“…Several segmentation methods have been applied to breast sonograms. The most used techniques are histogram thresholding, 6 – 8 active contours, 9 – 15 neural networks, 16 – 18 graph cuts, 19 , 20 and Markov random fields (MRFs) 21 , 22 . Histogram thresholding methods remove speckle noise or enhance lesion structures, obtaining satisfactory results in segmenting lesions with homogeneous content such as cysts, but it is often unreliable for segmenting cancerous lesions, which usually have a high variance of pixel intensities within the lesions.…”