title: Test characteristics of the 3-view abdominal radiograph series in the diagnosis of intussusception.
abstract: OBJECTIVE
  To determine the test characteristics of the 3-view abdominal radiograph series to exclude intussusception in children presenting to the pediatric emergency department.
  
  
  METHODS
  We performed a single-center retrospective review of children for whom supine, prone, and lateral decubitus abdominal radiographs were performed as part of our standard diagnostic evaluation for intussusception. A pediatric radiologist masked to the patient's clinical data and outcome reviewed all radiographs. The criterion evaluated was whether air was visualized in the ascending colon on each of the 3 radiograph views. We determined the presence or absence of intussusception hierarchically by definitive radiological study report, surgical operative note, or clinical outcome.
  
  
  RESULTS
  We analyzed 179 patients, of whom 27 (15.1%) were diagnosed with intussusception. The test characteristics of the 3-view radiograph series in the diagnosis of intussusception when all 3 views had air in the ascending colon were sensitivity of 100% (95% confidence interval [CI] 87-100), specificity of 18.4% (95% CI, 12.3-24.6), likelihood ratio for a negative test of 0 (95% CI, 0.01-1.53), and negative predictive value (NPV) of 100% (lower bound 95% CI, 98%). When at least 2 views had air in the ascending colon, the test characteristics were sensitivity of 96.3% (95% CI, 89.2-100), specificity of 41.4% (95% CI, 33.6-49.3), likelihood ratio for a negative test of 0.09 (0.01-0.62), and NPV of 98.4 (95% CI, 95.2-100).
  
  
  CONCLUSIONS
  Using specific criteria, the presence of air in the ascending colon on 2 or 3 abdominal radiograph views has the potential to substantially decrease the likelihood of or exclude intussusception.
authors.affiliation: Division of Pediatric Emergency Medicine, Morgan Stanley Children's Hospital of New York-Presbyterian, Columbia University College of Physicians & Surgeons, 622 West 168th Street, PH 137, New York, NY 10032, USA. cg278@columbia.edu
authors.forename: Cindy Ganis
authors.initials: CG
authors.lastname: Roskind
authors.forename: Carrie B
authors.initials: CB
authors.lastname: Ruzal-Shapiro
authors.forename: Erin K
authors.initials: EK
authors.lastname: Dowd
authors.forename: Peter S
authors.initials: PS
authors.lastname: Dayan
mesh_terms: D002675:Child, Preschool; D044682:Colon, Ascending / Q000000981:diagnostic imaging; D003108:Colonic Diseases / Q000175:diagnosis*; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D007223:Infant; D007443:Intussusception / Q000175:diagnosis*; D008297:Male; D011237:Predictive Value of Tests; D016684:Prone Position; D011860:Radiography, Abdominal / Q000379:methods*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016683:Supine Position