MRI 4D-flow virtual Work-Energy analysis of pulmonary arterial vortical flow and pressure reversal in pulmonary hypertension

Motivation: Pathological main pulmonary artery (MPA) vortex duration (Tvortex) assessed by 4D-flow MRI can potentially diagnose pulmonary hypertension (PH) non-invasively. Early systolic pressure reversal has been hypothesized but not proven to cause MPA vortical flow. Goal(s): To test whether Tvortex correlates with time to systolic pressure reversal (Trev) in the MPA. Approach: Thirty-six patients who had undergone right heart catheterization and MRI were analyzed retrospectively using virtual work energy relative pressure (vWERP) to measure Trev in the MPA. Results: Tvortex correlated significantly but weakly with Trev, indicating that early pressure reversal is not the sole mechanism behind MPA vortices in PH. Impact: Our results contribute to elucidating the mechanistic link between pulmonary hypertension and vortical blood flow in the pulmonary artery, which may in turn inform the appropriate clinical role of 4D-flow MRI in pulmonary hypertension.