Figure 4

Time-sequence of the Lambda2-detected 3D LV vortex structures (visualized as isosurfaces in red color) over all acquired diastolic phases of a sample normal subject, with E-filling onset (x), peak (y) and end (z), and A-filling onset (u), peak (v) and end (w). Diastasis is the duration between z and u. Every dot in the cardiac curve corresponds to a time point of the cardiac cycle in which a 4D Flow volume was acquired. With the start of diastolic phase (f1),the start of the presence of a compact ring-like shaped vortex ring during early- (f3) and late (f7) diastolic filling, the most developed vortex ring formed during early-(f5) and A-filling (f18), the start of vortex stretching or elongation in direction parallel to the LV long-axis (f10) and end of late filling while compact vortex ring is still identifiable (f19). Lambda2 isovalue threshold $\left({\mathrm{T}}_{{\lambda }_2}\right)=3\mathrm{\mu }$ was used to define the isosurfaces of vortex ring cores (with μ as the λ₂ average of voxels with λ₂ < 0). To avoid cluttered view, only large scale vortex cores of 1 cm³ or larger are visualized.