Legg-Perthes-Calvé disease: staging by MRI using gadolinium.

Twenty-one patients (26 hips) with typical signs of Legg-Perthes-Calvé (LPC) disease on plain radiographs were explored by MRI. Patients were imaged with a 0.5 T MR unit. Gadolinium-enhanced spin-echo MR images were obtained after nonenhanced T1-weighted (spin-echo) and T2*-weighted (gradient-echo) images. Four different areas were identified in the femoral epiphysis (necrosis, regenerative, cartilaginous and normal fatty bone tissue). The histological evolution of LPC is well described by Catterall and others. Comparing their descriptions with our MR findings, we suggest classification of LPC into five phases: necrosis: regeneration, reconstruction, reossification and sequelae.