yimeng zhang¹, zikang guo¹, and xinwei lei^2
1First Central Clinical College, Tianjin Medical University, Tianjin, Tianjin, China, ²Tianjin First Central Hospital, Tianjin, Tianjin, China

There are many clinical studies investigating the differences between non-radiographic axial spondyloarthritis and ankylosing spondylitis(AS), but few focus on radiology. Spondyloarthritis Research Consortium of Canada (SPARCC) and Sacroiliac Joint Structural Score (SSS) scoring systems can assess a broad spectrum of inflammatory and structural lesions. Our results indicate SPARCC scores were significantly improved after treatment. A significant increase in SSS scores for fat metaplasia and backfill was noted. Therefore, using semiquantitative MRI scoring methods can assess abnormal lesions and treatment response. Higher structural damages were seen in AS patients. SPARCC can assess severity of disease pre-treatment and treatment effectiveness.

Bili Wang^1,2, Jerzy Walczyk^1,2, Mohammed Ahmed¹, Madeline Rocks³, Stuart Elkowitz³, Louis Catalano³, Christopher Burke¹, Steven Daniels¹, and Ryan Brown^1,2
1Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States, ²Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States, ³Department of Orthopedic Surgery, New York University Grossman School of Medicine, New York, NY, United States

Dorsal wrist pain during extension or weight bearing is a common symptom, the etiology of which often remains unclear. Clinical MRI often fails to reveal causative pathology in part because it is performed in the neutral position. We built an apparatus to guide motion and used a flexible coil to capture signal in a range of positions that better match the conditions during which pain is reported. Results in nine asymptomatic volunteers show excellent tissue structure delineation, strong measurement agreement among readers, and increases in dorsal capsule thickness and radiocapitate, radiolunate, capitolunate and extensor tendon angulation during weight bearing.

Bobby Runderkamp¹, Matthan Caan², Wietske van der Zwaag³, Robert Hemke¹, Mario Maas¹, Mads Andersen^4,5, Gustav Strijkers², Karin Markenroth Bloch⁴, and Aart Nederveen^1
1Radiology & Nuclear Medicine, Amsterdam UMC, Amsterdam, Netherlands, ²Biomedical Engineering and Physics, Amsterdam UMC, Amsterdam, Netherlands, ³Spinoza Center for Neuroimaging, Amsterdam, Netherlands, ⁴Lund University Bioimaging Center, Lund, Sweden, ⁵Philips Healthcare, Copenhagen, Denmark

Imaging of the intricate arrangement of small structures in the wrist benefits from high resolution imaging, which the increased SNR at 7 Tesla can enable. However, the increased resolution requires longer scan times, decreasing patient comfort and increasing risk of motion artifacts. In this work, we evaluated compressed sensing (CS) acceleration of a clinical wrist 7T MRI protocol, 0.45mm isotropic resolution, in comparison to SENSE-acceleration. We show that CS-acceleration can produce adequate to good image quality in significantly shorter scan times, not achievable by increasing SENSE-acceleration.

Hari Umesh¹, Francesco Caliva², Jing Liu², Xiaojuan Li³, Thomas Link², Sharmila Majumdar², and Valentina Pedoia^2
1University of Illinois at Urbana-Champaign, Champaign, IL, United States, ²UCSF, San Francisco, CA, United States, ³Cleveland Clinic, Cleveland, OH, United States

Traditional MRI imaging involves injecting gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) , a pure substance that induces contrast to highlight inflammation and blood vessels in MRI images, proven to increase accuracy in radiologic diagnosis. We present a 2D V-net image contrast generation model that accurately predicts Gd-DTPA induced contrast from corresponding images without Gd-DTPA induced contrast.

Olli Nykänen^1,2, Antti Isosalo¹, Satu I Inkinen¹, Victor Casula^1,3, Mika Nevalainen^1,3,4, Riccardo Lattanzi⁵, Martijn Cloos⁶, Mikko J Nissi², and Miika T Nieminen^1,3,4
1Research Unit of Medical Imaging, Physics and Technology,, University of Oulu, Oulu, Finland, ²Department of Applied Physics, University of Eastern Finland, Kuopio, Finland, ³Medical Research Center, University of Oulu and Oulu University Hospital, Oulu, Finland, ⁴Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland, ⁵Center for Advanced Imaging Innovation and Research (CAI2R) and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States, ⁶Centre for Advanced Imaging, Queensland University, Brisbane, Australia

In this study, deep convolutional neural networks (DCNN) are used to synthesize contrast-weighted magnetic resonance (MR) images from quantitative parameter maps of the knee joint obtained with magnetic resonance fingerprinting (MRF). Training of the neural networks was performed using data from 142 patients, for which both standard MR images and quantitative MRF maps of the knee were available. The study demonstrates that synthesizing contrast-weighted images from MRF-parameter maps is possible utilizing DCNNs. Furthermore, the study indicates a need to tune up the dictionary used in MRF so that the parameters expected from the target anatomy are well-covered.

Laura Carretero^1,2, Xinzeng Wang³, Eugenia Sánchez⁴, Satish Nagrani⁴, Daniel Litwiller⁵, Pablo García-Polo¹, Maggie Fung⁶, and Mario Padrón^4
1GE Healthcare, Madrid, Spain, ²Rey Juan Carlos University, Madrid, Spain, ³GE Healthcare, Houston, TX, United States, ⁴Clínica Cemtro, Madrid, Spain, ⁵GE Healthcare, Colorado, CO, United States, ⁶GE Healthcare, New York, NY, United States

PROPELLER imaging is the choice for motion-prone anatomies, to generate good diagnostic quality images even for challenging patients. However, it is associated with prolonged scan times. In this study we evaluate the application of a new DL-based reconstruction algorithm to enhance a fast PROPELLER shoulder protocol with the goal of providing consistent diagnostic confidence and an overall improved image quality compared to conventional routine protocols. Our study demonstrates the proposed under 10min shoulder MRI protocols are interchangeable and have the same diagnostic confidence with better SNR and lesion conspicuity than routine MRI protocols for shoulder post-contrast and instability exams. 

Nico Sollmann^1,2,3, Noah B. Bonnheim⁴, Gabby B. Joseph¹, Ann A. Lazar⁵, Ravi Chachad¹, Jiamin Zhou¹, Jeannie F. Bailey⁴, Xiaojie Guo⁴, Thomas M. Link¹, Aaron J. Fields⁴, and Roland Krug^1
1Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, ²Department of Diagnostic and Interventional Radiology, University Hospital Ulm, Ulm, Germany, ³Department of Diagnostic and Interventional Neuroradiology, Technical University of Munich, Munich, Germany, ⁴Department of Orthopaedic Surgery, University of California San Francisco, San Francisco, CA, United States, ⁵Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, United States

Low back pain (LBP) is a global health burden, but patient phenotyping based on imaging that would facilitate timely and effective treatment regimens lacks behind. One issue is that associations between different structures at the degenerative lumbar spine are not yet well characterized. In this study we revealed that facet joint arthropathy (FJA) at level L4/L5 is associated with the fat fraction (FF) of adjacent paraspinal musculature (PSM) as derived from chemical shift encoding-based water-fat MRI (CSE-MRI), as well as with Modic-type endplate changes, endplate defects, and intervertebral degenerative disk disease (DDD) in patients with chronic LBP. 

Iman Khodarahmi¹, Mahesh B Keerthivasan², and Jan Fritz^1
1Radiology, New York University School of Medicine, New York, NY, United States, ²Siemens Medical Solutions USA Inc, Malvern, PA, United States

A robust B₁⁺ mapping technique in the presence of metallic hardware is still unavailable. Our proposed B₁⁺ quantification technique relies on turbo-spin echo or SEMAC acquisitions to decrease metal-related susceptibility artifacts while resolving B₁⁺ values from signal variations at various sets of excitation and refocusing flip angles. Apriori knowledge of signal evolution is obtained by simulating the Bloch equations at each B₁⁺ value. Phantom validation showed promising results, particularly at areas close to the metal surface, which are invisible with other mapping techniques.