Radiofrequency (RF) coil impacts the value and reproducibility of cartilage spin–spin (T2) relaxation time measurements

Summary Introduction T2 (spin–spin) relaxation time is frequently used for compositional assessment of articular cartilage. However little is known about the influence of magnetic resonance (MR) system components on these measurements. The reproducibility and range of cartilage T2 values were evaluated using different extremity radiofrequency (RF) coils with potential differences in flip angle uniformity and signal-to-noise ratio (SNR). Method Ten knees underwent 3 T MR exams using RF coils with different SNR: quadrature transmit/receive (QTR); quadrature transmit/eight-channel phased-array receive (QT8PAR). Each knee was scanned twice per coil (four exams total). T2 values were calculated for the central medial and lateral femoral (cMF, cLF) and medial and lateral tibial (MT, LT) cartilage. Results The flip angle varied across a central 40 mm diameter region-of-interest of each coil by