Objectives: To compare the ability of 2 different E-MRI units and conventional radiography (CR) to identify bone erosions in rheumatoid arthritis (RA) metacarpophalangeal (MCP) and wrist joints, with computed tomography (CT) as standard reference method.
Methods: 20 RA patients and 5 controls underwent, within 2 weeks, CR, CT and two E-MRI (Esaote Biomedica; Artoscan and MagneVu; MV1000) examination of one hand. In all modalities each bone of wrist and (MCP) joints was blindedly evaluated for erosions. Furthermore, MagneVu images were assessed for the proportion of each bone being visualized.
Results: 550 bones were examined. CT, Artoscan, MagneVu and CR detected 188, 116, 55 and 45 bones with erosions, respectively. The majority were located in the carpal bones.
The sensitivity of Artoscan for detecting erosions was higher than of MagneVu and CR (MCP joints: 0.68, 0.54 and 0.57, respectively; wrists: 0.50, 0.23 and 0.29).
Corresponding specificities for detecting erosions were 0.94, 0.93 and 0.99, respectively, in the MCP joints and 0.92, 0.98 and 0.98 in the wrist.
The MagneVu allowed visualization of 1.5 cm of the ventral-dorsal diameter of the bone. In the wrist 31.6% of bones were visualized entirely and 37.9% of bones were 67-99% visualized. In MCP joints, 84.2% of bones were visualized entirely and 15.8% of bones were 67-99% visualized.
Conclusion: With CT as reference method for detecting erosions in RA hands, Artoscan showed higher sensitivity than MagneVu and CR. All imaging modalities revealed high specificities. The better performance of Artoscan should be considered when selecting imaging method in RA.