Imaging in pulmonary hypertension: Echocardiography, computed tomography and cardiac magnetic resonance imaging

Abstract

Comprehensive imaging plays a central role in the detection, workup and management of pulmonary hypertension (PH). Determination of systolic pulmonary artery pressure by Doppler echocardiography continues to be the primary tool for the early detection of PH. Although systolic pulmonary artery pressure derived via measurement of tricuspid regurgitation velocity has an excellent correlation with invasive measurements, certain pitfalls must be recognized by the clinician. Recent work on novel indexes of right ventricular function and on the noninvasive assessment of pulmonary vascular resistance by echocardiography is promising. Computed tomography (CT) is increasingly being used in PH and is particularly useful in ruling out pulmonary parenchymal etiologies, and to detect potentially surgically treatable forms such as extracardiac left to right shunts and chronic thromboembolic PH. Cardiac magnetic resonance (CMR) imaging has also become an increasingly useful tool in clinical practice and is now considered by many to be the gold standard for the structural and functional evaluation of the right heart. Volumetric and functional assessment can be performed accurately and reproducibly with CMR imaging without radiation or the need for geometric assumptions. Recently, various morphometric variables on CT and CMR imaging have been shown to correlate well with invasive measurement of pulmonary artery pressure. With ongoing innovations in echocardiography, CT and CMR imaging, it is expected that these mutually complementary imaging techniques will play an increasingly important role in the patient with PH.