Alternative or additional diagnoses on unenhanced helical computed tomography for suspected renal colic: Experience with 1000 consecutive examinations

Objectives. To determine the incidence and spectrum of significant alternat ive or additional diagnoses established or suggested on unenhanced helical computed tomography (CT) in a large series of patients with suspected renal colic. Methods. One thousand consecutive unenhanced helical CT examinations were p erformed for suspected renal colic. All official CT reports were retrospect ively reviewed, which was followed by review of all available relevant foll ow-up radiology reports. A selected image and chart review was also perform ed. Results. Ureteral calculi were identified on 557 examinations, findings con sistent with a recently passed stone were discovered on 67 examinations, an d 275 CT examinations were unremarkable. An alternative or additional diagn osis was established or suggested on 101 examinations, including in 26 pati ents with concurrent ureteral calculi, There were 62 genitourinary and 39 n ongenitourinary tract diagnoses. Eighty-seven of the diagnoses could be con firmed on retrospective image review combined with patient follow-up. There were two false-positive diagnoses for significant, alternative pathologic findings. Conclusions. A wide spectrum of significant, alternative, and additional ge nitourinary and nongenitourinary diagnoses can be reliably established or s uggested on unenhanced helical CT performed for suspected renal colic. Thes e abnormalities were identified in 10% of cases in this series of 1000 cons ecutive CT examinations. UROLOGY 56: 53-57, 2000. (C) 2000, Elsevier Scienc e Inc.