To investigate features of urate deposition in gout and the association between these features and attacks of gouty arthritis using dual-energy computed tomography (CT).
Dual-energy CT scans of both feet were performed in 80 consecutive patients with gout and 22 with asymptomatic hyperuricemia.
Overall, 333 areas of urate deposition were found in patients with gout. The most commonly affected sites were the first metatarsophalangeal joint (MPJ; 57/333), the distal area of the first toe (59/333) and the calcaneal bone (61/333). For episodes of the first MPJ arthritis, urate deposits in the flexor pollicis longus muscle tendon (P = 0.02), as well as solitary and punctate depositions (P = 0.03 and 0.01, respectively) were positively related to the acute attacks. For episodes of arthritis around the ankle, deposits in the area, including the talus and inferior tibia, were associated with attacks of arthritis at the ankle (P = 0.02); additionally, deposits in the flexor tendon adjacent to the inferior tibia (P < 0.01) and a punctiform conformation were significantly associated with attacks of arthritis (P = 0.02). Logistic regression analysis showed that deposits around the first MPJ (OR = 3.38, 95% CI: 1.32, 8.17) or around the talus and inferior tibia (OR = 2.83, 95% CI: 1.11, 7.15) would increase the risk of an attack of arthritis.
Dual-energy CT imaging can be used to detect and analyze the features of urate deposition in patients with gout. Specific features of the deposits appeared to be associated with acute attacks of gouty arthritis.