How much cost/how much radiation on new ct scans would coronary calcium scan be on the whole body? could this be done with new tech x-ray and no ct?

Very small amount: However, a coronary calcium scan should only be done in the presence of intermediate or high risk of having coronary artery disease, Asymptomatic individuals without at least 3 risk factors for coronary artery disease (Diabetes, Hypertension, tobacco use, elevated cholesterol, Obesity, etc.) have a very high likelihood of having a falsely positive scan, thus rendering an abnormal scan unreliable.