Abnormal florid synovial thickening and proliferation is present around the wrist most pronounced involving the radiocarpal and intercarpal joints with the hypertrophied synovium relatively low signal on T2 weighted sequences. The hypertrophied synovium fills and distends the joint recesses as well as extrudes into surrounding tendon sheath most notably the ECU and EDM. A degree of infiltration into the ECU tendon itself just beyond the level of the ulnar styloid is also noted. This abnormal synovial proliferation also results in intra-osseous extension with multiple areas of bony erosions throughout the carpus, distal radius and proximal metacarpals. Median and ulnar nerves level of the wrist are within normal limits.
Conclusion:
Pigmented villonodular synovitis (PVNS) is felt less likely given an apparent polyarticular process. A crystalline arthropathy such as gout or CPPD or in the appropriate clinical context, amyloid arthropathy are the favoured diagnoses. Further evaluation with a duel energy CT of the wrist is suggested.