Figure 1:

Illustration of the Cartesian 4D flow sampling pattern as described in the Theory section on a simplified 30 × 30 k-space grid. The first 15 indices for each velocity encoding are shown, with initialization at the center. Self-gating indices are omitted for clarity. Each entry represents a readout along k_x. Dashed lines indicate radial lines for i = 7 and i = 8. Angular indices are advanced by 2π (2 − g_θ) ≈ 137.5◦, where g_θ is the golden ratio.