Sonographic detection of ureteral calculi in patients with normal excretory urography.

We report 3 cases of nonobstructing distal ureteral calculi diagnosed by sonography in which excretory urography was normal. In each case sonography was performed because of high clinical suspicion for a ureteral stone. In 2 patients a stone was impacted at an edematous ureteral orifice. All 3 patients subsequently passed the stone spontaneously. A high resolution ultrasound examination should be performed on patients with a history suggestive of ureteral calculus despite a normal excretory urogram.