Contrast-enhanced power Doppler ultrasonography of the metacarpophalangeal joints in rheumatoid arthritis

Abstract.

The aim of this study was to examine, with dynamic contrast-enhanced MRI as the reference, if contrast-enhanced power Doppler ultrasonography (CE PDUS) of rheumatoid arthritis (RA) metacarpophalangeal (MCP) joints provides additional information for evaluation of synovial inflammation compared with PDUS. One MCP joint in each of 15 RA patients and 3 healthy control persons were examined with PDUS before and after intravenous bolus Levovist contrast injection. Corresponding rates of early synovial enhancement (RESE), previously shown to be closely related to histopathological synovitis, were calculated from dynamic contrast-enhanced MR images obtained the same day. Prior to ultrasonography, the joint was evaluated clinically. Levovist increased the flow signal in 7 of 9 joints with pre-contrast flow-signal and in 0 of 9 without pre-contrast signal. No healthy controls showed CE PDUS signal. The results of CE PDUS and dynamic MRI were closely related: RESE in joints with CE PDUS signal was significantly higher than in joints without CE PDUS signal (Mann-Whitney test, p<0.001). Among the patients with pre-contrast PDUS signal no statistically significant difference in RESE values was found between joints with and without post-contrast flow-signal increase. No correlation was found between clinical examination and CE PDUS. Based on comparisons with dynamic contrast-enhanced MRI, PDUS appears to be reliable for assessment of synovitis in RA MCP joints. Intravenous contrast injection may provide additional information in selected cases but did not in the present study increase the sensitivity of the method.