chapter  8
12 Pages

Measurement of Coronary Artery Calcium by Computed Tomography

ByThomas C Gerber, Christoph R Becker, Birgit Kantor

The association between vascular calcification and vascular

atherosclerosis has been known to anatomists and patholo-

gists for centuries. The value of coronary artery calcification

(CAC) for predicting the presence of coronary artery disease

and the occurrence of future cardiac events is discussed in

detail elsewhere in this book in chapters 9 (Knez A) and 10

(Shaw LJ et al.). In short, calcium is deposited in diseased

coronary arteries in the form of hydroxyapatite, which con-

tains 40% calcium by weight. The area of CAC is propor-

tional to, but represents only approximately 20 percent of,

the coronary artery plaque area on histological examination

of excised coronary arteries.1 CAC does not correlate well

with the degree of coronary artery narrowing on a site-by-

site basis,2 and the relationship of CAC with coronary artery

plaque that is prone to rupture is not well understood.3

Nonetheless, if used in the appropriate clinical context,