Figure 3.

Four quantitative metrics derived from detected FAZ. (A) FAZ area. (B) Acircularity index (AI), defined as the ratio of perimeter of the FAZ (P1) to the perimeter of a circle equal area (P2).¹⁴ (C) STD4, defined as the standard deviation of the area of four sectors of the FAZ after excluding the maximum inscribed circle. (D) NR300, defined as the area of intersection of the FAZ with an annular region between the FAZ maximum inscribed circle and outer circle with a radius 300 μm greater than that of the FAZ maximum inscribed circle (R300) divided by the area of the entire annular region.