title: Extracolonic findings at CT colonography: evaluation of prevalence and cost in a screening population.
abstract: OBJECTIVE
  To assess the prevalence and spectrum of extracolonic findings in a screening population undergoing computed tomography colonography (CTC), and to evaluate the short-term direct medical costs incurred from subsequent radiologic follow-up evaluation.
  
  
  METHODS
  Six hundred and eighty-one asymptomatic patients undergoing colonoscopy screening consented to a CTC examination. Extracolonic CT findings were classified into high, medium, and low importance. Clinical and radiologic follow-up, missed lesions, and outcomes were assessed by chart review (time interval, 410-1513 days; median, 913 days). Short-term direct medical costs of radiologic follow-up were determined based on Medicare 2002 reimbursement rates.
  
  
  RESULTS
  Extracolonic findings were found commonly. These were categorized as high clinical importance in 71 (10%) individuals, as medium importance in 183 individuals (27%), and as low importance in 341 individuals (50%). Subsequent medical or surgical interventions resulted from these findings in 9 of the 681 patients (1.3%). Costs of subsequent radiologic follow-up studies were calculated as $23,380.59 (average added costs per CTC examination $34.33).
  
  
  CONCLUSIONS
  CTC commonly detects extracolonic findings that can be considered clinically important when applied to an asymptomatic screening population. Although such incidental findings add benefit to the screening intervention, moderate incremental costs are incurred based on additional radiologic procedures generated during short-term follow-up.
authors.affiliation: Department of Radiology, Mayo Clinic Rochester, Rochester, Minnesota 55905, USA.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Gluecker
authors.forename: C Daniel
authors.initials: CD
authors.lastname: Johnson
authors.forename: Lynn A
authors.initials: LA
authors.lastname: Wilson
authors.forename: Robert L
authors.initials: RL
authors.lastname: Maccarty
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Welch
authors.forename: David J
authors.initials: DJ
authors.lastname: Vanness
authors.forename: David A
authors.initials: DA
authors.lastname: Ahlquist
mesh_terms: D000328:Adult; D000368:Aged; D003108:Colonic Diseases / Q000000981:diagnostic imaging* / Q000191:economics / Q000453:epidemiology*; D023881:Colonography, Computed Tomographic / Q000191:economics* / Q000706:statistics & numerical data; D005260:Female; D005500:Follow-Up Studies; D017048:Health Care Costs; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000191:economics* / Q000706:statistics & numerical data; D008875:Middle Aged; D015995:Prevalence