Background: Magnetic resonance (MR) sequences for cartilage visualization have been the target of numerous studies, and the optimal sequence for cartilage imaging remains a matter of debate in the literature.
Purpose: To compare MR findings with different MR sequences for the detection of cartilage lesions in fresh deep-frozen human cadaveric patellae in an in vitro setting.
Material and methods: Ten cadaveric patellae were imaged on a 1.5T MR scanner with a 2x2 channel carotid sandwich coil and a conventional knee coil, and compared with orthopedic findings and gold-standard histopathology. MR sequences were: a) fat-saturated (FS) proton density-weighted (PDw) turbo spin-echo (TSE) sequence (TR/TE 4000/39 ms); b) T2-weighted (T2w) double-echo steady-state (DESS) 3D water-excitation (we) sequence (TR/TE 17/4.7 ms); c) 3D-PDw-SPACE (sampling perfection with application-optimized contrasts using different flip-angle evolutions)-we sequence (TR/TE 1800/19 ms). Accuracy, Kendall's tau-b correlation, and weighted kappa coefficients were calculated.
Results: Accuracy for cartilage lesion detection with the FS PDw-TSE sequence and the carotid coil was 78.3%, and with the knee coil 73.9%. For the T2wDESS-3D-we sequence, the corresponding values were 69.5% and 65.2%, and for the 3D-PDw-SPACE-we sequence 65.2% and 60.8%, respectively. Kendall's tau-b correlation ranged between 0.508 for the 3D-PDw-SPACE-we sequence (knee coil) and 0.720 for the FS PDw-TSE sequence (carotid and knee coil). Weighted kappa coefficient was lowest for the 3D-PDw-SPACE-we sequence (knee coil) at 0.607, and highest for the carotid coil and FS PDw-TSE sequence at 0.779.
Conclusion: The evaluated FS PDw-TSE sequences are superior in comparison to the T2wDESS-3D-we and 3D-PDw-SPACE-we sequences in the in vitro setting for the detection of cartilage lesions, and are comparable to results reported in the literature.