Diagnostic Accuracy of Noncontrast CT in Detecting Acute Appendicitis: A Meta-analysis of Prospective Studies

The aim of the study is to evaluate the diagnostic accuracy of noncontrast CT in detecting acute appendicitis. Prospective studies in which noncontrast CT was performed to evaluate acute appendicitis were found on PubMed, EMBASE, and Cochrane Library. Pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were assessed. The summary receiver-operating characteristic curve was conducted and the area under the curve was calculated. Seven original studies investigating a total of 845 patients were included in this meta-analysis. The pooled sensitivity and specificity were 0.90 (95% CI: 0.86–0.92) and 0.94 (95% CI: 0.92–0.97), respectively. The pooled positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio was 12.90 (95% CI: 4.80–34.67), 0.09 (95% CI: 0.04–0.20), and 162.76 (95% CI: 31.05–853.26), respectively. The summary receiver-operating characteristic curve was symmetrical and the area under the curve was 0.97 (95% CI: 0.95–0.99). In conclusion, noncontrast CT has high diagnostic accuracy in detecting acute appendicitis, which is adequate for clinical decision making.