13 March 2018 Tracking of liver vessel bifurcations in 3D+t ultrasound by subsequent approximations of a rigid shape model
Author Affiliations +
Abstract
Liver motion induced by respiratory or cardiac movement can limit the precision of diagnostic or therapeutic procedures like core biopsies or radiation therapy. Ultrasound provides higher image volume acquisition rates compared to CT or MRI. Notwithstanding the occasionally poor vessel contrast, tracking of vessel bifurcations in 3-D+t ultrasound sequences may improve the precision of image guided interventions. For tracking of vessel bifurcations only only the liver’s translation is considered and its rotation/expansion is neglected. Each 3-D sub-volume supposed to contain a bifurcation is translated and its voxels are locally adaptively binarized to separate tissue vs. vessel voxels. The surface of the vessel voxels is approximated to a data-driven time-varying Y-like shape model of the bifurcation. For each time-stamp, the binarization threshold and the bifurcation’s center translation vs. the predecessor volume are chosen such that the differences of successive shape models are minimized w.r.t. the ℓ0.5-norm. The sequence of bifurcation’s center translations defines its trajectory. The method is evaluated on 7 3-D+t volume sequences with 14 annotations, which are placed in bifurcations of vessels with diameters between 7 mm and 9 mm. Tracking performance is evaluated vs. manually annotated reference translations. For a voxel spacing of 1.1 mm × 0.6 mm × 1.2 mm, i.e. volume diagonal 1.8 mm, a 90%-quantile ℓ2- norm tracking error < 2.1 mm is achieved. The algorithm gives local translational motion information and tracks individual vessel bifurcations. Applying the algorithm to several bifurcations may additionally allow determining a more global displacement field of the liver.
© (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Heinrich M. Overhoff, "Tracking of liver vessel bifurcations in 3D+t ultrasound by subsequent approximations of a rigid shape model", Proc. SPIE 10576, Medical Imaging 2018: Image-Guided Procedures, Robotic Interventions, and Modeling, 105762P (13 March 2018); doi: 10.1117/12.2293632; https://doi.org/10.1117/12.2293632
PROCEEDINGS
7 PAGES


SHARE
Back to Top