title: Pitfalls and mimickers at 64-section helical CT that cause negative appendectomy: an analysis from 1057 appendectomies.
abstract: OBJECTIVE
  To determine the rate of negative appendectomy and clarify the causes of negative appendectomy in patients with clinically suspected acute appendicitis who had surgery after 64-section helical computed tomography (CT).
  
  
  METHODS
  A retrospective analysis of 1057 patients who had appendectomy after 64-section helical CT was performed to determine the rate of negative appendectomy. The 64-section helical CT examinations obtained with submillimeter and isotropic voxels in the patients with negative appendectomy were analyzed by two readers and compared to clinical, operative and histopathological reports, discharge summaries and original radiology reports.
  
  
  RESULTS
  The negative appendectomy rate was 1.7% (18/1057). Appendix enlargement (>6 mm) and fat stranding were present in 17 (17/18; 94%) and 6 patients (6/18; 33%), respectively. In 13 patients (13/18; 72%) 64-section helical CT findings were consistent with acute appendicitis. Interpretive errors in original imaging reports were identified in five patients (5/18; 28%).
  
  
  CONCLUSIONS
  The preoperative use of 64-section helical CT results in a very low rate of negative appendectomy. Patients with negative appendectomy have 64-section helical CT findings consistent with a diagnosis of acute appendicitis in the majority of cases. Interpretive errors are less frequent.
authors.affiliation: Department of Abdominal Imaging, Hôpital Lariboisière, Assistance Publique-Hôpitaux de Paris, 2 rue Ambroise Paré, 75475 Paris Cedex 10, France; Université Paris-Diderot, Sorbonne Paris Cité, 10 rue de Verdun, 75010 Paris, France; INSERM, U 965, 2 rue Ambroise Paré, 75475 Paris Cedex 10, France. Electronic address: philippe.soyer@lrb.aphp.fr.
authors.forename: Philippe
authors.initials: P
authors.lastname: Soyer
authors.forename: Anthony
authors.initials: A
authors.lastname: Dohan
authors.forename: Clarisse
authors.initials: C
authors.lastname: Eveno
authors.forename: Anne-Laure
authors.initials: AL
authors.lastname: Naneix
authors.forename: Marc
authors.initials: M
authors.lastname: Pocard
authors.forename: Karine
authors.initials: K
authors.lastname: Pautrat
authors.forename: Lounis
authors.initials: L
authors.lastname: Hamzi
authors.forename: Christelle
authors.initials: C
authors.lastname: Duteil
authors.forename: Anne
authors.initials: A
authors.lastname: Lavergne-Slove
authors.forename: Mourad
authors.initials: M
authors.lastname: Boudiaf
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D001062:Appendectomy / Q000706:statistics & numerical data*; D001064:Appendicitis / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D001065:Appendix / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D003951:Diagnostic Errors; D005260:Female; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D036542:Tomography, Spiral Computed; D055815:Young Adult
keywords: Acute appendicitis; Appendix, CT; Computed tomography; Helical CT