Figure 1

Concept of transluminal arterial flow encoding (TAFE). Contrast bolus moves slower in stenotic artery than in normal artery (points 1 to 3). Coronary CT angiography (CCTA) is a snapshot of contrast bolus advection driven by CBF at time T _d . Vessel-specific CBF is calculated from arterial input function of contrast cohort in ascending aorta (yellow-colored numbered circles), arterial volume (the product of length and median luminal area, approximately) to be filled by the contrast cohort, and TAG (slope of intraluminal contrast density) which reflects the flow velocity. Modified from Lardo et al.⁴ with permission.