Can appendix bending angle be an additional finding to detect acute appendicitis on MDCT?

Abstract

Aim: Computed tomography (CT) is frequently used as an imaging modality in the evaluation of acute appendicitis. The most frequently used measurement to detect acute appendicitis is maximal outer diameter of appendix on CT and several studies have reported other CT findings of acute appendicitis, such as thickness of the appendiceal wall, appendiceal wall enhancement, peri-appendiceal free fluid, peri-appendiceal inflammation, peri-appendiceal lymph node, appendicolith and cecal wall thickening. We investigated the value of the appendix bending angle (ABA) as an additional and novel finding in the diagnosis of acute appendicitis. Methods: This retrospective study was conducted after the local ethics committee’s approval. 52 consecutive patients who underwent appendectomies were assigned to the study group. The patients, who underwent abdominopelvic CT for any other reason than acute abdomen, were included as control group. Results: The mean age of the appendicitis group was 41.9±16.0; male predominance was present (n=32, 61.5%). Peri-appendiceal inflammation was seen in 65.4%, peri-appendiceal lymph node was seen in 73.1% and appendicolith was present in 9.6% of the appendicitis group. The mean ABA was 103.0±15.9 degree in study group and 118.8±23,8 degree in control group respectively (p<0.001). The sensitivity of ABA was calculated as 76.9% and the specificity was 58.3% at 113.15 degree which is the best cut-off point calculated by ROC curve. There was no appendicitis over 142.3 degrees. Conclusion: ABA can be used as an additional finding which is decreased in acute appendicitis.