Darryl Sneag

James Griffith

Eric E. Sigmund¹, Steven H. Baete¹, and Danielle Costanzo^1
1Radiology, NYU Langone Health, New York, NY, United States

We describe measurement of resistance dependence diffusion metric exercise response in thigh muscle with a multiple echo diffusion tensor imaging (MEDITI) on a clinical 3 T scanner.  With radial imaging, accelerated diffusion encoding, and compressed sensing reconstruction, spatial resolution of 3.4 mm and temporal resolution of 16 s was achieved.  Using an MR-compatible ergometer with pneumatic resistance and force/displacement monitoring, post-exercise recovery of DTI metrics in the rectus femoris following quadriceps extension was monitored as a function of resistance.  Significant dependences of response on resistance were observed.

Hyungseok Jang¹, Michael Carl², Yajun Ma¹, Mei Wu¹, Zhao Wei¹, Saeed Jerban¹, Eric Chang^1,3, and Jiang Du^1
1University of California, San Diego, San Diego, CA, United States, ²GE Healthcare, La Jolla, CA, United States, ³VA San Diego Healthcare System, San Diego, CA, United States

Double echo steady state (DESS) imaging allows acquisition of two MR images with different contrasts from FID and echo images. In this study, we explored the feasibility and efficacy of 3D UTE Cones-based DESS (3D UTE-Cones-DESS) imaging of short T2 tissues in the knee joint. In ex vivo study of four cadaveric knees and in vivo study of three healthy volunteers, the UTE-Cones-DESS sequence provided high contrast imaging of the osteochondral junction (OCJ), the menisci, and other short T2 tissues, as well as T2 maps, under a total scan time of three minutes.

Stephan Breda¹, Dirk Poot¹, Dorottya Papp¹, Gabriel Krestin¹, Robert-Jan de Vos², and Edwin Oei^1
1Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, Netherlands, ²Orthopedics & Sports Medicine, Erasmus University Medical Center, Rotterdam, Netherlands

Patellar tendinopathy (PT) is an overuse injury of the patellar tendon in athletes, often resulting from jumping activities such as playing basketball or volleyball. MR imaging with ultrashort echo times (3D-UTE MRI) is used to image the typical degenerative process of the proximal patellar tendon in PT. However, image analysis can be challenging within the heterogeneous patellar tendon affected by tendinopathy. Therefore, we propose a novel method for image analysis, in which voxels are sub-selected based on a parameter from bi-exponential fitting. This resulted in the identification of T2* biomarkers, specific for distinct tissue-compartments within the patellar tendon.

Andreas Port¹, Roger Luechinger¹, David Otto Brunner¹, and Klaas Paul Pruessmann^1
1Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland

Kinematic MR studies provide functional insights that corresponding static methods may not be able to provide. However, MR signal reception from body parts with large flexion ranges, such as the knee, can be challenging. Wearable RF coils that adapt well to a specific anatomy would offer good sensitivity and patient comfort at the same time. In the present work, we explore the practical utility of a wearable liquid metal coil. For this purpose a MR compatible knee bending setup is used. Static and kinematic imaging of a volunteer’s knee confirm sensitivity and coverage over the whole range of flexion.

Kenneth T. Gao¹, Valentina Pedoia¹, Radhika Tibrewala¹, Katherine A. Young², Feliks Kogan², Matthew F. Koff³, Garry E. Gold², Hollis Potter³, and Sharmila Majumdar^1
1Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States, ²Department of Radiology, Stanford University, Stanford, CA, United States, ³Department of Radiology and Imaging, Hospital for Special Surgery, New York, NY, United States

Magnetic resonance imaging (MRI) is commonly used to evaluate the morphology of athletes with high knee impact; however, the biochemical composition of their cartilage is not as well understood. In this study, we utilized voxel-based relaxometry (VBR), a fully automatic registration technique, to compare local distribution of knee articular cartilage T_1ρ and T₂ relaxation times between high knee impact athletes (basketball players) and non-knee impact athletes (swimmers). Statistical analysis revealed laminar differences near the patella, with basketball players having prolonged values in the deep layer. These findings, amongst others, related well to morphological evaluation of the image set.