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Non-invasive coronary artery imaging is useful in patients with an intermediate level of risk of coronary artery disease because it avoids the health risks associated with invasive coronary angiography, the current gold standard. The conventional non-invasive imaging techniques of myocardial perfusion scintigraphy, stress echocardiography and MRI rely on ischaemia as a marker for coronary artery disease. The more recently introduced techniques of electron beam tomography and multi-slice CT use atherosclerosis as a marker for coronary artery disease. These techniques allow for earlier detection of coronary artery disease, but provide limited information with regard to treatment decisions.

Coronary calcification is a specific marker for coronary atherosclerosis. It is therefore reasonable to assume that the risk ofcardiac events can be assessed by the quantification of the extent of coronary calcium. Until now, the predictive value of coronary calcium and its advantage over conventional risk factors has not been proven by any of the available prospective cohort studies. It is particularly likely that assessment of coronary atherosclerosis will help in the decision to initiate or discard a specific therapy in patients with an intermediate risk for cardiac events. Recently it has been suggested that the Framingham risk score (FRS) be replaced by a score corrected by assessing the amount of coronary calcium, which can be obtained by multislice spiral computed tomography (MSCT). To this end, the Commission Law Population Investigation has approved a study proposal to evaluate the effects of coronary-calcium screening in 4000 asymptomatic individuals with an intermediate likelihood of coronary artery disease. Based on the amount of calcium (calcium score > 100) obtained by MSCT, different treatment strategies will be initiated over a period of 5 years. Hard endpoints will be myocardial infarction, stroke and mortality due to cardiovascular disease.