Assessment Of The Severity Of Acute Pulmonary Embolism Using Retrospective ECG-gating CT Pulmonary Angiography

Objective To assess the severity of acute pulmonary embolism at retrospectiveECG-gating CT pulmonary angiography by CT pulmonary artery obstruction index (PAOI)and indices of RV function.Methods65cases underwent retrospective ECG-gating CTPA examinations.According to the clinical severity, all the patients were divided into three groups: high-riskgroup (20cases, group1), non-high-risk group (25cases, group2) and non-APE group (20cases). CT PAOI was analyzed comparatively on CT images between group1and group2. TheCT signs RV function, including right ventricular end-diastolic and end-systolic volume(RVEDV and RVESV), right heart stroke volume (SV), right ventricular ejection fraction(RVEF), RV/LV volume ratio of EDV and ESV, right ventricular maximal diameter andRV/LV maximal diameter ratio on4-chamber views (RVd4CH, RVd4CH/LVd4CH), pulmonaryartery trunk, superior vena cava and azygos vein diameters (DPA, DSVC, DAZ), the ratio ofpulmonary artery trunk and aortic diameter, interventricular septum morphology, contrastmedium reflux into inferior vena cava (IVC). Comparing the differences of parametersmentioned above among all of the three groups. Spearman rank coefficient was used to investigatecorrelation between signs of RV dysfunction and CT PAOI. Using receiver operatingcharacteristic curve to learn the accuracy, sensitivity and specificity of critical APE.Results CT PAOI in high-risk APE group was higher than that in non-high-risk one.All of the CT signs of RV dysfunction showed the differences among three groups andRVEDV、 RVEDV/LVEDV、 RVESV、 RVESV/LVESV、 RVd4CH/LVd4CHhad statisticaldifference in pairwise comparisons. CT PAOI was mildly or moderately correlated with indices of RV function (rs=0.194~0.503). Az values of CT PAOI, RVEDV, RVEDV/LVEDV,RVESV, RVESV/LVESV, RVEF, RVd4CH, RVd4CH/LVd4CHand Dazwere all higher than0.5.Conclusion Retrospective ECG-gating CTPA can be used to evaluate the severity ofAPE and provide important information for the clinical treatment and the prognosticevaluation.