Cardiovascular magnetic resonance imaging as applied to patients with pulmonary arterial hypertension

Numerous imaging techniques are currently used to evaluate pulmonary arterial hypertension (PAH), including echocardiography, x-ray, electrocardiogram (ECG), computed tomography and magnetic resonance imaging (MRI). All such modalities have inherent advantages and disadvantages governed by physical principles that result in their clinical utility. In that PAH is a progressive disorder characterised by abnormally elevated blood pressure of the pulmonary circulation that leads to extensive vascular remodelling and increased pulmonary vascular resistance, a technique that can encapsulate those specific features that depict the multiple facets of this disease has obvious advantages. Recent advances in cardiovascular MRI (CMR) technology have led to the development of dedicated techniques for non-invasive assessment of cardiovascular structure and function, including haemodynamical parameters in the pulmonary circulation, which are superior in their identification of pulmonary arterial right ventricular morphological changes. These advantages make CMR a very attractive modality for diagnosing, following and providing prognoses for PAH patients. In this review, we highlight the developments in the use of CMR for the diagnosis, assessment and monitoring of patients with PAH. These remarkable improvements in image acquisition, physiological imaging and contrast techniques place CMR in a prime position for defining this disease. In the coming decade, it is anticipated that continued improvements in CMR image acquisition, spatial and temporal resolution and analytical techniques will result in improved understanding of PAH pathophysiology, diagnosis and prognostic variables, as well as the replacement of the most, if not all, invasive procedures currently applied routinely to the evaluation of PAH.