Objective: The purpose of this study was to evaluate the usefulness of MR imaging in revealing occult fractures in patients with clinically suspected acute scaphoid fractures who have normal or equivocal findings on radiographs.
Subjects and methods: Thirty-six patients underwent MR imaging within 7 days of wrist injury. All had physical findings suggestive of scaphoid fracture. Coronal T1-weighted, short inversion time inversion recovery, and either T2-weighted or proton density-weighted fast spin-echo sequences with fat suppression were used. Follow-up radiographs were obtained at least 2 weeks after MR imaging whenever possible. All imaging studies were reviewed by two musculoskeletal radiologists.
Results: MR imaging revealed 22 occult fractures in 20 patients. Thirteen of these 22 fractures were in the scaphoid bone, and nine were in the distal radius. On MR images, 16 patients had no evidence of fracture. Follow-up radiographs were available in 14 of the 20 patients who had occult fracture revealed by MR imaging. Eleven of the 13 occult fractures of the scaphoid bone were followed up (two were lost to follow-up), and 10 of the 11 showed signs of healing. Five of the nine lesions of the distal radius were followed up, and three of these showed evidence of healing fracture. Three patients without MR evidence of a fracture had follow-up radiographs that showed no fracture. Three patients had findings consistent with bone contusion on MR images; in two patients, the contusion was associated with other fractures, and in one patient, the contusion was isolated.
Conclusion: MR imaging can reveal occult wrist fractures when findings on radiographs are normal or equivocal.