Pulmonary Obstruction Index in Multidetector Computed Tomographic Imaging for the Risk Assessment of Right Ventricular Dysfunction in Patients with Pulmonary Embolism

Abstract

Objectives: Rapid and accurate risk assessment is critical in selecting the appropriate treatment strategy in the management of pulmonary embolism. This study was designed to assess the relationship between multidetector computed tomographic (MDCT) imaging and the pulmonary obstruction index, right ventricular dysfunction, and serum D-dimer levels in normotensive patients with pulmonary embolism. Patients and Methods: In 74 patients with suspected pulmonary embolism (38 men, 36 women), two readers in consensus assessed the central clot score and the signs of right ventricular dysfunction using MDCT by quantifying right ventricular diameter (RVD), left ventricular diameter (LVD), the ratio of the right ventricle to left ventricle short-axis diameters (RV/LV), and septal deviation. Results: The patients were divided into three groups. Thirty five patients had negative CT pulmonary angiography (CTPA) and deep vein thrombosis (DVT) findings (group 1), 29 had positive CTPA and negative DVT findings of pulmonary embolism (PE) (group 2), and 10 patients had positive DVT and CTPA findings (group 3). Serum D-dimer levels were statistically higher in group 3 than in the other groups. It was found as 329.2 ± 46.9, 461.3 ± 70.5, and 1726.6 ± 543.5 in groups 1, 2, and 3 (P = 0.0001), respectively. We found a significant positive correlation between the lower extremity clot load score and the pulmonary artery obstruction index, and pulmonary artery clot volumes. The right ventricle (RV)/left ventricle (LV) short-axis ratio, azygos vein diameter, the RV wall thickness (RVW), reflux of contrast medium into the inferior vena cava (IVC), leftward septal bowing, and interventricular septal thickness were statistically different in group 1 compared to groups 2 and 3. Conclusion: Evaluation of the total pulmonary artery clot load and morphologic findings of the right heart obtained using CTPA are extremely important in order to follow up patients with suspected venous thrombosis.