Relationship of spontaneous passage of ureteral calculi to stone size and location as revealed by unenhanced helical CT.

Objective: Prior studies using radiography have examined the relationship of ureteral stone size and location to the probability of spontaneous passage. Given the improved accuracy and new role of unenhanced CT in the diagnosis of acute ureterolithiasis, we studied the relationship of stone size and location as determined by unenhanced CT to the rate of spontaneous passage.

Materials And Methods: Over a 29-month period, 850 patients with acute flank pain were evaluated with unenhanced CT.