Joost Verschueren MD, Presenter: Nothing to Disclose

Jasper Van Tiel MD, Abstract Co-Author: Nothing to Disclose

Max Reijman, Abstract Co-Author: Nothing to Disclose

Esther Bron BSC, Abstract Co-Author: Nothing to Disclose

Stefan Klein, Abstract Co-Author: Nothing to Disclose

Jan Verhaar, Abstract Co-Author: Nothing to Disclose

Sita Bierma-Zeinstra PhD, Abstract Co-Author: Nothing to Disclose

Gabriel P. Krestin MD, PhD, Abstract Co-Author: Consultant, General Electric Company Research Grant, General Electric Company Research Grant, Bayer AG Research Grant, Siemens AG Speakers Bureau Siemens AG

Gyula Kotek PhD, Abstract Co-Author: Nothing to Disclose

Edwin H.G. Oei MD, PhD, Abstract Co-Author: Nothing to Disclose

Delayed gadolinium enhanced MRI of cartilage (dGEMRIC) and T2-mapping are often used as quantitative imaging biomarkers in osteoarthritis (OA) research to measure proteoglycan content and collagen network integrity, respectively, and together offer comprehensive assessment of biochemical composition and structure of articular cartilage. Pre- and post-contrast T2 relaxation times have shown to be comparable in ex-vivo MRI of human osteochondral samples, but results obtained in OA and intact cartilage in-vivo at 1.5T are contradictory. As acquisition of dGEMRIC and T2-mapping within one post-contrast imaging session improves efficiency and reduces scan time and costs, our purpose was to assess the influence of contrast agent on T2 relaxation times acquired in-vivo at 3T in OA patients.

Ten knee OA patients (Kellgren-Lawrence grade 2-3) underwent dGEMRIC and T2 mapping at 3T. A 3D fast spin-echo sequence with 5 echo times (3, 13, 27, 40, 68 ms) for T2 mapping was performed before and 75 minutes after intravenous administration of gadolinium dimeglumine (0.2 mmol/kg) for dGEMRIC. Mean T2 relaxation times were calculated in 6 cartilage regions (located medially and laterally in the weight-bearing and posterior cartilage of the femoral condyles and tibial plateaus), using in-house developed post-processing software that incorporates automated rigid registration in 3D for motion correction. Pre- and post-contrast T2 relaxation times were compared with correlation analysis, intraclass correlation coefficient (ICC) and Wilcoxon signed-rank test.

Pre- (mean 41.5; range 28.8-64.7 ms) and post-contrast (mean 41.1; range 28.5-73.0 ms) T2 relaxation times were strongly correlated (r=0.87, r2=0.75, p<0.001) with a high ICC (0.92, 95CI: 0.86-0.95), and their mean values were not statistically significantly different (p=0.08).

The results indicate that pre- and post-contrast T2 relaxation times of in-vivo OA knee cartilage acquired at 3T are strongly correlated and that there is no evidence to suggest a difference in T2 relaxation times. Therefore, T2-mapping can be performed reliably within a single post-contrast imaging session in combination with dGEMRIC acquisition.

For comprehensive assessment of articular cartilage structure and biochemical composition, dGEMRIC and T2-mapping can be combined in one imaging session with reliable T2 relaxation time measurement.

Verschueren, J, Van Tiel, J, Reijman, M, Bron, E, Klein, S, Verhaar, J, Bierma-Zeinstra, S, Krestin, G, Kotek, G, Oei, E, T2 Relaxation Times of Knee Articular Cartilage in Osteoarthritis Patients Are Not Influenced by Gadolinium Contrast Agent.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14017532.html