Figure 6b. Synovial osteochondromatosis of the wrist. (a) Anteroposterior radiograph of the wrist demonstrates multiple small, calcified nodules (white arrows) of characteristically uniform size in the radioulnar joint. Note the erosive changes (black arrows) of the distal radius and ulna. (b) Coronal proton density-weighted MR image demonstrates an intermediate-signal-intensity mass (*) in the radioulnar joint. (c) Coronal T2-weighted image shows that the mass (*) is hyperintense. On both MR images, note the multiple low-signal-intensity areas (arrowhead), which correspond to areas of calcification seen on the radiograph.