title: CT scan in patients with suspected appendicitis: clinical implications for the acute care surgeon.
abstract: OBJECTIVE
  To determine the influence of computed tomography (CT) scans on diagnosis and management of patients with suspected appendicitis.
  
  
  METHODS
  Retrospective 2-year review of 1,630 patients with suspected appendicitis, categorized into three groups based on the likelihood (Alvarado scores) of having appendicitis. Group 1: low likelihood (Alvarado score < or =4); group 2: intermediate likelihood (Alvarado scores 5-7), and group 3: high likelihood (Alvarado score > or = 8). CT scan utilization, hospital course, and final pathology were retrospectively reviewed.
  
  
  RESULTS
  More patients received a CT scan in 2006 as compared with 2005 (60 vs. 52%; p = 0.001). The overall appendectomy rate was similar between the 2 years (57% in 2005 vs. 57% in 2006; p = 0.995). The overall appendectomy rate in patients with a CT was significantly higher as compared with those without (60 vs. 53%; p = 0.002). The appendectomy rate in patients with Alvarado scores < or =4 and no CT scan was significantly lower than in those with a CT scan (12 vs. 48%; p < 0.0001). The overall negative appendectomy rate in patients with a CT scan was similar to that in those without: 31/546 (6%) vs. 23/383 (6%).
  
  
  CONCLUSIONS
  CT scan utilization increased the appendectomy rate only in patients with a low clinical suspicion for appendicitis. Preoperative CT scans did not decrease the negative appendectomy rate.
authors.affiliation: Division of Emergency Surgery, Department of Surgery, Keck School of Medicine of University of Southern California and Los Angeles County + USC Medical Center, Los Angeles, Calif., USA.
authors.forename: M
authors.initials: M
authors.lastname: Petrosyan
authors.forename: J
authors.initials: J
authors.lastname: Estrada
authors.forename: S
authors.initials: S
authors.lastname: Chan
authors.forename: S
authors.initials: S
authors.lastname: Somers
authors.forename: W N
authors.initials: WN
authors.lastname: Yacoub
authors.forename: R L
authors.initials: RL
authors.lastname: Kelso
authors.forename: R J
authors.initials: RJ
authors.lastname: Mason
mesh_terms: D015746:Abdominal Pain / Q000000981:diagnostic imaging; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001062:Appendectomy / Q000706:statistics & numerical data; D001064:Appendicitis / Q000145:classification / Q000000981:diagnostic imaging* / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D004638:Emergency Treatment; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data; D019564:Unnecessary Procedures / Q000706:statistics & numerical data