What is the difference between Coronary Calcium Scoring and CT Coronary Angiogram (2023)

CT coronary angiogram (CTCA) and coronary artery calcium (CAC) scoring are both non-invasive imaging tests that provide valuable information about the coronary arteries, but they serve different purposes and have some key differences.
CTA is primarily used to evaluate the coronary arteries for the presence, and extent of narrowing (stenosis) caused by plaque buildup (atherosclerosis).

CAC is used to assess the amount of calcified plaque (calcium) present in the coronary arteries. This information is used to determine the risk of a heart attack in future.

CTCA Involves injecting a contrast agent (iodine-based dye) into a vein, usually in the arm. The contrast agent enables us to visualize the coronary arteries more clearly.

CT coronary angiogram is mainly used for diagnosing and evaluating coronary artery blockages by utilizing contrast material, while coronary calcium scoring is a tool for assessing the risk of developing CAD. They provide different types of information, and the choice between them depends on the clinical context and the patient's specific needs.