Vascular landmark detection in 3D CT data
David Liu, Shoujun Zhou, Dominik Bernhardt, Dorin Comaniciu · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2011
This work presents novel methods to accurately placing landmarks inside the vessel lumen. This task is an important prerequisite to automatic centerline tracing. Methods have been proposed in the past to determine the location of organ landmarks, and yet several challenges remain for vascular landmarks. First, placing landmarks inside the lumen could be challenging for narrow vessels. Second, contrast-enhanced arteries could be tightly surrounded by bones with similar intensity profiles, making detection difficult compared to arteries surrounded only by darker tissues. Third, landmarks not located at bifurcations could be ill-defined as they have high uncertainty in position. We first present a method to detect landmarks that are located at vessel bifurcations. Such landmarks have well-defined positions, and we detect them using machine learning techniques. We then present a method to detect vascular landmarks not located at bifurcations. First, a segment detector is created to detect a vessel segment. Annotating multiple points along a vessel segment is easier than annotating a single landmark position, as there is no well-defined position along a vessel. This resolves the ambiguity issue mentioned above. Second, spatial features are computed from the segment detector's response map, and a regression model is created which takes as input the local spatial features surrounding a voxel, and outputs a confidence score of how likely this voxel is inside the lumen. We evaluate the system on a set of 94 3D CT datasets.