| PARAMETER | TISSUE | PROBE |
| VOLUME FRACTION | vessels and vessel wall components e.g. tunica media | AREA FRACTION FRACTIONATOR |
| LENGTH | vessels | SPACEBALLS or IMAGE PLANE AS PROBE |
| NUMBER | nodes** or endothelial tip cells | OPTICAL FRACTIONATOR |
| CONNECTIVITY | vessel network | CONNECTIVITY |
| SURFACE | vessel walls | ISOTROPIC FAKIR or MERZ |
| THICKNESS | vessel walls | ORTHOGONAL INTERCEPTS |
**by assigning each node a valence the NUMBER of segments and microvessels can be estimated