Renal Tract Calculi: Comparison of Stone Size on Plain Radiography and Noncontrast Spiral CT Scan
- 1 December 2006
- journal article
- research article
- Published by Mary Ann Liebert Inc in Journal of Endourology
- Vol. 20 (12), 1005-1009
- https://doi.org/10.1089/end.2006.20.1005
Abstract
Noncontrast spiral CT (NCCT) has emerged as the investigation of choice in patients presenting with renal-tract calculi. As management guidelines are based on stone size measured on plain radiography of the kidneys, ureters, and bladder (KUB), it is important to assess the accuracy of stone size measured on NCCT compared with KUB films. The NCCT and KUB studies obtained from 24 patients (27 stones) presenting to the emergency department at a major metropolitan hospital were analyzed randomly and independently by two urologists and one uroradiologist. The NCCT scans were assessed separately from the KUB films. Only size in greatest dimension and stone location were recorded. The stone size was 2 to 38 mm on NCCT scans and 2 to 46 mm on KUB films. The mean stone size was 6.773 +/- 6.146 mm and 7.747 +/- 7.866 mm, respectively (P = 0.0398; Student's t-test). Almost three fourths (70%) of the stones were larger on KUB films than they were on NCCT scans, with a mean difference -0.974 mm (95% confidence interval -5.652, 3.703) for NCCT. Spiral CT underestimates stone size by approximately 12% compared with KUB films. This error may impact stone management as outlined in guidelines published by the American Urological Association, particularly for stones about 5 mm in greatest dimension. These patients may initially be managed conservatively when intervention would be more appropriate.Keywords
This publication has 9 references indexed in Scilit:
- A COMPUTER MODEL TO PREDICT THE OUTCOME AND DURATION OF URETERAL OR RENAL CALCULOUS PASSAGEJournal of Urology, 2004
- Limitations of Noncontrast CT for Measuring Ureteral StonesJournal of Endourology, 2003
- Correlation of Ureteral Stone Measurements by CT and Plain Film Radiography: Utility of the KUBJournal of Endourology, 2003
- COMPARISON OF HELICAL COMPUTERIZED TOMOGRAPHY AND PLAIN RADIOGRAPHY FOR ESTIMATING URINARY STONE SIZEJournal of Urology, 2002
- Prospective comparison of unenhanced spiral computed tomography and intravenous urogram in the evaluation of acute flank painUrology, 1998
- THE VALUE OF UNENHANCED HELICAL COMPUTERIZED TOMOGRAPHY IN THE MANAGEMENT OF ACUTE FLANK PAINJournal of Urology, 1998
- URETERAL STONES CLINICAL GUIDELINES PANEL SUMMARY REPORT ON THE MANAGEMENT OF URETERAL CALCULIJournal of Urology, 1997
- Accuracy of detection and measurement of renal calculi: in vitro comparison of three-dimensional spiral CT, radiography, and nephrotomography.Radiology, 1997
- STATISTICAL METHODS FOR ASSESSING AGREEMENT BETWEEN TWO METHODS OF CLINICAL MEASUREMENTThe Lancet, 1986