Elisa Ramos Gavila¹, Alejandra Duarte¹, Jenny Bencardino², Jonathan Samuel², Svetlana Krasnokutsky², and Jose Raya Garcia del Olmo^2
1Radiology, NYU Langone Health Hospital, New York, NY, United States, ²NYU Langone Health Hospital, New York, NY, United States

Early detection of knee osteoarthritis can be achieved by identifying early compositional changes of degenerative articular cartilage. The purpose of this case-control longitudinal study is to validate DTI as a biomarker for OA diagnosis, staging and progression in early stages of the disease.  60 patients with incipient OA (KL1) underwent 3 visits (baseline, 1.5 year and 3 years follow up). Clinical evaluation, Xray and MRI was performed. Positive correlation was demonstrated with morphological changes (KL and WORMS score). In addition, DTI showed changes in the follow up at 1.5 years that were not apparent in clinical MRI.

Ari Väärälä^1,2, Arttu Peuna³, Egor Panfilov^1,2, Victor Casula^1,2, Marianne Haapea^2,4, Eveliina Lammentausta^1,2,4, and Miika T Nieminen^1,2,4
1Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland, ²Medical Research Center, University of Oulu and Oulu University Hospital, Oulu, Finland, ³Medical Imaging, Central Finland Health Care District, Jyväskylä, Finland, ⁴Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland

In the present study, a gray level co-occurrence matrix-based 3D texture analysis of knee 3D DESS images was used to investigate longitudinal changes in articular cartilage using data from the Osteoarthritis Initiative (baseline, 36-month and 72-month visits). At baseline, all subjects included in the study had Kellgren-Lawrence grade < 2. Three groups were defined, based on time of progression into radiographic osteoarthritis (Kellgren-Lawrence grades ≥ 2): control, slow progressor and fast progressor groups. 3D texture analysis of 3D DESS images was able to distinguish progressors from controls before radiographic signs of osteoarthritis and showed significant longitudinal changes across all groups.

Frank Zijlstra¹ and Peter R Seevinck^1
1Image Sciences Institute, UMC Utrecht, Utrecht, Netherlands

This study proposes a 5 minute knee protocol using an extension of the double-echo steady-state (DESS) sequence to include multiple readouts. This multiple-echo steady-state (MESS) sequence supports quantification of water, fat, and T2, in a single, efficient acquisition. These parameters may provide additional tissue-specific MRI biomarkers, for example in muscle and bone, on top of the T2 quantification of cartilage provided by the DESS sequence. In vivo results on 5 volunteers show robust water-fat separation and that T2 quantification using MESS corresponds well with quantification on water-selective DESS images.

Azadeh Sharafi¹, Marcelo V. W. Zibetti¹, Gregory Chang¹, Martijn A. Cloos¹, and Ravinder R. Regatte^1
1Radiology, NYU Langone Health, New York, NY, United States

Osteoarthritis of the knee, the most common joint disease, is a degenerative heterogeneous musculoskeletal disease which is mainly recognized by the progressive loss of hyaline articular cartilage (1). Spin-lattice relaxation in the rotating frame (T_1ρ) and spin-spin relaxation (T₂) have been shown to be sensitive to the biochemical changes associated with osteoarthritis progression including: loss of proteoglycans, increased water content, and disruption of collagen and anisotropy (1, 2).  In this study, we propose a novel MR fingerprinting sequence for in-vivo simultaneous T1, T2, and T1ρ relaxation mapping of knee joint at 3T.

Marianne S Black^1,2, Katherine A Young¹, Akshay S Chaudhari¹, Feliks Kogan¹, Bragi Sveinsson³, Emily J McWalter⁴, Garry E Gold^1,5, Marc E Levenston^1,2, and Brian A Hargreaves^1,5,6
1Radiology, Stanford University, Stanford, CA, United States, ²Mechanical Engineering, Stanford University, Stanford, CA, United States, ³Massachusetts General Hospital, Boston, MA, United States, ⁴Mechanical Engineering, University of Saskatchewan, Saskatoon, SK, Canada, ⁵Bioengineering, Stanford University, Stanford, CA, United States, ⁶Electrical Engineering, Stanford University, Stanford, CA, United States

There is a pressing need for a single-time-point quantitative measure capable of predicting osteoarthritic change.  Bilateral knee imaging with T₂ cluster asymmetry analysis is a promising approach to achieve this goal. This study examines T₂ cluster asymmetry in ACL-injured subjects and controls. ACL-injured subjects showed elevated T₂ cluster asymmetry 9-months following reconstruction surgery relative to the controls in the superficial half of cartilage. This novel approach for analyzing T₂ relaxation times in femoral cartilage shows promise in detecting changes that may be indicative of early osteoarthritis onset.

Henri Leskinen¹, Nina E. Hänninen^1,2, and Mikko J. Nissi^1,2
1University of Eastern Finland, Kuopio, Finland, ²University of Oulu, Oulu, Finland

Number of studies have investigated the orientation dependence of T2 relaxation in articular cartilage and, more importantly, connected the orientation dependence to the properties of the collagen fiber network in cartilage. The dependence arises from the non-averaging secular part of the dipolar coupling, which in turn has been attributed to the water-orienting properties of the collagenous network. Using high angular resolution sample rotation, this study aimed to measure the in-plane fiber angle, collagen anisotropy as well as the isotropic and anisotropic components of T2 relaxation in cartilage. Potential for extracting physically meaningful properties of cartilage from multi-orientation measurements was demonstrated.

Matthew Grondin¹, Fang Liu², Sami Faruqui², Alexei Samsonov², Wan-Ju Li³, Corinne Henak¹, and Richard Kijowski^2
1Mechanical Engineering, University of Wisconsin-Madison, Madison, WI, United States, ²Radiology, University of Wisconsin-Madison, Madison, WI, United States, ³Orthopedic Surgery, University of Wisconsin-Madison, Madison, WI, United States

Multi-component Driven Equilibrium Single Pulse Observation of T1 and T2 (mcDESPOT) was used to measure single-component T2 relaxation time (T2_Single) and the fraction of the fast relaxing macromolecular bound water component (F_F) of 24 human patellar cartilage samples at 3.0T.  The cartilage samples underwent mechanical testing to measure linear modulus and energy dissipation and biochemical analysis to measure proteoglycan content.  There were significant (p<0.01) and moderate positive correlations between F_F and proteoglycan content, linear modulus, and energy dissipation of cartilage.  There were non-significant (p=0.06-0.21) and low negative correlations between T2_Single and proteoglycan content, linear modulus, and energy dissipation of cartilage.

Stefan Zbyn^1,2, Kai D. Ludwig^1,2, Lauren Watkins³, Alexandra R. Armstrong⁴, Russell L. Lagore^1,2, Amanda Nowacki¹, Marc A. Tompkins⁵, Ferenc Toth⁴, Gregor Adriany^1,2, Kevin G. Shea⁶, Garry Gold⁷, Armin M. Nagel⁸, Cathy S. Carlson⁴, Gregory J. Metzger^1,2, and Jutta M. Ellermann^1,2
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, ²Department of Radiology, University of Minnesota, Minneapolis, MN, United States, ³Department of Bioengineering, Stanford University, Stanford, CA, United States, ⁴Department of Veterinary Clinical Sciences, University of Minnesota, St. Paul, MN, United States, ⁵Department of Orthopaedic Surgery, University of Minnesota, Minneapolis, MN, United States, ⁶Department of Orthopaedic Surgery, Stanford Children's Hospital, Palo Alto, CA, United States, ⁷Department of Radiology, Stanford University, Stanford, CA, United States, ⁸Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany

Sodium imaging is quantitative technique sensitive to changes in cartilage glycosaminoglycan content. Changes in cartilage matrix, due to maturation or degeneration, may influence sodium relaxation times which can lead to incorrect sodium concentration estimates when not addressed. This ex vivo study employs pediatric knee specimens to evaluate the relationship between sodium relaxation parameters and compositional changes in the developing cartilage matrix. Our preliminary evaluation suggests that cartilage maturation is accompanied by a decrease in sodium T₁ and the short T₂* component. Sodium concentrations in studies comparing healthy, diseased or immature cartilage should be corrected for possible changes in relaxation times.

Lidi Wan^1,2, Xin Cheng³, Adam C Searleman¹, Yajun Ma¹, Jonathan H Wong^1,4, Mark E Murphy⁵, Jiang Du¹, Guangyu Tang², and Eric Y Chang^1,4
1Department of Radiology, UC San Diego, San Diego, CA, United States, ²Department of Radiology, Shanghai Tenth People's Hospital, Shanghai, China, ³Division of Histology and Embryology, Jinan University, Guangzhou, China, ⁴Radiology Service, VA San Diego Healthcare System, San Diego, CA, United States, ⁵Orthopaedic Surgery Service, VA San Diego Healthcare System, San Diego, CA, United States

A panel of quantitative UTE techniques have been developed to assess articular cartilage. Osteoarthritis (OA) is a multifactorial disease characterized primarily by degeneration and loss of hyaline articular cartilage. This study investigated whether quantitative 3D UTE-Cones-based biomarkers are sensitive to proteoglycan (PG) loss and collagen degradation induced by enzyme in human cartilage, and also to determine the specificity of these biomarkers in quantitative cartilage imaging.