MR imaging is advancing rapidly as an important imaging technique of the evaluation of internal derangements of the knee. The utility of MR imaging in the preoperative assessment of knee disorders has been documented. A number of normal anatomic structures within the knee may simulate diseases, such as meniscal and ligamentous tears and osteochondral and meniscal fragments. Careful attention of normal signal intensity of the knee ligaments and contiguous structures is crucial in the accurate assessment of potential disease.