title: Selective use of ultrasonography for acute appendicitis in children.
abstract: BACKGROUND
  To evaluate the role of ultrasonography in children with equivocal signs of acute appendicitis, and correlate with initial clinical impression and pathological findings.
  
  
  METHODS
  This is a prospective evaluation of all children presenting with a possible diagnosis of appendicitis during a 14-month study period. Patients with unequivocal clinical signs of appendicitis underwent appendectomy without ultrasonography. Patients with equivocal signs had documentation of the clinical impression and subsequent abdominal ultrasound. Statistical analysis of results was performed using the chi-square test (P <0.05 significant).
  
  
  RESULTS
  Two hundred fifteen consecutive children were enrolled. Signs were unequivocal in 116 and equivocal in 99. Seven patients in the first group had a normal appendix at operation. Of the 99 patients with equivocal signs, there were 28 true positives, 3 false positives, 64 true negatives, and 4 false negatives. In equivocal cases, sensitivity of the initial clinical impression versus ultrasound was 50% and 88%, respectively (P <0.05). Specificity was 85% and 96%, respectively. The positive and negative predictive values improved from 63% to 90% and 78% to 94%, respectively, with the use of ultrasonography.
  
  
  CONCLUSIONS
  The low false positive rate (6%) in clinically obvious cases of appendicitis does not, in our opinion, warrant ultrasonography. In clinically equivocal cases, ultrasonography is a fast, sensitive, and specific diagnostic modality to diagnose or rule out appendicitis, avoiding the need for prolonged observation and/or hospitalization.
authors.affiliation: Division of Pediatric Surgery, Brown University School of Medicine and Hasbro Children's Hospital, Providence, Rhode Island, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Lessin
authors.forename: M
authors.initials: M
authors.lastname: Chan
authors.forename: M
authors.initials: M
authors.lastname: Catallozzi
authors.forename: M F
authors.initials: MF
authors.lastname: Gilchrist
authors.forename: C
authors.initials: C
authors.lastname: Richards
authors.forename: L
authors.initials: L
authors.lastname: Manera
authors.forename: M T
authors.initials: MT
authors.lastname: Wallach
authors.forename: F I
authors.initials: FI
authors.lastname: Luks
mesh_terms: D000208:Acute Disease; D001062:Appendectomy; D001064:Appendicitis / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D001065:Appendix / Q000098:blood supply / Q000000981:diagnostic imaging; D001783:Blood Flow Velocity; D002648:Child; D003937:Diagnosis, Differential; D005189:False Positive Reactions; D005500:Follow-Up Studies; D006801:Humans; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D018608:Ultrasonography, Doppler