Can Conventional Examinations Contribute to the Diagnostic Power of Unenhanced Helical Computed Tomography in Urolithiasis?

Abstract

Introduction: To investigate whether ordinary tests used in urolithiasis can increase the diagnostic value of unenhanced helical computed tomography (HCT). Materials and Methods: Of all patients admitted with acute flank pain, 137 without radiocontrast allergy, pregnancy and renal insufficiency were included in the study. After urinalysis (Ur) and ultrasonography (USG), HCT without a contrast agent was taken by 5-mm collimation, thereafter excretory urography (EU) was obtained. Confirmation of a stone was done by various tests and/or treatment methods. Statistically, the predictive values of HCT, USG, EU and Ur and their combinations were evaluated using the area under the receiver operating characteristic curve (AROC). Results: The patients’ mean age was 38 (range 4–72) years. Sensitivity values of HCT, USG, EU and Ur were 97, 69, 71 and 81%, respectively. Their specificity values were 96, 87, 91 and 65%, respectively. The widest AROC was found for HCT (97%). The best test combination was [HCT or USG] according to the AROC value (93%), but none of the AROC values of the test combinations was higher than that of HCT. However, 95% confidence intervals of the AROC values of these tests and their combinations overlapped. Conclusions: Because the HCT combinations with other tests improved the diagnostic value of HCT, they should be preferred in some individuals suspected of having urolithiasis. However, the most feasible single test meeting the all usage purposes was HCT in terms of the AROC value, and the combination was [HCT or USG] in which either HCT or USG was positive.