Magnetic resonance image of INFH were correlated with histologic sections. Seventeen patients withe eighteen hips were included in this study. reoperative radiographs and MRI were taken for the patients. Three hips were in stage II, nine hips were in stage III, and remaining six were in stage IV respectively(Ficat and Alert). These hips were replaced with artificial joint and resected heads were examined. The specimens were bisected along the imaging plane, and studied histologically and matched with respective MR images of T1 and T2. Specimen MRI was performed on three femoral head immediately after femoral head removal. Necrotic portion of the femoral head in earlier stage showed higher signal intensity in T1-weighted image. Subchondral void, necrotic bone and saponified fat were responsible for low signal intensity in necrotic portion. Low signal band adjacent to the necrotic foci represented inner fibrous tissue and outer reactive sclerotic bone. Outside the fibrous band, the signal intensity diminished compared with normal fatty marrow. these findings were attributed by cellular infiltration and trabecular bony proliferation. MRI patterns were variable in various stages, but corresponded well with histologic findings.