Estimation of Right Ventricular Dysfunction by Computed Tomography Pulmonary Angiography: a Valuable Adjunct for Evaluating the Severity of Acute Pulmonary Embolism

To evaluate the feasibility and the efficacy of computed tomography pulmonary angiography (CTPA) in differentiating acute pulmonary embolism (PE) patients with or without right ventricular dysfunction and to evaluate the severity of right ventricular dysfunction in acute PE patients with CPTA. We retrospectively collected and measured the following parameters: right ventricular diameter by short axis in the axial plane (RVD), left ventricular diameter by short axis in the axial plane (LVD), right ventricular diameter by level on the reconstructed four-chamber views (RVD), left ventricular diameter by level on the reconstructed four-chamber views (LVD), main pulmonary artery diameter (MPAD), ascending aorta diameter (AOD), coronary sinus diameter (CSD), superior vena cava diameter (SVCD), inferior vena cava (IVC) reflux and interventricular septum deviation by CTPA, and we calculated the RVD/LVD, RVD/LVD and MPAD/AOD ratios in acute PE patients. We assessed right ventricular function and pulmonary artery systolic pressure (PASP) by echocardiography (ECHO) and then divided the patients into two groups: group A had right ventricular dysfunction, and group B did not have right ventricular dysfunction. We utilized a logistic regression model to analyse the relationship between right ventricular dysfunction and the measurement parameters obtained from CTPA, and we constructed the ROC curve to confirm the optimal cut-off value of the statistically significant parameter in the logistic regression model. After an initial screening, 113 acute PE patients were enrolled in our study. Among them, 42 patients showed right ventricular dysfunction (37.2 %), and 71 patients showed no right ventricular dysfunction (62.8 %). The difference between the patients with right ventricular dysfunction and patients without right ventricular dysfunction was statistical significant in RVD/LVD ratio. Logistic regression model analysis revealed that RVD/LVD ratio and interventricular septum deviation were correlated to right ventricular dysfunction with statistical significance (p = 0.001 and 0.03 respectively). RVD/LVD > 1.02 (95 % CI: 0.818-0.958, p < 0.0001, sensitivity: 90.2 %, specificity: 88.7 %) and RVD/LVD ratio > 0.999 (95 % CI 0.722-0.898, p < 0.0001) were determined as the optimal cut-off values following ROC analysis. There was a positive correlation between the MPAD/AOD ratio and PASP (r = 0.408, p = 0.01). Based on the analysis of the parameters obtained by CTPA, the RVD/LVD ratio and interventricular septum deviation could be utilized for predicting right ventricular dysfunction. The MPAD/AOD ratio is a potential adjunct to judge the severity of right ventricular dysfunction in acute PE.