title: A systematic review of whether oral contrast is necessary for the computed tomography diagnosis of appendicitis in adults.
abstract: BACKGROUND
  There are several methods of contrast administration when performing computed tomography (CT) scanning for suspected appendicitis. In this systematic review we evaluated the diagnostic performance of CT with and without contrast material.
  
  
  METHODS
  Twenty-three reports were identified using a Medline search.
  
  
  RESULTS
  The aggregated diagnostic performance characteristics of all modes of CT scanning were excellent with a range of sensitivity (83--97%), specificity (93--98%), positive predictive value (86--98%), negative predictive value (94--99%), and accuracy (92--97%). The diagnostic performance of CT without oral contrast was similar (sensitivity, 95% vs. 92% [not statistically significant]; negative predictive value, 96% for both protocols) or surprisingly better (specificity, 97% vs. 94%; positive predictive value, 97% vs. 89%; accuracy, 96% vs. 92%; P<.0001) than with oral contrast.
  
  
  CONCLUSIONS
  Noncontrast CT techniques to diagnose appendicitis showed equivalent or better diagnostic performance compared with CT scanning with oral contrast. A prospective comparative trial of CT with and without oral contrast for appendicitis should be performed to assess the adequacy of this modality.
authors.affiliation: Department of Surgery, University of Washington, BB 431, Seattle, WA 98195, USA.
authors.forename: Brock A
authors.initials: BA
authors.lastname: Anderson
authors.forename: Leon
authors.initials: L
authors.lastname: Salem
authors.forename: David R
authors.initials: DR
authors.lastname: Flum
mesh_terms: D001064:Appendicitis / Q000000981:diagnostic imaging*; D003287:Contrast Media; D006801:Humans; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media