MRI OF OSTEOCHONDRITIS-DISSECANS OF THE KNEE-JOINT AFTER IV GADOLINIUM-DTPA

20 patients with osteochondritis dissecans were studied by MRI over a period of 3-34 months in order to observe healing and determine the viability of the loose fragment. After intravenous contrast, there was increased signal intensity at the junction between the fragment and the epiphyseal bed on T2-weighted sequences; this was interpreted as fibrous granulation tissue surrounding the fragment. The fragments themselves also showed increased signal intensity after Gadolinium-DTPA. Intravenous Gadolinium allows accurate evaluation of the junctional zone between the fragment and the epiphyseal bed by demonstrating fibrous, vascularised granulation tissue. This can be distinguished from synovial fluid, and it also demonstrates viability of the fragment.