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

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).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.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 (p0.05 for all comparisons). In 3D-PDUS, there was a significant correlation of CRP with VFI (p0.05). 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.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.