Is Unenhanced Abdominal CT Scan Necessary for the Diagnosis of Acute Appendicitis in Children?

Kwak, Jae Ryoung; Jeon, Woo Chan; Park, Eun Jung; Lee, Doo Hwan; Choi, Sang Cheon; Min, Young Gi; Lee, Ji Sook

Abstract

PURPOSE
This study was designed to evaluate the question of whether a computed tomography (CT) protocol without an unenhanced phase could be used for diagnosis of appendicitis in pediatric patients who visited the emergency department (ED) with acute non-traumatic right lower abdominal pain.
METHODS
We retrospectively selected 100 samples from pediatric abdominal CT scans performed in the ED and read by pediatric radiologists. Thirty emergency physicians were separately asked to evaluate the samples twice. The first evaluation was performed without the unenhanced phase (protocol A). The second evaluation was performed with both the unenhanced phase and the contrast-enhanced phase (protocol B). The sensitivity and specificity of each protocol for diagnosis of suspected acute appendicitis were determined. Intraobserver and interobserver agreements were measured using kappa statistics.
RESULTS
The mean sensitivity and specificity of the two protocols were similar. The sensitivities of protocol A and protocol B were 97.13% (95% Confidence interval=96.13-98.14) and 97.60% (96.67-98.53), respectively. The specificities of protocol A and protocol B were 95.47% (94.34-96.59) and 94.67% (93.33-96.00), respectively. The mean kappa value for intraobserver agreement between results from the two protocols was 0.91 (0.88-0.93). The kappa value for interobserver agreement was 0.90 (0.89-0.91) for protocol A and 0.87 (0.86-0.88) for protocol B.
CONCLUSION
It is feasible to perform a CT scan without an unenhanced phase for evaluation of suspected appendicitis in children with abdominal pain visiting the ED.