MR imaging of the knee

This paper describes the two-tone meniscus, a sign of meniscal tear on MR imaging. MR images obtained at 0.3 and 1.5 T with 3-mm-thick sections were compared with arthroscopic findings for 86 patients studied over a 2-year period. Menisci described as two-tone menisci had two geographic regions of slightly different signal intensity: a region of subtle increased signal extending to at least one articular surface, which did not have linear or globular configuration, effacing a region of normal meniscal signal. The higher-signal-intensity region shows signal intensity greater than normal meniscus but less than grade 2 or 3 changes, hyalin cartilage, or joint fluid