Objective: A prospective study was performed to assess the usefulness of contrast-enhanced color Doppler ultrasound (CDUS) in the evaluation of intraarticular vascularization of finger joints in patients with rheumatoid arthritis (RA).
Methods: We investigated 198 finger joints in 46 patients with RA, and 80 finger joints in 10 healthy volunteers. Joints with varying levels of clinical activity of inflammation were classified as being active, moderately active, or inactive. CDUS was performed with a high-frequency multi-D linear array transducer. A microbubble-based ultrasound (US) contrast agent (Levovist; Schering, Berlin, Germany) was intravenously infused. Doppler findings were rated on the basis of both unenhanced and contrast-enhanced CDUS images.
Results: Healthy joints showed no intraarticular vascularization on either unenhanced or contrast-enhanced CDUS. Unenhanced CDUS detected intraarticular vascularization in 7 (8%) of 83 inactive joints, in 31 (52%) of 60 moderately active joints, and in 32 (58%) of 55 active joints. Contrast-enhanced CDUS detected intraarticular vascularization in 41 (49%) of 83 joints with inactive RA, in 59 (98%) of 60 joints with moderately active RA, and in all 55 joints with active RA. Detection of intraarticular vascularization was improved by administration of the microbubble-based US contrast agent (P < 0.001). Contrast-enhanced CDUS demonstrated differences in intraarticular vascularization between joints with inactive RA and those with active RA (P < 0.001), between joints with inactive RA and those with moderately active RA (P < 0.001), and between joints with moderately active RA and those with active RA (P < 0.001).
Conclusion: The use of a microbubble-based US contrast agent significantly improved the detection of intraarticular vascularization in the finger joints of patients with RA. This technique seems to be a useful adjunct in the assessment of disease activity.