[NMR tomography of lunate malacia]

Magnetic resonance imaging in Kienböck's disease

With a 1.5 tesla superconducting M.R. imager and surface coil, M.R. imaging achieved high resolution analysis of the wrist on five normal wrists and 26 wrists with Kienböck's disease. The purpose of this study was to establish new criteria for diagnosis, staging and prognosis of Kienböck's disease, based on signal characteristics on T1- and T2-weighted images. Focal loss of signal intensity of the lunate on T1-weighted image was an indication of Kienböck's disease. A decreased signal containing a high spot and increased signal intensity of the lunate on T2-weighted images indicated a better prognosis. After osteotomy of the radius, the signal intensity of the lunate returned to normal and Lichtman's stage II cases had better results than those in stage III. M.R. imaging is ideal for evaluating the lunate in Kienböck's disease.

Magnetic resonance imaging in scaphoid fractures

The use of a 1.5 tesla superconducting M.R. imager and surface coil was found to enhance the ability of M.R.I. to depict the fine anatomy of the wrist. Five healthy volunteers and 28 patients with scaphoid fractures underwent M.R.I., which made possible a definitive diagnosis of scaphoid fractures at an early stage. A fresh fracture was identified by decreased or iso signal intensity on the T1-weighted image and increased signal intensity on the T2-weighted image. This increase continued until bony union was apparent on radiographs. On the T2-weighted image, high signal intensity was characteristic of fresh fractures and suggested that bony union was possible. When bony union was complete, the intensity of the signal for the scaphoid on both T1- and T2-weighted images returned to normal. M.R.I. should thus prove useful in the diagnosis of scaphoid fractures.