title: Diagnosis of intussusception by physician novice sonographers in the emergency department.
abstract: OBJECTIVE
  We investigate the performance characteristics of bedside emergency department (ED) ultrasonography by nonradiologist physician sonographers in the diagnosis of ileocolic intussusception in children.
  
  
  METHODS
  This was a prospective, observational study conducted in a pediatric ED of an urban tertiary care children's hospital. Pediatric emergency physicians with no experience in bowel ultrasonography underwent a focused 1-hour training session conducted by a pediatric radiologist. The session included a didactic component on sonographic appearances of ileocolic intussusception, review of images with positive and negative results for intussusceptions, and a hands-on component with a live child model. On completion of the training, a prospective convenience sample study was performed. Children were enrolled if they were to undergo diagnostic radiology ultrasonography for suspected intussusception. Bedside ultrasonography by trained pediatric emergency physicians was performed and interpreted as either positive or negative for ileocolic intussusception. Ultrasonographic studies were then performed by diagnostic radiologists, and their results were used as the reference standard. Test characteristics (sensitivity, specificity, positive and negative predictive values) and likelihood ratios were calculated.
  
  
  RESULTS
  Six pediatric emergency physicians completed the training and performed the bedside studies. Eighty-two patients were enrolled. The median age was 25 months (range 3 to 127 months). Thirteen patients (16%) received a diagnosis of ileocolic intussusception by diagnostic radiology. Bedside ultrasonography had a sensitivity of 85% (95% confidence interval [CI] 54% to 97%), specificity of 97% (95% CI 89% to 99%), positive predictive value of 85% (95% CI 54% to 97%), and negative predictive value of 97% (95% CI 89% to 99%). A positive bedside ultrasonographic result had a likelihood ratio of 29 (95% CI 7.3 to 117), and a negative bedside ultrasonographic result had a likelihood ratio of 0.16 (95% CI 0.04 to 0.57).
  
  
  CONCLUSIONS
  With limited and focused training, pediatric emergency physicians can accurately diagnose ileocolic intussusception in children by using bedside ultrasonography.
authors.affiliation: Department of Pediatrics, Section of Emergency Medicine, Yale University School of Medicine, New Haven, CT, USA. antonio.riera@yale.edu
authors.forename: Antonio
authors.initials: A
authors.lastname: Riera
authors.forename: Allen L
authors.initials: AL
authors.lastname: Hsiao
authors.forename: Melissa L
authors.initials: ML
authors.lastname: Langhan
authors.forename: T Rob
authors.initials: TR
authors.lastname: Goodman
authors.forename: Lei
authors.initials: L
authors.lastname: Chen
mesh_terms: D002675:Child, Preschool; D002983:Clinical Competence / Q000706:statistics & numerical data; D004636:Emergency Service, Hospital; D006801:Humans; D007077:Ileal Diseases / Q000000981:diagnostic imaging*; D007223:Infant; D007443:Intussusception / Q000000981:diagnostic imaging*; D010865:Pilot Projects; D019095:Point-of-Care Systems; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D014463:Ultrasonography