Fast three-dimensional MR imaging of the knee: comparison with arthroscopy

Twenty patients with suspected internal derangement of the knee were examined with fast, three-dimensional (3D) magnetic resonance (MR) imaging and arthroscopy with a numerical classification system designed for use by both the radiologist and orthopedist. MR volume acquisitions allowed delineation of all arthroscopically diagnosed meniscal tears and high-grade meniscal degeneration. All arthroscopically visible ligamentous injuries, including partial cruciate tears, were detected with MR imaging. There was excellent correlation for high-grade cartilaginous lesions, although MR imaging appeared insensitive to small cartilage irregularities. Additionally, MR imaging allowed diagnosis of ten bone abnormalities not accessible to arthroscopic evaluation. The high accuracy of MR imaging that was found in this study was in large part due to the thin, contiguous sections generated in volume imaging. With the added advantage of high patient throughput, fast volume MR imaging is an accurate and efficient method for evaluation of knee abnormality.