NONINVASIVE VISUALIZATION OF CORONARY-ARTERIES WITH AND WITHOUT CALCIFICATION BY ELECTRON-BEAM COMPUTED-TOMOGRAPHY

Coronary artery disease (CAD) is one of the leading causes of mortalit y and morbidity in the western industrialized countries. Recent studie s demonstrate the feasability of successful primary and secondary prev ention. However, the detection of early stages of coronary artery dise ase is an unresolved issue. Whereas sensitivity and specificity of tra ditional risk factor assessment and stress tests are limited, the anal ysis of coronary calcification allows to obtain a direct sign of coron ary atherosclerosis. This concept has been applied using fluoroscopy a nd conventional computed tomography (CT). However, the exact localizat ion and quantification of coronary calcification only became possible with the advent of electron beam CT (EBCT). This new method showed a h igh prevalence of coronary calcification in the asymptomatic populatio n. With the definition of a standardized ''calcium score'' the normal age-specific distribution and amount of coronary calcification was inv estigated EBCT proved to be more sensitive in the diagnosis of both no n-obstructive and obstructive coronary artery disease than risk factor analysis and stress testing, respectively. Obstructive coronary arter y disease, however, cannot yet be predicted with high enough accuracy. A close correlation of EBCT coronary calcification was found to a) th e total coronary plaque volume defined by histo-pathology, b) intracor onary ultrasound findings, c) the number of coronary risk factors, d) the coronary prognosis. Using EBCT, a reliable non-invasive identifica tion of persons at risk was obtained for the first time. Guidelines fo r the use of EBCT in the early diagnosis and treatment of coronary art ery disease are being developed.