Diagnosis of Pulmonary Hypertension Aided By MR Imaging of Blood Flow Vortices
In a recent study entitled “Blood Flow Vortices along the Main Pulmonary Artery Measured with MR Imaging for Diagnosis of Pulmonary Hypertension” the authors report that phase-contrast magnetic resonance (MR) imaging is an accurate method for diagnosing pulmonary hypertension by estimating increased mean pulmonary arterial pressure. The study was published in the Radiology journal.
Pulmonary Hypertension (PH) is characterized by increased blood pressure in lung arteries due to their abnormal constriction, specifically by a mean pulmonary arterial pressure (mPAP) equal to or exceeding 25 mmHg at rest. It is also associated with vortical motion of blood in the main pulmonary artery. PH-related symptoms include shortness of breath, dizziness, fainting, and leg swelling among others. Therefore, PH patients have decreased exercise tolerance to the disease frequently escalating to heart failure. PH-associated exercise impairment is determined by abnormally low oxygen levels in the blood, right ventricular hypertrophy, and skeletal and respiratory muscle weakness.
Diagnosis of PH is often determined invasively via right heart catheterization. However, other non-invasive methods have been developed to predict PH, including echocardiography and magnetic resonance (MR) imaging. In this study, the authors wanted to determine the functional relationship between an invasive and a non-invasive method in measuring mPAP — right heart catheterization and phase-contrast MR imaging-derived duration of vortical blood flow along the main pulmonary artery.
The researchers analyzed 145 patients suspected of suffering from PH. Diagnosis was performed with the two techniques, invasive and non invasive, and they evaluated what the relationship was between vortical blood flow in the pulmonary artery measured with MRI and mPAP measure by right heart catheterization. The authors found an increasing linearity between both methods. Therefore, determining vortical blood flow duration in the main pulmonary artery by phase-contrast (MR) imaging represents an accurate and reliable method of elevated mPAP and diagnosis of PH. The new findings will in turn help specialists in help determining both diagnosis and prognosis in PH patients.