Degenerative changes of the menisci of the knee. Value of different MR pulse sequences.

Increased meniscal MR signal attributable to meniscal degeneration is a common finding. The role of different MR sequences in the analysis of the extent and distribution of meniscal degeneration in middle-aged and elderly patients has not been thoroughly evaluated. We retrospectively studied the role of different MR sequences in 175 anatomic meniscal sections originating from 20 freshly frozen knees from 10 cadavers using MR-anatomic correlation. T1-weighted and proton-density spin-echo images as well as postprocessed meniscal windows based on T1-weighted spin-echo images proved to be the most reliable in this diagnosis (53.7%, 54.9%, and 53.1% correctly diagnosed meniscal sections, respectively). T2-weighted spin-echo images and gradient-echo images proved to be less reliable (37.1% and 40.0% correctly diagnosed meniscal sections). While the T2-weighted spin-echo images commonly underestimated the extent of meniscal degeneration, gradient-echo images commonly overestimated the extent of such changes. These last two types of sequences should not be used alone in the description of meniscal degeneration.