The relationship between ureteral stone characteristics and secondary signs in renal colic.

PURPOSE: To assess correlations between stone size/location and severity of secondary signs for ureteral obstruction.

METHODS: Unenhanced multi-detector computed tomography examinations of 150 patients with acute renal colic were reviewed. Stone size, location in the ureter, kidney size and Hounsfield unit values, perinephric edema, and degree of hydronephrosis were assessed.

RESULTS: Pale kidney sign was detected in 36%. Hydronephrosis was mild in 63% and severe in 21%; severe hydronephrosis was associated with larger stones. Mid-ureter and ureteropelvic junction stones were more likely to cause hydronephrosis. Perinephric edema (56%) was not correlated with stone size/location.

CONCLUSION: Only severe hydronephrosis was significantly associated with larger stone size.