral bone proximal coronal plane at fixed time points

Results: DCE-MRI combined with Micro-CT quantitative parameters is feasible to evaluate endothelial progenitor cell function and changes in bone microstructure in diabetes mellitus

Impact: The results of this study will provide a new perspective on the pathological and physiological mechanisms underlying bone marrow changes in diabetic patients with concurrent critical limb ischemia.

Keywords: Bone, Bone, ZTE long-T2 subspace

Motivation: Recent work has shown that achieving CT-like contrast highlighting bone can be obtained either indirectly through contrast inversion or directly through long-T2 suppression. While direct methods offer advantages, existing techniques are inefficient, resulting in long scan times.

Goal(s): To create an efficient long-T2 suppressed bone imaging MR scan.

Approach: We combined inversion recovery long-T2 suppression in a Zero Echo-Time sequence with subspace reconstruction to allow continuous data collection during the scan, eliminating dead time and improving efficiency.

Results: A two minute silent scan that produces bright bone and suppressed soft tissues

Impact: We have created a fast positive contrast bone MRI scan that has potential as an alternative to CT

Keywords: Skeletal, Bone

Motivation: Visualizing cortical bone with short T2 value is challenging since long-T2 tissues and fat usually obscure it. 

Goal(s): This study develops a new long-T2- and lipidic tissue-suppressed sequence with silent acoustic noise to improve patient scanning comfort. 

Approach: We use an AFP inversion RF with controlled timing to maintain the long-T2 components at a low level and optimize the sequence parameters to null the fat signal. 

Results: We apply the PETRA to reduce the SPL to only 1.9 dBA higher than the background. The head cortical bone structure can be successfully visualized with positive contrast.

Impact: The designed silent long-T2 tissue-suppressed PETRA sequence can be potentially useful for investigating the newborns bone development, which can decrease neonatal hearing injury risks and might be helpful for early-age skeletal maturation assessment.  

Keywords: Bone, Bone, Deep Learning reconstruction

Motivation: Bone MRI using ZTE has the potential to provide clinically relevant information on mineral bone but its routine use remains limited by its low SNR and chemical shift artifacts especially at 3.0T

Goal(s): We evaluated the impact of a deep learning reconstructions for ZTE which performs denoising, improves resolution and minimizes chemical shift artifacts (DLCSC).

Approach: ZTE sequences prospectively obtained in 10 patients were reconstructed with the DLCSC algorithm. Native and processed images were compared for their performance to detect bone lesions, taking CT as gold standard.

Results: DLCSC increased image quality and significantly improved bone lesion detection compared to native ZTE images.

Impact: DLCSC reconstruction overcomes the pitfalls of the ZTE sequence (low SNR and chemical shift artifacts) and improves its diagnostic performance. A complete study of the skeleton, including mineral bone assessment, becomes possible within a single MRI examination.

Keywords: Bone, Bone, Ultra High Field, 7T, knee, bone marrow, pTx RF pulse, spatial-spectral RF pulse design, water excitation, fat supression

Motivation: To make knee bone marrow arterial spin labeling (ASL) imaging a viable and clinically practical approach.

Goal(s): To increase knee bone marrow ASL imaging signal-to-noise efficiency and quality by using parallel transmit spatial-spectral localized water excitation pulses for ASL image readouts.

Approach: Spatial-spectral water excitation pulses inside a 2D arbitrarily-shaped region of interest were designed and validated in a knee phantom and healthy volunteers using an 8-channel transceiver knee coil.

Results: The designed spatial-spectral pulses could produce localized water excitation inside targeted regions with effective fat suppression.

Impact: The validated pulse design provides an effective way for localized water excitation and eliminate the need for additional fat saturation with reduced RF power deposition, having a great potential to improve knee ASL imaging efficiency at ultrahigh field.

Keywords: Bone, Bone, Plug-and-Play Denoiser, IR-UTE, AI and Machine Learning

Motivation: (IR-)UTE MRI enables (quantitative) investigation of bony tissue. Imaging protocols, however, are still time consuming. 

Goal(s): To develop a reconstruction method, which can transfer undersampled / accelerated IR-UTE scans of bone into high quality images.

Approach: A thresholded Landweber algorithm was implemented, which uses both an L1-sparsity model and a pre-trained denoising convolutional network as regularizers of the physical MR model.

Results: The reconstruction method was capable of delivering superior image quality compared to reconstructions based on straightforward NUFFT or iterative SENSE, especially in the case of significant undersampling.

Impact: IR-UTE imaging accelerated by our proposed reconstruction based on L1-sparsity and a pre-trained denoising convolutional neural network shortens investigations by a factor of up to five, thereby facilitating further research on the topic as well as clinical transfer.

Keywords: Functional/Dynamic, Visualization, kinematic, real-time

Motivation: Joint Maltracking or improper loading cannot be assessed with conventional, static MRI.

Goal(s): Demonstrate the feasibility of using images without motion to de-noise and segment real-time 4D images and generate 4D moving models.

Approach: In 31 subjects, a fully sampled image and many highly-undersampled images reconstructed from the same data acquired without motion are used to train a neural network to generate artifact-free images and bone segmentations for images acquired with motion.

Results: The resulting real-time images are recognizable however more work is needed to improve the reliability of the segmentation, especially in cases of large-scale or fast motion.

Impact: Deep learning based de-noising and segmentation of real-time 3D kinematic MR imaging make it possible to model knee kinematics and open the doors for the study of the knee in motion and under load for improved identification of pain generators.

Keywords: Bone, MR Value

Motivation: The relationship between vertebral bone marrow T2* value and bone mineral density (BMD) has been rarely reported and remains controversial.

Goal(s): The study aimed to analyze the correlation between T2* and BMD and evaluate the efficacy of T2* in diagnosing osteoporosis. 

Approach: The IDEAL IQ MR Sequence was used to measure vertebral bone marrow T2* and quantitative computed tomography (QCT) was used to measure BMD. 

Results: Vertebral T2* was negatively correlated with BMD. While T2* can serve as a supplementary indicator for diagnosing osteoporosis, it should not be relied upon as the sole diagnostic indicator.

Impact: MRI-based T2* value provides a safer way for quantitative assessment of OP, and may be used as a complement to BMD to improve the accuracy of early diagnosis of OP.

Keywords: Bone, Relaxometry

Motivation: Denoising algorithms may significantly improve the SNR of relaxation time maps of the bone and cartilage. 

Goal(s): To compare the performance of T-NORDIC and MPPCA denoising techniques for 3D T2 mapping of the femoral head.

Approach: 3D T2 maps of the femoral heads from 12 piglets imaged at 3T MRI were denoised using MPPCA and T-NORDIC with parametric dimensions of 4 and 12. The results of qualitatively and quantitatively compared for image quality and quantitative accuracy.
 

Results: T-NORDIC provided superior performance with limited parametric dimension (4 weighted images), demonstrating its promise for magnetization-prepared mapping sequences of the hip joint.

Impact: T2 relaxation time mapping is critically investigated for addressing several MSK related diagnosis, but possibly due to thin and sensitive structures in the femoral head even slightest of the perturbations can lead to ineffective computation of quantitative mapping.

Keywords: Bone, Quantitative Imaging, Synthetic MR, ONFH

Motivation: Both qualitative and quantitative diagnosis of ONFH can be achieved through Synthetic MRI.

Goal(s): To investigate the value of Synthetic MRI in evaluating the osteonecrosis of femoral head(ONFH).

Approach: 336 hips in 168  cases of clinically diagnosed patients with ONFH were recruited and measured with T1, T2 and PD mapping derived by Synthetic MRI, 70 hips were normal as controls and 256 were ONFH.

Results: T1 , T2 and PD values showed significantly different values between ONFH and normal hip(all P<0.001). .With further ROC analysis, the diagnostic efficacy of T1 in the necrosis region and edema region was better than T2 and PD.

Impact: MRI images are important for clinical diagnosis of ONFH, while conventional MRI is qualitative diagnosis, quantitative diagnosis of ONFH is not yet available, therefore, Synthetic MRI may be considered an effective quantitative method in differentiating ONFH from normal femoral.

Keywords: Bone, Diffusion/other diffusion imaging techniques, RESOLVE DWI; multi-b-values-fitting; axial spondyloarthritis; quantitative; tumour necrosis factor inhibitors

Motivation:  Methods to quantitatively assess disease activity and efficacy of axSpA are still being explored.

Goal(s): To find a reliable quantitative indicator for evaluating disease activity and curative effect of axSpA, using multi-b-values-fitting RESOLVE DWI. 

Approach: By comparing the ADC values calculated by fitting different b values between different groups, a relatively reliable b-values-fitting sequence was obtained, further evaluating curative effect of the treatment group in different cycles. 

Results: Multi-b-values-fitting (b=50,500,700s/mm²) RESOLVE DWI has a certain advantage in evaluating disease activity and efficacy of axSpA, but the effect of short-term review (3 weeks or less) is unsatisfactory.

Impact: Multi-b-Values-Fitting RESOLVE DWI can differentiate the severity of axSpA disease activity more intuitively, by measuring the ADC values of bone marrow edema of sacroiliac joints, providing a new idea for clinical search for more objective and accurate quantitative parameters.

Keywords: Other Musculoskeletal, Magnetization transfer, osteoporosis、Q-Dixon

Motivation: More research has confirmed the important role of new MRI techniques in early screening and efficacy evaluation of osteoporosis. 

Goal(s): The purpose of this study is to construct a nomogram clinical prediction model for predicting osteoporosis based on Q-Dixon、MT technology and clinical data

Approach: logistic regression analysis confirmed that four risk factors (gender, age, FF value, MTR value) were significant independent predictors of osteoporosis, and the calibration curve of the nomogram had good reliability in evaluating osteoporosis in training and validation cohorts

Results: The Nomogram model has more advantages in predicting osteoporosis than the FF model and MTR model

Impact: The clinical prediction model based on gender, age, FF value, and MT value nomogram has good universality and clinical benefits, is easy to promote, and helps to better screen for osteoporosis in the general elderly population, achieve early detection.

Keywords: Bone, Bone

Motivation: Hip fractures pose a substantial health concern commonly associated with osteoporosis. Bone mineral density from Dual-energy X-ray absorptiometry (DXA) is the standard-of-care test for assessment of osteoporosis and fracture risk, yet many who sustain fragility fractures are above the diagnosis threshold. 

Goal(s): The objective of this study was to conduct a preliminary investigation into the validity of MRI Finite Element Analysis (FEA) for predicting bone strength.

Approach: Ultrashort Echo Time MRI was used on cadaveric human femur sections and FEA was performed.

Results: The stiffness derived from UTE FEA showed a strong correlation with stiffness derived from mechanical testing.

Impact: This study compared UTE-based Finite Element Analysis to mechanical testing and found that there was a significant correlation between computational and experimental values. This indicates the potential for UTE MRI to be used in the clinical evaluation of bone strength.

Keywords: Muscle, Rare disease, metabolism, molecular imaging

Motivation: Pompe disease is a glycogen storage disease which leads to abnormal glycogen accumulation in tissues such as skeletal muscle, but there is a lack of suitable noninvasive methods to assess disease progression and treatment response.

Goal(s): To develop an MRI method for assessing glycogen levels in skeletal muscle of Pompe disease patients.

Approach: We used glycoNOE MRI to detect glycogen and quantified signals using a Voigt and polynomial hybrid lineshape fitting model.

Results: The glycoNOE signals showed significantly higher glycoNOE contrast in skeletal muscle for Pompe patients compared to the control (p < 0.0001).

Impact: Glycogen level is an import marker for Pompe disease. Our proposed method is expected to be a useful tool for assessing disease progression and treatment response in Pompe disease and other glycogen storage diseases.

Keywords: Muscle, MSK

Motivation: Water-T2 (T2_H2O) is a frequently used biomarker of neuromuscular active muscle damage. Complementarity with water-T1 (T1_H2O) has been recently suggested, with significant correlations found between T1_H2O and T2_H2O values in subject with different neuromuscular disorders.

Goal(s): In this work, we aimed to explore the behavior of these two biomarkers in the calf muscles of healthy volunteers under different physiological conditions.

Approach: T1_H2O and T2_H2O were measured  under different vascular filling conditions expected to modify muscle extracellular volume.

Results: There was a significant correlation between T1_H2O and T2_H2O values in all conditions.
T1_H2O and T2_H2O variations correlated only between the draining and recovery condition.

Impact: Water relaxation times  T1_H2O and T2_H2O were measured in the calves of volunteers under different  vascular filling conditions. Their distinct behavior suggests that these two biomarkers are complementary in the study of neuromucular diseases.

Keywords: Muscle, Muscle, Multiparametric, relaxometry, biomarkers, fat

Motivation: Skeletal muscle degeneration (sarcopenia) is more prevalent in patients with heart failure (HF) than the general population and is associated with worsened outcomes. However, HF-associated muscle degeneration remains incompletely understood.

Goal(s): To evaluate quantitative MRI in calf muscle compartments of HF patients and to investigate associations with function and overall condition.

Approach: Relaxometric (T₁/T₂/T_1ρ) and proton density fat fraction (PDFF) measures were obtained in calf muscle compartments of patients with HF. Functional and survey measures were obtained. Correlation analyses between all measures were performed.

Results: Relaxometry and PDFF correlated with muscle function but differed by muscle compartment, suggesting heterogeneous changes as function declines.

Impact: Quantitative MRI, including relaxometry and fat fraction as complementary measures, may detect muscle compartmental changes in heart failure associated sarcopenia. Characterization of degradation in patients’ specific muscle compartments may provide insight to the degenerative process and targets for intervention.

Keywords: Muscle, Deuterium, Quadrupolar effects

Motivation: Although it is known that deuterium (²H) quadrupolar splittings arise in muscle, it is not clear to what extent they can be used to characterise tissues.

Goal(s): To investigate quadrupolar splittings by measuring angular dependence and double-quantum-filtered signals, and to determine whether splittings were related to specific muscles. 

Approach: Deuterium oxide loading was used to increase the ²H signals. The angular dependence of the splitting was measured in the forearm and DQF spectra were acquired on forearm and lower leg muscles. 

Results: Evidence was obtained for quadrupolar splittings which were shown to depend on angle and muscle group, and exhibited DQF spectra.  

Impact: Deuterium quadrupolar splittings have the potential to characterise muscle fibres in vivo. Understanding the origin of the splittings, and factors affecting their magnitude, could lead to new or complementary methods in musculoskeletal or physiological investigations.   

Keywords: Muscle, Aging

Motivation: Physical therapy and exercise are proposed to slow down the aging-associated loss in muscle strength, but it is currently not known which compositional or architectural aspects of skeletal muscle cause reduced muscle strength.

Goal(s): Our goal was to exploit quantitative MRI to identify determinants of muscle strength production across the lifespan.

Approach: We used quantitative MRI (fat fraction, diffusion parameters, fiber length and muscle T₂) to predict quadriceps torque (n=24, 30-80 y/o). 

Results: We found that the inclusion of FA greatly improved the prediction of torque over morphology alone.  This might be explained with modifications of fiber typing with aging.

Impact: We have demonstrated that DTI parameters provide quantitative metrics of muscle quality which can be used to study force production in skeletal muscle, independently of volume. These compositional aspects might be amenable to interventions and provide specific targets for treatment.

Keywords: Muscle, Muscle

Motivation: Asymmetrical muscle atrophy and hypertrophy are known to occur in muscular atrophy. Musclar subtle changes are important indicators for early detection and tracking changes longitudinally with intervention.

Goal(s): To automatically segment thigh muscle subregions and assess their muscular volume and trends with ageing on large-scale data.

Approach: We trained nnU-Net for thigh muscle segmentation, and applied on the UK-Biobank data to assess the association between muscular volume and aging and diseases.

Results: Thigh musclar volume decreases as we are aging, and is significantly inversely associated with type-2 diabetes, hyptertebnsion and dementia.

Impact: Lower volume of the anterior thigh muscle was found in type-2 diabetes, hypertension and dementia patients. Lower volumes of the medial and posterior thigh muscle were found in dementia patients.

Keywords: Muscle, Spectroscopy

Motivation: Due to its pH-buffering function in skeletal muscle, carnosine reveals muscle fibre specific concentrations and is therefore suitable as a marker for the evaluation of muscle fibre composition in pathologies.

Goal(s): This study examines the reproducibility of muscle carnosine quantitation with ¹H-MRS, and is further targeting to adjust scan parameters for future clinical studies.

Approach: ¹H-MRS was applied in healthy volunteers to evaluate carnosine lateralization in leg muscles as well as quantitation reproducibility and precision in various parameter settings.

Results: Muscular carnosine can be measured with a sufficient precision and reproducibility in less than four minutes and in small voxels.

Impact: ¹H-MRS enables reliable in vivo measurements of carnosine in skeletal muscles in clinical protocol settings, which is important for the assessment of disease- and age-related as well as myodegenerative changes in muscle fibre composition.

Keywords: Muscle, MSK, UTE, T2* mapping, shoulder, muscle, supraspinatus, deltoid

Motivation: No previous studies have evaluated relative supraspinatus-deltoid force couple (Supra-Delt-FC) muscle T2*-metrics or considered their potential as biomarkers for Supra-Delt-FC function

Goal(s): Evaluate/compare Supra-Delt-FC T2*-values within 6 supraspinatus injured-case, and 6 (age/sex matched) uninjured-control subjects

Approach: Unilateral, 3T, 3D-Cones, 15-echo-UTE MRI acquisitions were utilized for calculation and evaluation of Supra-Delt-FC muscle T2*-values

Results: Independent evaluations of deltoid and supraspinatus muscle T2*-values revealed no significant differences between injured-case and uninjured-control subjects. However, evaluation of relative T2*-metrics (mean difference & FC-ratios) revealed significant case-to-control differences – suggesting that relative supraspinatus-to-deltoid T2* metrics may be more sensitive to alterations in Supra-Delt-FC and shoulder function following injury

Impact: While independent comparisons of respective supraspinatus and deltoid muscle T2*-values revealed no significant case-to-control differences, relative Supra-Delt-FC muscle T2*-metrics were significantly different between groups. Results suggest that relative Supra-Delt-FC muscle T2*-metrics may be more sensitive to alterations in Supra-Delt-FC function.

Keywords: Muscle, Relaxometry, Multi-component water T2

Motivation: Developing an objective measure of specific histopathological changes in the skeletal muscle in Duchene Muscular Dystrophy.

Goal(s): To investigate distinct histopathological changes in dystrophic muscle by assessing histological tissue water compartmentation in vivo.

Approach: A cohort of Golden Retriever Muscular Dystrophy (GRMD), carrier, and wild type dogs underwent quantitative MRI. Tissue water compartmentation, microvascular fraction (f) and extracellular volume (ECV) were assessed using multi-component water-T2 relaxometry, Intravoxel Incoherent Motion (IVIM) and T1 maps acquired before and after gadolinium (Gd) injection.

Results: In GRMD, ECV, f, long-T2 fraction and main-T2 value were increased. Carrier dogs displayed mild non-significant abnormalities.

Impact: Evaluating tissue water compartmentation in GRMD provided histopathologic specificity, distinguishing vascular from parenchymal changes in dystrophic muscle. The ability to assess histopathologic changes non-invasively will drastically improve our understanding of the disease evolution, treatment strategies and, ultimately, therapeutic development.

Keywords: Muscle, Neuroscience

Motivation: Current biomarkers for serial functional muscle assessments (eg., for therapeutic response assessment) are limited by sensitivity, spatial resolution, and coverage.

Goal(s): We aimed to utilise the high spatial resolution offered by recently developed phase contrast motor unit MRI (PC-MUMRI) techniques to identify potential biomarkers.

Approach: We prospectively trialled a novel PC-MUMRI fatigue and recovery paradigm before and after a 12-week exercise intervention in seven participants with genetic mitochondrial disorders.

Results: Time-to-half-maximum of PC-MUMRI recovery reduced from a mean of 254 (+/- 109) seconds to 137 (+/- 41) seconds following the intervention. This was not statistically significant (p = 0.074).

Impact: We have developed and tested a novel therapeutic response biomarker for muscle-based intervention based on measuring recovery of stimulated muscle twitch velocities following fatigue. This may address problems with spatial resolution, sensitivity, or coverage associated with previously reported biomarkers.

Keywords: Muscle, Muscle

Motivation: Looking for a convenient tool to detect the skeletal muscle fiber atrophy non-invasively in the early stage of diabetic sarcopenia.

Goal(s): This study aims to assess the pathological changes in skeletal muscle of diabetic sarcopenia rats using muscle MR texture analysis.

Approach: Type 1 diabetic sarcopenia rat model was conducted via STZ intraperitoneal injection. 2D MR texture features of the gastrocnemius muscle were extracted, followed by histopathological examination using HE stains.

Results: Muscle MR texture features exhibited significant differences between the diabetic sarcopenia group and the control group, and demonstrated a strong correlation with pathological characteristics of skeletal muscle fibers.

Impact: Texture features derived from muscle MR images show potential for non-invasively identifying skeletal muscle atrophy in diabetic sarcopenic rats and providing insights into underlying disease mechanisms.

Keywords: Muscle, Aging, Sarcopenia, muscle quality, fat replacement

Motivation: Deposition of fat in skeletal muscle increases with age, leading to reduced muscle quality, but it is currently unclear which muscles are affected first and thus may serve as markers for the onset of this process.

Goal(s): To measure intramuscular fat in individual thigh muscles in a healthy ageing cohort.

Approach: We applied chemical-shift-based water-fat-separation imaging in 94 participants (median age=56, range=22-89yrs), and proton density fat fraction was calculated for 12 thigh muscles and different muscle groups.

Results: We showed age associations with fat deposition in the whole thigh overall (β=0.60, p≪0.001), with associations being stronger in women and in the hamstring muscles.

Impact: Understanding the relationship between proton density fat fraction and age in the thigh musculature—particularly in women and in the hamstring muscles—will help clinicians to identify specific muscle targets for interventions designed to reduce functional decline with ageing.

Keywords: Tendon/Ligament, Multimodal, Ultrasound-MRI fusion, myotendinous injury, sports medicine, injury prognosis, lesion follow-up

Motivation: US-MRI fusion could provide more accurate information for muscle injury evaluation and follow-up. To date, some works were conducted in the scope of prostate pathology, but only a few focused on musculoskeletal imaging.

Goal(s): This study aimed to evaluate if US-MRI fusion would allow more detailed and precise characterization of myotendinous injuries. 

Approach: US only and US-MRI fusion images were reviewed and scored in terms of muscle injury detection, as well as scar, tendon and edema visualization. 

Results: US-MRI fusion allowed a better characterization of lesions and healing process on professional athletes suffering from myotendinous injuries compared to US alone.

Impact: Diagnosis of muscle injuries by US is a challenge, so MRI is still the gold standard in most cases. Combining both techniques, we can better characterize and follow-up lesions, detecting a slowdown in healing or complications as soon as possible.

Keywords: Tendon/Ligament, Quantitative Imaging, Temperature

Motivation: While the dependence of the relaxation parameters T₁ and T₂^* on temperature has been studied in aqueous solutions and in some biological tissues, such observations for complex organized tissues including tendons have not been investigated previously.

Goal(s): To measure how T₁ and T₂^* change with temperature in Achilles tendon samples.

Approach: T₁ and T₂^* were continuously measured while fresh ex vivo Achilles tendon samples were placed in a heated environment and cooled down over several hours.

Results: The change in T₂^* with temperature was nonlinear and much higher than that reported in the literature for other tissues

Impact: The change in T₂^* in Achilles tendons was 4.8+/-2.1%/°C, which is substantially higher than reported in other biological tissues and indicates that the theory of temperature dependence of MRI relaxation parameters may not apply to highly organized tissues like tendons.

Keywords: Muscle, Rare disease, dystrophy, dysferlinopathy

Motivation: To characterize the skeletal muscle and assess progression of the Miyoshi dystrophy by quantitative MRI.

Goal(s): Compare the changes in fat fractions in individual calf muscles 10 months apart in time.

Approach: Lower extremity of 4 dystrophic patients  were measured in 3T scanner by multiecho-Dixon sequence  in two time points. Three asymptomatic DYSF gene carriers served as reference.

Results: Fat fraction increased in all measured muscles in dystrophic patients while staying stable in controls. The most significant increments were detected in the muscles most preserved (TP, FDL, EXT, FHL). Variation can be observed even within the patients with the same genotype.

Impact: Using quantitative analysis based on automatically generated fat fraction maps for assessment of Miyoshi dystrophy in muscles allow clinically feasible monitoring of the disease progression and description of the pattern of the disease.

Keywords: Muscle, Diabetes, Vertebral Bone Quality score, paravertebral muscles; magnetic resonance imaging

Motivation: Patients with T2DM are at an increased risk of vertebral fractures, but the specific risk factors remain unclear. 

Goal(s): Investigate the correlation between changes in lumbar vertebrae and paravertebral muscles observed through MRI and the occurrence and severity of vertebral fractures in T2DM patients.

Approach: Retrospectively collect general information and lumbar spine MRI images of patients diagnosed with T2DM. Develop a diagnostic model based on MRI vertebral body and paravertebral muscle parameters and evaluate the model's diagnostic performance.

Results: Higher VBQ scores, decreased relative CSA of paravertebral muscles, and increased fat infiltration of the paravertebral muscles indicate an elevated risk of fractures.

Impact: The findings of this study could potentially have a significant impact on the management and prevention of vertebral fractures in T2DM patients. By identifying specific MRI-based risk factors, clinicians can improve fracture risk assessment and implement targeted interventions.

Keywords: Muscle, Muscle, Chronic low back pain; Vertebral bone quality

Motivation: The relationship between paraspinal muscles fat infiltration and vertebral body changes remain unclear. So motivation is to explore the relationship between the two and gain new insights about their interaction.

Goal(s): This study is to determine whether there is a correlation between paraspinal muscles fat infiltration and VBQ score and MCs.

Approach: A multimodal magnetic resonance imaging technique was employed to assess paraspinal muscles fat infiltration, VBQ score, and MCs in patients with CLBP

Results: There is no significant difference in paraspinal muscles PDFF between Modic classification. A positive linear relationship is observed between VBQ and total paraspinal muscles PDFF.

Impact: These findings contribute to our understanding of the association between paraspinal muscles fat infiltration and VBQ in CLBP patients. Further research can explore the clinical implications of these findings to improve alleviate CLBP symptoms.

Keywords: Muscle, Diffusion Tensor Imaging, paraspinal muscle, muscle fat infiltration, proton density fat fraction

Motivation: With the rise of aging-related muscle diseases, particularly sarcopenia, there's a pressing need for advanced diagnostic methods to assess muscle health.

Goal(s): Investigate the relationship between DTI imaging parameters and fat infiltration in paraspinal muscle, to identify novel biomarkers for early detection of muscle degeneration.

Approach: Employing DTI on 16 volunteers, we measured fat infiltration using PDFF and conducted a correlational analysis between DTI metrics and fat content across 64 ROIs.

Results: DTI successfully visualized paraspinal muscle fibers and showed significant correlations between FA values and PDFF, MD, AD, and RD values.

Impact: The research underscores the potential of DTI in detecting imaging biomarkers for muscle degeneration, setting the stage for advanced non-invasive assessments of musculoskeletal health.

Keywords: Muscle, Diffusion Tensor Imaging, Low back pain , Muscle fiber

Motivation: The development of discogenic low back pain (DLBP) and myofiber-type transformation in paraspinal muscles are strongly related. However, the impact of diffusion tensor imaging (DTI) in identifying myofiber-type transformation in paraspinal muscles remains uncertain.

Goal(s): Exploring the value of DTI in evaluating myofiber-type transformation in paraspinal muscles, and contributing to improved clinical diagnosis and intervention strategies for DLBP.

Approach: Prospective case-controlled animal experiments and establish the DLBP model in rats. DTI scanning and immunofluorescence of myofibers were performed to assess myofiber-type transformation.

Results: The fractional anisotropy (FA) was identified as a noninvasive imaging marker for detecting myofiber-type transformation in DLBP rats (r=0.4930, P<0.05).

Impact: Detection of myofiber-type in muscle biopsies is challenging. By utilizing DTI, clinicians can diagnose pathological alterations in paraspinal muscles early on, intervene quickly, and alleviate the burden on patients before the pain worsens.

Keywords: Cartilage, MSK, Spine, Lumbar, Endplate, Intervertebral Disc

Motivation: Despite crucial roles in normal function of the lumbar spine, discovertebral junction (DVJ) is seldom evaluated during MRI.   

Goal(s): Using ultrashort echo time (UTE) MRI, evaluate DVJ in subjects with chronic low back pain and asymptomatic controls.

Approach: Disc degeneration was assessed using Pfirrmann grading on the conventional spin echo T2, while DVJ morphology was assess using UTE MRI. Effect of low back pain  on disc degeneration and abnormal DVJ morphology was assessed.

Results: UTE MRI of the DVJ was feasible in vivo. In the symptomatic group, statistically greater prevalence of disc degeneration and abnormal DVJ morphology were found, suggesting a possible pain-correlation.  

Impact: This study advances MR imaging of the lumbar spine, suggesting that DVJ may be implicated in low back pain and the need for wider assessment of DVJ in routine lumbar MRI.

Keywords: Muscle, Quantitative Imaging

Motivation: Chronic low back pain (CLBP) is frequently associated with fatty infiltration and alterations in the cross-sectional area (CSA) of the paravertebral muscles. However, the precise relationship between disc-related changes and paravertebral muscles remains incompletely understood.

Goal(s): Study correlation between lumbar disc herniation, paravertebral muscle fat infiltration, CSA and chronic low back pain.

Approach: MRI images of the lumbar spine were analyzed in patients with chronic low back pain to correlate findings with paraspinal muscle CSA and PDFF.

Results: CLBP patients with disc herniation had lower PDFF in the multifidus muscle at L4/5 and reported higher pain levels (VAS score) than the control group.

Impact: This study provides valuable insights for clinicians, enabling them to implement targeted interventions for CLBP patients based on specific MRI findings and key characteristics of muscle remodeling.

Keywords: Bone, Cartilage

Motivation: Ruptured lumbar disc herniation (RLDH) can lead to severe clinical symptoms, significantly impacting patients' daily lives. 
. Understanding factors influencing disc resorption, particularly Modic change (MC), is crucial for making treatment decisions.

Goal(s):  To investigate the relationship between MC and the occurrence of disc resorption in RLDH patients.

Approach: This longitudinal study examined the presence of MC at baseline and assessed disc resorption at follow-up to determine the potential influence of MC on RLDH resorption.

Results: The study revealed that MC is an independent influencing factor for RLDH resorption failure, highlighting its significance in the management of this condition.

Impact: First, our study validated the efficacy of nonsurgical treatment of RLDH in resorption. Second, we demonstrated that MC is an independent factor hindering resorption, which helps clinicians to forecast resorption in RLDH patients, to select appropriate treatment methods. 

Keywords: Bone, Data Analysis

Motivation: Fractures can be highly detrimental for the elderly population. Assessing bone density alone is insufficient in accurately predicting fracture risk in osteopenia patients with and without fragility fracture. MRI can provide additional information on vertebral strength. 

Goal(s): To develop and validate a three-dimensional texture analysis method based on MRI for quantifying grayscale and distribution information of vertebrae.

Approach: We extracted MR texture features of the L4 vertebra and selected the most relevant features. A logistic regression model was established for fracture risk prediction.

Results: In a comprehensive model, the training and testing set achieved an AUC of 0.84 and 0.80 respectively.
 

Impact: Detecting subtle texture information that is imperceptible to the naked eye during the osteopenia stage. Analyzing these texture features specifically can help slow down the process of bone loss.

Keywords: Skeletal, MR Value

Motivation: Quantifying the extent of bone marrow infiltration or bone destruction plays a key role in assessing tumor burden and evaluating prognosis.

Goal(s): Previous semi-quantitative tumor burden scoring methods had limitations.

Approach: We developed a new whole spinal MRI-based tumor burden scoring method in participants with newly diagnosed multiple myeloma and to explore its prognostic significance by evaluating its role in predicting the early treatment response and its association with the R-ISS.

Results: The tumor burden score was an independent predictor of poor response and the AUC was 0.842. The tumor burden score was higher in R-ISS-III than in R-ISS-I and R-ISS-II.

Impact: This study quantified the extent of bone marrow infiltration or bone destruction in multiple myeloma and showed that high tumor burden scores were associated with poor early treatment response and high R-ISS stage.

Keywords: Skeletal, Skeletal, CT like image

Motivation: There is no consensus on the use of anterior or posterior surgery for ossification of the posterior longitudinal ligament (OPLL). 

Goal(s): The purpose of this study was to evaluate the usefulness of the FRACTURE MRI sequence in comparison to CT in the detection of OPLL of the cervical spine.

Approach: Seven radiological parameters were analyzed though the inter-observer and inter-modality agreement. 

Results: MRI with FRACTURE may be sufficient for the assessment of cervical spine OPLL, with good performance compared to CT in type of OPLL, distribution of OPLL, ossification thickness, canal-occupying ratio, K-line, and dural calcification.

Impact: In the evaluation of ossification of the posterior longitudinal ligament of the cervical spine, FRACTURE sequence might be a useful alternative to conventional CT scan.

Keywords: Cartilage, Cartilage, sodium MRI, 23Na, IVD, lumar Spine, lower pack pain, ex vivo, quantitative imaging

Motivation: The global impact of lumbar back pain requires an understanding of degenerative disc disease. Conventional MRI often misses early changes, necessitating a more sensitive technique for accurate detection.

Goal(s): To determine the efficacy of 3T-MRI with 23Na in accurately assessing degeneration to provide a deeper understanding of the correlation between sodium concentrations and proteoglycan levels in intervertebral discs.

Approach: Examination of human lumbar spine samples ex vivo using a 23Na-surface-coil, which enabled accurate determination of 23Na relaxation times and quantification of tissue sodium concentrations (TSCs).

Results: Results showed a significant correlation between decreasing TSC values and progression of Thompson grading.

Impact: This exciting research represents a significant advance in the field of lumbar disc degeneration assessment and promises to be an important part of a paradigm shift in diagnostic approaches and treatment strategies for patients with lumbar back pain.

Keywords: Other Musculoskeletal, Elastography, slip interface imaging, myofascial tissue, myofascial mobility, muscle, muscle function

Motivation: Investigating abnormal myofascial adhesion is crucial for understanding chronic low back pain in myofascial pain syndrome (MPS), necessitating objective, non-invasive imaging methods to characterize myofascial mobility in the lower back.  

Goal(s): To evaluate the efficacy of MR-Elastography (MRE)-based slip interface imaging (SII) technique for visualizing myofascial mobility in the lower back of healthy volunteers. 

Approach: A custom-built MRE driver and a new SII biomarker (D_norm) were introduced for detecting slip interfaces across thoracolumbar fascia and inter-muscular myofascial interfaces. 

Results: The D_norm map at a lower MRE frequency successfully provided clear visualization of lumbar slip interfaces, indicating unrestricted mobility in healthy volunteers. 

Impact: The new SII biomarker enhances visualization of the interface mobility in thoracolumbar fascia and other inter-muscular interfaces in the lower back. This may benefit assessment of myofascial mobility differences between healthy individuals and patients with MPS.

Keywords: Other Musculoskeletal, PET/MR, back pain, molecular imaging

Motivation: Diagnosis of chronic low back pain remains a challenge with conventional diagnostic methods leading to unsatisfactory treatment in a vast majority of patients.

Goal(s): To investigate the use of sigma-1 receptor (S1R) radioligand, [¹⁸F] FTC-146 in conjunction with positron emission tomography/magnetic resonance imaging (PET/MRI) for identifying the pain generator in chronic low back pain.

Approach: Correlation of [¹⁸F] FTC-146 PET-MRI imaging in patients with unresolved chronic low back pain to clinical findings. 

Results: S1R PET/MRI imaging matched the clinical diagnosis in all cases. Additionally, it offered benefit over traditional MRI by identifying additional “functional” findings both within and outside the spine.

Impact: Future clinical implementation of S1R-PET/MR can potentially help reveal previously unidentified pain generator in patients with chronic low back pain that have exhausted standard clinical care leading to better-targeted treatment. 

Keywords: Neurography, MSK

Motivation: DTI based on single-shot EPI is established method to evaluate lumbar nerve roots compression, but EPI-DTI has a high geometric distortion. 

Goal(s): To improve the image quality of the lumbar nerve roots, thereby improving the accuracy of tractography visualization and quantitative measurements.

Approach: To reduce distortion, we developed a method to reduce the number of phase encodes per acquisition by combining iZoom 2D RF excitation, IRIS and LIPO (SSGR) only fat suppression.

Results: Compared to the conventional EPI-DTI, LION iZoom IRIS-DTI improves the tractography image quality. LION iZoom IRIS-DTI was superior to the EPI-DTI, in accuracy of FA values measurement and ICC.

Impact: LION iZoom IRIS-DTI is effective in reducing image distortion and might improve the accuracy and reproducibility of FA measurements of lumbar nerve roots.

Keywords: Skeletal, Skeletal

Motivation: Could lumbar fat and water MRI be as an opportunistic screening tool?

Goal(s): To develop autoML radiomics-Based Classification for osteoporosis prediction using lumbar fat and water MRI.

Approach: A TPOP-radiomics classification model was trained using lumbar fat and water images obtained through the IDEAL-IQ method in normal and osteoporosis patients identified by DeXA. Three datasets of radiomics features were used, categorized based on their dimension (2D, 3D, and projection map)

Results: Our results indicate that the best model from the AutoML process demonstrated mean sensitivity of 0.745 and mean specificity of 0.758 in distinguishing between normal and osteroporosis.

Impact: Because osteoporosis is often considered a 'silent' disease, routine IDEAL-IQ lumbar scans have the potential to serve as an opportunistic screening tool for reducing the risk of fragility fractures, which are associated with morbidity and mortality.

Keywords: Other Musculoskeletal, Degenerative

Motivation: Lumbar disc degeneration (LDD) is a major cause of lower back pain, but the relationship of LDD and adjacent structures, especially bone mineral density (BMD), is unclear, which confuses clinicians in estimating condition.

Goal(s): To investigate the relationship between LDD and BMD in a non-specific low back pain (NSLBP) population.

Approach: We assessed the relationship between the extent of LDD, obtained from MRI, and BMD of vertebral bodies, measured using quantitative CT, in NSLBP patients. 

Results: Our results showed that LDD was negatively correlated with vertebra BMD in NSLBP patients, with L2/3 disc degeneration serving as an independent influencing factor for vBMD.

Impact: L2/3 intervertebral disc degeneration is an independent influencing factor for vBMD. Further investigation can explore if the degree of L2/3 intervertebral disc degeneration through MRI can predict OP, thereby reducing the occurrence of complications such as osteoporotic fractures.

Keywords: Bone, Bone

Motivation: In preoperative cervical spine assessment, precise visualization of the vertebral artery (VA) course is of paramount importance. We present a new sequence called FRACTURE-Angiography.

Goal(s): The purpose is to evaluate the clinical applicability of FRACTURE-Angiography compared to FRACTURE and TOF-MRA.

Approach: Both quantitative and qualitative evaluations were performed. In the quantitative evaluations, we assessed the depiction ability of the VA and bone tissue based on the contrast ratio with background tissue. The qualitative evaluations for 3D-fusion images were conducted from the perspectives of bone morphology and VA course. 

Results: FRACTURE-Angiography could image arterial signals and bone morphology simultaneously and satisfy clinical requirements.

Impact: FRACTURE-Angiography allows simultaneous acquisition of bone tissue and arterial images in a single imaging session. As a result, it has the advantage of shortening scan time and minimizing the gap between scans.

Keywords: Whole Joint, New Devices

Motivation: Traction imaging helps visualize the wrist articular cartilage, intrinsic ligaments, and triangular fibrocartilaginous complex (TFCC). The current traction method is cumbersome to use limiting more widespread usage.

Goal(s): To design a direct wrist traction device that is practical, comfortable, effective, and versatile.

Approach: A new traction device was designed. One patient underwent wrist imaging before and after traction with this device. The degree of joint distraction and articular cartilage, ligament and TFCC visibility was evaluated as was the degree of subject discomfort.

Results: The traction device was easy to apply, achieved good traction with minimal subject discomfort.

Impact: This practical traction device can potentially improve the quality of wrist MR imaging, negating the need for wrist arthrography and improving the detection of articular cartilage, intrinsic ligament and TFCC injury. 

Keywords: Bone, MSK, tumor; MRI; APT

Motivation: Current imaging methods for detecting tumor protein content are immature, thereby limiting early diagnosis, qualitative assessment, and post-treatment evaluation. 

Goal(s): Magnetic resonance imaging (MRI) has contributed significantly to improvement in the management of bone and soft tissue tumors. However, the use of MRI based amide proton transfer (APT) technique to diagnose bone and soft tissue tumors remain less explored. 

Approach: We use APT imaging to distinguish benign, intermediate and malignant bone and soft tissue tumors.

Results: APT value was different in benign, intermediate and malignant tumors. There is high sensitivity and specificity for the qualitative diagnosis of bone and soft tissue tumors.

Impact: APT imaging can provide diagnostic basis for the qualitative diagnosis of bone and soft tissue tumors. However, this imaging method is interfered by many factors. Whether tumors of different tissue sources have different APT characteristics needs further study.

Keywords: Bone, Tumor

Motivation: Clinical applications of APTWI for differentiating benign and malignant bone and soft tissue tumors are scarce.

Goal(s): This work investigated and evaluated the ability of APT and DWI parameters in distinguishing benign from malignant bone and soft tissue tumors.

Approach: MTRasym and ADC values of ninety-six patients in benign and malignant lesions were compared using either the independent samples t-test or Mann-Whitney U test. The ROC curve was used to assess the diagnostic performance in differentiation between benign and malignant tumors. 

Results: APTWI combined with DWI showed a significantly improved differentiation between benign and malignant tumors.

Impact: The combination of APTWI and DWI offers valuable insights into changes in cellular proteins and peptides. When MTRasym_max is combined with ADC_min, it yields superior diagnostic performance for distinguishing between malignant and benign bone and soft tissue tumors.

Keywords: Bone, Diabetes, critical limb ischemia; endothelial progenitor cells; dynamic contrast enhanced magnetic resonance imaging; metabolomics

Motivation: Diabetic lipid metabolism induces impairments of bone marrow endothelial progenitor cells (EPCs) ¹, accelerates microangiopathy of critical limb ischemia ^2,3 and increases amputation rate ⁴.

Goal(s): To explore the effect of diabetes mellitus (DM) on EPCs function and fatty acid metabolism in rabbits with critical limb ischemia using DCE-MRI.

Approach: DISCO-acquired DCE-MRI, EPCs function assessment, fatty acid metabolomics and CD31 immunohistochemical staining of proximal femur were performed.

Results: DM increased the significant differences of microvascular permeability parameters among time points and those were correlated with mobilization, migration and angiogenesis of EPCs, and fatty acid anabolism indices in both experimental groups at week 4.

Impact: Early non-invasive evaluating bone marrow endothelial progenitor cell functions in diabetic rabbits with critical limb ischemia could monitor functions of bone marrow EPCs during lipid regulation using DISCO MRI and timely adjust treatment strategies to improve microcirculation and reduce amputation.

Keywords: Bone, Tumor, Neoadjuvant chemotherapy · Response prediction

Motivation: The efficacy of neoadjuvant chemotherapy (NAC) directly affects the clinical treatment of osteosarcoma (OS) patients. Consequently, it is essential to accurately assess the effectiveness of NAC.

Goal(s): To develop an automated method for accurately segmenting tumors and predicting the response to NAC in OS patients from conventional sequences of preoperative MRI.

Approach: In the present study, we accomplished two tasks. One involves constructing a deep learning model for automatic tumor segmentation, while the other entails predicting the response to NAC using different feature extraction methods in OS patients.

Results: Radiomics models can serve as a non-invasive tool for predicting treatment response in OS.

Impact: Radiomics have the potential to non-invasively predict the neoadjuvant chemotherapeutic responses. This tool could significantly contribute to avoiding ineffective chemotherapy and optimizing the management of OS patients in the era of personalized medicine.

Keywords: Bone, Skeletal

Motivation: Treatment options for spinal tumors are challenging.

Goal(s): To predict the progression-free survival (PFS) of aggressive spinal tumors based on MRI combined with clinical features to aid early personalized treatment decisions.

Approach: Clinical, pathological and imaging data of 211 patients underwent spinal tumor surgery at two research centers were retrospectively analyzed. Tumoral and peritumoral features were extracted from T1WI and T2WI images. Clinical-radiomics nomogram was developed by radiomics signatures and the predictive clinical parameters.

Results: The integrative model showed best performance in PFS evaluation for the prediction of postoperative PFS, with the AUC was 0.86 and 0.81 in the training and test cohort. 

Impact: Rad-score is an independent factor for PFS after resection for spinal tumor. The nomogram established in this study could be an effective tool for the clinical prediction of PFS after surgery.

Keywords: Other Musculoskeletal, Tumor, CEST

Motivation: The precise assessment of the efficacy of preoperative neoadjuvant chemotherapy in osteosarcoma is important for clinical decision making, which requires the consideration of complex factors.

Goal(s): In this study, we investigated the ability of ioversol chemical exchange saturation transfer (CEST) imaging in detecting pH in the microenvironment of rat osteosarcoma.

Approach: Assessing pH in the microenvironment of osteosarcoma using CEST imaging.

Results: It was found that the lower pH value, the lower ratiometric value acquired by two different saturation power of 1μT and 3μT.

Impact: In addition, CEST can detect the pH-dependent ratiometric value of tumor microenvironment non-invasively and sensitively. It is expected to become one of the methods for early evaluation of the effect of preoperative neoadjuvant chemotherapy in cancer patients.

Keywords: Whole Joint, Radiomics, femoroacetabular impingement, Radiomics, machine learning

Motivation: Radiomics could differentiate the symptomatic hip from the asymptomatic contralateral hip in patients with femoroacetabular impingement (FAI). This study investigates its potential in distinguishing FAI patients from healthy subjects.

Goal(s): To compare the diagnostic performance of radiomic features and clinical metrics in FAI diagnosis.

Approach: We used 3D Dixon MRI data (10 healthy subjects and 10 FAI patients). We trained machine learning models on radiomic features extracted from MRI to classify subjects as healthy or FAI. Models were trained also on clinical metrics for comparison.

Results: Radiomic features accurately identified FAI patients without errors (100% accuracy). Clinical metrics achieved 74% accuracy.

Impact: Radiomic features exhibited a remarkable diagnostic performance, accurately identifying all FAI patients and healthy subjects. This study shows the promise of radiomics to enable automated FAI diagnosis.

Keywords: Whole Joint, Infection

Motivation: Magnetic resonance imaging (MRI) is the gold standard for diagnosis of acute pediatric musculoskeletal infection. However, there are several barriers in the pediatric population, namely poor efficiency of image acquisition. 

Goal(s): The present study evaluates physician perspectives on a novel rapid MRI protocol for capturing rapid, non-contrast, limited sequence protocol that has been shown to greatly decrease sedation, scan time, hospital length of stay, and charges without missing actionable diagnoses. 

Approach: We administered a series of traditional and rapid protocol cases and associated quiz to six providers.

Results: We found similar success rates of diagnoses and physician confidence between rapid and traditional sequences.

Impact: Our study shows that rapid MRI protocols can be adopted without impeding diagnostic accuracy or reducing the confidence of readers.

Keywords: Cartilage, Joints, knee, joints, mri, radiomic

Motivation: Predicting total knee replacement surgery can help patients and healthcare providers make informed treatment decisions.

Goal(s): To develop a machine learning model for predicting patients that will undergo a total knee replacement using radiomics.

Approach: To extract radiomic features from images of patients and healthy subjects and train different machine learning models to predict patients' outcomes. 

Results: The best model achieved an accuracy of 87.2%. Three out of the four most significant radiomic features selected in the All subset were derived from the meniscus areas, suggesting that the meniscus may play a crucial role in predicting patient outcomes.

Impact: Radiomic features from MRI scans effectively classify TKR-positive patients, particularly those incorporating meniscus features. These models potentially can predict patient outcomes and guide treatment decisions, but further research is needed to enhance performance and validate findings in broader patient populations.

Keywords: Other Musculoskeletal, Tumor

Motivation: The integration of various diffusion models can yield more precise insights into tumor diffusion and perfusion.

Goal(s): To investigate the utility of combining DWI, IVIM and DKI in the differential diagnosis of benign and malignant bone tumors.

Approach: Six parameters derived from three diffusion models of 107 patients were statistically compared through either the independent samples t-test or Mann-Whitney U test. Diagnostic performance was assessed using ROC curves for both individual examinations and their combined analysis in distinguishing between benign and malignant tumors.  

Results: The combination of ADC, D, D*, MK, and MD values had better diagnostic efficacy than these parameters alone.

Impact: Statistically significant differences were observed in the values of ADC, D, D*, MD, and MK between benign and malignant bone tumors. Furthermore, the combination of ADC, D, D*, MK, and MD values had better diagnostic efficacy than these parameters alone.

Keywords: Bone, Bone, Radiation, MRI, Texture Analysis

Motivation: To promote a non-invasive method to evaluate the radiation induced femoral head changes.

Goal(s): To investigate the value of MRI texture analysis for evaluating radiation induced femoral head changes in rectal cancer patients after radiotherapy.

Approach: The texture parameters of T1WI, T2WI and DWI images were extracted in femoral head. And the differences of texture parameters before and after radiotherapy were compared.

Results: We found that when combined the texture parameters of T1WI, T2WI and DWI images, the diagnostic efficiency of femoral head changes was optimal with AUC of 0.85 (sensitivity,0.81; specificity,0.80).

Impact: MRI texture analysis may provide a non-invasive method to evaluate the radiation induced femoral head changes, providing imaging clues for monitoring the potential radiation-induced femoral head injury.

Keywords: Cartilage, MSK

Motivation: Identifying patients with a  backfill progression is crucial for predicting clinical prognosis and adjusting treatment approaches in the disease process.

Goal(s): This study aimed to extract radiomics features for the sacroiliac joint on MRI images in patients with axSpA to predict backfill progression within one year.

Approach: This retrospective study analyzed 257 patients diagnosed with axSpA. The radiomics and clinical models were combined to construct a nomogram model through multivariable logistic regression analysis.

Results: Seven radiomics features were extracted to generate a Rad-score. The AUCs of the radiomics, clinical, and nomogram models in the training cohort were 0.90, 0.78 and 0.93, respectively.

Impact: The built radiomics-based nomogram has good predictive value for structural progression in patients with axial spondyloarthritis.

Keywords: Bone, Relaxometry, Axial spondyloarthritis, T1 mapping

Motivation: Currently, there is a lack of an objective quantitative measure to comprehensively evaluate the inflammatory activity of axSpA, which poses certain challenges in accurately assessing the disease activity.

Goal(s): To establish a more reliable combined-parameter model for assessing the inflammatory activity of axSpA.

Approach: T1 mapping values, T2* mapping values and the frequency of MAIT cells and CD69⁺MAIT cells are constructed into single-parameter and combined-parameter models using logistic regression. The diagnostic efficacy was evaluated by employing the ROC curves.

Results: The model combining T1 mapping with CD69+MAIT cells showed relatively superior diagnostic efficacy in differentiating the severity of axSpA disease activity.

Impact: The combined-parameter model incorporating T1 mapping and CD69+MAIT cells provided an effective objective quantitative indicator for evaluating the inflammatory activity of axSpA.

Keywords: Bone, Artifacts

Motivation: Metal artifact reduction techniques needs longer scan time and shows incomplete MRI visibility for postoperative spinal evaluation. 

Goal(s): We assessed the reliability of localizer sequence image factors for predicting the metal artifact range in MRI. 

Approach: Multivariate ordinal logistic regression models were generated using prosthesis information and imaging factors measured on localizer images, to verify the factors correlated to the visibility of spinal canal and neural foramen on MRI. 

Results: Metal artifact degree at midline and foramen level of sagittal plane and inter-screw distance of coronal plane in localizer images were significant factors affecting metal artifact range of MRI.

Impact: We found that the metal artifact degree in localizer sequence image can be correlated with the metal artifact range of diagnostic sequence image, and used to screen proper patients to apply metal artifact reduction sequence in postoperative spinal MRI.

Keywords: Tendon/Ligament, Quantitative Imaging, T2*, Bi-exponential, UTE, CONES

Motivation: Tendon laxity, which may cause skeletal maltracking, can lead to pain and increased injury risk. Non-invasive measurement of tendon laxity remains a challenge but Ultrashort echo time (UTE)-T2* mapping may serve as a potential evaluation method.

Goal(s): This study aims to evaluate the sensitivity and repeatability of UTE-T2* mapping to tendon laxity.

Approach: We scanned the Achilles tendons of human subjects under tension and relaxation using UTE sequences.

Results: T2* relaxation times seemed to decrease as tendon load increased, from plantar flexion to dorsiflexion. However, the changes observed were small and intra-subject variability with position did not show any specific trends.

Impact: As the changes in T2* relaxation times were small and showed poor reproducibility, UTE-T2* mapping may not be sensitive enough to changes in tendon tensile loading and laxity.

Keywords: Muscle, Muscle

Motivation: Understanding the visual representation of spontaneous activities in DWI.

Goal(s): Automatically identifying visual differences in patterns of spontaneous muscular activities.

Approach: Deep-learning based detection and segmentation with subsequent feature analysis.

Results: Feasibility of feature-based clustering in individual subjects was shown.

Impact: Investigation of a pipeline for automated image processing for exploring differences in spontaneous muscular activities visible in DWI.

Keywords: Muscle, Motion Correction

Motivation: Respiratory muscles are often altered in subjects with neuromuscular diseases. Characterizing their structure using quantitative MRI is then crucial but challenging due to respiratory motion.

Goal(s): We developed a 3D free-breathing Magnetic Resonance Fingerprinting sequence for quantifying fat fraction (FF) and water T1 (T1_H2O) of upper body muscles at 3T.

Approach: We estimated the free-form respiration motion deformation on a 3D pre-scan using VoxelMorph and subsequently applied it in an iterative reconstruction framework to retrieve the MRF image series.

Results: This method allows a significant reduction of motion artefacts on parametric FF and  T1_H2O maps.

Impact: Free-breathing MRF T1-FF on 3T scanners paves the way for high resolution quantification of FF and T1_H2O in the upper body muscles for monitoring their structural alterations in subjects with neuromuscular diseases with high precision.

Keywords: Tendon/Ligament, Tendon/Ligament, Knee, Tendinopathy, Joint, Patient Reported Outcomes, Sports Injury

Motivation: Patellar tendinopathy (PT) is a common athletic overuse injury affecting either or both knees that can lead to pain and early sport retirement. However, athlete reported differences between bilateral and unilateral PT remains unknown.

Goal(s): We tested the hypothesis that athletes with MRI signs of bilateral PT have more self-reported knee problems compared to athletes with no or unilateral PT.

Approach: 53 pre-season elite college athletes were bilaterally imaged and completed knee surveys. Statistical tests were conducted to determine differences between no, unilateral, or bilateral PT.

Results: Significant differences in pain and quality of life in athletes with bilateral PT exist.

Impact: Elite athletes with bilateral patellar tendinopathy (PT) have more pain and a reduced quality of life, problems that may keep athletes from optimal sport performance. MR may help identify at-risk athletes for preventive care, potentially keeping athletes from further injury.

Keywords: Muscle, Bone, lumbar,paravertebral muscle,mDixon-Quant, T2 mapping

Motivation: Ankylosing spondylitis (AS) may cause changes in the patient's lumbar region, so it’s worth investigating whether AS affects the paraspinal muscles.

Goal(s):   To examine the changes in both the lumbar region and paraspinal muscles in AS patients, as well as any correlations between them.

Approach:  In this study, we utilized mDixon-Quant and T2 mapping to assess the FF and T2 values of the lumbar region and paraspinal muscles.

Results:  The AS group showed significantly higher FF and T2 values in the lumbar region and psoas major compared to the healthy controls, and there was a positive correlation between them.

Impact: This investigation has revealed a notable correlation between changes in the paravertebral muscles and the vertebral body. Clinicians will be able to perform thorough assessments of patients with AS and develop effective treatment plans.

Keywords: Muscle, Diabetes

Motivation: Fat deposition in skeletal muscle plays a vital role in type 2 diabetes mellitus (T2DM) but it lacks assessment of muscle fat infiltration in various stages of progression. 

Goal(s):  Quantitatively detect skeletal muscle fat content in T2DM patients with different courses and severity.

Approach: We measured thigh and paravertebral muscle fat fraction (FF) in T2DM patients using the mDixon-quant sequence and analyzed its association with other ectopic fat and clinical markers. 

Results: The FF value of skeletal muscle in T2DM patients was significantly higher than in the healthy group and was correlated with visceral adipose tissue and the course of T2DM.

Impact: Analyzing the variation in muscle fat deposition in diabetes may provide a more accurate assessment of insulin resistance, which can be utilized to guide clinical medication.

Keywords: Muscle, Diffusion/other diffusion imaging techniques, Magnetic Resonance Spectroscopic Imaging, Radial trajectories

Motivation: To investigate the diffusion of calf muscle intra-myocellular droplets in diabetes and obesity.

Goal(s): To validate  diffusion-weighted radial echo-planar spectroscopic imaging (DW-REPSI) in calf muscle. 

Approach: We acquired DW-REPSI spectra using 2 different b-values  in 3 young healthy subjects and one type2 diabetic patient; regional variations of intra- and extra- myocellular lipids (IMCL and EMCL), creatine and trimethylamines (TMA) and their diffusivities were quantified. 
 

Results: Decreased TMA was recorded in the tibialis anterior muscle compared to that of soleus and gastronomic muscles. ADCs of IMCL and EMCL and metabolites were quantified. Lower ADCs of IMCL indicated restricted motion. Shifts in EMCL was observed.
 

Impact: A  diffusion-weighted spectroscopic imaging sequence was evaluated to investigate the diffusion characteristics and regional variations of IMCL, EMCL and metabolites in calf muscle. The outcome may provide new biophysical insights in the investigation of lipid metabolism in diabetes.
 

Keywords: Muscle, Quantitative Imaging, Neuropathy, Follow-up

Motivation: Intramuscular fat fraction (FF) quantified using MRI has emerged as one of the few responsive outcome measures in neuropathic patients.

Goal(s): In the present one-year follow-up study we tracked changes in multiple qMRI biomarkers for CMT1A patients.

Approach: We assessed correlations between MRI and clinical parameters and compared 2D vs 3D segmentation analysis.

Results: As expected, we quantified a significant FF rise in both thigh and leg muscles and a length-dependent gradient in leg muscles. Given the varied FF distribution, the existence of a length-dependent gradient, and the differential fatty involution across muscles, 3D volume analysis appeared more faithful than single slice analysis.

Impact: Our longitudinal study further supports FF as a outcome of interest in neuropathic patients. The complexity of fat infiltration in terms of distribution among muscles and heterogeneity along the proximo-distal axis can be identified using a 3D volume analysis.

Keywords: CEST / APT / NOE, CEST & MT

Motivation: CrCEST measurements are sensitive to the changes in muscle pH, which confound the measurement and interpretation of τCr. Our motivation was to develop a technique that removed acidic bias from CrCEST measurements to ensure OXPHOS measurement. 

Goal(s): Develop a personalized mild exercise technique that limits acidosis in the calf to ensure measurement of OXPHOS using CrCEST.

Approach: To test the dependence of CrCEST recovery time on pH with different exercise regimes. 

Results: Carnosine ¹HMRS can be used to quickly measure pH change induced by a prescribed exercise regime and can facilitate an unbiased measurement of personalized muscle group specific OXPHOS capacity with CrCEST. 

Impact: Carnosine ¹HMRS can be used to quickly measure pH change induced by a prescribed exercise regime and can facilitate an unbiased measurement of personalized muscle group specific OXPHOS capacity with CrCEST. 

Keywords: Muscle, Muscle, Data Analysis, MSK

Motivation: Estimating physical performance including muscle function is conventionally done by having a subject complete physical tasks. MRI-based estimates leveraging deep learning could complement such measures.

Goal(s): To investigate the feasibility of predicting measures physical performance including muscle strength from MRI scans of the leg using deep learning.

Approach: We used large MRI databases (OAI and SOMMA) to train a neural network for classification into high or low physical performance. We also tried the method on a small prospective cohort.

Results: We obtained over 70% accuracy for estimating high or low muscle function, indicating high predictive power.

Impact: We demonstrate the feasibility of predicting muscle function from anatomical MRI scans using deep learning, leveraging advances in deep learning and musculoskeletal MRI databases that include functional measures. Such MRI-based predictions could complement conventional methods for estimating muscle function.

Keywords: Muscle, Diffusion Tensor Imaging, Hamstring muscle, diffusion tensor imaging, axial diffusivity, mean diffusivity, radial diffusivity, nordic hamsrting exercise, eccentric training

Motivation: To unveil the mechanism of preventative action offered by eccentric exercise regimes towards hamstring strain injuries, understanding muscle adaptations at microstructural level is crucial.

Goal(s): To investigate microstructural adaptations in hamstring muscles post 9-weeks of eccentric NHE using diffusion tensor imaging (DTI) metrics like axial (AD), mean (MD), and radial (RD) diffusivities.

Approach: Ten participants underwent Dixon and DTI scans pre and post 9-weeks of supervised eccentric NHE training.

Results: Post intervention, significant increases in AD, MD, and RD were observed, suggesting muscle hypertrophy, exercise-induced microtrauma, structural remodelling and potential Type II muscle fiber adaptations.

Impact: This study explored the ability of DTI to provide novel insights into microstructural adaptations of hamstring muscle to eccentric training. The findings highlight hypertrophy, structural remodelling, and fiber type shifts, advancing injury prevention and rehabilitation strategies through a fiber-level perspective.

Keywords: Neurography, Nerves, Muscle

Motivation: To evaluate the feasibility and reliability of an accelerated T2 mapping technique (GRAPPATINI) for MR neurography and muscle evaluation.

Goal(s): The study aims to qualitatively and quantitatively evaluate GRAPPATINI for MR neurography in patients with foot drop.

Approach: To compare the image quality from GRAPPATINI T2-weighted images against conventional T2-weighted images, and to compare T2 values between abnormal and normal muscles.

Results: No significant qualitative differences were observed between GRAPPATINI and conventional images diagnostically; there was complete agreement in assessment of nerve signal hyperintensity and size, and muscle edema. Significant differences in GRAPPATINI T2 values were observed between abnormal and normal muscles.

Impact: In one acquisition, GRAPPATINI can simultaneously provide clinically equivalent qualitative information and quantitative T2 maps for MR neurography evaluation of foot drop.

Keywords: Muscle, MSK

Motivation: Conservative treatment can lead to lumbar disc herniation (LDH) regression. However, the relationship between LDH regression and paraspinal muscle (PSM) fat content remains unclear.

Goal(s): To assess radiological changes in LDH with conservative treatment and investigate the connection between LDH regression and PSM fat content.

Approach: 80 LDH patients underwent MRI before and after conservative treatments. They were divided into resorption and non-resorption groups. PSM fat content and age were analyzed.

Results: 64% experienced LDH regression, mainly those with lower PSM fat content. Age-related muscle atrophy played a role. We highlights PSM fat content as a predictor of LDH regression during conservative treatment.

Impact: The fat content of paraspinal muscles serves as an important predictor of the conservative treatment outcomes for LDH patients. Patients with lower fat content in their paraspinal muscles are more likely to experience lumbar disc reabsorption.

Keywords: Muscle, Nervous system, Mitochondrial function, energy metabolism

Motivation: Parkinson’s disease (PD) is a leading neurodegenerative disorder. Currently there are no medical interventions or medications to slow the progression of PD. Rehabilitation for aerobics, strength and motor control is critical to consider as it ameliorates symptoms, decrease falls, and improves quality of life. However, the metabolic mechanism of rehab is not fully understood.

Goal(s): Report evidence that, upon targeted muscle exercise training, the muscle energetics is improved at cellular and molecular level.

Approach: PD patients were scanned by 31P MRS before and after a 4-week progressive strengthening program. 

Results: Upon rehabilitation, PCr decline with exercise is slowed in parallel to delayed fatigue.

Impact: The metabolic findings in the present study support the note and practice that strength-focused rehab programs can benefit patients with PD in the management of their weakness and improving quality of life.

Keywords: fMRI Analysis, fMRI

Motivation: Understanding the link between paraspinal muscle changes and common causes is crucial for improving treatment approaches for chronic lower back pain (CLBP), which has diverse underlying factors.

Goal(s): Assessing the relationship between MRI findings and paraspinal muscle changes in patients with CLBP.

Approach: We prospectively collected lumbar spine MRI images from CLBP patients. Analyses assessed correlations and regressions between MRI findings and paraspinal muscle cross-sectional area (CSA) and proton density fat fraction (PDFF).

Results: Degenerative lumbar spondylolisthesis (DLS) and intervertebral disc degeneration (IVDD) have a significant impact on the increase in the PDFF of paraspinal muscles.

Impact: This study provides valuable insights for clinicians, enabling them to implement targeted interventions for CLBP patients based on specific MRI findings and key characteristics of muscle remodeling. By improving prevention and treatment approaches.

Keywords: Muscle, Aging, Dixon, fat fraction, texture analysis

Motivation: Pathological changes in the masseter muscle have been associated with head and neck cancer (HNC). Nevertheless, investigations on the quantification of fatty infiltration in the masseter muscle and its correlation with HNC is limited.

Goal(s): We aim to assess fatty infiltration, morphological characteristics, and texture features of the masseter muscle in HNC.

Approach: This study sought to employ the Dixon method for fat fraction estimation conjugated with a machine learning-based auto-segmentation of the masseter muscle.

Results: Our analysis revealed an elevated level of fatty infiltration in the masseter muscle among patients with head and neck cancer.

Impact: Dixon method conjugated with machine learning-based auto-segmentation should facilitate in reliably assessing masseter fat alteration in head and neck cancer (HNC), this may be beneficial in response prediction in HNC treatment.

Keywords: Whole Joint, Cartilage, Cartilage, Biomechanics, Bone, Segmentation, Personalized

Motivation: Automated analysis of MRI and biomechanics data can provide personalized information about cartilage pressures.

Goal(s): Our goal was to develop an automated pipeline to create a personalized biomechanical knee joint model from MRI data, to simulate personalized knee mechanics during gait in comparison to knee mechanics of a generic knee joint geometry.

Approach: Bone and cartilage geometry was automatically segmented from knee MRI scans via deep learning. Gait simulations were performed on musculoskeletal models with personalized and generic knee models.

Results: Personalizing knee joint geometries affected cartilage pressure distributions in the joint but maintained peak cartilage pressures and contact forces.

Impact: Biomechanical models personalized with MRI data enable understanding of how bone geometry influences cartilage pressures during gait, which may lead to better tailoring and evaluation of interventions.

Keywords: Osteoarthritis, Cartilage, Reproducibility, coils

Motivation: T2 and T1rho reproducibility is essential for evaluating the small changes that occur during early osteoarthritis that are predictive of disease progression.

Goal(s): To evaluate the reproducibility of T2 and T1rho relaxation times in multiple coils and with multiple imaging sequences.

Approach: We studied the reproducibility of T1rho and T2 relaxation times with a MAPSS and qDESS sequence in a Transmit-Receive knee coil and two different flexible extremity coil arrays. 

Results: Intra-coil CVs of less than 5% (QIBA Goal) in qDESS T2 measurements with all coils tested, MAPSS T2 measurements with both flexible-coil-arrays and MAPSS T1rho measurements only with the Air coil.  

Impact: Preliminary findings suggest that flexible, receive-only coil arrays show similar or improved reproducibility for evaluating cartilage T2 and T1rho relaxation times compared to standard T/R knee coils.  

Keywords: Cartilage, Low-Field MRI, T2 mapping, T1 mapping

Motivation: To study knee tissue properties at Ultra-low-field (ULF) for sequence design/optimization, enabling ULF MRI  for wide-ranging applications.

Goal(s): To measure the T2 and T1 values of various tissues in vivo human knee at 0.05T.

Approach: Multiple TE and TR measurements were conducted on a home-built and RF shielding-free 0.05T MRI scanner for T2 and T1 mapping through pixel-wise numerical fitting.

Results: Phantom results exhibited a linear relationship between the Gadolinium concentration and relaxation rate, demonstrating the feasibility of mapping procedure. Additionally, the T2 and T1 values of cartilage, tendon, fat, and skeletal muscle in human knee were estimated and reported.

Impact: The estimated Gadolinium T2 and T1 relaxivities at 0.05 Tesla are significantly higher than those at 1.5T and 3.0T, guiding the usage of contrast agent dose. Moreover, T2 and T1 mapping of musculoskeletal tissues can facilitate sequence design/optimization.

Keywords: Cartilage, Cartilage, MRF

Motivation: Early signs of cartilage degeneration include changes in proteoglycan content, which cannot be diagnosed using standard clinical imaging tools.

Goal(s):

Prediction of cartilage proteoglycan content from quantitative MR fingerprinting data at 3T.

Approach:

Gaussian process regression (GPR) models were trained to predict optical density of safranin-O stained cartilage sections, representing proteoglycan content, from MRF data on a voxel-by-voxel basis.

Results: The trained GPR models reached very high accuracy (mean correlation of 0.81 with a respective NRMSE of 11.7%) and had clearly enhanced performance when compared to linear models.

Impact: Non-invasive prediction of proteoglycan content in cartilage using MR fingerprinting at clinical field strength is feasible, holding promise for direct clinical imaging of cartilage composition in the future.

Keywords: Cartilage, Quantitative Imaging

Motivation: Bi-exponential T2 and T1rho mapping of the knee cartilage can potentially improve early detection of knee osteoarthritis.

Goal(s): Scan time is usually long and SNR is low with standard methods. We plan to improve these aspects with a machine-learned pulse sequence.

Approach: We use a machine learning approach, called optimized variable flip-angles (OVFA) on magnetization-prepared gradient-echo (MPGRE) sequences to improve bi-exponential T2 and T1rho mapping on the knee cartilage.

Results: We observed an improvement of ~50% in SNR and a reduction of acquisition time by almost 2X when compared to standard MAPSS, typically used for quantitative T1rho and T2 mapping.

Impact: This study shows that the learned pulse sequence, named MPGRE-OVFA, can obtain similar bi-exponential T2 and T1rho mapping values as MAPSS, but it is 2 times faster and has 50% more SNR, potentially improving early detection of osteoarthritis.

Keywords: Cartilage, MSK

Motivation: High-resolution T1ρ mapping is desired for improved sensitivity to small lesions and less partial volume averaging effects. However, the low image SNR can induce bias in T1ρ quantification. 

Goal(s): To develop and evaluate advanced fitting methods of high-resolution T1ρ mapping in a multi-site multi-vendor setting. 

Approach: High-resolution T1ρ mapping in volunteers were collected with a harmonized protocol from three sites and three MR platforms. Data were fitted with nonlinear least-squares (NLS) fitting, noise-corrected NLS fitting (NCNLS), and maximum-likelihood estimation (MLE).  

Results: :NLS overestimated T1ρ while NCNLS and MLE reduced the overestimation. The results were consistent across all sites

Impact: Advanced fitting methods can reduce fitting errors induced by low SNR for high-resolution T1ρ mapping, which may provide improved diagnosis of osteoarthritis.

Keywords: Cartilage, Cartilage

Motivation: If fat signal is not properly suppressed, it can lead to errors in the T2 calculations in human articular cartilage.

Goal(s): This work aimed to quantify the influence of fat suppression on T2 values as well as texture features extracted from T2 maps.

Approach: Ten donors were scanned in 3T MRI with DESS, T2-TESS and CPMG with and without fat suppression.

Results: The results of this study showed the importance of using fat suppression while acquiring T2 maps. The influence of fat suppression was substantially greater for CPMG-T2-mapping compared to TESS-T2-mapping.

Impact: If fat signal is not properly suppressed, it can lead to errors in the T2 calculations in human articular cartilage which can have a significant impact on longitudinal clinical trials.

Keywords: Cartilage, Cartilage

Motivation: 3D-MRF sequence for simultaneous multi-parametric mapping has the potential to provide a more time-efficient comprehensive evaluation of the knee cartilage.

Goal(s): However, evaluation of 3D-MRF repeatability of knee cartilage is limited. 

Approach: 3D-MRF and conventional sequences for knee cartilage were acquired four times on fourteen healthy subjects. Multi-parametric maps were computed and repeatability was evaluated.

Results: High inter- and intra-subject repeatabilities were found using the 3D-MRF sequence over seven days with good agreement to conventional sequences.

Impact: The 3D-MRF sequence showed high T₁, T₂, and T_1ρ repeatability on knee cartilage on different days and good agreement with conventional methods. 

Keywords: Cartilage, Osteoarthritis

Motivation: Scientific literature on osteoarthritis of the hip is very sparse, especially compared to the knee, because MRI assessment of the hip is incredibly challenging. 

Goal(s): Our goal was to determine clinical feasibility for cartilage assessment of the hip captured through radial imaging planes. 

Approach: We acquired 2D radial images of the hip joint at three different time points and assessed them using standard image processing techniques. 

Results: We demonstrate that 2D radial imaging is a constructive approach for mitigating partial volume artifacts and the resulting images can be effectively processed for quantitative and qualitative analyses of the hip joint cartilage. 

Impact: We demonstrate a processing pipeline for analysis of hip cartilage longitudinally acquired through radial imaging planes. The proposed methods could facilitate the clinical translation of quantitative radial imaging for assessment of the hip cartilage for pre-symptomatic indicators of disease.  

Keywords: Osteoarthritis, Bone

Motivation: Cartilage degradation has been recognized as an early and crucial feature in axSpA. 

Goal(s): The objectives of the present study were (1) to determine the performance of T2^* cartilage mapping in diagnosing and assessing disease activity in early axSpA, (2) to investigate the interaction of cartilage damage with clinical characteristics and sacroiliitis. 

Approach: Sacroiliac joints cartilage T2^* values were higher in patients with early axSpA compared to controls without axSpA. 

Results: The combination of T2^* values and ‘positive MRI’ improve diagnostic efficiency of axSpA. Sacroiliac joints cartilage damage correlates with age, disease activity, acute sacroiliitis, and structural damage.

Impact: T2* relaxation time may be a promising imaging biomarker for diagnosing and differentiating disease activity in early axSpA. T2* mapping could be a recommended addition to routine MRI protocol of SIJs.

Keywords: Cartilage, Osteoarthritis, T2 mapping, MR Value, MSK, Relaxometry

Motivation: Simultaneous measurement of multiple parameters during single acquisition saves measurement and post-processing time with reduced motion artifacts.

Goal(s): To evaluate and compare T2 mapping of global and focal knee articular cartilage via MR fingerprinting and conventional CPMG sequences.

Approach: Volunteer and patient knees were scanned with protocol including MRF and CPMG T2 mapping. The two T2 mapping methods were compared in global cartilage, focal cartilage lesions and morphologically normal appearing cartilage segments.

Results: The average bias between the two methods was 17.09 ± 6.3 ms, and correlation was moderate to very high in global cartilage and high in focal cartilage.

Impact: T2 mapping with MR fingerprinting is reliable in global and focal articular knee cartilage in terms of segment bulk T2 value assessment when compared to conventional method. Future study will concentrate on longitudinal change in T2 during patient follow-up.

Keywords: Cartilage, MSK

Motivation: Quantitative MRI (qMRI) studies of cartilage regions need both regional segmentation and pixel-wise fitting analysis, which can be time-consuming and subject to inter-individual variability.

Goal(s): To design a deep neural network for simultaneous qMRI mapping and accurate tissue segmentation.

Approach: By leveraging different scan sequences, we proposed a RMQ-net with Uncertainty-awareness(UA) module, or UA-QMR-net. A majority-voting strategy was applied for robust cartilage segmentation and accelerated qMRI analysis.  

Results: The results demonstrated that the UA-RMQ-net achieved higher performance than the original RMQ-net for both UTE-T1 and UTE-T1r analyses of articular cartilage. 

Impact: By leveraging information from different scan sequences, the proposed UA-RMQ-net could obtain higher performance for accelerated qMRI analysis.  

Keywords: Cartilage, Cartilage, UTE, DESS, UTE-DESS, Diffusion, T1, T2

Motivation: A comprehensive validation of parameter mapping for T1, T2, and ADC based on qUTE-DESS has not been conducted yet.

Goal(s): To investigate the feasibility and accuracy of qUTE-DESS for estimating T1, T2, and ADC parameters in human patellar cartilage and to compare these results with conventional MR techniques.

Approach: The study used a qUTE-DESS sequence with variable flip angles and gradient moment adjustments. The cartilage sample was imaged using this approach and conventional imaging sequences, and the acquired data were processed using signal fitting.

Results: Significant correlations exist between the parameters estimated by qUTE-DESS and those from conventional sequences.

Impact: This study pioneers the comprehensive validation of T1, T2, and ADC parameter mapping using qUTE-DESS for knee joint imaging. Its findings offer a promising avenue to enhance the assessment of short T2 tissues and advance clinical applications in musculoskeletal diagnostics.

Keywords: Cartilage, Low-Field MRI

Motivation: Baseline healthy-knee-cartilage reference comparisons across 0.55T and 3.0T can be utilized for comparing healthy to diseased cartilage in early-to-moderate OA at 0.55T.

Goal(s): To compute and compare T_2-baseline relaxation time measurements of healthy knee cartilage obtained at 0.55T using Radial-TSE approach with 3.0T using MAPSS, paired with DL-based cartilage segmentation. 

Approach: Phantom and Healthy Knee-cartilage-compartmental T₂ relaxation values are compared using Exp2 and Sepg3 approaches with Radial TSE at 0.55T and 3.0T MAPSS. 

Results: We demonstrated healthy knee cartilage reference T_2-values at 0.55T using Radial-TSE. Average T₂-increase from 3.0T to 0.55T yields a wider range for detecting voxel-by-voxel granular changes of the cartilage. 

Impact: Baseline healthy-knee-cartilage reference Radial-TSE-T₂ at 0.55T and T₂-MAPSS-3.0T comparisons can be utilized for assessing healthy and diseased cartilage in early-to-moderate OA at 0.55T. Research findings at 3.0T could be translated at low-field economic scanners with a wider range of early-detection.   

Keywords: Cartilage, Radiomics

Motivation: Our study examines the utility of graph-based analyses in revealing the interplay of radiomic features in knee osteoarthritis (OA), specifically to discover patterns that are hidden in traditional analyses.

Goal(s): To differentiate radiomic profiles of healthy individuals from OA patients using graph-based methodologies and identify key features associated with OA progression.

Approach: We analyze feature interconnections within knee joint compartments using MRI-based radiomics and cosine similarity graphs to evaluate features from 20 subjects.

Results: Clustering coefficients and path lengths within the graphs revealed a distinct, pathology-driven convergence of radiomic features in OA patients compared to controls.

Impact: The graph analysis revealed a convergence of radiomic features in OA, potentially contributing to a better understanding of the disease and therefore opening the path to novel analysis strategies.

Keywords: Cartilage, Cartilage, ankle, kinematics, eversion

Motivation: Flat-footedness and pronated ankle posture have been observed in patients with knee osteoarthritis.

Goal(s): This works seeks to determine if compositional changes to cartilage assessed from T2 relaxation times are associated with foot and ankle posture.  

Approach: Foot center of pressure, ankle eversion and tibial rotation were compared to tibiofemoral cartilage T2 in 24 participants with healthy knees. 

Results: Lower medial femoral cartilage T2 correlated to more medial foot center of pressure and greater ankle eversion (R=-0.71, p<0.0005; R=-0.54, p=0.006; respectively). Higher lateral tibial T2 correlated to more internal tibial rotation (R=-0.52, p=0.009).

Impact: Correlation of foot and ankle posture to cartilage composition at the knee suggest that gait or shoe interventions to appropriately alter weight distribution at the foot and ankle could be utilized to benefit to knee cartilage health.

Keywords: Neurography, MSK

Motivation: In 3-D double-echo steady-state sequence with water excitation, fat suppression may be incomplete due to system imperfections, such as B0 and B1 inhomogeneity.

Goal(s): This study describes implementing an adapted Dixon reconstruction to further suppress residual fat signal.

Approach: The images between default and proposed reconstructions were compared in 16 patients undergoing routine upper extremity MR neurography.

Results: The preliminary results demonstrated the feasibility of using the proposed reconstruction to remove residual fat signals incompletely suppressed by the water excitation.

Impact: A benefit of the further suppressed fat provided by the proposed reconstruction was the improved depiction of small, yet clinically important peripheral nerves (particularly subcutaneous sensory branches surrounded by fat).

Keywords: Muscle, Quantitative Imaging, Analysis/Processing; Software Tools

Motivation: Quantitative magnetic resonance imaging (qMRI) is a common tool for assessing neuromuscular disorders, but its quantitative parameters often lack specificity and generally do not directly relate to muscle function. 

Goal(s): In our ongoing MOTION study, we are collecting whole-leg qMRI data and assessing muscle structure, function, and lifestyle in a large cross-sectional cohort to identify confounding factors in qMRI evaluation. 

Approach: To streamline data analysis for this cohort, we've developed a fully automated muscle-Bids-based data analysis pipeline, including automated muscle segmentation.

Results: Here, we introduce our data analysis pipeline, demonstrated using repeated scans of one volunteer.

Impact: The implementation of fully automated qMRI data processing streamlines large-scale studies and enhances its integration into clinical workflows. This standardization we expect to reduces variability for more dependable and reproducible outcomes.

Keywords: Whole Joint, Bone

Motivation: MRI provides superior soft-tissue contrast, however, cortical bone and ultrashort-T2* tissues are invisible in routine clinical MRI. Multi-echo Ultrashort TE (mecho-UTE) may allow visualization and quantification of bone and ultrashort-T2* tissues, however, its acquisition time is often long.

Goal(s): We used CG-SENSE and Deep Learning Reconstruction (CG-SENSE+DLR) to accelerate mecho-UTE, making it clinically feasible.

Approach: 5-min, 3-min, and 2-min mecho-UTE scans were prospectively acquired and reconstructed with Gridding and CG-SENSE+DLR. Resolution, sharpness, and T2* were measured and compared.

Results: CG-SENSE+DLR allows 2- and 3-min mecho-UTE with improved resolution and sharpness compared to 5-min mecho-UTE with Gridding reconstruction.

Impact: Routine MRI and mecho-UTE enable comprehensive MSK imaging, providing soft-tissue contrast and visualization-and-quantification of bone and ultrashort-T2* tissues. CG-SENSE+DLR allows accelerated 2- and 3-minunte mecho-UTE, which would enable widespread clinical utilization to demonstrate the value of mecho-UTE compared to CT.

Keywords: Cartilage, Machine Learning/Artificial Intelligence, Deep Learning, T1rho

Motivation: Estimating proton density (PD) and T1$$$\rho$$$ maps in the knee joint is time-consuming with nonlinear least squares (NLS) algorithms. Deep learning (DL) methods can do it faster.

Goal(s): Find the best DL model for this task, comparing different DL models.

Approach: We compared UNet, DenseNet, Encoder-Decoder, and Convolutional Neural Network (CNN). The proposed models directly transform k-space data into T1$$$\rho$$$ and PD maps, eliminating the need for traditional exponential fitting.

Results: UNet and Encoder-Decoder-based models obtained the best performance, using short training and prediction times and minimal memory requirements. The proposed models are 129 times faster than the benchmark NLS method.

Impact: This study compared different aspects of four DL models for joint PD and T1$$$\rho$$$ maps in the knee cartilage, indicating the most recommended models for this task.

Keywords: Whole Joint, Quantitative Imaging

Motivation: We seek better validation and QA of musculoskeletal intensive-variable MR biomarkers.

Goal(s): We aimed to devise and evaluate a phantom with suitable form factor and composition for practical use in this setting.

Approach: “Expected” temperature- and B₀-dependent R₁ values were calculated from prior data and verified by inversion recovery (IR). Practical QA use cases for hand and knee trials were exemplified using product-sequence 3D variable flip angle (3DVFA) R₁measurements on three vendors’ scanners.

Results: There was little deviation between “Expected” and IR-measured R₁ (rms 3.8%).  3DVFA R₁ exhibited bias (mean +23%) which must be subtracted during within-study QA.

Impact: This work will improve QA in real-world musculoskeletal clinical trials which use  intensive-variable MR biomarkers, and will help validate such biomarkers.

Keywords: Other Musculoskeletal, MSK, Temporomandibular Joints

Motivation: Patients with temporomandibular joint (TMJ) disorders often cannot endure long MRI examination due to facial pain, thus necessitating accelerated MRI.

Goal(s): To investigative the feasibility of AI-assisted compressed sensing (ACS) accelerated MRI technique in TMJ, and compare its performance with parallel imaging (PI) protocol and standard protocol.

Approach: Forty-four participants with 88 TMJs were qualitatively and quantitatively evaluated. Diagnostic agreement of joint effusion and disc displacement were analyzed.

Results: Overall image quality, SNR, and most structures visibility of ACS protocol were significantly higher than standard protocol, and similar to PI protocol. Diagnostic agreement was excellent with kappa values ranging from 0.81 to 1.00.

Impact: This study demonstrated that ACS accelerated MRI is feasible in TMJ with reduced acquisition times, good image quality, and excellent diagnostic precision, which holds great promise in clinical practice and is especially helpful for patients with TMJ disorders.

Keywords: Whole Joint, Machine Learning/Artificial Intelligence

Motivation: The broad clinical application of knee 3D-MRI has been constrained by scanning time.

Goal(s): To investigate the potential of AI-assisted compressed sensing (ACS) in knee MRI to optimize the scanning process.

Approach: 3D-ACS, 3D compressed sensing (CS), and 2D parallel acquisition technology (PAT) scans were performed. The 3D-ACS images underwent 3.5 mm/2.0 mm multiplanar reconstruction (MPR); radiologists evaluated the quality of images and diagnosed diseases.

Results: 3D-ACS provided poorer bone structure visualization, improved cartilage visualization, and less satisfactory axial images with 3.5 mm/2.0 mm MPR than 2D-PAT. High levels of diagnostic agreement and accuracy were observed across all diagnoses.

Impact: 3D-ACS provided poorer bone structure visualization, improved cartilage visualization, and less satisfactory axial images with 3.5 mm/2.0 mm MPR than 2D-PAT. High levels of diagnostic agreement and accuracy were observed across all diagnoses.

Keywords: Bone, MSK, Bone stress, finite element modelling

Motivation: Finite element modeling could help us better understand the role of bone strain in stress fractures. MRI, the standard for diagnosis, characterizes geometry but not bone density.

Goal(s): To evaluate the sensitivity of finite element model-estimated strain to the use of generic material properties.

Approach: Finite element models of the tibia-fibula complex were created with heterogeneous (CT referent) or homogeneous (simulating MR) material properties. Errors in strain and percent changes across running stride length conditions were calculated.

Results: Strains were substantially underestimated by models using homogeneous material properties, but relative changes in peak strain between and within individuals illustrated strong agreement.

Impact: MRI can be used to explore relative changes in bone strain in healthy adults when CT is not available. This option improves the feasibility of using finite element modelling to study bone strain and will enable opportunistic studies. 

Keywords: Whole Joint, Joints

Motivation: The application of 3D SPACE-DIXON techniques for musculoskeletal MRI has advantages in terms of fat suppression capacities, but drawbacks with regard to substantially longer acquisition times compared with SPAIR fat suppressed 3D SPACE.

Goal(s): To reduce the acquisition time of 3D SPACE-DIXON to that of 3D SPACE-SPAIR while maintaining superior fat suppression capabilities.

Approach: Six-fold CAIPIRINHA acceleration was combined with a deep learning-based image reconstruction algorithm to decrease the acquisition time and maintain image quality.

Results: Image quality parameters in volunteer scans were rated equivalent to the conventional 3D SPACE-DIXON sequence and superior to the 3D SPACE-SPAIR sequence.

Impact: We present a 3D SPACE-DIXON technique with improved fat suppression performance and similar acquisition time compared with 3D SPACE-SPAIR for musculoskeletal 3D MRI. Preliminary in vivo results indicate the clinical utility of this technique for proton density-weighted 3D MRI.

Keywords: Whole Joint, Joints

Motivation:  knee injury is common in clinical practice. DTI enables quantitative assessment of tissue changes in pathological joints, but its clinical application is limited due to prolonged scan time.

Goal(s): This study aims to explore the feasibility of using SMS technique in RESOLVE- DTI in knee joint to reduce acquisition time without compromising image quality.

Approach: There protocols, Conventional RESOLVE-DTI with 12 directions, and SMS-RESOLVE-DTI with 12 and 20 directions, were used to fully assess the image quality and quantitative parameters.

Results: The use of SMS technique greatly reduced the acquisition time without compromise image quality and quantitative evaluation accuracy.

Impact: The SMS technique greatly shortens the acquisition time of RESOLVE-DTI and provides similar image quality, allowing clinical doctors to simultaneously evaluate cartilage and ligaments of the knee joint in one scan. SMS-RESOLVE-DTI has high clinical application potential.

Keywords: Whole Joint, Joints, QSM, UTE, UTE-QSM, artifact reduction

Motivation: Quantitative susceptibility mapping (QSM) in MRI is valuable for characterizing tissue composition in the human body. Ultrashort echo time (UTE) is crucial for QSM of short T2 tissues in the musculoskeletal system. 

Goal(s): As UTE-QSM is susceptible to motion-related streaking artifacts, our study aimed at reducing those artifacts.

Approach: A novel approach called Streaking Artifact Reduction using Edge Detection (SARED) is proposed to mitigate such artifacts. The method involves edge detection, exclusion of pixels near edges, and two-step QSM processing. 

Results: Experimental results from knee and ankle joint imaging showed that SARED significantly reduces streaking artifacts, improving the accuracy of UTE-QSM.

Impact: The proposed Streaking Artifact Reduction using Edge Detection (SARED) approach significantly reduced motion-induced streaking artifacts in ultrashort echo time quantitative susceptibility mapping (UTE-QSM), enhancing accuracy in characterizing musculoskeletal tissues.

Keywords: Whole Joint, MSK

Motivation: Ankle MRI usually requires a long examination time. A faster scan with adequate image qualities is desired in clinical practice.

Goal(s): To evaluate a deep-learning reconstruction accelerated turbo spin echo (DLR-TSE) sequence in ankle application.

Approach: Four radiologists independently assessed the image quality and reviewed structural abnormalities of 56 consecutive patients on DLR-TSE and compared these results with those of conventional TSE.

Results: Overall, DLR-TSE achieved superior image qualities with a 57.4% reduction in total acquisition time compared with conventional TSE images. There were no differences in the differentiation of anatomic details, diagnostic confidence, or assessments of structural abnormalities between the two techniques.

Impact: Deep learning reconstruction can accelerate the turbo spin echo imaging without compromising the image quality or lesion detectability in ankle MRI.

Keywords: Cartilage, MSK

Motivation: High-resolution T1ρ mapping is desired to improve the early diagnosis of diseases such as osteoarthritis; however, it suffers from long acquisition times.

Goal(s): To accelerate high-resolution T1ρ mapping using compressed-sensing reconstruction in a multi-site multi-vendor setting.

Approach: We standardized the T1ρ imaging protocol between three sites using three MR platforms (GE/Philips/Siemens). Accelerated high-resolution T1ρ mapping with accelerator factors (AF) ranging 8-12 were performed using both retrospective and prospective downsamplings with compressed-sensing reconstruction.

Results: The coefficients-of-variation between reference and accelerated maps were <5% for all sites. Reliable high-resolution T1ρ mapping of the whole knee can be acquired within 7 mins.

Impact: Standardization of the acquisition and reconstruction of accelerated high-resolution T1ρ mapping across sites and MR platforms will greatly facilitate its future use in clinical trials and clinical practice, significantly improving diagnosis and evaluation of responses to interventions/treatments for OA.

Keywords: Muscle, Muscle, Perfusion, Reactive Hyperemia, BOLD

Motivation: Lower extremity reactive hyperemia BOLD have been used to evaluate the skeletal muscle perfusion status. The existing methods, such as multi-echo GRE and single-echo EPI, have limitations in terms of spatial coverage and signal quantification.

Goal(s): The study aims to apply dual-echo multi-band EPI to achieve high temporal and spatial resolution, and large coverage in BOLD experiment.

Approach: The study applied dual-echo EPI to sample the T2* along the reactive hyperemia experiment. Images at TE of zero were synthesized to investigate the intrinsic signal change.

Results: The proposed method can provide semi-quantitative indicators of the perfusion status of the lower extremity skeletal muscle.

Impact: This work demonstrates the advantages of dual echo EPI acquisition for lower extremity reactive hyperemia experiments. Compared to the commonly used acquisition strategies, the proposed one can be used to enhance the quality and efficiency of lower extremity perfusion imaging.

Keywords: Cartilage, MSK

Motivation: To accelerate knee imaging for T1ρ mapping in clinical practice

Goal(s): To evaluate deep learning reconstruction from undersampled knee imaging

Approach: Three different sampling strategies were proposed to further decrease scan time and reconstruct images with deep learning

Results: Deep learning reconstruction results are in good agreement with reference images. 

Impact: This work will allow use of novel contrasts including T1ρ to be performed within clinical workflow and improve patient diagnosis

Keywords: Bone, Perfusion, Hip, avascular necrosis, blood flow

Motivation: Avascular necrosis of the hip is due to disturbed blood supply related to various causes. Early evaluation currently requires contrast enhanced MR perfusion imaging.

Goal(s): Evaluate human hip perfusion using non-contrast MR perfusion technique.

Approach: Bilateral hips of healthy volunteers were imaged coronally at 3-T using a 2D spin labeling MR perfusion technique using tag-on tag-off acquisition at varying TI and processing to determine tagged blood signal into the acetabulum, femoral head, and femoral neck. 

Results: We found distinct perfusion signal in the acetabulum but the signal in the femoral head and neck were more subdued. 

Impact: This study demonstrates the feasibility of non-contrast MR perfusion imaging of the human hip, with future application in evaluation of avascular necrosis. 

Keywords: Osteoarthritis, MSK

Motivation: While radiomics has been applied to various MRI data to predict knee osteoarthritis (KOA) incidence, there is a lack of knowledge on the combination of radiomics features from different knee structures.

Goal(s): To assess the ability of MRI-based radiomic features extracted from automatically segmented femur, tibia, patella, and infrapatellar fat pad to predict KOA incidence.

Approach: 710 DESS MRIs were segmented using deep learning, trained with 30 manually delineated images. KOA incidence was predicted using Elastic Net, based on radiomic features from the four knee structures.

Results: The model combining features from the four knee structures resulted in a ROC AUC of 0.65.

Impact: While further research should be conducted to improve the accuracy of the developed radiomics pipeline in order to improve its applicability in clinical practice, radiomic features gathered from different knee structures are promising imaging biomarkers for early KOA prediction.

Keywords: Muscle, Fat, Muscle, fat fraction, fatty infiltration, hip OA

Motivation: Hip abductor muscles have a fundamental role in walking and other daily physical tasks. Relating hip abductor muscle fat fractions to patient-reported hip outcomes at a later timepoint could provide insights on exercise targets for patients with hip osteoarthritis who may become candidates for total hip arthroplasty.

Goal(s): The study seeks to determine if hip abductor muscle fat fractions predict patient-reported hip outcomes after 4 years.

Approach: Linear mixed-effects regressions were performed to investigate relationships between baseline hip abductor fat fractions and PROMS at follow-up.

Results: Higher baseline TFL fat fraction was associated with worse patient-reported hip pain scores at 4-year follow-up.

Impact: Our findings suggest performing further research into tensor fascia lata fat fraction in relation to future clinical outcomes for patients with hip osteoarthritis.

Keywords: Osteoarthritis, Osteoarthritis

Motivation: The three-dimensional ultrashort echo time adiabatic T1ρ (3D UTE-AdiabT1ρ) sequence can provide magic angle-insensitive evaluation of proteoglycan depletion in both short- and long-T2 tissues in the knee joint. 

Goal(s): Our goal was to assess its clinical performance. 

Approach: We applied this sequence to healthy volunteers and patients with different degrees of osteoarthritis.

Results: The sequence could be used for quantitative evaluation of meniscus degeneration. The UTE-AdiabT1ρ values in different subregions showed a significant positive relationship with WORMS, Stoller grades and KL groups. The 3D UTE-AdiabT1ρ biomarker can diagnose meniscal degeneration at an early stage.

Impact: The 3D UTE-AdiabT1ρ sequence allows quantitative imaging of the menisci. The UTE-AdiabT1ρ biomarker can diagnose meniscal degeneration at an early stage. Early detection of compositional changes in the menisci is of critical importance in avoiding or slowing down OA progression.

Keywords: Bone, fMRI

Motivation: Evaluation of sacroiliac subarticular bone marrow edema for active inflammation of ankylosing spondylitis（AS）before and after biologic treatment. 

Goal(s): MRI T2 mapping, DWI and SPARCC scores were used to compare the changes of BME in patients with AS before and after biologic treatment. 

Approach: DWI, SPARCC scores and T2mapping were compared to evaluate the changes of bone marrow edema in patients with sacroiliac arthritis alone or in combination. 

Results: The integrated diagnostic efficacy of DWI and T2 mapping demonstrates an optimal performance.

Impact: The combined application of magnetic resonance diffusion-weighted imaging (DWI), T2 mapping, and STIR-T2WI SPARCC scores provides an effective quantitative method for the clinical evaluation of the therapeutic efficacy of biologics in AS.

Keywords: Functional/Dynamic, fMRI (resting state)

Motivation: Understanding the neuropathological mechanisms of chronic ankle instability (CAI) is clearly of interest to both the practicing clinician and researchers on sports medicine.

Goal(s): Ankle proprioception deficits occur in patients with CAI. The underlying central neuropathology is unclear. This study examined cerebellar vermis structure/function in CAI patients vs controls and associations with proprioception deficits.

Approach: This research is a cross-sectional laboratory investigation.

Results: Patients with CAI showed reduced gray matter volume (VBM) and increased functional connectivity (fALFF) in cerebellar vermis subregions IV/V compared to controls. Proprioceptive deficits in CAI patients were associated with lower VBM and higher fALFF values in these subregions.

Impact: We hope the similar strategies could be applied to modulate our observed compensatory overactivation of vermis, make cerebellum more more efficient when handling the increased proprioceptive demands, and finally bring optimal clinical function to the patients with CAI.

Keywords: Cartilage, Quantitative Imaging

Motivation: It is important to examine and correct inter-scanner variability of T1rho/T2 values to improve the accuracy of longitudinal studies

Goal(s): To evaluate the inter-scanner variability of T1rho/T2 values and measure longitudinal changes in hip cartilage T1rho/T2 values after calibration.

Approach: TCalibrate the hip cartilage T1rho/T2 values using Voxel-based relaxometry  and Z-score normalization techniques

Results: The T1rho/T2 values showed that there was no statistically significant cartilage region (p<0.05) between the scanners. The longitudinal results showed an increase in number of subjects showing positive slope was increased in T1rho/T2 values after calibration (36.84 and 34.21%) compared without calibration (15.8% for both T1rho/T2).

Impact: The technique used for reducing the inter-scanner variability of T1rho/T2 values may benefit the longitudinal assessments of hip OA, specifically for evaluating disease progression over time on different scanners/before and after scanner upgrades

Keywords: Cartilage, Quantitative Imaging

Motivation: Validation of compressed sensing accelerated T1rho dispersion measurement of spontaneously degenerated human cartilage tissue samples. 

Goal(s): To study the effect the data reduction has on the ability to detect differences between the intact and degenerated articular cartilage specimens at different spin-lock amplitudes.

Approach: T1rho dispersion measurement with compressed sensing technique for reconstruction.

Results: Four-fold acceleration of T1rho dispersion measurement by compressed sensing approach was feasible without loss in the sensitivity to osteoarthritic changes within the articular cartilage. Differences were significant between intact and OA groups in the superficial and transitional zones, and T1rho correlated moderately with the reference methods.

Impact: Compressed sensing allowed reducing the scan-time required for measurement of T1rho dispersion, while still retaining the ability to detect degenerative changes in articular cartilage. Thus, the study brings T1rho dispersion measurements closer to clinical viability.

Keywords: Other Musculoskeletal, MSK

Motivation: 3D DIR-UTE can provide high short T2 contrast that is useful in knee imaging, however with a prohibited long acquisition time. 

Goal(s): The goal is to maintain high short-T2 contrast while significantly reducing the acquisition time.

Approach: The approach involves employing an accelerated IR-prepared fat-saturation UTE sequence along with advanced compressive sensing reconstruction.

Results: This approach achieved a threefold acceleration without sacrificing image quality and produced high short-T2 contrast, making structures like the meniscus and ligament clearly visible.

Impact: This technique holds potential for various musculoskeletal applications, such as in the early detection of conditions such as osteochondral junction alterations, osteoarthritis and meniscal tears.

Keywords: Osteoarthritis, Contrast Agent

Motivation: There is still a lack of noninvasive technique in quantifying the acidic extracellular pH of damaged cartilage in early osteoarthritis (OA).

Goal(s): We aimed to fabricate an advance reactive oxygen species (ROS) responsive CEST-MRI contrast agent for damaged cartilaged imaging and treatment in OA.

Approach: We use CEST-MRI to investigate whether our sythesized PLGE-TK-PEG@PDA-SA nanoparticles repond to ROS accumulating in damaged cartilage could result in the exsistance of CEST signal, while no CEST signal would be tested in normal cartilage without excessive ROS.

Results: The PLGA-TK-PEG@PDA-SA nanoparticles could effectively respond to ROS and then produce significant CEST effect for precisely pH measurement.

Impact: The novel PLGA-TK-PEG@PDA-SA CEST- MRI contrast  could be used to noninvasively monitor the extracellular pH of cartilage in osteoarthritis, and eliminate excessive ROS to defend against its damage to cartilage. This smart, sensitive ROS-responsive nanoprobe is promising for OA theranostics.

Keywords: Other Musculoskeletal, MSK

Motivation: MRI-based texture features have been used to identify abnormalities within the infrapatellar fat pad (IPFP) of middle-aged to elderly adults, yet no existing investigations have evaluated IPFP quality in young athletes.

Goal(s): To quantify and compare texture features of the IPFP in collegiate athletes comprised of men and women basketball players and swimmers.

Approach: Image texture features of the IPFP were calculated from bilateral MRIs acquired at 2 time points. (baseline and 1 yr. follow-up) for collegiate men and women basketball and swimming athletes.

Results: The IPFP of collegiate basketball players significantly differed from the swimmers, with greater global and local image homogeneity.

Impact: While the texture features of swimmer IPFPs remained consistent across sexes and timepoints, swimmers had significantly greater texture heterogeneity than basketball players at baseline. Observed variability indicates the need for further longitudinal investigation of IPFP structure within low impact sports.

Keywords: Other Musculoskeletal, MSK

Motivation: The detection of structural damage of the sacroiliac joint is essential for diagnosing axial spondyloarthritis.

Goal(s): To assess the diagnostic performance of FRACTURE sequence in detecting structure lesions compared to CT.

Approach: A retrospective study was conducted on 83 patients with definite axial SpA who underwent MRI and CT scans of the sacroiliac joint between 2021 and 2022.  An overall impression of sacroiliitis grade was also provided according to the scoring system of the modified New York criteria.

Results: When compared to CT as the standard, FRACTURE demonstrated high agreement with AUC values of 0.908, 0.943, 0.918 and 0.944 for sacroiliitis grade.

Impact: FRACTURE can evaluate structural lesions and demonstrate good diagnostic performance in patients with SpA.

Keywords: Other Musculoskeletal, MSK, Implant mode scan, Prescan, Calibration, Mavric

Motivation: Patients are often unaware of the presence and location of metal implants, which may be confirmed only after localizer scan, thus potentially disrupting workflow.  

Goal(s): To detect the presence of metal implant within the first few seconds of prescan and further characterize the location and shape of the metal from the calibration.

Approach: Prescan data of phantom with metal screws and human volunteer with metallic implants were used.

Results: The skewness of the center frequency signal is from 1.37 to 4.47 for implants, while for normal subjects, the signal is very symmetric and the calculated skewness is <0.3.

Impact: Automated MR scanning workflow for the patients with implants to improve efficiency of the MR technologists.

Keywords: Cartilage, Inflammation

Motivation: Cartilage abnormalities of the sacroiliac joints (SIJs) in spondyloarthritis(SpA) manifest as degeneration, fragmentation and erosions, fibrosis, and ossification.

Goal(s): To test whether MULTIPLEX(MTP) sequence of the sacroiliac joints (SIJs) might help identifying patients with SpA.

Approach: This study included 20 patients with axial SpA and 20 controls who prospectively underwent SIJs MRI using an oblique coronal MTP sequence.

Results: The PD and T2* values of cartilage in patients with SpA were significantly higher than those of healthy volunteers, p<0.05. There was no statistical difference between SpA and healthy group in T1 values of SIJ cartilage, P>0.05.

Impact: The MTP sequence represents a significant advancement in the imaging of SpA. By providing quantitative PD and T2* values of the SIJ cartilage, it offers a novel  tool for the early diagnosis of SpA.

Keywords: Cartilage, Quantitative Imaging

Motivation: Combing T2 mapping with routine knee MRI increase diagnostic efficacy especially early identification of joint degeneration.

Goal(s): To explore the feasibility of high-resolution deep-learning reconstruction (DLR) synthetic MRI with equivalent to higher diagnosis performance using conventional routine knee MRI as reference.

Approach: To test reliability of T2 mapping for in vitro phantom and in vivo human knees and explore the image quality of DLR synthetic contrast MR images in comparison with conventional MR images.

Results: DLR synthetic MRI offer reliable T2 mapping and provide sufficient image quality for diagnosis of knee.

Impact: There has been always a demand for high-resolution knee MRI acquisition and straightforward diagnosis in clinics. DLR synthetic MRI is a rapid-acquisition and high-image-quality contrast images and quantitative maps and may improves diagnosis, prognosis and follow-ups. 

Keywords: Cartilage, MSK, cartilage, osteoarthritis, IR-ZTE MR imaging

Motivation: The recently developed IR-ZTE MR technique is being proposed to have osteochondral junction (OCJ) region detection capability. The signal source in IR-ZTE imaging of the OCJ remains to be investigated. Validation by histology would provide strong corroboration of the signal sources. 

Goal(s): Our goal was to evaluate the correlation between the knee cartilage signal using IR-ZTE and degree of histological degeneration. 

Approach: Three patients were imaged using IR-ZTE before total knee replacement. Histological analysis was performed using the OARSI osteoarthritis cartilage histopathology assessment system.

Results: Results demonstrated that the signal changes of IR-ZTE was correlated strongly degree of histological degeneration in knee cartilage.

Impact:  IR-ZTE signal seems to serve as an in vivo indicator of the cartilage degeneration in knee OA progression.