Bilateral ultrasound of metacarpophalangeal and metatarsophalangeal joints and magnetic resonance imaging of the dominant hand were superior to X-ray in detecting erosive disease in patients with mild and moderate rheumatoid arthritis, according to study results.
Researchers in Germany examined 26 patients (mean age, 48 years; 53.8% women) with active mild or moderate rheumatoid arthritis (RA; mean Disease Activity Score 28, 3.9; mean disease duration, 19 months). The patients were examined clinically, by ultrasound and by gadolinium-enhanced low-field magnetic resonance imaging (MRI) at baseline and after 6 and 12 months. At baseline and after 12 months, X-rays of dominant hands and forefeet were taken. Metacarpophalangeal (MCP) 1-5 or metatarsophalangeal (MTP) 1-5 joints were evaluated by MRI of 14 hands and 12 forefeet. Those same joints, along with all other second and fifth MCP and fifth MTP joints, were examined by ultrasound.
Of 78 examinations, erosive disease was detected in 67 MRI examinations and 56 ultrasound examinations (P<.01). Erosive disease was detected in eight of 52 X-ray examinations (P<.001). MRI and ultrasound detected synovitis in 64 and 66 examinations, respectively. Thirty-eight ultrasound examinations displayed synovial power Doppler signals. Thirty-seven MRI exams revealed bone marrow edema presence. Ultrasound detected 30 cases of tenosynovitis compared with 15 cases detected by MRI (P=.001).
“MRI and ultrasound are valuable diagnostic tools in early and mild or moderate RA, particularly in two scenarios,” the researchers reported, “firstly, when it appears clinically difficult to decide whether arthritis or tenosynovitis are present or absent, and secondly, when it is important to decide if erosions have already developed despite negative findings on radiographs of hands and forefeet.
“MRI is slightly but significantly more sensitive to detect erosions than ultrasound. Both imaging modalities show synovitis and tenosynovitis comparably well.”