Magnetic resonance imaging of knee menisci. Comparison of spin echo pulse sequences

Magnetic resonance imaging (MRI) is accurate in evaluating meniscal tears using spin echo pulse sequences. The purpose of this study was to systematically compare T1-weighted pulse sequences to two echo proton density/T2 (2eT2)-weighted sequences. Menisci were separated into four grades based on signal characteristics. In addition, all menisci were graded as positive or negative for tear. Twenty-three patients (46 menisci) were studied with both pulse sequences and the results were compared with arthroscopic findings. Using T1 sequences, 14 of 18 torn menisci and 26 of 28 untorn menisci were identified. Using 2eT2 sequences, 13 of 18 torn menisci and 26 of 28 untorn menisci were correctly identified. There was high correlation between T1 and 2eT2 sequences for torn versus untorn menisci and for grade of injury (P = .99). There is very little difference between T1- and 2eT2-weighted pulse sequences in evaluation of meniscal tears.