Double Echo Steady State (DESS) Magnetic Resonance Imaging of Knee Articular Cartilage at 3 Tesla – a Pilot Study for the Osteoarthritis Initiative

Objective: Quantitative magnetic resonance imaging (qMRI) may provide valuable measures of cartilage morphology in osteoarthritis (OA) but has been confined to sequences with relatively long acquisition times at 1.5 Tesla (T). Here we test the accuracy and precision of knee cartilage qMRI with a fast double echo steady state (DESS) sequence with water excitation (we) at 3T. Methods: As a pilot study for the Osteoarthritis Initiative, test-retest MR images were acquired in the knees of 19 participants with no to moderate degrees of clinical OA. Two double oblique coronal fast low angle shot (FLASHwe) sequences (1.5 mm slice thickness) were acquired at 3T, and two sagittal DESSwe sequences (0.7 mm slice thickness). Double oblique coronal multiplanar reformats (MPR) were performed (1.5 mm slice thickness) from the sagittal DESSwe. Knee joint cartilage plates were quantified unpaired in random order with blinding to subject identification. Results: In the femorotibial joint, precision errors (RMS CV% for unpaired analysis) for cartilage volume and thickness were 3.1% to 6.4% with coronal FLASHwe, 2.5% to 6.2% with coronal MPR DESSwe, and 2.3% to 8.2% with sagittal DESSwe. Correlation coefficients between DESSwe and FLASHwe ranged from r = 0.88 to 1.0. In the femoropatellar joint, precision errors (sagittal DESSwe) were 3.4% to 8.5%. Conclusions: DESSwe permits accurate and precise analysis of cartilage morphology in the femorotibial joint at 3T. Further studies are needed to address the accuracy of DESSwe in the femoropatellar joint and its ability to characterize sensitivity to longitudinal changes in cartilage morphology.