Graph-Based Vertebra Segmentation Using a Cubic Template

Abstract

Purpose -The current development of the population's structure leads to a growing part of older patients with a more frequent insistence for surgical treatment like lumbar spinal stenosis (LS), which is the most common cause of spinal surgery in individuals older than 65 years of age Methods -The presented approach is an extension from our recent articles [3, 4] to a third dimension and it starts by setting up a directed 3D graph from a user-defined seed point that is located inside the vertebra. To set up the graph, the method samples points along rays, which are distributed on a cube's surface. The sampled points are the nodes n V of the graph G(V,E) and e E is a corresponding set of edges. Besides, there are (inter-) edges between the nodes and there are edges that connect the nodes to a source s and a sink t. An additional delta value determines the construction of the xy-edges and therefore the smoothness of the segmentation results, like shown in the image on the right side. After the graph has been generated, the minimal cost closed set on the graph is calculated via a polynomial time s-t-cu