High-resolution T1 mapping with ANGIE detects increased right-ventricular extracellular volume fraction in patients with pulmonary arterial hypertension

Background Right ventricular (RV) failure is associated with increasing morbidity and mortality in pulmonary arterial hypertension (PAH). Pressure overload in PAH leads to a complex series of changes in cardiomyocytes and the extracellular matrix of the RV. Thus, quantitative T1 mapping of the RV to assess myocardial extracellular volume fraction (ECV) may be a valuable noninvasive marker of RV fibrosis in these patients. However, current clinically preferred T1 mapping techniques have limited spatial resolution, restricting their application to assessment of left ventricular (LV) ECV. We recently developed a novel technique, termed ANGIE, which uses navigator gating and acceleration with compressed sensing (CS) to provide high-resolution T1 mapping for assessment of thin structures such as the wall of the RV. The aim of the present study was to use ANGIE to test the hypothesis that RV ECV is elevated in patients with PAH compared to reference subjects.