title: Does computed tomography have any additional value after sonography in patients with suspected acute appendicitis?
abstract: OBJECTIVE
  The purpose of this study was to evaluate the additional value of supplementary computed tomography (CT) after sonography for diagnosing acute appendicitis.
  
  
  METHODS
  Among 140 consecutive patients with suspected acute appendicitis who underwent both initial sonography and supplementary CT within 12 hours, 88 patients whose appendices could not be visualized on sonography were excluded. The remaining 52 patients (mean age, 37.3 years; range, 15-98 years) were enrolled in this study. Two radiologists retrospectively reviewed the findings of 52 sonographic and CT examinations, and the appendix of each patient was classified as normal, equivocal appendicitis, nonperforated acute appendicitis, or perforated appendicitis. Causes of right lower quadrant pain other than appendicitis were also recorded. The additional value of supplementary CT was evaluated by performing head-to-head comparisons between CT and sonographic results.
  
  
  RESULTS
  No patients with a normal appendix on sonography showed appendicitis on CT. In addition, there were no patients with a sonographic diagnosis of appendicitis who had a normal appendix on CT. Ten patients (19.2%) were determined to have additional value gained from CT. Among these 10 patients, however, the additional information from CT affected treatment modality decisions in only 5.
  
  
  CONCLUSIONS
  Initial sonography can be as effective as CT in patients with suspected acute appendicitis when the results are definite. Supplementary CT should only be performed when sonography is inconclusive.
authors.affiliation: Department of Radiology, Kyung Hee University Hospital at Gangdong, Gangdong-gu, Seoul 134-727, Korea.
authors.forename: Hye Soo
authors.initials: HS
authors.lastname: Koo
authors.forename: Hyun Cheol
authors.initials: HC
authors.lastname: Kim
authors.forename: Dal Mo
authors.initials: DM
authors.lastname: Yang
authors.forename: Sang Won
authors.initials: SW
authors.lastname: Kim
authors.forename: Seong Jin
authors.initials: SJ
authors.lastname: Park
authors.forename: Jung Kyu
authors.initials: JK
authors.lastname: Ryu
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001064:Appendicitis / Q000175:diagnosis* / Q000453:epidemiology*; D003951:Diagnostic Errors / Q000517:prevention & control* / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000706:statistics & numerical data*; D015588:Observer Variation; D015995:Prevalence; D056910:Republic of Korea / Q000453:epidemiology; D018570:Risk Assessment; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*; D014463:Ultrasonography / Q000706:statistics & numerical data*; D055815:Young Adult
keywords: appendicitis; computed tomography; sonography