Pectoral Muscle boundary detection in Mammograms using homogeneous contours

Breast occupies over Pectoral muscle (PM) which is a predominant portion in Medio-Lateral Oblique (MLO) view of mammogram. The similarity in density among PM area and the breast region may generate false positive results which can adversely affect early breast cancer detection. Noise, wedges, opaque markers etc along with labels are unnecessary in mammographic images. The suspicious segments of PM boundary are obtained by extracting contours of homogeneous regions. The geometrical properties of contour segments are analyzed for extracting PM boundary component. An intensity similarity approach extends the detected major PM boundary segment to the two boundaries of mammogram. Experimental analyses were carried out on mammograms obtained from Mammographic Image Analysis database. The proposed methods yields low values for average false positive, average false negative and Hausdorff distance. From the performance analysis of the proposed algorithm, 97% of images have an average error less than 4 mm. Low values of performance measures for the proposed method shows that the extracted PM boundary is close to radiologist drawn PM border.