Computed tomography (CT) is a diagnostic medical test that, like traditional x-rays produces multiple images or pictures of the inside of the body.
The cross-sectional images generated during a CT scan can be reformatted in multiple planes, and can even generate three-dimensional images. These images can be viewed on a computer monitor, printed on film or transferred to a CD or DVD.
CT images of internal organs, bones, soft tissue, and blood vessels typically provide greater detail than traditional x-rays, particularly of soft tissues and blood vessels.
CT calcium scoring uses x-ray equipment to produce pictures of the coronary arteries to determine if they are blocked or narrowed by the buildup of plaque. Your arteries supply oxygen-containing blood to the heart muscle. Plaque in the arteries calcifies resulting in a build-up of fat under the inner layer of the artery, which can lead to an increased risk of a heart attack.
CT scans produces cross-sectional images to see many multiple directions inside the body. The amount of calcium detected in the CT is given a calcium score measurement. If your scoring is negative, no calcification within the coronary arteries is present. A positive test means coronary artery disease (CAD) is present. The extent of CAD is graded according to your calcium score:
No evidence of CAD
Minimal evidence of CAD
Mild evidence of CAD
Moderate evidence of CAD
Extensive evidence of CAD
The National Cancer Institute's research shows that low-dose CT lung screening can reduce lung cancer caused deaths by 20% compared to x-ray imaging. Screenings are performed before symptoms occur so that they detect disease in its earliest stages. Low dose CT produces quality images with 90% less ionizing radiation than a conventional chest CT scan.
Low dose CT lung screenings are considered a preventative service and are covered by insurance once a year is the following conditions are met:
CT scans usually take 5 to 15 minutes depending on the imaging site but special preparation may be required with contrast agents, which may take up to 90 minutes.
No, CT scans do not hurt. You will have to lie still and follow special breathing instructions but you should not feel any pain. An IV catheter may be required, which may cause discomfort.
Our goal is to always give the lowest radiation possible while still achieving quality images. The amount of radiation exposure depends on the area of the body being imaged and the patients size. Please visit our Radiation Safety page for more information on radiation exposure.
MRI uses a powerful magnet and radio waves to send images of the body to a computer. MRI does not produce radiation. CT uses radiation and a computer to make images of the body. CT scans are faster and quieter than MRI scans.
Contrast agents are used to improve images of the body taken by x-ray, CT, MRI, and ultrasound. Usually a contrast agent is used to help the radiologist distinguish between normal and abnormal conditions. The agent works by temporarily changing the way imaging tests interact with the body. Depending on the part of the body being scanned and the patients medical history, contrast may be given orally or intravenously.
Most patients do not need sedation. CT scans are faster and more open than MRI and usually only require the head to be under the scanner for short periods of time.
A sub-specialty radiologist will evaluate your CT scan and send a report to your doctor within a few days.