Renal Stone Detection Using Unenhanced Multidetector Row Computerized Tomography—Does Section Width Matter?

Purpose: We determined the effect of reconstructed section width on sensitivity and specificity for detecting renal calculi using multidetector row computerized tomography.Materials and Methods: Three to 5 renal stones 2 to 4 mm in size were randomly placed into 14 human cadaveric kidneys and scanned by 16-row detector computerized tomography at 1.25 mm collimation and identical scanning parameters. After acquisition images were reconstructed with a section width of 1.25, 2.5, 3.75 and 5.0 mm, and reviewed independently by 2 blinded radiologists. Comparisons of sensitivity and specificity between different section widths were assessed with the McNemar test and Cochran's Q statistics.Results: Specificity was not significantly affected by section width (94.6% to 97.7%). In contrast, sensitivity increased as stone size increased and as section width decreased. Sensitivity to detect all stones was 80.7%, 80.7%, 87.7% and 92.1% for 5.0, 3.75, 2.5 and 1.25 mm section widths, respectively. Interobserver agreemen...