Assessment of CT urography in the diagnosis of urinary tract abnormalities.

BACKGROUND To evaluate the accuracy of helical computerized tomography urography (CTU) in diagnosing urinary tract disease. METHODS We collected 102 patients who underwent CTU from March 2001 to September 2002. The clinical symptoms of these patients included: flank pain or hematuria, which were clinically suggestive of urinary system disorders. All patients received CT scan with or without intravenous contrast medium administration, except patients who had allergy history or poor renal function. Reformatted CT urography was performed and the accuracy of imaging diagnosis was evaluated. RESULTS Of these 102 patients, 40 cases were proved to have urolithiasis, 24 cases were with renal or ureteral tumors, and there were 38 cases of other urinary system disorders (including inflammation, ureteral stricture and congenital anomalies). Precontrast CTU correctly diagnosed 39 of 40 urolithiasis cases (97.5%). Precontrast and contrast-enhanced CTU were performed in the non-urolithiasis group and correctly diagnosed 23 cases of renal or ureteral tumors, 4 cases of congenital disorder (2 duplications, 1 congenital renal agenesis due to VATER syndrome and 1 retrocaval ureter). Five of 34 patients with chronic inflammatory process of urinary tract or ureteral stricture were indistinct from malignancies according to the imaging of CT urography. CONCLUSIONS CTU is good modality for demonstration of urinary tract disorders. It is better in showing radiolucent stones and non-opacified urinary system. CTU demonstrates more soft tissue information than IVU in the patients with urinary tract tumors. CTU may be an alternative modality for patients with deterioration of renal function or allergic history of contrast medium.