Diagnostic values of supine and erect abdominal radiographs for patients with acute abdomen: which is better for decision making?

Abstract

Background: Plain abdominal radiography including supine and erect abdominal radiographs (SAR and EAR) is a frequently used image modality for preliminary evaluation of acute abdomen. We aimed to explore which one of the SAR or EAR has a higher diagnostic value in overall diagnosis of acute abdomen, including their respective advantages over each other for the various underlying diseases. Methods: We retrospectively analyzed the imaging findings of plain abdominal radiography of patients with acute abdomen who received abdominal computed tomography (CT) within 24 hours at the emergency department of a medical center in northern Taiwan between October 2019 and February 2020. Final diagnosis was made by CT reports and clinical data. The relevance between the imaging findings and clinical diagnosis in the groups of SAR and EAR were compared. Results: A total of 1009 cases with acute abdomen were included, of which 341 (33.8%) underwent EAR and 668 (66.2%) underwent SAR. Among them, 820 cases had final diagnosis confirmed by CT and clinical data. In comparison of the diagnostic relevance of SAR and EAR, there were no significant difference in the overall acute abdomen, but EAR showed a better diagnostic relevance in cases with bowel obstruction than SAR did (100% vs 87.2%, p < 0.05). No statistical difference in other abdominal diseases. Conclusion: There is no significant difference between SAR and EAR in evaluation of overall acute abdomen. However, EARs has a diagnostic advantage over SAR for evaluation of suspected bowel obstruction.