The purpose of the CT calcium scoring exam is to understand your risk for coronary heart disease (CAD) so you can take preventive measures based on the results. CAD (heart attack or other cardiovascular event) is the number one cause of death among adults in the US.
Coronary arteries are the vessels that supply oxygen-rich blood to the heart. Over time, these arteries can collect a hard buildup called plaque, which is made of calcium, fat, and other substances that slowly narrow and even close the arteries. Dangerous or even fatal heart events can happen when these arteries close and cannot supply the heart with necessary blood.
CT calcium scoring uses advanced computer tomography (CT) technology to help radiologists detect plaque in the arteries of the heart which may indicate the presence of coronary artery disease (CAD). Since CT scans can easily detect calcium, this makes CT calcium scoring a useful tool in the evaluation of heart disease risk. It is an exam that is sometimes recommended for patients with high risk factors for CAD in order to catch the disease before the patient even has symptoms. Early detection of CAD may help improve your health and increase your chances for survival. Please refer to the Computed Tomography section for more details about CT scans and the associated benefits and risks.
Even if you have no symptoms, your doctor may recommend CT calcium scoring based on the presence of other heart disease risk factors. The major risk factors for CAD are:
- High blood pressure
- High cholesterol
- Cigarette smoking
- Family history of heart disease
- Physical inactivity
If no calcification is seen on your CT calcium score, the test is “negative.” This means your risk for heart attack over the next 2 to 5 years is very low.
A “positive” test means that calcium has been detected in your coronary arteries by the scan. The calcium score is used to indicate the evidence of coronary artery disease (CAD) based on the CT image findings. Calcium scores are divided into the following categories:
- 0 (zero) – No identifiable atherosclerotic plaque. Very low cardiovascular disease risk. Less than 5% chance of presence of coronary artery disease. A negative examination.
- 1-10 – Minimal plaque burden. Significant coronary artery disease very unlikely.
- 11-100 – Mild plaque burden. Likely mild or minimal coronary stenosis (narrowing of the arteries).
- 101-400 – Moderate plaque burden. Moderate nonobstructive (not blocking the arteries) coronary artery disease highly likely.
- Over 400 – Extensive plaque burden. High likelihood of at least one significant coronary stenosis (narrowing of the arteries).
After your CT calcium scoring is done, it is important to discuss the results with your health care provider to establish a health plan that is appropriate to your risk factors.
- CT calcium scoring is a fast, painless and non-invasive way to identify evidence for coronary heart disease (CAD). The test may eliminate the need for other more invasive or time-consuming forms of testing.
- CT calcium scoring does not require the injection of contrast.
- Unlike MRI, if you have metal in your body (shrapnel, bullets, needles, etc.) or an implanted medical device, you can still have CT calcium since no magnets are used in the procedure.
- X-rays used in CT scans have no immediate side effects and do not remain in the body.
- Excessive radiation can increase the risk for cancer. However, the amount of radiation received from CT calcium scoring alone is unlikely to cause cancer or increase cancer risk significantly.
- Pregnant women should be aware of the risk of radiation to the developing child. In some cases, doctors may recommend a different test instead of CT calcium scoring. For more details, please refer to the section What if I am pregnant? Can I still have a CT scan?
- If CT calcium scoring shows evidence of CAD, your doctor may recommend more tests for confirmation and to determine the extent of disease. Further testing may or may not improve your overall health, and it can be associated with side effects.
If you are, or think you are pregnant, be sure to notify your doctor or technologist before undergoing a CT scan. The amount of radiation received during a CT scan is unlikely to harm you or your baby. However, in general, CT scans are not recommended in pregnant women. In every case, the mother’s health must be considered as well. The benefit to the pregnant woman of having the CT scan to diagnose an illness may outweigh the small amount of risk to the baby from a low-dose CT scan.
The part of your body being scanned should also be considered. For example, brain CT exposes the unborn baby to little or no radiation. Even if the fetus is directly exposed to CT scan radiation (such as in CT scans of the abdomen or pelvis), the increased risk of developing cancer later in life is one in 1000. Some doctors may recommend another type of exam (ultrasound or MRI) to avoid exposing your baby to radiation.
The ACR states that current information suggests breastfeeding is safe after the use of intravenous contrast. Please discuss your breastfeeding options with your medical provider.
For more information on contrast, please see About CT Contrast.
- CT calcium scoring is available at multiple ARA imaging centers. The procedure takes about 10 minutes.
- You will be asked to change into a hospital gown for the procedure.
- Since metal can distort the CT images, all metal objects and jewelry should be removed prior to the exam. This may include hearing aids, removable dental prostheses, eyeglasses, piercings, hairpins, etc.
- The CT scanner is a large box shaped machine with a large hole in the middle.
- You’ll be placed on a moveable exam table which may have straps or bolsters to help keep your body from moving. You will need to remain as still as possible so the images will be clear.
- Your heart will be monitored during the exam via sticky electrocardiogram (ECG) leads placed on your chest. This makes it easier to time image capture for when the heart is relaxed.
- The technologist will leave the CT scan room where you are and conduct the exam from a computer in a nearby room. You will be able to talk with the technologist at all times.
- The table will make a first quick pass through the scanner to set your body position. Next, the table will move you through the scanner more slowly while the CT images are being taken. It may require several passes through the machine to complete the scan.
- You may hear slight buzzing, clicking or rotating sounds during the scanning process.
- You may be asked to hold your breath for 10-20 seconds during some parts of the scan. Breathing or any other movement can distort the images.
- When the scan is finished, you may be asked to wait a few minutes while the technologist checks the quality of the images. If needed, more images may need to be taken.
- You should eat and take your medications as usual.
- Wear comfortable, loose fitting clothing. You may want to leave all jewelry, piercings and any other metal objects at home.
- Inform your radiologist if you are pregnant. Although the risk of CT calcium scoring is very low for the unborn baby, your doctor may choose an alternate exam. Depending on the circumstances, both the physician and patient may decide it is necessary to go ahead with the test. For more details, please refer to the section What if I am pregnant? Can I still have a CT scan?
- CT calcium scoring is fast and painless. If you feel like you might be anxious during the exam, tell your scheduler. ARA technologists and our clinical staff are experts at helping people through CT exams with minimum anxiety.
- You can return to your normal activities after the exam.
A radiologist, a physician specifically trained to interpret radiological examinations, will analyze the images and send a signed report to the provider who referred you to ARA. The physician will then share the results with you.