Researchers have discovered that right ventricle (RV) flow components that are qualified with 4-dimensional phase-contrast cardiovascular magnetic resonance imaging (4D flow CMR) are a useful, noninvasive method for assessing RV function and hemodynamics in patients with pulmonary arterial hypertension (PAH), according to a study published in Quantitative Imaging in Medicine and Surgery.

They suggest using this method in the evaluation of patients with PAH, a disease that eventually leads to RV failure.

The purpose of this study was to assess RV flow components in PAH patients using 4D flow CMR and investigate the role of RV flow in general. Studies show RV ejection fraction is the strongest indicator of mortality in PAH patients. 4D flow MRI is useful for the measurement of blood flow velocity in any direction; it can also be used to assess multidimensional intracardiac hemodynamic status.

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This retrospective study enrolled patients who underwent CMR and right heart catheterization (RHC) from January 2019 to July 2020 at the China-Japan Friendship Hospital in Beijing, China. Thirty PAH patients were enrolled, while 13 healthy volunteers were recruited as controls. Researchers measured hemodynamics using RHC and used 4D flow CMR to quantify various RV flow components. Researchers also used Spearman’s correlation analysis to investigate any possible associations between RV flow components and other CMR metrics, hemodynamics, and clinical data.

Results show that in PAH patients, the RV stroke volume index (RVSVI), ejection fraction (RVEF), cardiac output (RVCO), and cardiac index (RVCI) were markedly reduced, while the RV functional metrics in PAH patients, including RV end-diastolic volume index (RVEDVI), end-systolic volume index (RVESVI) and myocardial mass index (RVMI) were increased. The percentage of direct flow (RVPDF) was markedly reduced in patients with PAH compared with the control group, while residual volume (RVPRVo) was significantly increased.

The wealth of information regarding cardiac function from this study suggests that the method is highly useful in evaluating various parameters in patients with PAH.


Wang L, Liu M, Zhang PY, et al. Analysis of right ventricular flow with 4-dimensional flow cardiovascular magnetic resonance imaging in patients with pulmonary arterial hypertension. 2021;11(8):3655-3665. Quant Imaging Med Surg. doi:10.21037/qims-20-1267