title: Diagnostic accuracy and patient acceptance of MRI in children with suspected appendicitis.
abstract: OBJECTIVE
  To compare magnetic resonance imaging (MRI) and ultrasound in children with suspected appendicitis.
  
  
  METHODS
  In a single-centre diagnostic accuracy study, children with suspected appendicitis were prospectively identified at the emergency department. All underwent abdominal ultrasound and MRI within 2 h, with the reader blinded to other imaging findings. An expert panel established the final diagnosis after 3 months. We evaluated the diagnostic accuracy of three imaging strategies: ultrasound only, conditional MRI after negative or inconclusive ultrasound, and MRI only. Significance between sensitivity and specificity was calculated using McNemar's test statistic.
  
  
  RESULTS
  Between April and December 2009 we included 104 consecutive children (47 male, mean age 12). According to the expert panel, 58 patients had appendicitis. The sensitivity of MRI only and conditional MRI was 100% (95% confidence interval 92-100), that of ultrasound was significantly lower (76%; 63-85, P < 0.001). Specificity was comparable among the three investigated strategies; ultrasound only 89% (77-95), conditional MRI 80% (67-89), MRI only 89% (77-95) (P values 0.13, 0.13 and 1.00).
  
  
  CONCLUSIONS
  In children with suspected appendicitis, strategies with MRI (MRI only, conditional MRI) had a higher sensitivity for appendicitis compared with a strategy with ultrasound only, while specificity was comparable.
  
  
  CONCLUSIONS
  • In children, MRI has a higher sensitivity for appendicitis than ultrasound. • Ultrasound followed by MRI in negative or inconclusive findings is accurate. • The tolerance for ultrasound and MRI in children is comparable. • MRI can be performed in children in an emergency setting.
authors.affiliation: Department of Radiology, Medical Centre Alkmaar, Alkmaar, Netherlands, mai.thieme@gmail.com.
authors.forename: Mai E
authors.initials: ME
authors.lastname: Thieme
authors.forename: Marjolein M N
authors.initials: MM
authors.lastname: Leeuwenburgh
authors.forename: Zaldy D
authors.initials: ZD
authors.lastname: Valdehueza
authors.forename: Donald E
authors.initials: DE
authors.lastname: Bouman
authors.forename: Ivar G J M
authors.initials: IG
authors.lastname: de Bruin
authors.forename: W Hermien
authors.initials: WH
authors.lastname: Schreurs
authors.forename: Alexander P J
authors.initials: AP
authors.lastname: Houdijk
authors.forename: Jaap
authors.initials: J
authors.lastname: Stoker
authors.forename: Bart M
authors.initials: BM
authors.lastname: Wiarda
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D001064:Appendicitis / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D004632:Emergency Medical Services; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000592:standards*; D008297:Male; D010342:Patient Acceptance of Health Care; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires; D014463:Ultrasonography