Detection of neprolithiasis and ureterolithiasis:comparison of low-dose unenhanced 16-detector helical CT and intravenous urography

Objective:To compare low-dose unenhanced 16-detector helical CT and intravenous urography in the detection of renal and ureteral stones.Methods:Ninty-two patients with suspected neprolithiasis and ureterolithiasis were collected.Low-dose helical CT scans were obtained by using 60mAs(other technical parameters remain same to the standard-dose scan),then it was immediately followed by IVU,to note the cases,location,size,number of calculi and signs of obstruction.Low-dose scans and IVU were compared by using paired χ2-test.Results:In low-dose scan,81 cases found to have calculi,53 cases had renal calculi,59 cases had ureteral calculi,there were 156 stones,78 cases had pelvicaliectasis and 63 cases had ureteral dilatation,in IVU,62 cases had calculi,40 cases had renal calculi,42 had ureteral calculi,there were 101 stones,67 cases had pelvicaliectasis and 45 had ureteral dilatation,there were significant differences in cases of calculi,number of calculi and the obstruction between low-dose scan and IVU.Conclusion:Low-dose unenhanced 16-detector helical CT is superior to IVU in detecting renal and ureteral calculi.