title: Accuracy and interobserver agreement between MR-non-expert radiologists and MR-experts in reading MRI for suspected appendicitis.
abstract: OBJECTIVE
  To compare accuracy and interobserver agreement between radiologists with limited experience in the evaluation of abdominal MRI (non-experts), and radiologists with longer MR reading experience (experts), in reading MRI in patients with suspected appendicitis.
  
  
  METHODS
  MR imaging was performed in 223 adult patients with suspected appendicitis and read independently by two members of a team of eight MR-inexperienced radiologists, who were trained with 100 MR examinations previous to this study (non-expert reading). Expert reading was performed by two radiologists with a larger abdominal MR experience (>500 examinations) in consensus. A final diagnosis was assigned after three months based on all available information, except MRI findings. We estimated MRI sensitivity and specificity for appendicitis and for all urgent diagnoses separately. Interobserver agreement was evaluated using kappa statistics.
  
  
  RESULTS
  Urgent diagnoses were assigned to 147 of 223 patients; 117 had appendicitis. Sensitivity for appendicitis was 0.89 by MR-non-expert radiologists and 0.97 in MR-expert reading (p=0.01). Specificity was 0.83 for MR-non-experts versus 0.93 for MR-expert reading (p=0.002). MR-experts and MR-non-experts agreed on appendicitis in 89% of cases (kappa 0.78). Accuracy in detecting urgent diagnoses was significantly lower in MR-non-experts compared to MR-expert reading: sensitivity 0.84 versus 0.95 (p<0.001) and specificity 0.71 versus 0.82 (p=0.03), respectively. Agreement on urgent diagnoses was 83% (kappa 0.63).
  
  
  CONCLUSIONS
  MR-non-experts have sufficient sensitivity in reading MRI in patients with suspected appendicitis, with good agreement with MR-expert reading, but accuracy of MR-expert reading was higher.
authors.affiliation: Department of Surgery, Academic Medical Center, University of Amsterdam, The Netherlands; Department of Radiology, Academic Medical Center, University of Amsterdam, The Netherlands. Electronic address: m.m.leeuwenburgh@amc.uva.nl.
authors.forename: Marjolein M N
authors.initials: MM
authors.lastname: Leeuwenburgh
authors.affiliation: Department of Radiology, Alkmaar Medical Center, Alkmaar, The Netherlands.
authors.forename: Bart M
authors.initials: BM
authors.lastname: Wiarda
authors.affiliation: Department of Radiology, Sint Lucas Andreas Hospital, Amsterdam, The Netherlands.
authors.forename: Sebastiaan
authors.initials: S
authors.lastname: Jensch
authors.affiliation: Department of Radiology, Sint Antonius Hospital, Nieuwegein, The Netherlands.
authors.forename: H Wouter
authors.initials: HW
authors.lastname: van Es
authors.affiliation: Department of Surgery, Kennemer Gasthuis, Haarlem, The Netherlands.
authors.forename: Hein B A C
authors.initials: HB
authors.lastname: Stockmann
authors.affiliation: Department of Radiology, Gelre Hospitals, Apeldoorn, The Netherlands.
authors.forename: Jan Willem C
authors.initials: JW
authors.lastname: Gratama
authors.affiliation: Department of Radiology, Haaglanden Medical Center, Leidschendam, The Netherlands.
authors.forename: Lodewijk P J
authors.initials: LP
authors.lastname: Cobben
authors.affiliation: Department of Clinical Epidemiology, Academic Medical Center, University of Amsterdam, The Netherlands.
authors.forename: Patrick M M
authors.initials: PM
authors.lastname: Bossuyt
authors.affiliation: Department of Surgery, Academic Medical Center, University of Amsterdam, The Netherlands.
authors.forename: Marja A
authors.initials: MA
authors.lastname: Boermeester
authors.affiliation: Department of Radiology, Academic Medical Center, University of Amsterdam, The Netherlands.
authors.forename: Jaap
authors.initials: J
authors.lastname: Stoker
mesh_terms: D000006:Abdomen, Acute / Q000175:diagnosis*; D000328:Adult; D001064:Appendicitis / Q000175:diagnosis*; D002983:Clinical Competence / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D015588:Observer Variation; D011860:Radiography, Abdominal / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: Abdominal pain; Magnetic resonance imaging appendicitis observer variation sensitivity and specificity