Convex Hull analysis

Overview

Use this analysis to measure the size of a microvascular network.

Vesselucida Explorer measures the size of the network by interpreting a structure as a solid object controlling a given amount of physical space. The amount of physical space is defined in terms of volume, surface area, area, and/or perimeter.

Analysis options

Vessel Structures

Each vessel individually: Check the box to report on each vessel individually, rather than on selected vessels collectively

All Selected Objects

Choose the type of convex hull analysis to run on the selected objects:

Convex Hull 3D: A convex polygon is generated by connecting the tips of the distal segments. The volume and surface area of the polygon are reported.

Another way to think about the analysis is to imagine a plastic sheet wrapped around the selected structure(s), with the plastic stretched tightly between the most distal points of adjacent segments. The volume encased by the sheet is calculated, and the surface area is reported as well.

XY Area Convex Hull: This 2D analysis treats selected tracings as planar shapes and calculates the area enclosed by a "rubber band" around the them. It is performed on a projection of the data.

  • Z information is not used in the Area reported.

  • The perimeter reported is the distance around the most distal points that form the convex hull (length of the "rubber band")

Visualize surface checkbox: Check the box to view the hull that is drawn in the graphical window.

Procedure

  1. Open the data file.
  2. Select the structures to analyze (see Selecting structures).
  3. Select Analyze > Spatial> Convex Hull to display the Convex Hull Analysis window.
  4. Select the desired parameters and click OK to run the convex hull analysis.

References

Rodieck, R. W. (1973). The vertebrate retina: Principles of structure and function. Oxford, England: W. H. Freeman.