The ratio of mammary gland in the breast is useful information for the risk analysis of breast cancer. In this study, we proposed the novel automated measurement technique of the mammary gland ratio in mammogram. It employed Gabor filter in order to detect the mammary gland in mammogram. Filtered image was binarized by automated thresholding method; mammary region was segmented. In the experiments, we calculated Jaccard index to evaluate the degree of coincidence between the detected mammary region and sketched mammary region drawn by radiologist. Subsequently, accuracy of mammary gland ratio was evaluated. Measurement error of mammary gland ratio was 4.9%, and mean Jaccard index was 78.31%; they were better than those of conventional method. These results indicate that proposed method may be useful for the automated analysis of mammary gland for risk analysis of breast cancer.
