A Cardiac CT scan combines x-rays of thin cross-sections of your heart in order to create a 3D image. A contrast dye is injected, and you are placed onto a table that gradually moves you through a CT machine. While you travel through the machine, a rotating x-ray tube takes the images of your heart. Each x-ray dose is at a very minimal level and lasts a fraction of a section. Despite the minimal invasion, a cardiac CT scan offers healthcare providers very detailed images that aid providers in accurately detecting problems regarding the heart and arteries.