RESUMO
Purpose: To evaluate the impact of nonenhanced helical computed tomography on the diagnosis of acute flank pain due to urolithiasis. Material and The study included 247 consecutive patients complaining of acute loin pain. Their ages ranged from 16 to 67 years with a mean age of 23 years. Sixty-seven patients were females and 180 were males. Patients were referred to the radiology department for plain radiography and Ultrasonography for the urinary tract. Of these patients, 193 were selected to have helical nonenhanced CT scan for the urinary tract. A total of 413 urolithiasis were detected by NHCT in the 193 patients. Of these calculi, 22% were detected only by CT scan and were not seen on plain radiography. The proximal ureter was the commonest site of stone lodgment. The CT findings for urinary tract stones causing obstructive uropathy were perirenal permeation in [63%], tissue rim sign due to impacted ureteric stone with surrounding oedema in [56%], and the tail sign of phleboliths in [18%] of cases. Other pathologies were identified as a cause of flank pain resembling that of acute renal colic in 22 patients; ovarian cyst in 12 patients [6.2%] and acute appendicitis in 10 patients [5.2%]. - Nonenhanced helical computed tomography can detect all the urinary tract stones including those not seen on plain radiography with unprecedented sensitivity and specificity. The technique can also detect causes for flank pain outside the genitourinary tract