Ultrasound detects missed signs of rheumatoid arthritis

May 29, 2007

Ultrasound could make the diagnosis of rheumatoid arthritis considerably more accurate, aiding in recommendations for treatment. Treatment decisions can depend on how far the disease has progressed, and the only way to measure the progression of rheumatoid arthritisis to identify which of a patient’s joints show synovitis. Yet a recent study shows that doctors miss swelling in the shoulder joints of 30% of patients.

Ultrasound could make the diagnosis of rheumatoid arthritis considerably more accurate, aiding in recommendations for treatment. Treatment decisions can depend on how far the disease has progressed, and the only way to measure the progression of rheumatoid arthritisis to identify which of a patient's joints show synovitis. Yet a recent study shows that doctors miss swelling in the shoulder joints of 30% of patients.

Rheumatoid arthritis initially presents in small joints such as the fingers and toes, with inflammation and damage spreading to other joints. The presence of extra fluid in the shoulder joint is an indication of disease progression.

Dr. Reijo Luukkainen and colleagues in the rheumatology department at Satakunto Central Hospital in Rauma, Finland, compared ultrasound diagnosis of effusion in shoulder joints of rheumatoid arthritis patients with a doctor's diagnosis of swelling in the same joints. Effusion usually means synovitis in patients with rheumatoid arthritis.

They studied 100 shoulder joints in 50 consecutive patients with rheumatoid arthritis and 40 shoulder joints in 20 healthy controls. The clinical assessments were performed by one doctor and the ultrasound studies by another, both blinded to the other's results. The clinical examination and ultrasound had similar results in 70 of the rheumatoid arthritis patients' shoulder joints. In the remaining 30, ultrasound detected synovitis undetected by clinical exam.

The researchers concluded that ultrasound could considerably improve the accuracy of diagnosis for patients with rheumatoid arthritis.