Unenhanced spiral CT in acute ureteral colic: A replacement for excretory urography?

Objective: To compare the usefulness of unenhanced spiral CT (UCT) with tha t of excretory urography (EU) in patients with acute flank pain. Materials and Methods: Thirty patients presenting with acute flank pain und erwent both UCT and EU. Both techniques were used to determine the presence , size, and location of urinary stone, and the presence or absence of secon dary signs was also evaluated. The existence of ureteral stone was confirme d by its removal or spontaneous passage during follow-up. The absence of a stone was determined on the basis of the clinical and radiological evidence . Results: Twenty-one of the 30 patients had one or more ureteral stones and nine had no stone. CT depicted 22 of 23 calculi in the 21 patients with a s tone, and no calculus in all nine without a stone. The sensitivity and spec ificity of UCT were 96% and 100%, respectively. EU disclosed 14 calculi in the 21 patients with a stone and no calculus in eight of the nine without a stone. UCT and EU demonstrated secondary signs of ureterolithiasis in 15 a nd 17 patients, respectively. Conclusion: For the evaluation of patients with acute flank pain, UCT is an excellent modality with high sensitivity and specificity. In near future i t may replace EU.