Ultrasound detects rapid progression of erosive disease in early rheumatoid arthritis: a prospective longitudinal study.

OBJECTIVE

To evaluate and compare sequential ultrasound exams (US) with power-Doppler (PD) to radiography for the detection of synovitis and erosions in patients with early RA.

METHODS

Radiographs and US with PD of the hands and feet were performed at baseline and 6+/- 2 months afterwards in 21 early RA patients. Their mean (range) age was 42.6 (21-81) years and the female/male ratio was 4:3; mean disease duration was 9 (1-28) months. Joints assessed were bilateral 2nd and 5th MCPs, 5th MTPs and the most swollen PIP in each hand, for a total of eight joints per patient. Radiographs (PA, lateral and pronated oblique) were read for erosions using the method of Sharp/van der Heijde. On US, erosions were defined as cortical defects greater than 2 mm in diameter with an irregular floor. Synovitis was rated as +1 (increase in joint fluid without synovial hyperemia), +2 (mild blood flow), +3 (moderate blood flow), and +4 (severe blood flow). Two blinded trained assessors read all images.

RESULTS

US detected 15 erosions in 10 patients at baseline and 31 erosions in 12 patients on follow-up; radiographs could detect only one erosion at baseline and five erosions in three patients on follow-up. PD detected synovitis in all patients at baseline and on follow-up. Of the joints found to have synovitis, 64% were identified as such at baseline and 38% on follow-up.

CONCLUSIONS

Sequential US can determine disease progression in patients with early RA. Such data may allow the clinician to treat RA patients earlier in the hope of preventing joint damage.