Figure 6

The behavior of D _s during a simulated increase in vessel density. The graph shows that different D _s values can be obtained for images with the same vessel density. As the only variable in these images is their distribution pattern, D _s depends on the irregular arrangement of the vessels in the surrounding environment (note the standard deviation of each cell density group). D _s also increases significantly when a higher vessel density is introduced into the system because of the greater space filled by the vascular component. The increase in vessel density reduces the variability of their space-filling properties, thus reducing the standard deviation.