Sensitivity and specificity of focused CT for the diagnosis of acute appendicitis

Abstract

Background: Contrast-enhanced CT abdomen and pelvis plays the key role in the workup of acute appendicitis. With increasing rates of CT scans, concerns about the risks from radiation exposure are also increased. Focused CT is one of alternative protocols that has been suggested considering to radiation dosage. Therefore, accuracy of focused CT for the diagnosis of acute appendicitis was studied.

Objective: To determine accuracy of focused CT for the diagnosis of acute appendicitis

Method: Retrospective review of 270 patients with CT scans for evaluation of suspected appendicitis in Krabi hospital from April 2023 to September 2023 were included in this study. From those CTs, we reconstructed images with limited scan range from superior border of L3 to superior border of pubic symphysis which served as the focused CT. These focused CTs were reviewed, assessing for appendix visualization and diagnosis of acute appendicitis or other diseases. The reference standard was obtained from medical records, intra-operative findings, and/or histopathology.

Results: The appendix was completely covered by focused CT in 269 cases and partially covered in 1 case. 94 cases (34.81%) showed acute appendicitis, 73 cases (27.04%) showed other diseases, whereas 103 cases (38.15%) showed no relevant findings. The sensitivity, specificity, positive predictive value, and negative predictive value of focused CT were 92.86%, 98.26%, 96.81%, and 96.02%, respectively.

Conclusion: For the diagnosis of acute appendicitis, CT scan range can be limited to cover from superior border of L3 to superior border of pubic symphysis.