Sonia Bajaj MD, Abstract Co-Author: Nothing to Disclose

Robert R. Lopez-Ben MD, Presenter: Nothing to Disclose

Graciela Alarcon MD, Abstract Co-Author: Nothing to Disclose

To evaluate and compare sequential US with radiography for the detection of erosions (Er) in patients with early rheumatoid arthritis (RA). Detection of progression of synovitis by Power Doppler in this cohort was also evaluated.

Radiographs of the hands and feet and US with PD were performed at baseline (Bas) and 6±2 months afterwards (follow up-FU) in 21 RA patients. Joints assessed were bilateral 2nd and 5th MCP, 5th MTP and the most swollen PIP in each hand (for a total of 8 joints per patient). These joints were selected due to their preferential detection by US in early RA. Radiographs were read for Er using the method of Sharp/van der Heijde. On US, Er were defined as cortical defects greater than 2mm in diameter. Synovitis was rated as +1 (increase in joint fluid), +2 (mild hyperemia), +3 (moderate hyperemia), and +4 (extensive hyperemia). Two blinded trained assessors read all images. Our previously published preliminary study had shown the comparable accucracy of US with MRI in erosion detection in established RA patients with our technique.

168 joints in 21 patients were studied. Their mean (range) age was 42.6 (21-81) years. Their mean disease duration was 9 (1-28) months. US detected 15 erosions in 10 patients at baseline while radiography detected only 1 erosion (p<0.001). On follow-up US detected 31 erosions in 12 patients compared with 5 erosions in 3 patients by radiography (p<0.001). Thus compared to radiography US detected 15 fold more erosions at baseline and 6.2 fold more erosions on follow-up. PD detected synovitis in all patients at baseline (58-joints) and on follow-up (78-joints).The inter-observer reliability for erosions by US was excellent with kappa score of 0.98, for severity of synovitis it was 0.96 and for radiographic erosions was 0.88.

A significant larger number of Er and of patients with Er were detected by US than with radiographs at both time points. Within a short time the number of joints with Er in these patients increased two-fold. As expected, PD identified sub-clinical synovitis. Our data suggest that sequential US may be a valuable tool in the assessment of disease progression in early RA.

Bajaj, S, Lopez-Ben, R, Alarcon, G, Utilizing Ultrasound in Early RA to Establish Progression of Erosive Disease.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4414851.html