MR imaging of cartilage: evaluation and comparison of MR imaging techniques

There is an increasing need for an accurate, noninvasive technique for the evaluation of cartilage. Magnetic resonance (MR) imaging, with its excellent contrast resolution and multiplanar imaging capability, was considered by many as the future gold standard for chondral imaging. Although substantial improvements in MR technology and understanding have occurred, the ideal imaging protocol and the role of MR imaging for cartilage evaluation has not been established. A confusing plethora of sequences have been advocated, with variable results and reproducibility. Often, techniques are not widely available or feasible from a practical point of view and many still require rigorous clinical evaluation. MR arthrography, although invasive and time consuming, provides excellent detailed evaluation of cartilage and can rival arthroscopy for the preoperative evaluation of traumatic osteochondral lesions or osteochondritis dissecans. Recently, encouraging results have been obtained with fat-suppressed imaging; however, further clinical trials are still awaited. This article attempts to place the various chondral MR imaging sequences in perspective, with discussion of their relative benefits and disadvantages.