Nian Wang^1,2, Qiuting Wen¹, Surendra Maharjan¹, and Charles Spritzer^3
1Radiology and Imaging Sciences, Indiana University, Indianapolis, IN, United States, ²Stark Neurosciences Research Institute, Indiana University, Indianapolis, IN, United States, ³Radiology Department, Duke University, Durham, NC, United States

Magic Angle Effect (MAE) has been demonstrated to play an important role in both T2 and T1rho relaxation times in articular cartilage, its impact on the DTI measurements is still unknown. In this study we imaged rat knee, rat brain, and human brain at different orientation to explore the magic angle effect.

Harry Lanz¹, Karyn Elizabeth Chappell², and Mihailo Ristic^3
1Mechanical Engineering, Imperial College London, London, United Kingdom, ²Surgery and Cancer, Imperial College London, London, United Kingdom, ³Mechanical Engineering Department, Imperial College London, London, United Kingdom

By exploiting the field-dependent anisotropy of collagen, valuable clinical information can be obtained, such as fibre tractography. We investigated the use of a priori anatomical knowledge such as scout scan, using both simulations and experimentally acquired images. We conclude that only 3 scanning directions may be sufficient for robust analysis, instead of 9 or more in the case when no such information is used. The method is also compatible with low SNR values associated with low-field MRI.

Karyna Isaieva¹, Justine Leclère^1,2, Xavier Dubernard², Jacques Felblinger^1,3, and Pierre-André Vuissoz^1
1IADI, Université de Lorraine, INSERM, Nancy, France, ²Oral Medicine Department, University Hospital of Reims, Reims, France, ³CIC-IT, CHRU de Nancy, INSERM, Nancy, France

Current diagnosis of temporomandibular disorders includes clinical examination and MRI; however, static MR images in only two key positions are not sufficient for detection of some cases of temporomandibular disk displacement. We acquired jaw opening and closure movements for 5 healthy volunteers with a real-time MRI in axial plane. The condyles were segmented with a convolutional neural network approach and motion curves of their mass centers were calculated. It was shown that the proposed protocol gives straighforward evaluation of condylar motion assymetry.

Jennifer Morgan Watchmaker¹, Ding Xia², Etan Dayan¹, Idoia Corcuera-Solano¹, Justin E Ngeow¹, Samantha T By³, Gang Chen³, Elena Kaye³, John Pitts³, Rafael O'Halloran³, Zahi A Fayad^1,2, Mingqian Huang¹, and Li Feng^2
1Department of Diagnostic, Molecular and Interventional Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, ²BioMedical Engineering and Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States, ³Hyperfine, Guilford, CT, United States

In this work, we present results of knee imaging using a portable, point-of-care MRI system in healthy subjects and subjects with knee pathology. To the best of our knowledge, this is the first reported results for knee imaging using the portable Swoop MRI system, a portable 0.064 T MRI scanner. The low-field images show good performance in visualizing the knee joint, and there was not a significant difference in the readers’ ability to evaluate the anatomic structures. 

Maxim Zaitsev¹, Olgica Zaric², and Sigfried Trattnig^2
1High Field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria, ²High Field MR Center, Department of Biomedical Imaging and Image- Guided Therapy, Medical University of Vienna, Vienna, Austria

Sodium imaging has a great potential for basic research and clinical MRI, but its applications are limited due to poor SNR achievable in typical in vivo scanning times. Image acquisition times can be substantially extended if involuntarily subject motion is compensated for, e.g. by using an external optical motion tracking system. In this proof-of-concept study we demonstrate 1mm isotropic 23Na MRI with the achieved image quality sufficient for the anatomical orientation based on the native sodium images. The used ultra-short echo time 3D imaging sequence was implemented in Pulseq, an open-source platform-independent development environment.

Ananya Goyal¹, Christopher Beaulieu¹, Maggie Fung², Trevor Kolupar³, Akshay Chaudhari¹, Kathryn Stevens¹, and Feliks Kogan^1
1Radiology, Stanford University, Stanford, CA, United States, ²GE Healthcare, New York, NY, United States, ³GE Healthcare, Milwaukee, WI, United States

Conventional knee MRI protocols use numerous 2D-FSE sequences with multiple contrasts, which have long scan times and don’t fully use modern parallel imaging and improved SNR technologies.In this abstract, we outline four approaches that reduce protocol times to <6 minutes and potentially add diagnostic value through quantitative data or oblique reformats.These include an accelerated conventional 2D protocol, SNR-efficient 3D qDESS and CUBE approaches, and a thin-Slice protocol with high slice resolution.We propose a study that will evaluate the performance of each of these knee MRI protocols, and determine diagnostic utility and confidence with respect to fluid sensitivity and tissue pathologies.

Timothy JP Bray^1,2, Carolyna JP Hepburn¹, Alexis Jones³, Alan Bainbridge⁴, Hui Zhang⁵, and Margaret A Hall-Craggs^1,2
1Centre for Medical Imaging, University College London, London, United Kingdom, ²Department of Imaging, University College London Hospital, London, United Kingdom, ³Rheumatology, University College London Hospital, London, United Kingdom, ⁴Medical Physics, University College London Hospital, London, United Kingdom, ⁵Centre for Medical Image Computing, University College London, London, United Kingdom

Short inversion time inversion recovery (STIR) MRI is widely used in clinical practice to identify and quantify inflammation in patients with axial spondyloarthritis. However, assessment of STIR images is limited by the qualitative nature of image interpretation, which depends on observer expertise, and can be biased by the clinical setting. To address this, we propose the volume of hyperintense inflammation (V_HI) as a quantitative imaging biomarker of inflammation load, underpinned by a recently-described segmentation method incorporating deep learning and intensity-based segmentation.

Laura Carretero^1,2, Pablo García-Polo¹, Alejandro Congo³, Michael Carl⁴, Graeme C McKinnon⁵, Maggie Fung⁶, and Mario Padrón^3
1GE Healthcare, Madrid, Spain, ²Rey Juan Carlos University, Madrid, Spain, ³Clínica Cemtro, Madrid, Spain, ⁴GE Healthcare, San Diego, CA, United States, ⁵GE Healthcare, Waukesha, WI, United States, ⁶GE Healthcare, New York, NY, United States

In this study we evaluate the viability of using ZTE, a novel MRI sequence for bone imaging, with deep-learning (DL) reconstruction to assess glenohumeral shoulder instability, aiming to improve signal-to-noise ratio (SNR) and get comparable images to CT, the gold standard technique for surgical planning. Bone loss measurements were performed on both techniques achieving almost perfect inter-modality agreement on 20 patients. This approach could prevent the patient from receiving ionizing radiation concomitant to CT examination and could be combined in a single routine shoulder examination with other MR sequences for a complete study and optimized patient workflow.

Erol Akkoc¹, Jan Fritz¹, and Hoi Cheung Zhang^1
1NYU Grossman School of Medicine, New York, NY, United States

Elbow MRI contributes essential information in acute and chronic elbow injuries. Elbow MRI is ideally obtained in the superman position (prone position with elbow extended, arm elevated above the head, and hand pronated); however, this position can be challenging for patients due to injury-related pain and positioning-related discomfort. To shorten the exam time and reduce patient discomfort, we developed a 4-fold accelerated 5-sequence 6-minute clinical MRI protocol using combined simultaneous multi-slice and parallel imaging acceleration of turbo spin echo sequences. In this study, we compared the image quality of our conventional and novel accelerated elbow MRI protocols.

Charlotte L Hewitt-Dedman¹, Sarah E Taylor¹, Tobias Schwarz¹, Carola R Daniel¹, Maria Chiara Pressanto¹, and Lucy E Kershaw^2
1Royal Dick School of Veterinary Studies and Roslin Institute, Royal Dick School of Veterinary Studies and Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom, ²BHF Centre for Cardiovascular Science and Edinburgh Imaging, BHF Centre for Cardiovascular Science and Edinburgh Imaging, University of Edinburgh, Edinburgh, United Kingdom

Fractures of the third metacarpal/tarsal bone are common in racehorses. Racehorse cadaver limbs underwent single voxel magnetic resonance spectroscopy (MRS) and computed tomography. The percentage fat content (FC) and the mean bone mineral density (BMD) was calculated at 3 locations within the bone. A significant negative correlation was identified for mean BMD and percentage FC for all condyles and in bone marrow of the third metacarpal/tarsal distal diaphysis. The median percentage FC was lower in horses with fractures compared to controls. These findings suggest that fat and bone are capable of mutual regulation in Thoroughbred racehorses.