Transient osteoporosis of the hip: MR imaging.

Three patients with transient osteoporosis of the hip underwent magnetic resonance (MR) imaging. MR images showed decreased signal intensity of bone marrow in the femur on T1-weighted images and increased signal intensity relative to the intensity of normal bone marrow on T2-weighted images. Joint effusions were seen on MR images of all patients on T2-weighted images. The findings on MR images concurred with histologic findings, such as increased bone turnover and mild inflammatory reaction, in one patient. The clinical symptoms and abnormalities on MR images regressed completely within 6-10 months. Familiarity with the distinct features of transient osteoporosis on MR images may be important in the differential diagnosis of adults with hip pain.