title: Incidental findings on CT for suspected renal colic in emergency department patients: prevalence and types in 5,383 consecutive examinations.
abstract: OBJECTIVE
  This study aimed to determine the prevalence, importance, and types of incidental findings (IF) in non-enhanced CT scans performed for suspected renal colic, based on ACR white papers and other accepted radiographic recommendations.
  
  
  METHODS
  Retrospective review of 5,383 consecutive finalized reports of nonenhanced CT using renal colic protocol performed on adult patients at 2 emergency departments over a 5.5-year period. IF were defined as those unrelated to symptoms (as opposed to alternate causes of symptoms) and were categorized as "important" if follow-up was recommended based on recently published consensus recommendations. Subsets of reports of those with important IF were blindly re-reviewed to calculate inter-rater variability for presence and categorization of important IF.
  
  
  RESULTS
  Important IF were identified in 12.7% (95% confidence interval [CI]: 11.8%-13.6%) of scans. Prevalence of important IF increased with age: important IF in individuals age >80 years were 4 times more common than for those aged 18-30 years: 28.9% (95% CI: 22.4%-36.4%) versus 6.9% (95% CI: 5.5%-8.6%), respectively, P ≤ .05. Women had a higher prevalence of important IF compared with men: 13.4% (95% CI: 12.2%-14.7%) versus 11.9% (95% CI: 10.7%-13.2%), but the difference was not statically significant (P = .09). There was substantial inter-rater agreement (kappa ≥ 0.69) regarding presence and classification of important IFs using published guidelines.
  
  
  CONCLUSIONS
  Important IF occurred in 12.7% of non-enhanced CT scans performed for suspected renal colic in the emergency department and are more common in older individuals. Prospective studies that use radiographic recommendations to characterize IF and examine the outcome and cost of their workup are encouraged.
authors.affiliation: Department of Radiology, Yale University School of Medicine, New Haven, Connecticut. Electronic address: Mohammad.samim@yale.edu.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Samim
authors.affiliation: Department of Emergency Medicine, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: Sarah
authors.initials: S
authors.lastname: Goss
authors.affiliation: Department of Emergency Medicine, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: Seth
authors.initials: S
authors.lastname: Luty
authors.affiliation: Department of Radiology, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Weinreb
authors.affiliation: Department of Emergency Medicine, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: Christopher
authors.initials: C
authors.lastname: Moore
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D003237:Connecticut / Q000453:epidemiology; D004632:Emergency Medical Services / Q000706:statistics & numerical data; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D033162:Incidental Findings; D008171:Lung Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D000292:Pelvic Inflammatory Disease / Q000000981:diagnostic imaging / Q000453:epidemiology; D015995:Prevalence; D056844:Renal Colic / Q000000981:diagnostic imaging / Q000453:epidemiology*; D018570:Risk Assessment; D017678:Sex Distribution; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*; D052878:Urolithiasis / Q000000981:diagnostic imaging / Q000453:epidemiology*; D055815:Young Adult
keywords: CT; Incidental findings; renal colic