Magnetic resonance imaging and miniarthroscopy of metacarpophalangeal joints - Sensitive detection of morphologic changes in rheumatoid arthritis

Objective. To evaluate and characterize magnetic resonance imaging (MRI) fi ndings in the metacarpophalangeal (MCP) joints of rheumatoid arthritis (RA) patients macroscopically, using miniarthroscopy (MA; needle arthroscopy). Methods. The second MCP joint of the dominant hand of 22 RA patients (13 wi th various RA activities/ stages; 9 with early RA [less than or equal to1.5 years' duration]) was examined by MRI followed by MA. Findings were evalua ted by standardized semiquantitative measures of synovial and bony patholog ic changes of the MCP joint, and were compared with the clinical and conven tional radiologic findings. Results. Erosions and pre-erosions were detected in 17 of 22 patients by MR I; 2 of the other 5 patients (all early RA) displayed bony changes on MA. A ll 10 joints with pre-erosions on MRI (grade 1 bony alterations on MRI) exh ibited significant cartilaginous and bony pathology on MA. Synovial membran e pathology was detected in all but 1 patient by MRI and in all patients by MA, although findings of plain radiography were normal in 6 of the 22 pati ents and another 9 patients had a Larsen score of 1. Semiquantitative analy sis of synovial findings of MRI revealed gadolinium diethylenetriaminepenta acetic acid enhancement as a significant marker of macroscopically varied s ynovial vascularity and hyperemia, both of which strongly correlated with c linical activity (as measured by the Disease Activity Score). The extent of synovitis/synovial proliferation shown by MA and MRI were significantly co rrelated with each other, but not with any other activity or damage paramet er analyzed. Conclusion. In RA, both MRI and MA findings support early detection and sta ging of synovial changes. Ongoing longitudinal studies are aimed at evaluat ing the value of synovial proliferation as visualized by both methods.