MR-IMAGING OF DIGITAL MUCOID CYSTS

PURPOSE: To assess the usefulness of magnetic resonance (MR) imaging i n the diagnosis and clarification of the physiopathology of digital mu coid cysts. MATERIALS AND METHODS: Twenty-three patients (14 women, ni ne men; aged 52-75 years) with mucoid cysts underwent MR imaging at 1. 5 T with a local surface gradient coil. The pixel size was 117 mu m in one direction. T2 relaxation times were measured. Contrast material w as intravenously administered in 15 patients. RESULTS: All mucoid cyst s had high signal intensity and sharp borders on T2-weighted images. I ntracystic septa were present in nine patients (39%). Most cysts were solitary (n = 13) and/or in the proximal nail fold (n = 16). Satellite cysts were present in five patients. Nineteen patients (83%) had cyst s with pedicles that extended to the joint. Osteoarthritis of the dist al interphalangeal joint was present in 16 patients (70%). Five patien ts (22%) had multiple flattened cysts that were usually independent of the joint. In seven patients (30%), MR images showed cysts beneath th e nail plate. CONCLUSION Digital mucoid cysts may be polymorphic. MR i maging is helpful when cysts are in the nail bed.