[Image-based screening].

Screening is a special issue in medical questions concerning disease prevention. Preconditions for screening are clearly defined by the World Health Organization. High prevalence, effectiveness of therapy, availability of accepted test procedure and consensus concerning the economic concerns are necessary for successful implementation of a screening program. Preventive diagnostic studies can only be understood if one is familiar with the statistical terms sensitivity, specificity, prevalence, incidence and bias (especially overdiagnosis and lead time bias). Aspects of radiation protection are especially important in asymptomatic volunteers. The new radiation protection law in Germany also gives the opportunity to define new screening procedures even with use of radiation exposure in individual prevention programs. Potential diseases for radiological secondary prevention with high mortality are malignant tumors (especially breast cancer, lung cancer, colorectal cancer) and cardiovascular diseases (coronary heart disease, stroke or aortic aneurysm).