Occult wrist fractures: high definition macroradiography versus MRI.

To compare the diagnostic value of high definition macroradiography and MRI in patients with the suspicion of occult wrist fractures. Materials and Me thods: In a prospective study, 23 patients with clinically suspected wrist fractures and normal initial-plain radiographs underwent high resolution ma croradiography and MR imaging shortly after trauma. Macroradiographs were t aken with a microfocus tube using an anode of 0.03-0.3 mm providing a 4 x m agnification of the wrist, which was obtained in 4 projections. MR images w ere performed on a 1.0T MR unit in coronal planes using T(1)weighted SE, T- 2-weighted 3D GE, and Turbo-STIR sequences. Follow-up radiographs after 6 w eeks were used to confirm the diagnosis of a primary occult wrist fracture. Results: Macroradiography depicted 5 wrist fractures: 4 fractures of the s caphoid bone and 1 fracture of the capitate bone. MRI demonstrated 11 fract ures (one of them false-positive): 9 fractures of the scaphoid bone and two fractures of the capitate bone. Using macroradiography, the sensitivity fo r the detection of occult fractures of the wrist was 50% with a specificity of 100%, using MRI the sensitivity was 100% with a specificity of 92%. Con clusion: MRI seems to be superior to high resolution macroradiography in th e detection of occult scaphoid fractures and thus is recommended in the man agement of patients with clinically suspected scaphoid;fractures not eviden t on initial plain films.