Oral Contrast in Diagnosing Acute Appendicitis; Is It Necessary?

Abstract

Abstract

BACKGROUND: The diagnosis of acute appendicitis clinically is challenging due to variant age groups at presentation; multidetector computed tomography (MDCT) has become the standard modality with high sensitivity and specificity The American College of Radiology (ACR) appropriateness criteria evidence-based guidelines recommend the use of intravenous (IV) contrast-enhanced computed tomography (CECT) for suspected cases of acute appendicitis but no explicit comment on the use of enteral contrast which creates diversity in the literature for the appropriate MDCT protocols worldwide. The objective of the present study is To compare the accuracy, sensitivity, and specificity of variant MDCT protocols in diagnosing acute appendicitis at Alnoor Specialist Hospital, Makkah, Saudi Arabia.

METHODOLOGY: A retrospective cross-sectional study was conducted at Alnoor Specialist Hospital – Makkah between January 2016 and December 2020. The study included all the patients who presented to the emergency department with clinical suspicion of acute appendicitis and performed preoperative MDCT scans with subsequent surgical intervention by either open or laparoscopic appendectomy. A total number of 385 MDCT scans were retrieved from the hospital Picture Archiving and Communication System (PACS). All data processing was made on exported coded Excel sheet data and analyzed by SPSS 26.0 statistical software package.

RESULTS: 385 MDCT scans with different protocols were collected (NECT, ORAL only, IV only, ORAL, and IV). Final impressions of diagnoses that were not available were excluded from the final analysis. Therefore, 355 MDCT scans were analyzed: 285 patients with positive CT findings for appendicitis were confirmed by correlating the radiological findings with histopathological findings. Radiologists’ ability to detect acute appendicitis was higher in patients administered both oral and IV contrast (sensitivity =92.44%), following IV only (89.61%), NECT (82.35%), and oral contrast (73.47%), respectively (Table 1). Diagnostic accuracy was higher in patients administered both oral and IV contrast (accuracy = 89.23%). 

CONCLUSION: The diagnostic sensitivity and accuracy utilizing IV contrast are comparable to both IV and oral contrast; therefore, oral contrast can be omitted in routine appendicitis protocol. A higher specificity was found with the use of oral contrast due to the luminal filling of the appendix. Yet, it can be reserved for contraindicated cases to IV iodinated contrast administration.