Correlation between pulmonary artery pressures measured by Doppler echocardiography and pulmonary arteries` diameters measured by CT pulmonary angiography in patients with pulmonary hypertension secondary to respiratory disorders

Abstract

Pulmonary hypertension is defined as mean pulmonary artery pressure greater than 25 mm Hg during rest (normal level 10 mm Hg) or greater than 30 mm Hg during exercise (normal level 15 mm Hg) as determined with right heart catheterization (Frazier et al., 2000). Right-heart catheterization is currently the gold standard method used to measure PH and to grade its severity. Cardiac catheterization, like any invasive procedure, is associated with important risks and complications, such as bleeding, infection, arrhythmias, or cerebrovascular events (Grubstein et al., 2008). Echocardiography is a key screening method in the diagnostic algorithm because it has special advantages over invasive procedures. It is safe, portable and repeatable. Therefore, echocardiography is more practical for evaluation of PAH at the beginning of the disease and during the follow up (Ginghina et al., 2009). Computed tomography is commonly performed in patients suspected of having PH or in patients with an underlying diffuse lung disease who may be at risk for PH. In addition, the structure of the pulmonary vasculature at CT has been extensively studied as marker of increased MPAP. In this regard, most investigators have concentrated on dilation of the main pulmonary artery (both in absolute terms and in relation to the size of the ascending aorta) at axial CT as a sign of PH (Devaraj et al., 2008). Multi-detector CT angiography is now the first line of investigation in the diagnosis of most of pulmonary vascular disorders, it is a relatively available minimally invasive investigation that can now be considered as the first line of investigation in diagnosis of pulmonary embolism with its ability to detect small emboli down to the segmental and sub segmental and it is of value in patients with PH as it show different signs of PH as well as the possible cause (Addis et al., 2001).