Mammogram registration, a critical step in automated detection of breast cancer, is an ongoing research topic. The pectoral muscle is a few and apparent anatomical landmarks on mediolateral oblique (MLO) view mammograms. It provided an important control p Mammogram registration, a critical step in automated detection of breast cancer, is an ongoing research topic. The pectoral muscle is a few and apparent anatomical landmarks on mediolateral oblique (MLO) view mammograms. It provided an important control p