title: Ultrasonography/MRI versus CT for diagnosing appendicitis.
abstract: BACKGROUND
  Cross-sectional imaging increases accuracy in diagnosing appendicitis. We hypothesized that a radiation-free imaging pathway of ultrasonography selectively followed by MRI would not change clinical end points compared with computed tomography (CT) for diagnosis of acute appendicitis in children.
  
  
  METHODS
  We retrospectively reviewed children (<18 years old) who had diagnostic imaging for suspected acute appendicitis between November 2008 and October 2012. Before November 2010 CT was used as the primary imaging modality (group A); subsequently, ultrasonography was the primary imaging modality followed by MRI for equivocal findings (group B). Data collected included time from triage to imaging and treatment and results of imaging and pathology.
  
  
  RESULTS
  Six hundred sixty-two patients had imaging for suspected appendicitis (group A = 265; group B = 397, of which 136 [51%] and 161 [41%], respectively, had positive imaging for appendicitis). Negative appendectomy rate was 2.5% for group A and 1.4% for group B. Perforation rate was similar for both groups. Time from triage to antibiotic administration and operation did not differ between groups A and B. There was higher proportion of positive imaging and appendectomies in group A and thus more negative imaging tests in group B (ultrasonography and MRI), but diagnostic accuracy of the 2 imaging pathways was similar.
  
  
  CONCLUSIONS
  In children with suspected acute appendicitis, a radiation-free diagnostic imaging of ultrasonography selectively followed by MRI is feasible and comparable to CT, with no difference in time to antibiotic administration, time to appendectomy, negative appendectomy rate, perforation rate, or length of stay.
authors.affiliation: Division of Pediatric Surgery.
authors.forename: Gudrun
authors.initials: G
authors.lastname: Aspelund
authors.forename: Abbey
authors.initials: A
authors.lastname: Fingeret
authors.forename: Erica
authors.initials: E
authors.lastname: Gross
authors.forename: David
authors.initials: D
authors.lastname: Kessler
authors.forename: Connie
authors.initials: C
authors.lastname: Keung
authors.forename: Arul
authors.initials: A
authors.lastname: Thirumoorthi
authors.forename: Pilyung Stephen
authors.initials: PS
authors.lastname: Oh
authors.forename: Gerald
authors.initials: G
authors.lastname: Behr
authors.forename: Susie
authors.initials: S
authors.lastname: Chen
authors.forename: Brooke
authors.initials: B
authors.lastname: Lampl
authors.forename: William
authors.initials: W
authors.lastname: Middlesworth
authors.forename: Jessica
authors.initials: J
authors.lastname: Kandel
authors.forename: Carrie
authors.initials: C
authors.lastname: Ruzal-Shapiro
mesh_terms: D001064:Appendicitis / Q000175:diagnosis* / Q000000981:diagnostic imaging; D002648:Child; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D064847:Multimodal Imaging; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography
keywords: MRI; appendicitis; child; computed tomography; ultrasonography