Active contours based on weighted gradient vector flow and balloon forces for medical image segmentation

Active contours, or snakes, have been widely used for image segmentation purposes. However, high noise sensitivity and poor performance over weak edges are the most acute issues that hinder the segmentation accuracy of these curves, particularly in medical images. In order to overcome these issues, we propose a novel external force that integrates gradient vector flow (GVF) field forces and balloon forces based on a weighting factor computed according to local image features. The proposed external force reduces noise sensitivity, improves performance over weak edges and allows initialization with a single manually selected point. We evaluate the proposed external force for segmentation of various regions on real MRI and CT slices. Evaluation results show that the proposed approach leads to more accurate segmentation than snakes using traditional external forces.