Objective: The purpose of this study was to prospectively investigate the correlation between CT angiographic clot load (CTACL) score, pulmonary perfusion defect (PPD) score and the global right ventricular function in the assessment of pulmonary embolism (PE) severity.
Methods: 49 patients with acute PE, who underwent dual-source CT scan, were included in the study. CT angiography and perfusion imaging were performed. Data from electrocardiogram-gated coronary angiography scanning protocol were used for right ventricular function analysis. Two readers evaluated the CTACL and PPD scores using the Qanadli and Chae methods, respectively.
Results: The PPD score had a strong positive correlation with the CTACL score (r=0.72, p<0.001) and both scores in turn had a strong positive correlation with the right ventricular/left ventricular (RV/LV) diameter ratio (r=0.60, r=0.62, p<0.001). However, the PPD score had a strong negative correlation with ejection fraction (EF) (r=-0.63, p<0.001) while the CTACL score had a low negative correlation with EF (r=-0.33, p=0.02). Between the RV/LV<1 group (n=35) and the RV/LV >1 group (n=14), the PPD score, CTACL score, pulmonary artery trunk diameter, EF and reflux of inferior vena cava were significantly different, all with p<0.001. The end-systolic volume (p=0.01) was significantly different but the end-diastolic volume (p=0.11) and stroke volume (p=0.08) showed no statistically significant difference between the two groups.
Conclusion: Therefore, considering PPD scores, CTACL scores and cardiovascular manifestations together may be helpful in the evaluation of PE severity.