ISMRM 24th Annual Meeting & Exhibition • 07-13 May 2016 • Singapore

Scientific Session: Imaging of Joint Health & Disease

Monday, May 9, 2016
Summit 2
10:45 - 12:45
Moderators: Emily McWalter, Edwin Oei

Imaging Cartilage-Bone Interactions in Osteoarthritis using Simultaneous 18F-NaF PET-MR imaging– the “Bone-Cartilage Connectome”
Dragana Savic1,2, Valentina Pedoia1, Youngho Seo1, Matthew Bucknor1, Benjamin Franc1, and Sharmila Majumdar1
1University of California San Francisco, San Francisco, CA, United States, 2University of Oxford, Oxford, United Kingdom
This first in human study evaluated cartilage biochemistry and bone function in sixteen knee osteoarthritis patients using simultaneous Time-Of-Flight (TOF) PET/MR imaging.  Bone turnover and blood flow was studied using 18F Sodium Fluoride (NaF) and quantitative voxel by voxel MR derived T relaxation times characterizing the biochemical cartilage degeneration. Increased degeneration of cartilage, was associated with increased turnover in the adjoining bone as well as in the non-adjoining compartments. These observations highlight the complex biomechanical and biochemical interactions in the whole knee joint, alluding to a “bone-cartilage connectome”, that potentially changes during the natural history of the disease. 

Dynamic analysis of [18F]-sodium fluoride uptake in knee osteoarthritis with PET-MRI
Audrey P Fan1, Feliks Kogan1, Aleema Patel1, Edwin HG Oei2, Andrew Quon1, and Garry E Gold1
1Radiology, Stanford University, Stanford, CA, United States, 2Erasmus MC: University Medical Center Rotterdam, Rotterdam, Netherlands
This study investigates dynamic uptake of [18F]-fluoride in bone marrow lesions (BMLs) and osteophytes observed on MRI of patients with knee osteoarthritis. Through kinetic modeling, we characterized rate constants of bone metabolism in bone pathology relative to healthy bone. BMLs and higher-grade osteophytes showed higher total bone metabolism Ki (P < 0.01) and higher bone mineralization rate k3 (P < 0.01) relative to grade 1 osteophytes and normal bone. While a similar trend was observed for blood flow, the differences from normal tissue were subtler suggests that rate of mineralization k3 and not blood flow is a key driver of [18F]-fluoride accumulation in OA lesions. These new physiological parameters may help differentiate between different grades of OA lesions or identify which lesions are active parts of the disease process.

Longitudinal Evaluation of Cartilage Component of Matrix-Associated Autologous Chondrocyte Transplants using Biochemical MR Imaging
Xian Xu1, Ningyu An1, Panli Zuo2, and Esther Raithel3
1Department of Radiology, Chinese PLA General Hospital, Beijing, China, People's Republic of, 2Siemens Healthcare, MR Collaborations NE Asia, Beijing, China, People's Republic of, 3Siemens Healthcare GmbH, Berlin, Germany
This study combined T2 mapping and delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) technique to evaluate the repair cartilage tissue after Matrix-associated autologous chondrocyte implantation (MACI). We found that the T2 and ΔR1 values of the repair tissue were significantly higher than the native tissue at 1, 3 and 6 months after MACI, but showed a downward trend and showed no difference with native tissue at 12 months, which suggested that the integrity of the collagen and GAG of repair tissue was similar to native cartilage. 

Loaded MRI – A Surrogate Measurement of in vivo Knee Joint Contact Mechanics
Matthew F. Koff1, Hongsheng Wang2, Suzanne Maher2, Scott Rodeo3, and Hollis G Potter1
1Department of Radiology and Imaging - MRI, Hospital for Special Surgery, New York, NY, United States, 2Department of Biomechanics, Hospital for Special Surgery, New York, NY, United States, 3Sports Medicine and Shoulder Service, Hospital for Special Surgery, New York, NY, United States
The relationship between calculated articular cartilage deformation when using an MR compatible loading device and actual contact mechanics has not been assessed. This study evaluated the accuracy of in vivo cartilage deformation as a surrogate for in vivo contact mechanics. Meniscal allograft transplantation patients underwent loaded MR pre-operatively and direct stress measurement intra-operatively. Good correlation, 0.72 (range: 0.56 to 0.85), between cartilage deformation and contact stress measurements was found. In vivo cartilage deformation may be a surrogate for in vivo contact mechanics.

Incorporation of Finite Pulse Correction for Improved MT-Corrected Multicomponent T2 analysis of Cartilage
Fang Liu1, Alexey Samsonov1, Wally Block2, and Richard Kijowski1
1Department of Radiology, University of Wisconsin-Madison, Madison, WI, United States, 2Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, United States
Nuclear magnetic resonance studies have identified multiple water components within cartilage tissue. Previous studies using steady-state sequences based rapid method such as mcDESPOT and mcRISE have shown feasibility of multicomponent T2 analysis of cartilage. However, steady-state signal can be influenced by the finite pulse effect which might lead to biased parameter estimation. In this study, we incorporated the finite pulse correction in the mcRISE model and demonstrated the potential MT and finite pulse effect in-sensitive T2 parameters for multicomponent cartilage relaxometry analysis.

Correlation of MRI Appearance of Total Hip Arthroplasty With Wear Metric and Histologic Evaluation
Matthew F. Koff1, Parina H. Shah1, Mauro Miranda1, Christina Esposito2, Elexis Baral2, Kara Fields3, Thomas Bauer4, HSS Adult Reconstruction & Joint Replacement Division5, Douglass Padgett5, Timothy Wright2, and Hollis G. Potter1
1Department of Radiology and Imaging - MRI, Hospital for Special Surgery, New York, NY, United States, 2Department of Biomechanics, Hospital for Special Surgery, New York, NY, United States, 3Healthcare Research Institute, Hospital for Special Surgery, New York, NY, United States, 4Cleveland Clinic Foundation, Cleveland, OH, United States, 5Adult Reconstruction and Joint Replacement Division, Hospital for Special Surgery, New York, NY, United States
A majority of primary total hip arthroplasty (THA) function well but implant failure may occur. We propose MRI to evaluate adverse local tissue reactions (ALTRs) in patients with THA. In this study, we correlate indirect measures of ALTRs with direct measurements of implant wear. Greater volumetric wear and visual damage was found in subjects with ALTR on MR images. MR also correlated with histologic metrics of implant wear. The results indicate that MRI allows for accurate diagnosis of different synovial patterns in THA, which correlate to wear analysis at retrieval.

In Vivo Evaluation of Low-grade Cartilage Defects in the Knee using Sodium MRI at 7T
Stefan Zbyn1,2, Vladimir Mlynarik1, Vladimir Juras1, Markus Schreiner1,3, Didier Laurent4, Joerg Goldhahn4, Nicole Getzmann4, Stefan Marlovits5, and Siegfried Trattnig1
1Department of Biomedical Imaging and Image-Guided Therapy, Medical University Vienna, Vienna, Austria, 2CD Laboratory for Clinical Molecular MR Imaging, Vienna, Austria, 3Department of Orthopaedics, Medical University Vienna, Vienna, Austria, 4Novartis Institutes for Biomedical Research, Basel, Switzerland, 5Department of Trauma Surgery, Medical University Vienna, Vienna, Austria
To our best knowledge, this is the first report on employing sodium (23Na) MRI for the in vivo evaluation of low-grade cartilage defects in the knee joint. In this 7T study, regions with chondral defect, weight-bearing, and non-weight-bearing femoral cartilage were evaluated in 23Na-images of patients after knee injury. Test-retest comparison showed high robustness and repeatability of sodium data. 23Na-MRI allowed differentiation between normal-appearing cartilage and low-grade chondral defects. 23Na-MRI can be used for noninvasive follow-up of changes in GAG content associated with cartilage degeneration. This method might be particularly useful for the evaluation of cartilage regenerating therapies.

Local Analysis of T1?, T2, and R2–R1? Compositional MR Imaging in Patients with ACL Injury Using Voxel-Based Relaxometry
Colin Russell1, Valentina Pedoia1, Keiko Amano1, and Sharmila Majumdar1
1Radiology and Biomedical Imaging, University of California, San Francsico, San Francisco, CA, United States
This multicenter study employs VBR as a novel technique to analyze patients with ACL tears at the time of injury and 6 months after ACL reconstruction. T and T2 analysis, correlation, and dispersion difference (R2–R) are three methods employed to highlight significant cartilage changes. The most posterior region of the posterior lateral tibia and the patella indicated partial cartilage recovery 6 months after reconstruction, demonstrated by decreasing T and T2, decreased T T2 correlation baseline to 6 months, and dispersion differences (R2–R). The trochlea displayed symptoms of cartilage degeneration, such as elevated T and T2 and dispersion differences.

In vivo assessment of T2* in menisci under loading conditions at 3 Tesla: preliminary results
Vladimir Juras1,2, Lenka Hornakova3, Petr Kubovy3, Daniel Hadraba3,4, Pavel Stursa5, David Gerych3, Pavol Szomolanyi1, Karel Jelen3, and Siegfried Trattnig1,6
1Department of Biomedical Imaging and Image-Guided Therapy, High Field MR Centre, Medical University of Vienna, Vienna, Austria, 2Department of Imaging Methods, Institute for Measurement Science, Bratislava, Slovakia, 3Department of Anatomy and Biomechanics, Faculty Of Physical Education and Sport, Prague, Czech Republic, 4Department of Radiology, Hospital na Homolce, Prague, Czech Republic,5Academy of Sciences of the Czech Republic, Prague, Czech Republic, 6Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria
Meniscus behavior under loading in vivo has been studied using parametric MR imaging. T2* has been acquired with vTE using very short first TE = 0.8 ms to secure the precise estimation. The knees of the subjects were loaded in situ with custom made compression device and T2* mapping was performed in 5 time points (without loading, and 4 consequent scans under the loading 7 min apart). The increase in T2* was observed in all compartments, significance was found in medial meniscus only. vTE T2* mapping might be a prospective marker for detecting the dynamic response of the meniscal tissue. 

3D UTE Cones-IDEAL Imaging of the Knee and Ankle joints: Fast Volumetric Imaging with Robust Fat/water Separation
Qun He1,2, Michael Carl3, Graeme Bydder1, and Jiang Du1
1University of California, San Diego, San Diego, CA, United States, 2Ningbo Jansen NMR Technology Co., Ltd., Cixi, Zhejiang, China, People's Republic of, 3Global MR Applications & Workflow, General Electric, San Diego, CA, United States
UTE sequences combined with IDEAL processing produces high contrast images of short T2 tissues or tissue components such as menisci, ligaments, and tendons. In this work, we report the use of 3D UTE Cones imaging and IDEAL processing (3D Cones-IDEAL) for volumetric imaging of short T2 tissues in the knee and ankle joints at 3T. High resolution volumetric imaging of the knee and ankle joints, together with robust fat/water separation, field map estimation, R2*/T2* mapping and fat fraction mapping are demonstrated.

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