title: Simple way to improve accuracy in diagnosis of quadrant inflammatory disease: how to avoid adverse laparotomy by using plain CT.
abstract: OBJECTIVE
  It has been reported that contrast computed tomography (CT) provides a rapid and accurate diagnosis of acute appendicitis, and could potentially prevent adverse appendectomy. In the present study, we evaluated the diagnostic value of precontrast CT combined with that of serum C reactive protein (CRP) concentration for right lower quadrant inflammatory diseases.
  
  
  METHODS
  One hundred consecutive patients who had rebound tenderness and muscular rigidity or guarding on right lower quadrant underwent an emergency abdominal CT without contrast medium and laboratory tests. Based on the CT findings, 10 patients with peritonitis and 41 patients with definite acute appendicitis underwent emergency operations. Of 19 patients with negative CT findings, 11 patients who had positive CRP levels also underwent emergency appendectomies. The remaining patients, of whom 8 had negative CRP levels and 30 had CT findings of other inflammatory diseases, underwent conservative therapy and were examined again later on.
  
  
  RESULTS
  The final diagnosis was acute appendicitis in 58 cases, other intestinal diseases in 21, gynecological disease in 6, urolithiasis in 1, and unknown in 14. Among 86 patients who underwent emergency operations and had a pathological diagnosis, CT had a sensitivity of 81% for the diagnosis of appendicitis, with a specificity of 89%, and an accuracy of 84%. CT combined with serum CRP concentration yielded a sensitivity of 100%, an accuracy of 97%, and a specificity of 89%. The adverse appendectomy rate was 3%. None of the patients underwent a delayed appendectomy. CT differentiated other inflammatory diseases from acute appendicitis in 23 patients.
  
  
  CONCLUSIONS
  It may be concluded that precontrast CT scan combined with serum CRP can provide a rapid and accurate diagnosis of acute appendicitis and other right lower quadrant inflammatory diseases.
authors.affiliation: Department of General Surgery, Chiba University Graduate School of Medicine, Inohana, Chuo, Chiba, Japan. a-togawa@umin.ac.jp
authors.forename: Akira
authors.initials: A
authors.lastname: Togawa
authors.forename: Fumio
authors.initials: F
authors.lastname: Kimura
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Chiku
authors.forename: Wataru
authors.initials: W
authors.lastname: Sano
authors.forename: Tsuguhiko
authors.initials: T
authors.lastname: Tashiro
authors.forename: Masaru
authors.initials: M
authors.lastname: Miyazaki
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001062:Appendectomy; D001064:Appendicitis / Q000097:blood / Q000175:diagnosis* / Q000601:surgery; D002097:C-Reactive Protein / Q000032:analysis*; D003937:Diagnosis, Differential; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
chemical_list: D002097:C-Reactive Protein