Detection of monosodium urate crystals with dual-energy CT in gout patients

Abstract

Objective To evaluate the application of the dual-energy CT (DECT) in detection of monosodium urate (MSU) crystals in gout patients. Methods The imaging and clinical data of 101 patients with suspected gout were retrospectively analyzed, including 64 cases of clinically diagnosed gout (gout group) and 37 non-gout cases (non-gout group). The DECT examination was performed for 85 joints in gout group and 42 joints in non-joint group. The value of DECT in detection of MSU crystals was evaluated with receiver operating characteristic (ROC) curve. Results There were significant differences in gender (χ2=5.32, P=0.03) and blood uric acid levels (t=1.95, P=0.04) between gout and non-gout groups. The detection rate of MSU in gout group was significantly higher than that of non-gout group (χ2=30.52, P<0.001). The area under the ROC curve (AUC) of DECT in detection of was 0.74±0.05 (Mean±SE), 95%CI: 0.64-0.85. The sensitivity, specificity, positive predictive value and negative predictive value of the DECT in detection of gouty stone was 0.844, 0.703, 83.1% and 72.2%, respectively. Conclusion The dual-energy CT has high sensitivity, specificity and reliability for the detection and diagnosis of monosodium urate crystals in joints of gout patients. Key words: Radiography, dual-energy scanned projection; Gout; Arthritis, gouty; Crystallization, uric acid