Calcium scoring of coronary arteries

Calcium scoring of coronary arteries

Calcium scoring of coronary arteries can be done with electron beam computed tomography, while the vessel assessment can be done only with multi detector computed tomography. The calcium scoring scale is known as Agatston score. A score of 0 means that there is no identifiable calcium. The radiation exposure of EBCT is much less than that of MDCT. But MDCT can utilise contrast injections to reconstruct three dimensional views of coronary arteries and assess the coronary lesions with accuracy.

If there is no calcium there is no obstructive coronary artery disease; if calcium score is more than 100, it predicts obstructive CAD. Calcium scoring is useful to differentiate ischemic dilated cardiomyopathy from the idiopathic variety. If the calcium score is negative, it is unlikely to be ischemic in origin.

As the calcium score increases, the relative risk also increases. A relative risk of 4.3 has been considered with an Agatston score of 100 to 400. When the score is between 400 to 1000, the relative risk may reach 7.2 and if it is above 1000, the relative risk is as high as 10.8. Though calcium score is specific for presence of plaques in the coronaries, it is not specific for obstructive coronary artery disease. But as the score goes up, the possibility of having obstructive coronary artery disease also increases, as some plaques may be obstructive though others may not be.