[Magnetic resonance arthrography in chondral disease of the knee]

The clinical usefulness of Magnetic Resonance Imaging (MRI) of the knee in the depiction of meniscal, ligament and tendon lesions is well known. In contrast, the role MRI plays in the diagnosis of chondromalacia remains debated, the gold standard being arthroscopy. A new technique, i.e., MR arthrography (MRA), has been recently proposed which consists of the intraarticular injection of a paramagnetic contrast agent (Gd-DTPA) during MRI. Thirty-one patients with clinically suspected chondromalacia of the knee were examined with MRA. The exams were performed with a 1T superconductive magnet and a dedicated coil. All the patients were examined before (baseline scans) and after paramagnetic contrast agent injection. MRA results were compared with arthrographic findings. Baseline MRI had 25% sensitivity, 77.9% specificity and 83% diagnostic confidence in the diagnosis of chondromalacia; these figures increased to 93%, 97.6% and 91.5% after contrast agent injection. This preliminary experience confirms MRA to be a useful tool in the diagnosis of chondral knee conditions.