Prospective comparison of magnetic resonance imaging and computed tomography in diagnosing occult scaphoid fractures.

BACKGROUND: Suspected scaphoid fracture (SF) after a fall on an outstretched hand is a common presentation in the emergency department. Magnetic resonance imaging (MRI) or computed tomography (CT) has been suggested to assist in the diagnosis or exclusion of SF.

PURPOSE: To compare MRI and CT at diagnosing occult SFs.

MATERIAL AND METHODS: We routinely perform CT scans in patients with clinically suspected occult SF, after 7-10 days of injury following two negative radiographs. All eligible patients with a clinically suspected SF, but negative radiographs and a negative CT, underwent an MRI scan to assess further for evidence of occult fracture.

RESULTS: A total of 100 patients were included in our study. MRI showed fractures in 16% of the time (in 15 patients) when plain radiographs and CT did not. Of these fractures, 8% were SFs. In addition to fractures, 10% had bone bruising. A total of 25% of patients with fractures and bone bruising were referred to the hand surgery team for further follow-up.

CONCLUSION: The study demonstrated that MRI would identify a radiographically occult SF more often than CT. This supports NICE guidelines which recommend MRI as the best early diagnostic tool for occult SFs.