Occult fractures of the proximal femur: MR imaging.

Coronal T1-weighted magnetic resonance (MR) images were obtained on a 1.5-T system in 23 patients in whom there was a high clinical suspicion of hip fracture although initial radiographs were normal. MR imaging correctly demonstrated fracture in nine of nine patients; the precise configuration of the fracture line was delineated in eight patients. MR imaging was useful in excluding fractures in 14 of 14 patients, who were subsequently followed up clinically for a minimum of 3 months. Radionuclide scans were positive in four of four patients with fractures and equivocal in one patient who was subsequently demonstrated to have no fracture. Additional imaging studies were requested by clinicians in all cases in which the bone scan was positive. The results of this study suggest that MR imaging can provide a rapid, cost-effective, and anatomically precise diagnosis of hip fracture in patients with normal or equivocal initial radiographs. The specificity of the diagnosis achieved can obviate supplemental imaging examinations, with their attendant additional expense and radiation exposure.