[vmtk-users] Centerline branch topology?

[Simon W. <s.w...@uq...>]

Hi all,

I've just started working with VMTK again after a long hiatus, and have started integrating the C++ classes into an application. My goal is to obtain the centreline topology, so that I can build a UI around this to allow for interactive segmentation.

I found the method vtkvmtkCenterlineUtilities::FindAdjacentCenterlineGroupIds(...), which I thought would give me the full connected tree, but it doesn't seem to work that way. 

I have a simple structure of a single vessel that branches into two smaller vessels in a Y-shape. From this, vtkvmtkCenterlineBranchExtractor finds a total of 6 segments, but after calling FindAdjacentCenterlineGroupIds(), two of these branches are "orphaned" -- they have no upstream and no downstream groups. These both correspond to two parts of one branch, distal to the bifurcation. 

The other oddity I've noticed is that, from the group that has the bifurcation in it (1 upstream, 2 downstream groups), the branch which has the two orphaned segments attaches another copy of the proximal part instead of the orphaned branches. I've noticed there are methods within vtkvmtkCenterlineUtilities for "unique" group IDs, but I've yet to try this out. 

In short, how should I go about constructing the topology of the centerline? Ideally, I just need 3 segments (the common proximal part, and the two distal branches from the bifurcation), though I can deal with additional "inter-bifurcation" parts if there's no other way.

Thanks,

Simon Wilson