I have X-ray tomography images of a vascular tissue consisting of multiple conduits arranged parallel to each other. The conduits are tracheids that have tapered endings. When visualized in VG Studio Max 2.2, the lengths of the tracheids seem to be different when viewed in the xz and yz plane. That is probably because the tissues are not arranged parallel to the plane being used to view the slices but are rather arranged at some angle. How do I estimate the lengths of these tracheids accurately using either VG Studio or Avizo Fire?