A coronary computed tomography angiogram (CTA) is aheart-imaging test that helps your doctor determine whetherfatty deposits or calcium deposits have built up in yourcoronary arteries, the arteries that supply blood flow to theheart. coronary computed tomography angiogram (CTA) is aheart-imaging test that helps your doctor determine whetherfatty deposits or calcium deposits have built up in yourcoronary arteries, the arteries that supply blood flow to theheart.