Accuracy of Computed Tomography in Differentiating Perforated from Nonperforated Appendicitis, Taking Histopathology as the Gold Standard

Abstract

Introduction Acute appendicitis is one of the more common causes of acute abdominal pain. It occurs when the lumen of the appendix is obstructed, leading to inflammation and finally perforation. The preoperative differentiation of perforated from nonperforated appendicitis is important and helpful to define prognosis and determine an adequate therapeutic approach, including consideration for nonsurgical treatment. This study recommends computed tomography (CT), a noninvasive method of investigation, be used frequently in clinically suspected cases of perforated appendicitis in the Pakistani population for better patient outcomes. Objective To determine the diagnostic accuracy of CT in differentiating perforated from nonperforated appendicitis by using histopathology as the gold standard. Material and methods A total of 236 patients with a clinical suspicion of appendicitis were included in this study. CT was performed in Liaquat National Hospital and Medical College. At the time of scanning, intravenous contrast was administered. Histopathology was used as the diagnostic gold standard. CT findings were documented using a proforma. The patient was returned to the referring department and followed after surgery for histopathology. Results Sensitivity, specificity, and positive and negative predictive values, as well as the accuracy of CT in the detection of perforated appendicitis, was 71.4%, 90.7%, 62.5%, 93.6%, and 87.3%, respectively. Conclusion CT findings can be used to select patients with perforated appendicitis for initial nonoperative management.

Keywords: acute appendicitis; computed tomography; non-perforated appendicitis.

Figure 1. Acute appendicitis without perforation

Axial image without contrast shows the swollen appendix with appendicolith (arrow). Periappendiceal inflammatory changes seen.

Figure 2. Coronal image of abdomen showing swollen appendix (blue arrow) with marked periappendiceal inflammatory fat stranding (arrowhead). Small amount of free air also seen (white arrow)

Figure 3. Acute appendicitis with perforation

A) Coronal and B) axial images demonstrated collection (blue arrow), inflammatory changes in the right iliac fossa (white arrow); appendicolith (arrowhead)