The ventricular residence time distribution derived from 4D flow particle tracing: a novel marker of myocardial dysfunction

Abstract4D flow cardiac magnetic resonance (CMR) imaging allows visualisation of blood flow in the cardiac chambers and great vessels. Post processing of the flow data allows determination of theresidence time distribution (RTD), a novel means of assessing ventricular function, potentially providing additional information beyond ejection fraction. We evaluated the RTD measurement of efficiency of left and right ventricular (LV and RV) blood flow. 16 volunteers and 16 patients with systolic dysfunction (LVEF  <  50%) underwent CMR studies including 4D flow. The RTDs were created computationally by seeding virtual ‘particles’ at the inlet plane in customised post-processing software, moving these particles with the measured blood velocity, recording and counting how many exited per unit of time. The e fficiency of ventricular flow was determined from the RTDs based on the time constant (RTDc = − 1/B) of the exponential decay. The RTDc was compared to ejection fraction, T1 mapping and global longitudinal strain (GLS). There was a significant difference between groups in LV RTDc (healthy vo lunteers 1.2 ± 0.13 vs systolic dysfunction 2.2 ± 0.80, p <  0.001, C-statistic = 1.0) and RV RTDc (1.5 ± 0.15 vs 2.0 ± 0.57, p = 0.013, C-statistic = 0.799). The LV RTDc correlated significantly with LVEF (R = − 0.84, P <  0.001) and the RV RTDc had significant correlation with RVEF (R = − 0.402, p = 0.008). ...
Source: The International Journal of Cardiovascular Imaging - Category: Radiology Source Type: research