CT UROGRAPHY IN THE EVALUATION OF URINARY-TRACT DISEASE

Objective: The purpose of this study was to evaluate the efficacy of u sing limited CT through the kidneys following excretory urography in s elected situations. Materials and Methods: Within 2 h of excretory uro graphy 568 patients had add-on CT without using additional contrast me dium. In 487 patients with hematuria the results of the combined studi es were compared with blinded prospective interpretations of each. In addition 81 patients had add-on CT for specific urographic questions. Results: Of the 345 renal parenchymal masses seen on CT in both groups , only 185 were detected prospectively on excretory urography. For the 81 patients who had CT because of abnormalities seen on excretory uro graphy, including 54 with pseudotumors, findings were clarified and th e correct diagnosis made. In 27 of 30 patients with lesions in the col lecting system the lesions were detected only on excretory urography. Conclusion: Excretory urography followed by limited CT increases the d iagnostic accuracy for detecting, characterizing, or ruling out urinar y tract disease by combining the high sensitivity of traditional excre tory urography for detecting lesions in the collecting system and uret er with the high accuracy of CT for parenchymal and perinephric lesion s without an additional patient visit or additional contrast medium. B ecause it leaves so few unanswered questions, the combination of stand ard excretory urography and limited CT is an excellent screening study in selected situations. It can be performed quickly, at controlled co st, is highly accurate, and is convenient for the patient, the referri ng physician, and the examining department.