Breast cancer is the most common cancer in women and represented over a quarter of all reported cancer cases in Australia in 2006 (Australian Institute of Health and Welfare, 2009). In Australia alone, more than 2500 women die from the disease every year (2007, Australian Institute of Health and Welfare, 2009). Moreover, health expenditure on breast cancer in Australia from 2004 to 2005 was over A$330 million (Australian Institute of Health and Welfare, 2009). The cause of breast cancer is still unknown and thus prevention is impossible. Therefore, early detection and medical imaging-guided therapy form the main strategy for improving mortality rates caused by breast cancer.�
Breast cancer screening is commonly based on x-ray mammography owing to its low cost and the short acquisition time that provides a high throughput. X-ray mammography, however, has a high false-negative rate (i.e. low sensitivity)