MR-IMAGING IN EVALUATION OF SUSPECTED HIP FRACTURE - FREQUENCY OF UNSUSPECTED BONE AND SOFT-TISSUE INJURY

PURPOSE: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.