RADIOGRAPHICALLY OCCULT SCAPHOID FRACTURES - VALUE OF MR-IMAGING IN DETECTION

PURPOSE: To evaluate the diagnostic value of magnetic resonance (MR) i maging in patients with clinical suspicion of scaphoid fractures and n ormal initial plain radiographs. MATERIALS AND METHODS: MR imaging was performed within 7 days after trauma in 42 patients with clinical sus picion of scaphoid fractures and normal plain radiographs. T1-weighted spin-echo, T2-weighted gradient-echo, and short inversion time inver sion-recovery (STIR) sequences were performed. MR images were evaluate d independently by two radiologists. Six-week follow-up radiographs we re used as a standard to diagnose fractures. RESULTS: MR imaging depic ted occult fractures of the scaphoid bone in 14 patients (33%), the ca pitate bone in four (10%), the trapezium in one (2%), and the distal r adius in two (5%). All wrist fractures were detected with a combinatio n of STIR and T1-weighted spin-echo sequences. The sensitivity and spe cificity for detection of radiographically occult fractures of the wri st were 100% each for the first and 95% and 100%, respectively, for th e second radiologist with an almost perfect interobserver agreement (k appa = 0.953). CONCLUSION: MR imaging has a high sensitivity for detec tion of fractures of the scaphoid bone and wrist not evident on plain radiographs and may enable early diagnosis and treatment.