MR diagnosis of meniscal tears of the knee: value of fast spin-echo vs conventional spin-echo pulse sequences.

OBJECTIVE: Contrast can be similar on fast spin-echo and conventional spin-echo MR images, but data acquisition is faster with fast spin-echo sequences. This study was designed to evaluate the performance of fast spin-echo sequences in the detection of meniscal tears in the knee, with the established conventional spin-echo technique used as a reference standard. SUBJECTS AND METHODS: We imaged 66 consecutive patients (129 menisci) who were referred for MR examination with suspected meniscal tears. We used our routine two-dimensional, multisection, long repetition time/double-echo spin-echo sequence and one of two fast spin-echo sequences. The fast spin-echo parameters were chosen to minimize the loss of high-resolution detail while otherwise maintaining the sequence as close as possible to the spin-echo sequence. We then did a retrospective evaluation of the fast spin-echo images, using the spin-echo images as the gold standard. RESULTS: Fast spin-echo images showed only 30 (65%) of the 46 meniscal tears seen on the conventional spin-echo images. In addition, four of the 30 tears seen with both sequences were diagnosed with greater confidence on the conventional spin-echo images. In the cases in which both sequences allowed a diagnosis of definite meniscal tear, the abnormalities tended to be more conspicuous on the spin-echo images. CONCLUSION: Our results suggest that the fast spin-echo sequence should not be used for the diagnosis of meniscal tears.