title: Unenhanced helical computed tomography in the evaluation of acute flank pain.
abstract: OBJECTIVE
  The purpose of this study was to determine the value of unenhanced helical computed tomography (UHCT) in the diagnosis of acute flank pain at our institution.
  
  
  METHODS
  Two hundred and thirty-three consecutive UHCT examinations, performed for suspected renal/ureteral colic between July 2000 and August 2001 were reviewed, along with pertinent medical records.
  
  
  RESULTS
  Ureteral calculi were identified in 148 (64%) examinations, evidence of recent passage of calculi was found in 10 (4%) and no calculi were found in 75 (32%). Thirty-two of the conservatively managed patients were excluded for inadequate follow-up. In the remaining 201 patients, sensitivity of UHCT in diagnosing calculi was 99% and specificity was 98%, while the positive predictive value was 99% and negative positive predictive value was 98%. Overall, an alternative or additional diagnosis was established in 28 (12%) patients. Upon diagnosis of ureterolithiasis on UHCT, none of the patients required additional imaging studies for confirmation.
  
  
  CONCLUSIONS
  UHCT is a highly sensitive imaging modality for the detection of urinary tract calculi and obstruction.
authors.affiliation: Section of Urology, Department of Surgery, Aga Khan University, Karachi, Pakistan.
authors.forename: Nazim Ali
authors.initials: NA
authors.lastname: Ahmad
authors.forename: Mohammad Hammad
authors.initials: MH
authors.lastname: Ather
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Rees
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008096:Lithotripsy; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000000981:diagnostic imaging*; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D036542:Tomography, Spiral Computed; D014545:Urinary Calculi / Q000000981:diagnostic imaging* / Q000628:therapy