Fig. 6

Longitudinal changes of 4D flow-derived PA area, velocity, and helicity were associated with mean PA pressure (mPAP), total pulmonary resistance (TPR), and percent predicted RV end-systolic volume (RVESV) from pre-PEA to post-PEA (negative ∆ values indicating a decrease in value from pre- to post-PEA). Decreases in minimum MPA area were associated with decreases in (a) mPAP and (b) TPR, but not with (c) % predicted RVESV. Increases in RPA centerline velocity was associated with decreases in (d) mPAP and (e) TPR, but not (f) % predicted RVESV. Increases in RPA helical flow index (HFI) were strongly associated with decreases in (g) mPAP and (h) TPR. Decreases in the MPA fraction of positive helicity were strongly associated with decreases in (i) % predicted RVESV. Correlations with area used n = 20 patients with clear anatomical resolution in the 4D flow images; velocity and helicity correlations used n = 15 patients to exclude 4D flow CMRs that did not maintain conservation of flow. Colored dots in (c)-(h) represent the San Diego classification of the PEA specimens for each patient – red = Type I, blue = Type II, green = Type III, grey = not recorded. Significance of the Spearman correlation denoted by: *=p < 0.05, **=p < 0.01