Diagnostic value of uric acid quantification in feet and ankles in gout patients using gemstone spectral imaging computerized tomography technology

Objective To investigate the diagnostic value of gemstone spectral imaging (GSI) CT technology in detecting uric acid quantification in gout patients' feet and ankles. Methods From August 2013 to April 2016, a total of 89 patients in the department of rheumatology in Hainan Branch of Chinese PLA General Hospital were enrolled in this study and underwent CT scans with GSI mode. These patients were divided into three groups: 35 gout patients with clinically detectable tophus in group A, 36 patients with asymptomatic hyperuricemia in group B, and 18 patients with other arthropathies in group C as controls. Two locations including soft tissues beside bilateral first metatarsophalangeal joints (FMTPJs) and bilateral exteral malleoli were selected for quantitative analysis of uric acid and hydroxyapatite (HAP). Results There were significant differences in uric acid (HAP) concentration of three groups in soft tissues beside FMTPJs A: (1 186.32±23.86) mg/cm³＞ B: (1 157.71±19.35) mg/cm³＞ C: (1 123.62±10.51) mg/cm³, P＜ 0.05 and soft tissues beside malleoli A: (1 162.71±30.12) mg/cm³＜ B: (1 139.32±11.57) mg/cm³＜ C: (1 123.0±9.07) mg/cm³, P＜ 0.05, respectively. Conclusion The uric acid deposits in feet and ankles of patients with tophaceous gout is more serious than that in the same locations of those patients with hyperuricemia examined by GSI-CT technology.