Hyun Suk Cho, Presenter: Nothing to Disclose

Hye-Suk Hong, Abstract Co-Author: Nothing to Disclose

Ji Young Woo MD, Abstract Co-Author: Nothing to Disclose

Ah Young Jung, Abstract Co-Author: Nothing to Disclose

Ik Yang, Abstract Co-Author: Nothing to Disclose

Su Kyung Jeh, Abstract Co-Author: Nothing to Disclose

Ji-Young Hwang MD, Abstract Co-Author: Nothing to Disclose

Yul Lee MD, Abstract Co-Author: Nothing to Disclose

The authors suggest that presence of intraluminal air is a useful additional criterion to exclude acute appendicitis and investigated to determine its diagnostic efficacy in the CT evaluation of suspected patients with the enlarged (>5 mm) appendix.

A total of 373 consecutive patients visited the emergency department with acute abdominal pain and underwent CT with a clinical suspicion of acute appendicitis. Outer diameter of the appendix was measured on CT and 272 patients (M:F=141:131; age range, 11-90 years) with enlarged appendix (outer diameter >5 mm) were enrolled as a study population. Seventy-six of the 272 patients were confirmed as acute appendicitis with surgery. The remaining 196 were considered negative by means of pathology (n = 5) or clinical improvement (n = 191). Two reviewers retrospectively analyzed the CT in consensus and investigated presence or absence of intraluminal air. In addition, the reviewers gave a tentative diagnosis to each case referring to the established criteria of acute appendicitis. We made an assumption that presence of intraluminal air can exclude acute appendicitis or absence of air is a finding positive for acute appendicitis. The study population was then divided into ‘concordant’ or ‘discordant’ group. When the assumption and tentative diagnosis were consistent, it was defined as concordant, otherwise as discordant. Sensitivity, specificity, PPV, NPV, and accuracy of presence of intraluminal air for the exclusion of acute appendicitis were evaluated. The prevalence of intraluminal air was investigated.

There were 231 cases with 62 acute appendicitis in concordant and 41 with 14 in discordant group. Sensitivity, specificity, PPV, NPV, and accuracy of the presence of intraluminal air for the exclusion of acute appendicitis were 92%, 62%, 81%, 82%, and 81%, respectively, for total population, while 98%, 81%, 92%, 95%, and 93%, respectively, for concordant subgroup. Intraluminal air was seen in 14 (18%) of 76 pateitns with acute appendicitis in the total population, whereas only 3 (5%) of 62 in the concordant group.

When concordant with a tentative diagnosis, air in the enlarged appendix showed excellent diagnostic efficacy in the exclusion of acute appendicitis.

When radiologists think acute appendicitis is not likely on CT despite the enlarged appendix, intraluminal air aids in confident exclusion of the disease.

Cho, H, Hong, H, Woo, J, Jung, A, Yang, I, Jeh, S, Hwang, J, Lee, Y, Diagnostic Value of Air in the Enlarged (>5 mm) Appendix in Patients with Clinically Suspected Appendicitis: Evaluation with CT.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11014782.html