<title>Three-dimensional active surface approach to lymph node segmentation</title>

Abstract

A three-dimensional active surface model has been suggested as a possible solution to the difficult problem of segmenting lymph nodes in CT x-rays. In this paper, a computationally simple active surface, or balloon, is proposed which requires minimal user interaction or a priori shape knowledge. A structure is proposed for the balloon model in which each balloon point is guaranteed a fixed number of neighbors, and a method is provided for adding points to the model while still maintaining that structural regularity. Equations are provided for deriving surface energy from 3D shape and 3D image data. Minimal user interaction is required, with only a single point somewhere inside the node needed to initialize the algorithm. The balloon naturally inflates to find the correct surface due to a unique candidate point selection algorithm that is biased in favor of outward moves. Preliminary results show the model to be successful in finding boundaries in synthetic 3-D images.