Sensitivity and specificity of the Tokyo Guidelines 2018 for acute cholecystitis diagnosis using different imaging modalities: ultrasonography or computed tomography

Background: Acute cholecystitis diagnosis is crucial in emergency room patients with upper right quadrant pain, however, there is little unanimity regarding the diagnosis. The Tokyo Guidelines 2018 (TG18) examine diagnostic, grading, and severity criteria for acute cholecystitis based on the consensus reached by global experts during talks at the Tokyo Consensus Meeting. However, the imaging modalities utilized by TG18 for diagnosis can impact the precision of this tool. The aim of this study was to evaluate the sensitivity and specificity of TG18 using different imaging modalities (ultrasonography or computed tomography). Methods: This prospective study recruited patients with a suspected history of acute cholecystitis who were admitted to the emergency department of a secondary hospital between December 2021 and August 2022. The acute cholecystitis was analyzed through the use of TG18 diagnosis (imaging modality = ultrasonography), TG18 diagnosis (imaging modality = computed tomography), and histopathology analysis. Results: 46 people were included. Using ultrasonography as an imaging modality, TG18 showed a decreased specificity (0.36) if compared to computed tomography (0.86). The sensitivity of TG18 was comparable to that of ultrasonography (1.00), as well as computed tomography (0.89). Utrasonography revealed a greater number of false positives, which dropped after the adoption of computed tomography as an imaging modality. Conclusions: The use of TG18 for the diagnosis of acute cholecystitis using computed tomography led to better identification of individuals with acute cholecystitis, with ultrasonography having a lower specificity if compared to computed tomography. They showed similar sensitivity, though.