[Clinical value of artifact identification in ankle dual-energy CT for gout diagnosis]

Objective: To investigate the clinical value of artifact identification in ankle dual-energy CT for gout diagnosis. Methods: A total of 58 patients with gout, who were definitely diagnosed in Peking University Third Hospital from December 2018 to May 2019, were included in the case group, which were composed of 57 males and 1 female. And 37 individuals without gout were regarded as control group, which were composed of 36 males and 1 female. Dual-energy CT was performed for one foot, and the affected side or the more serious side was chosen in the case group. The dual-energy data were used in gout-recognition software to highlight the monosodium urate (MSU) with green-colored. And to compare the difference in MSU relevance ratio on the images of toenail, submillimeter spots, skins, movements and vascular calcification between two groups. Results: In the case group, 55 patients were revealed with MSU green-colored toenails (relevance ratio 94.8%), while 22 cases in the control groups (relevance ratio 59.5%). There was significantly statistical difference on the mean toenails numbers and the MSU distribution scores in the two groups (all P<0.01). In the case group, 47 patients were revealed with green-colored submillimeter spots (relevance ratio 81.0%),while 5 cases in the control group (relevance ratio 13.5%). The relevance ratio of submillimeter spots on tendon and ligament in the case group and control group were 75.9% (44/58) and 13.5%(5/37). There was also significantly statistical difference in the two groups on submillimeter spots (all P<0.01). And there was no significantly statistical difference in the two groups on MSU green-colored skins, movements and vascular calcification. Conclusion: There is great value for gout clinical diagnosis when green-colored MSU is detected on toenails and submillimeter spots, which should not be judged as artifact simply.