ANTERIOR HORN OF THE LATERAL MENISCUS - ANOTHER POTENTIAL PITFALL IN MR-IMAGING OF THE KNEEL

PURPOSE: To demonstrate that speckled increased signal intensity at th e anterior horn of the lateral meniscus near its central attachment si te on sagittal magnetic resonance (MR) images of the knee is a normal finding. MATERIALS AND METHODS: In 22 patients (17 male and five femal e patients; age range, 13-74 years; mean, 38 years) who underwent arth roscopy after MR imaging, knee MR images that showed speckled increase d signal intensity at the anterior horn of the lateral meniscus near i ts central attachment site on two consecutive sagittal proton-density- weighted images were selected for retrospective review. In addition, a review of 11 knee MR examinations of nine healthy volunteers (five me n and four women; age range, 27-43 years; mean, 34 years) was performe d. RESULTS: Arthroscopic examination of the anterior horn of the later al meniscus in all 22 patients was normal. Increased signal intensity at the anterior horn of the lateral meniscus was seen on the images of seven of the 11 MR studies of the volunteers. CONCLUSION: Increased s ignal intensity at the anterior horn of the lateral meniscus near its central attachment site on knee MR images does not represent a menisca l tear.