Today mammography is the most effective technique available for the early detection and diagnosis of breast cancer. One of the most difficult tasks in the context of mammogram interpretation is the discrimination of benign and malignant lesions based on their appearance in mammograms. When a lesion is suspected to be malignant, usually a breast biopsy is performed. Several studies have shown that the positive predictive value (PPV) of mammography interpretation usually is not higher than 30 percent. And therefore, only few breast biopsies actually show a malignant pathology. The resulting high percentage of unnecessary breast biopsies on benign lesions causes both considerable mental and physical discomfort for the patients as well as unnecessary costs for the health care system.