Diagnostic limitations of 10 mm thickness single-slice computed tomography for patients with suspected appendicitis.
OBJECTIVE
The aim of this retrospective analysis was to evaluate the accuracy of 10 mm thickness single helical computed tomography (CT) examination for confirming the diagnosis of appendicitis or providing a diagnosis other than appendicitis, including underlying periappendical neoplasms.


METHODS
From April 1, 2001 to March 30, 2005, a total of 272 patients with suspected appendicitis underwent CT examinations. Of the 272 patients, 106 (39%) underwent surgery. Seven CT examinations for seven patients were excluded because of inconsistency of the CT protocol. We therefore reviewed 99 CT images (99 patients) with correlation to surgical-pathological findings to clarify the diagnostic accuracy of CT examinations. We compared the postoperative diagnosis with the preoperative CT report. The final diagnoses were confirmed by macroscopic findings at surgery and pathological evaluations if necessary.


RESULTS
Of the 99 patients, 87 had acute appendicitis at surgery. The sensitivity, specificity, and accuracy of CT were 98.9%, 75.0%, and 96.0%, respectively. The positive predictive value and negative predictive value were 96.6% and 90.0%, respectively. Among nine patients in the true-negative category, five had colon cancers; and among three patients in the false-positive category, two had cancer of the cecal-appendiceal region as the underlying disease.


CONCLUSIONS
CT examination is useful for patients with suspected appendicitis, but radiologists should be aware of the limitation of thick-sliced single helical CT. They should also be aware of the possibility of other diseases, including coincident abdominal neoplasms and underlying cecal-appendiceal cancer.
Kaidu
Motoki
M
Department of Diagnostic Imaging and Internal Medicine, Sado General Hospital, 113-1 Chigusa, Sado, 952-1209, Japan. kaidu@cocoa.ocn.ne.jp
Oyamatu
Manabu
M
Sato
Kenji
K
Saitou
Akira
A
Yamamoto
Satoshi
S
Yoshimura
Norihiko
N
Sasai
Keisuke
K
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001064:Appendicitis / Q000175:diagnosis* / Q000601:surgery; D001065:Appendix / Q000000981:diagnostic imaging* / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media / Q000008:administration & dosage; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007414:Intestinal Neoplasms / Q000175:diagnosis* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement / Q000379:methods; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D036542:Tomography, Spiral Computed / Q000379:methods*
D003287:Contrast Media