Room 355 BC

10:30 - 12:30

Moderators:

Hollis G. Potter, Siegfried Trattnig

Favian Su¹, Joan Hilton², Lorenzo Nardo¹, Samuel Wu¹, Fei Liang¹, Thomas M. Link¹, C. Benjamin Ma³, and Xiaojuan Li^1,3
1Musculoskeletal Quantitative Imaging Research, Department of Radiology and Biomedical Imaging, University of California, San Francisco (UCSF), San Francisco, CA, United States, ²Department of Epidemiology and Biostatistics, University of California, San Francisco (UCSF), San Francisco, CA, United States, ³Department of Orthopaedic Surgery, University of California, San Francisco (UCSF), San Francisco, CA, United States

Previous studies suggested that subjects with ACL injuries have a high risk of developing post-traumatic osteoarthritis even after ACL reconstruction. Cartilage matrix and morphology changes were evaluated within the medial and lateral regions of the femur and tibia of ACL-injured knees using 3 T MRI T1ρ and T2 quantification two years following reconstruction. Elevated T1ρ values and thicker medial compartments in ACL-injured patients was observed over the two years. T1ρ values in posterolateral tibial cartilage were significantly higher in ACL-reconstructed knees and were not fully recovered at the 2-year follow-up. These results suggest quantitative MRI can be a powerful tool for stratifying injury, monitoring and potentially predicting post-traumatic OA development in ACL-injured joints.

Wei Li¹, Martin Lazarus¹, Jason Koh², Ewa Gliwa¹, and Pottumarthi Vara Prasad^1
1Radiology, NorthShore University HealthSystem, Evanston, Illinois, United States, ²Orthopaedic Surgery, NorthShore University HealthSystem, Evanston, Illinois, United States

Based on the logistical advantage of the ia-dGEMRIC over the iv-dGEMRIC, we conducted a preliminary trial using ia-dGEMRIC to assess biochemical changes in cartilage in 39 patients with hip pain who underwent MR-arthrography at our institution. The T1 of articular cartilage was moderately correlated with T1 of joint fluid. This finding suggests that in ia-dGEMRIC, the cartilage T1 measurements may not be specifically related to the proteoglycan (PG) content in the cartilage, but may also reflect the contrast concentration in articular cavity. This will impact the interpretation of T1 values observed and inter-subject comparisons in articular cartilage

Daniele Ascani¹, Catherine Petchprapa², James S. Babb², Michael P. Recht², and Riccardo Lattanzi^1,3
1Radiology/Center for Biomedical Imaging, NYU Langone Medical Center, New York, NY, United States, ²Radiology, NYU Langone Medical Center, New York, NY, United States, ³The Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, NY, United States

Early detection of articular cartilage damage is critical to the success of joint preserving surgeries for patients with femoroacetabular impingement (FAI). Delayed Gadolinium-Enhanced MRI of Cartilage (dGEMRIC) and T2 mapping can detect early biochemical changes in cartilage. We investigated the relationship of dGEMRIC and T2 with morphologic cartilage assessment at 3T. dGEMRIC was very sensitive to cartilage damage (71% and 86% for minor and severe lesions, respectively), whereas T2 was very specific (87% for any type of lesion). This preliminary study suggests that the combination of morphologic MRI, dGEMRIC and T2 could be effective in detecting and staging cartilage damage.

Benjamin Schmitt¹, Beser Ferzan Suezer², Patrik Zamecnik³, Vladimir Jellus⁴, Marco Essig³, Siegfried Trattnig⁵, and Rainer Siebold^6
1Department of Radiology, Medical University of Vienna, Vienna, Vienna, Austria, ²Atos Hospital Heidelberg, Heidelberg, BW, Germany, ³German Cancer Research Center, Heidelberg, BW, Germany,⁴Healthcare Sector, Siemens AG, Erlangen, BY, Germany, ⁵Medical University of Vienna, Vienna, Vienna, Austria, ⁶Center Hip-Knee-Foot Surgery, Atos Hospital Heidelberg, Heidelberg, BW, Germany

The study was performed to assess to compare the results from gagCEST imaging and T2 mapping in 30 patients after autologous cartilage transplantation with a novel chondrosphere-based approach. While T2 mapping showed no significant differences between transplants and reference values taken from the contralateral knee, gagCEST signal intensities were lower in the transplants. This hints towards a reduced GAG content in repair tissue compared to native cartilage, although a high morphologic integrity of the transplants was demonstrated via MOCART scoring. The employed transplantation technique yielded a superior biochemical and morphologic outcome compared to previous MR studies.

Fang Liu¹, Samuel A. Hurley¹, Alexey Samosonov¹, Andrew L. Alexander¹, Sean C. L. Deoni², Walter F. Block^1,3, and Richard Kijowski^4
1Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, United States, ²Division of Engineering, Brown University, Providence, RI, United States, ³Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin, United States, ⁴Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin, United States

Multi-component T2 mapping using mcDESPOT three pool model was performed for correcting synovial fluid partial volume contamination in human knee cartilage in-vivo scan at 3.0T. T2 relaxation time for the bulk water loosely bound to the proteoglycan matrix (Wb) were shown to be mostly affected at the superficial layer of the cartilage with increasing T2 values more than 100% compared to the deep layer. mcDESPOT three pool model shows significant advantage of correcting the T2 relaxation time estimation bias while has no influence on measurements within the remaining portions of the cartilage.

Thomas Lange¹, Michael Herbst¹, Julian R. Maclaren², Cris Lovell-Smith¹, Kaywan Izadpanah³, and Maxim Zaitsev^1
1Department of Radiology, University Medical Center Freiburg, Freiburg, Germany, ²Department of Radiology, Stanford University, Stanford, California, United States, ³Department of Orthopedic and Trauma Surgery, University Medical Center Freiburg, Freiburg, Germany

Knee MRI can be used to probe the mechanical properties of the articular cartilage by comparative volumetric measurements with and without mechanical loading. However, to date MRI studies with in situ loading have been hampered by excessive subject motion. In this work, it is demonstrated that almost artifact-free high-resolution cartilage MRI of loaded tibiofemoral as well as patellofemoral joints can be performed using prospective motion correction based on optical tracking with appropriate tracking marker placement. Load-induced compression of the patellar cartilage is quantified in six healthy subjects. The method might provide new insight into the altered biomechanics associated with chondromalacia.

Guillaume Madelin¹, James S. Babb¹, and Ravinder R. Regatte^1
1Radiology Department, New York University Langone Medical Center, New York, NY, United States

Statistical learning algorithms, such as support vector machine (SVM), k-nearest neighbor (KNN), naive Bayes (NB) and discriminant analysis (DA), and logistic regression (LR), are compared for classifying subjects with and without osteoarthritis (OA) from sodium MRI data of articular cartilage at 7T. The best accuracy results are obtained with SVM and LR. SVM can classify the data with an accuracy of 78-80% by combining MRI measurements acquired with and without fluid suppression. LR generates a slightly lower accuracy (74-79%), but use only a single MRI measurement acquired with fluid suppression.

Ashley A. Williams¹, Yongxian Qian², and Constance R. Chu^1
1Cartilage Restoration Center, University of Pittsburgh, Pittsburgh, PA, United States, ²Radiology, University of Pittsburgh, Pittsburgh, PA, United States

This study examines UTE-T2* maps in 16 subjects acquired prior to and 12-months following ACL reconstruction surgery. UTE-T2* values decrease to asymptomatic levels in deep pMFC cartilage, suggesting healing of the deep articular cartilage matrix over 12 months following surgery. Meniscus UTE-T2* values in half of the subjects remain elevated or show further increases over the 12 months, demonstrating evidence of persistent subsurface degeneration a year after operative stabilization of the ACL-injured knee. Together these findings suggest that UTE-T2* provides a useful non-invasive tool to monitor cartilage and meniscal status in knees at risk of developing OA.

Alissa J. Burge¹, Danyal H. Nawabi², Stephanie Gold¹, Stephen Lyman³, Douglas E. Padgett², Matthew F. Koff¹, and Hollis G. Potter^1
1Department of Radiology and Imaging, Hospital for Special Surgery, New York, NY, United States, ²Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, NY, United States, ³Division of Epidemiology and Biostatistics, Hospital for Special Surgery, New York, NY, United States

An MRI classification system was developed to predict adverse local tissue reactions (ALTRs) in patients with metal-on-metal hip arthroplasty. MR images from 70 patients were assessed for osteolysis, synovitis, synovial thickness, presence of edema, synovial decompression, low signal intensity deposits, pseudocapsule dehiscence, disrupted abductors and neurovascular compression. Synovial tissues were obtained intra-operatively and were graded to assess tissue reaction. The presence and volume of synovitis, and the synovial thickness were found to correlate with histologic scoring. In patients with failed metal-on-metal (MOM) hip arthroplasty, MRI can be used to identify an adverse tissue reaction and predict the presence of soft tissue damage, helping guide the need for revision.

Jukka Hirvasniemi¹, Katariina A.M. Kulmala², Eveliina Lammentausta³, Risto Ojala⁴, Petri Lehenkari^5,6, Alaaeldin Kamel³, Jukka S. Jurvelin², Juha Töyräs^2,7, Miika T. Nieminen^3,4, and Simo Saarakkala^1,3
1Department of Medical Technology, University of Oulu, Oulu, Finland, ²Department of Applied Physics, University of Eastern Finland, Kuopio, Finland, ³Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland, ⁴Department of Diagnostic Radiology, University of Oulu, Oulu, Finland, ⁵Department of Anatomy and Cell Biology, University of Oulu, Oulu, Finland, ⁶Department of Surgery, Oulu University Hospital, Oulu, Finland, ⁷Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio, Finland

dGEMRIC with intravenous (dGEMRIC_IV) and intra-articular contrast agent injection (dGEMRIC_IA) and delayed quantitative CT arthrography (dQCTA) were compared in a patient study. dGEMRIC_IVand dGEMRIC_IA were performed at 90 minutes after gadopentetate injection. dQCTA was performed at 5 and 45 minutes after intra-articular injection of ioxaglate. Normalized dQCTA was in best agreement with dGEMRIC_IV at 45 minutes after ioxaglate injection (r_s=0.72). dGEMRIC_IV and dGEMRIC_IA were not correlated without taking account of synovial fluid. The findings of the study indicate the importance of taking account of the contrast agent concentration in synovial fluid in dQCTA and dGEMRIC_IA.