Comparison of Balloon Snake and GVF Snake in Segmenting Masses from Breast Ultrasound Images

The active contour or Snake is a computational model that can trace boundaries of images. It is formulated based on controlled continuous splines and adopts energy minimization conception. This paper presents the application of Snakes for the segmentation of masses on breast ultrasound images. The boundaries of the masses identified may be used in locating potential cancerous cases for further analysis. Initially, Balloon Snake and Gradient Vector Flow (GVF) Snake are applied in segmenting the masses in the breast ultrasound phantom images. Comparison on the masses areas segmented by the Balloon Snake and the GVF Snake is done against the actual masses area. The better method with smaller values of average percentage area difference is chosen to be applied in segmenting masses on real breast ultrasound images. The performance is measured in terms of average percentage area difference traced by the chosen method against the area traced by expert radiologist. It is found that from eighty breast ultrasound phantom images (40 cyst and 40 solid masses) tested, the values of average percentage area difference for cyst and solid masses in the Balloon Snake are 3.07% and 9.17% respectively while GVF Snake are 13.43% and 48.37% respectively. Therefore Balloon Snake is chosen to segment real breast ultrasound images. Fifty images are tested. Segmentation on the images shows that the average percentage area difference of Balloon Snake is 4.29% which mean 95.71% accurate.