Assessment of wrist joint inflammation in patients with rheumatoid arthritis by quantitative two- and three-dimensional power Doppler ultrasonography.

OBJECTIVES

We aimed to compare the use of computer-aided quantification methods with 3 different power Doppler ultrasonography (PDUS) modes to assess wrist inflammation in patients with rheumatoid arthritis (RA).

METHODS

This study enrolled 49 patients (60 hand joints) with RA. Clinical parameters (rheumatoid factor [RF], erythrocyte sedimentation rate [ESR], and C-reactive protein [CRP]) were measured and pain was evaluated by a visual analogue scale (VAS, range: 0 to 10). Imaging of the affected wrist joints was performed with 2D- and 3D-PDUS imaging. The 2D imaging used a volumetric transducer and a linear transducer and the 3D imaging employed a volumetric transducer. Software was used to calculate the vascularisation index (VI), flow index (FI), and vascularisation flow index (VFI) under different measurement conditions.

RESULTS

There were 8 males and 41 females, with an average age of 47.59±15.17 years, and average VAS score of 3.63±2.22. In 2D-PDUS with a linear probe, there were significant correlations of ESR with VI and VFI, and of CRP with area, VI, and VFI (p<0.05 for all comparisons). In 3D-PDUS, there was a significant correlation of CRP with VFI (p<0.05). In all 3 measurement modes, there were moderate or high levels of inter- and intra-operator agreement in measurement of area/volume, VI, FI, and VFI.

CONCLUSIONS

All 3 PDUS measurement modes had high accuracy and reliability in assessment of wrist inflammation. These results suggest that use of a 3D transducer, which is more expensive and time-consuming, is not necessary for assessment of wrist inflammation.