title: Trends in the use of unenhanced helical CT for acute urinary colic.
abstract: OBJECTIVE
  Unenhanced helical CT for urolithiasis detection is a limited CT examination that was designed specifically for the detection of urolithiasis. The purpose of this study was to repeat a prior study to assess whether clinicians had broadened the indications and changed the yield and findings of unenhanced helical CT.
  
  
  METHODS
  One hundred consecutive patients with suspected renal colic or flank pain referred for unenhanced helical CT were selected for this study. We reviewed the original radiographic reports for each patient and recorded the presence of ureteral calculi. Other urinary abnormalities and extraurinary lesions were also recorded and compared with the results of the previous study.
  
  
  RESULTS
  In this study, 56% of the patients who underwent unenhanced helical CT had symptoms of urinary colic, and 44% of patients had unspecified flank pain, compared with 100% of patients with symptoms of urinary colic 1 year earlier. The sensitivity and specificity of unenhanced helical CT in detecting ureteral calculi were 96% and 99%, respectively. Ureteral calculi were identified in only 28% of the patients versus 49% of patients (p < .01) 1 year earlier. Extraurinary lesions were identified in 45% of the patients versus 16% (p < .01) 1 year before.
  
  
  CONCLUSIONS
  As clinicians developed familiarity with this technique, the indications for performance of unenhanced helical CT were expanded with a consequent reduction in the rate of detection of stone disease and identification of an increased number of extraurinary lesions, which suggests a demand for emergency abdominal CT studies.
authors.affiliation: Department of Radiology, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1088, USA.
authors.forename: M Y
authors.initials: MY
authors.lastname: Chen
authors.forename: R J
authors.initials: RJ
authors.lastname: Zagoria
authors.forename: H S
authors.initials: HS
authors.lastname: Saunders
authors.forename: R B
authors.initials: RB
authors.lastname: Dyer
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003085:Colic / Q000000981:diagnostic imaging* / Q000209:etiology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000000981:diagnostic imaging / Q000209:etiology; D007674:Kidney Diseases / Q000000981:diagnostic imaging* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement / Q000639:trends; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000639:trends*; D014514:Ureteral Calculi / Q000000981:diagnostic imaging / Q000209:etiology