CAT scan radiation - is it too much; the right drug to take if you have carotid artery disease; low-carb vs. low-fat

CAT scans are an excellent way to help diagnose disease, but is there a possible danger from too much radiation? If you have carotid artery disease, a new study indicates there's one drug in particular you should take. Low-carb versus low-fat – is one diet better than the other for your heart? Dr. Cooper takes calls