title: Systematic review and meta-analysis of the accuracy of MRI to diagnose appendicitis in the general population.
abstract: To perform a systematic review and meta-analysis of all published studies since 2005 that evaluate the accuracy of magnetic resonance imaging (MRI) for the diagnosis of acute appendicitis in the general population presenting to emergency departments.
  
  
  
  All retrospective and prospective studies evaluating the accuracy of MRI to diagnose appendicitis published in English and listed in PubMed, Web of Science, Cinahl Plus, and the Cochrane Library since 2005 were included. Excluded studies were those without an explicitly stated reference standard, with insufficient data to calculate the study outcomes, or if the population enrolled was limited to pregnant women or children. Data were abstracted by one investigator and confirmed by another. Data included the number of true positives, true negatives, false positives, false negatives, number of equivocal cases, type of MRI scanner, type of MRI sequence, and demographic data including study setting and gender distribution. Summary test characteristics were calculated. Forest plots and a summary receiver operator characteristic plot were generated.
  
  
  
  Ten studies met eligibility criteria, representing patients from seven countries. Nine were prospective and two were multicenter studies. A total of 838 subjects were enrolled; 406 (48%) were women. All studies routinely used unenhanced MR images, although two used intravenous contrast-enhancement and three used diffusion-weighted imaging. Using a bivariate random-effects model the summary sensitivity was 96.6% (95% confidence interval [CI]: 92.3%-98.5%) and summary specificity was 95.9% (95% CI: 89.4%-98.4%).
  
  
  
  MRI has a high sensitivity and specificity for the diagnosis of appendicitis, similar to that reported previously for computed tomography. J. Magn. Reson. Imaging 2016;43:1346-1354.
authors.affiliation: Department of Emergency Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.|Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Repplinger
authors.affiliation: Department of Population Health Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: Joseph F
authors.initials: JF
authors.lastname: Levy
authors.affiliation: Department of Emergency Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: Erica
authors.initials: E
authors.lastname: Peethumnongsin
authors.affiliation: Department of Emergency Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: Megan E
authors.initials: ME
authors.lastname: Gussick
authors.affiliation: Department of Emergency Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: James E
authors.initials: JE
authors.lastname: Svenson
authors.affiliation: Department of Emergency Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: Sean K
authors.initials: SK
authors.lastname: Golden
authors.affiliation: Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: William J
authors.initials: WJ
authors.lastname: Ehlenbach
authors.affiliation: Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: Ryan P
authors.initials: RP
authors.lastname: Westergaard
authors.affiliation: Department of Emergency Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.|Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin, USA.|Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.|Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, USA.|Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: Scott B
authors.initials: SB
authors.lastname: Reeder
authors.affiliation: Department of Population Health Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Vanness
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001064:Appendicitis / Q000000981:diagnostic imaging* / Q000453:epidemiology* / Q000473:pathology; D002648:Child; D004632:Emergency Medical Services / Q000706:statistics & numerical data*; D019317:Evidence-Based Medicine; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: MRI; appendectomy; appendicitis; diffusion weighted imaging; meta-analysis