Elective full-body screening examinations: a plea for MRI.

The use of imaging is generally focussed on detecting and characterising suspected or known disease in symptomatic patients. Experience with preventative imaging, aiming at the detection of disease prior to its symptomatic manifestation, is limited. Screening involves the evaluation of asymptomatic individuals at risk for the presence of a particular disease. A screening test is designed to detect a targeted disease at a stage which still permits treatment to succeed in avoiding morbidity and/or mortality. Diseases worthy of screening should be associated with high morbidity and/or mortality if proper treatment is not applied sufficiently early. The screening test itself must not cause harm to the examined subjects. For the test to be cost-effective, the target disease should be highly prevalent in the screened population. Restricting screening to a population known to be at increased risk for the target disease enhances the test's effectiveness.