Dual-energy computed tomography for characterizing urinary calcified calculi and uric acid calculi: A meta-analysis.

OBJECTIVE: A meta-analysis was conducted to determine the accuracy of dual-energy computed tomography (DECT) for differentiating urinary uric acid and calcified calculi.

METHODS: The databases PubMed, EMBASE, Web of Science, and the Cochrane Library were searched up to May 2016 for relevant original studies. Data were extracted to calculate the pooled sensitivity, specificity, diagnostic odds ratio (OR), positive and negative likelihood ratios (PLR and NLR), and areas under summary receiver operating characteristic (AUROC) curves for analysis.

RESULTS: Nine studies (609 stones in 415 patients) were included. For differentiating uric acid (UA) and non-UA calculi with DECT, the analysis indicated: pooled weighted sensitivity, 0.955 (95% CI, 0.888-0.987); specificity, 0.985 (95% CI, 0.970-0.993); PLR, 0.084 (95% CI, 0.041-0.170); NLR 33.327 (95% CI, 18.516-59.985); and diagnostic OR 538.18 (95% CI, 195.50-1478.5). The AUROC value was 0.9901. For calcified stones, the analysis indicated: pooled weighted sensitivity, 0.994 (95% CI, 0.969-1); specificity, 0.973 (95% CI, 0.906-0.997); PLR, 11.200 (95% CI, 4.922-25.486); NLR 0.027 (95% CI, 0.010-0.072); and diagnostic OR 654.89 (95% CI, 151.31-2834.4). The AUROC value was 0.9915.

CONCLUSION: This meta-analysis found that DECT is a highly accurate noninvasive method for characterizing urinary uric acid and calcified calculi.