[Value of MR for the diagnosis, differential diagnosis and therapy follow-up of Perthes' disease].

59 children were examined by MR, including 31 with Perthes' disease, 7 with subluxating Perthes' disease and 12 with hip pain of unknown origin; the results were compared with conventional radiological findings. MR was superior for the early recognition and for the exact determination of the extent and localisation of juvenile femoral epiphyseal necrosis. It was also of great help in differential diagnosis. It appears to be a suitable method for judging the effect of therapy at an early stage.