A new study has shown that MRI can identify and describe the features of gout.
Although magnetic resonance imaging (MRI) is commonly used to define disease activity and damage in autoimmune inflammatory arthritis, its role in gout is unclear. But a recent study using MRI to identify and describe the features of gout show that the condition clearly affects the joints, bones, and tendons.
But bone edema in patients with chronic tophaceous gout is usually mild. This is in contrast with the “severe bone edema” observed in patients with concomitant osteomyelitis, according to the study from researchers in New Zealand. The study was published in the Journal of Rheumatology.
For the study, the researchers identified patients with gout who underwent MRI scanning of the hands or feet over a 10-year period. A musculoskeletal radiologist and twp rheumatologists reviewed the scans in a blinded manner for erosions, synovitis, tenosynovitis, tendinosis, bone edema, and tophi. “MRI features in patients with uncomplicated gout were compared with features where concomitant osteomyelitis was diagnosed,” the authors wrote in the study abstract.
The study included 47 gout patients with 51 scans. Of those, 33 (70%) had uncomplicated gout and 14 (30%) had gout complicated by osteomyelitis. “MRI features included tophi in 36 scans (71%), erosions in 35 (69%), bone edema in 27 (53%), synovitis in 15 (29%), tenosynovitis in 8 (16%), and tendinosis in two (4%). Uncomplicated gout and gout plus osteomyelitis did not differ for most MRI features,” the authors wrote.
But they found that severe bone marrow edema was more common in gout plus osteomyelitis, occurring in 14/15 scans (93%) compared with 3/36 scans (8%) in uncomplicated gout (OR 154.0, 95% CI 14.7-1612, p < 0.0001).
“Sensitivity and specificity of severe bone edema for concomitant osteomyelitis were 0.93 (95% CI 0.68-0.99) and 0.92 (95% CI 0.78-0.98), respectively,” they wrote.