Diagnosis and management of pulmonary arterial hypertension using MR imaging.

Pulmonary arterial hypertension (PAH) is a syndrome that results from restricted blood flow through the pulmonary arterial circulation, which leads to a pathological increase in pulmonary vascular resistance (PVR) and ultimately to right heart failure. The prognosis of patients with PAH has improved with the recent development of new medications. The need for new noninvasive diagnostic tools is increasing. Magnetic resonance (MR) imaging is the gold standard for assessing the right ventricle (RV). Its high degree of reproducibility makes it ideal for monitoring changes in RV parameters in response to therapy. MR imaging can also provide both anatomical and functional information about pulmonary hemodynamics. This article reviews the current status of MR imaging of the right side of the heart and pulmonary circulation in patients with PAH and other associated pulmonary diseases.