Unenhanced spiral CT scan in the initial evaluation of renal colic: AUBMC experience.

BACKGROUND AND OBJECTIVE: Until recently, intravenous urography and ultrasonography have been the standard diagnostic modalities in the initial evaluation of acute flank pain. However, since 1995 the role of non-enhanced CT scan (NECT) has become more important in establishing the diagnosis of renal colic. In this retrospective descriptive study, we evaluated the usefulness of NECT in the diagnosis and management of patients with suspected urinary tract stones at the American University of Beirut-Medical Center (AUBMC).

MATERIALS AND METHODS: We reviewed the records of 102 patients who presented to AUBMC over a period of two years for flank pain with or without hematuria. NECT were obtained in all patients. We studied the images for the presence of stones and frequency of associated urinary findings. Incidental abdominal and pelvic abnormalities were recorded.

RESULTS: Fifty-four patients were found to have positive CT examinations for the presence of urinary tract stones on the ipsilateral side of the flank pain. Twenty-two stones were present in the kidneys, 23 in the ureters and 16 at the ureterovesical junction (UVJ). In these 54 patients with stone disease, 31 had associated pelvicalyceal dilatation (57%), and 16 had perinephric streaking (29.6%). In the 39 patients with ureteral and UVJ stones, 26 had ureteral dilatation (66.6%), and 17 had periureteral streaking (43.5%). In the 23 patients with only ureteral stones, 10 had a positive rim sign (43.4%).

CONCLUSION: A diagnosis of urinary tract stone is not always readily apparent on the basis of physical exam and laboratory studies. NECT is now universally accepted as a preferred method for the evaluation of ureteral and kidney stones in patients with suspected renal colic.