Heart CT scan
A computed tomography (CT) scan of the heart is an imaging method that uses x-rays to create detailed pictures of the heart and its blood vessels.
CAT scan - heart; Computed axial tomography scan - heart; Computed tomography scan - heart; Calcium scoring; Multi-detector CT scan - heart; Electron beam computed tomography - heart; Agatston score; Coronary calcium scan
How the Test is Performed
You will be asked to lie on a narrow table that slides into the center of the CT scanner.
A computer creates separate images of the body area, called slices.
You must be still during the exam, because movement causes blurred images. You may be told to hold your breath for short periods of time.
The entire scan should only take about 10 minutes.
How to Prepare for the Test
Certain exams require a special dye, called contrast, to be delivered into the body before the test starts. Contrast helps certain areas show up better on the x-rays.
Before receiving the contrast:
If you weigh more than 300 pounds (135 kilograms), find out if the CT machine has a weight limit. Too much weight can cause damage to the scanner's working parts.
You will be asked to remove jewelry and wear a hospital gown during the study.
How the Test will Feel
Some people may have discomfort from lying on the hard table.
Contrast given through an IV may cause a:
These sensations are normal and usually go away within a few seconds.
Why the Test is Performed
CT rapidly creates detailed pictures of the heart and its arteries. The test may diagnose or detect:
Results are considered normal if the heart and arteries being examined are normal in appearance.
Your "calcium score" is based on the amount of calcium found in the arteries of your heart.
What Abnormal Results Mean
Abnormal results may be due to:
If your calcium score is high:
Risks for CT scans include:
CT scans do expose you to more radiation than regular x-rays. Having many x-rays or CT scans over time may increase your risk for cancer. However, the risk from any one scan is small. You and your provider should weigh this risk against the benefits of getting a correct diagnosis for a medical problem.
Some people have allergies to contrast dye. Let your provider know if you have ever had an allergic reaction to injected contrast dye.
Rarely, the dye may cause a life-threatening allergic response called anaphylaxis. If you have any trouble breathing during the test, you should notify the scanner operator immediately. Scanners come with an intercom and speakers, so the operator can hear you at all times.
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Min JK. Cardiac computed tomography. In: Zipes DP, Libby P, Bonow RO, Mann DL, Tomaselli GF, Braunwald E, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 11th ed. Philadelphia, PA: Elsevier; 2019:chap 18.
Review Date: 4/14/2019
Reviewed By: Michael A. Chen, MD, PhD, Associate Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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