The authors reviewed findings of enhanced adbominal computed tomographic (CT) scans to know the difference between a higher dose fo conventional ionic contrast media (iothalamate meglumine) and a lower dose of a new, nonionic contrast material (ioversol). One hundred adult patients were intravenously administered in each group. The ratio of the male to female in the former was 28:22 and the latter 29:21 We examine the degree of renal streak artifact and measure the Hounsfield number of urine in renal collecting system. There were significant differences of the degree of the streak depending upon the osmolality of contrast media used and that was related with urine CT number (P value<0.005) We authors conclude that nonionic low osmolar contrast media is prone to cause streak artifacts and distortions of renal image than conventional ionic high osmolar contrast media.