Value of Coronary Artery Calcium Scores from Nongated CT Scans

Coronary artery calcium (CAC) scores generally are obtained using computed tomography (CT) scans with electrocardiogram gating, which synchronizes image acquisition with the cardiac cycle. But how well do nongated CT scans — the way that most chest CTs are performed — predict cardiac risk? Almost 2500 participants (median age, 68) in the Multiethnic Study of Atherosclerosis (MESA) study underwent both gated and nongated scans. Each scan was quantitatively scored for CAC and categorized as absent (CAC, 0), mild (CAC, 1–99), moderate (CAC, 100–299), or severe (CAC, ≥300).