[Application of dual-energy computed tomography for detecting uric acid deposition in patients with gout]

To assess the value of dual energy computed tomography (DECT) for the detection of uric acid (UA) deposition in patients with gout.

A total of 37 patients with tophaceous gout (including 8 crystal-proven cases) and 10 control patients (5 with unknown arthropathy, 3 with rheumatoid arthritis, and 2 with osteoarthritis) were included. DECT was performed for all peripheral joints (wrists, hands, elbows, knees, ankles and feet) . Color coding was used to display the localization of UA deposition. Images were reviewed independently by two trained radiologists.

With DECT, patients with gout were found to have UA deposits in hands and wrists 46% (17/37) , elbows 16% (6/37) , knees 27% (10/37) , ankles and feet 89% (33/37) . No UA deposit was observed in all 10 control patients (P=0.000) . Among the 37 patients with gout, the number of UA deposition sites detected by DECT (n=297) was 2.25 times of that detected by physical examinations (n=132) (P=0.000) .

DECT allows the visualization of UA deposition in gouty arthropathy. Even subclinical disease can be delineated with this technique. However, the accuracy of DECT requires further investigations.