MR imaging in evaluation of suspected hip fracture: frequency of unsuspected bone and soft-tissue injury.

Abstract

To determine the frequency of unsuspected pelvic fracture and soft-tissue injury in patients referred for magnetic resonance (MR) imaging for possible radiographically occult hip fracture. Seventy patients with symptoms of possible hip fracture but negative plain radiographs were evaluated with MR imaging. Large-field-of-view T1-weighted coronal images were obtained, and additional T2-weighted or short inversion time inversion recovery (STIR) sequences were used. The number of soft-tissue and bone injuries identified was recorded. Eighty percent of patients had bone or soft-tissue abnormalities. Occult femoral and pelvic fractures were demonstrated in 37% and 23% of patients, respectively. Soft-tissue abnormalities were noted in 74% of patients. When a proximal femoral fracture was not present, MR imaging revealed a 27% frequency of occult pelvic fracture and a 50% frequency of bone or soft-tissue abnormality. A high prevalence of occult pelvic fracture and soft-tissue injury may be identified with MR studies designed to evaluate occult hip fracture when large-field-of-view T1-weighted coronal sequences are combined with T2-weighted or STIR sequences.