A computerized (or computer) tomography (CAT or CT) scan is a special type of x-ray. Although a CAT scan is used to get images of many body parts of the body, let's use the example of the heart. A traditional x-ray shows two- dimensional images of the heart- its length and width. But a CAT scan uses an x-ray machine that moves around your body and takes multiple images of the heart as small amounts of x-rays pass through your body and take multiple images of the heart. As small amounts of x-rays pass through your body, different types of tissue absorb different amounts of the x-rays. This helps provide a more precise image compared to a traditional x-ray.
The CAT scan images are viewed together on a video monitor, offering a three- dimensional view- length, width and depth. Because it is a three- dimensional image, a CAT scan offers a much better picture of the entire heart than a traditional two-dimensional x-ray scan.
A CAT scan is used to detect many health conditions- tumors, for example, or bone problems like osteoporosis. As it relates to heart and blood vessel disease, a CAT scan is often used to identify:
- Some types of heart disease, such as heart failure
- A blood vessel blockage or blood clot
What can I expect? When you have a computed tomography (CAT) scan, you typically undress and put on a hospital gown or sheet. You lie on an exam table. As the test begins, the table slowly moves inside a doughnut- shaped machine.
Sometimes you receive a contrast dye- usually through an Intravenous (IV) line that is put into your arm. The dye allows your heart or blood vessels to show up as images on a monitor. For instance, if the test is being done to look at your blood vessels, the dye makes them visible- almost like roads on a map. You might notice some effects from the dye:
- Warm flushing feeling, and maybe nausea for a minute or so
- Metallic taste when the dye reaches the blood vessels in your mouth