Diagnostic Performance of Quantitative Computed Tomography Pulmonary Angiography Parameters in Patients With Pulmonary Embolism.

Introduction: Pulmonary embolism (PE) is the third leading cause of cardiovascular death after stroke and myocardial infarction. Accurate and timely identification of patients could have a significant impact on reducing the mortality rate and better patient management. Aim: The purpose of this study was to evaluate the diagnostic performance of quantitative parameters measured based on CTPA images to determine the most important and relevant imaging parameters for diagnosing patients with PE. Methods and Materials: In this cross-sectional, multicenter study, the electronic files of 1428 cases suspected of PE were reviewed from 2021 to 2023. The diagnostic performances of anthropometric parameters, right ventricle-to-left ventricle (LV) diameter ratio, and CT obstruction index measured based on CTPA images were evaluated for the diagnosis of PTE. Results: Radiological manifestations associated with PE were IV septum deviation, RV/LV diameter ratio, CT obstruction score, and pulmonary infarction with OR values of 10.53, 38.71, 6.59, and 78.16, respectively (p < 0.001). CT obstruction index with a threshold of 1 was the best parameter for the diagnosis of PE. Accuracy, sensitivity, specificity, and AUC of the CT obstruction index were 96.10%, 98.68%, 94.84%, and 0.96%, respectively. Pulmonary infarction with multifocal involvement as the second strongest parameter had a sensitivity of 81.58%, specificity of 98.76%, accuracy of 93.25%, kappa coefficient of 0.93, and an AUC of 0.90. Conclusion: CT obstruction index and pulmonary infarction with multifocal involvement perform better than the reports of the presence of disease in CTPA images. Therefore, these two parameters must be reported by radiologists and implemented as the primary criteria for diagnosing PE.