Table 3.
Summary of biomarkers definition
| Biomarkers | Definition |
|---|---|
| Richness of vessel | |
| VD | vascular density. Ratio of vascular area to lesion area. |
| NV | number of vessels. After removing the bifurcation point. the number of vascular segments. |
| NB | number of branches. Intersection of three or more blood vessels. |
| NVR | density of NV. Ratio of NV and lesion area. |
| NBR | density of NB. Ratio of NB and lesion area |
| Vascular distribution | |
| mvFD | microvessel fractal dimension. |
| VDR | ratio of central and surrounding area. Calculate the ratio between the central VD and the surrounding VD. |
| SVP | vascularity pattern (= 1: VDR > = 1; = 0: VDR < 1). |
| Each vessel | |
| Dmax* | maximum of diameter. |
| Dave* | average of diameter. |
| Tmax | maximum of tortuosity. Tortuosity was defined as the ratio of the path distance between two vertices of blood vessels to the Euclidean distance. |
| Tave | average of tortuosity. |
| Each branch point | |
| MDmax | maximum of Murray’s deviation. For vessels connected to one branch point, the vessel with the largest diameter was defined as the mother branch (V-mother), and the other branches were child branches (V-child) **. |
| MDave | average of Murray’s deviation |
| MDmin | minimum of Murray’s deviation |
| BAmax+ | maximum of bifurcation angle. The bifurcation angle was defined as the angle between two V-childs. If the number of V-childs is over 2, select the largest bifurcation angle. |
| BAave+ | average of bifurcation angle |
| BAmin+ | minimum of bifurcation angle |
Note. *: the unit is centimeters (cm). **: Dmon is the diameter of V-mother; Dchild is the diameter of V-child
+: the unit is angle (°). max: maximum. ave: average. min: minimum. V-: Vessel-