October 17, 2023
October 17, 2023

What Is a CT Angiogram and What Can It Find?

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What Is a CT Angiogram and What Can It Find?

A CT angiogram is an imaging test to diagnose several vascular conditions such as aneurysms, atherosclerosis, and blood clots. Here, we’ll discuss how a CT angiogram works and when (and why) someone would get one. We'll also discuss what a CT angiogram can show and how it compares to a low-dose CT coronary artery calcium test. 

What Is a CT Angiogram?

A computed tomography angiogram (CTA, or computed tomography angiography) is an imaging test that creates detailed pictures of various blood vessels and tissues in your body. This type of imaging technique uses computed tomography, which is thousands of X-rays taken at one time to produce detailed pictures of a particular area of your body. CTA also uses a type of contrast dye injection that helps visualize the blood vessels and surrounding tissues.

The CT scanner itself is a donut-shaped machine with a tunnel that the exam table slides into. Once the scan begins, X-ray beams will examine the particular area of the body. A nearby computer translates that information into pictures and the images are then read by a radiologist.

Why Would Someone Need a CT Angiogram?

Medical providers order a CT angiogram when they’re looking for an abnormality involving the blood vessels of a specific area. Depending on the area of concern, a CTA can be done on different body regions, such as the heart, brain, and kidneys. 

Some conditions it can diagnose include:

  • Aneurysms: This is a widened area of a blood vessel that can grow over time and can ultimately rupture or bleed. Aneurysms can be found throughout the body but major areas of concern are in the brain, coronary arteries (vessels that supply the heart), and the aorta, which is the largest artery in the body.
  • Atherosclerosis: Atherosclerosis is cholesterol deposits or plaque build-up in the blood vessels that can cause blood vessel narrowing over time. This increases the risk of high blood pressure and vascular disease.
  • Arteriovenous malformations: AVMs are abnormal connections between veins and arteries that have the potential to rupture or bleed.
  • Blood clots: Blood clots can be seen on a CT angiogram. These can include pulmonary embolisms, which are blood clots in the lungs that usually have traveled from veins in the legs.
  • Blood flow to tumors: A CT angiogram can also be used to evaluate the blood flow or supply to tumors, which can be helpful when planning for tumor removal surgery.

How Is a CT Angiogram Performed and How Can I Prepare?

Before your scan, you may have to stop eating several hours beforehand. Make sure you wear comfortable clothes and remove all metal objects before your test as metal can affect the CT images. Once you arrive at the imaging center, you'll change into a hospital gown and lie on the exam table. 

It’s important to notify your CT technologist of any medical conditions before your exam, such as kidney disease or diabetes. This is because contrast dye can affect the function of the kidneys and people with a history of kidney disease or diabetes may be more susceptible.

You’ll then have an IV (intravenous) line placed for the contrast dye to be injected. Let your CT technician know ahead of time if you’ve ever had any allergic reactions to IV contrast in the past. Sometimes people with a history of contrast dye allergy are pre-medicated with steroids to decrease their risk of an allergic reaction. 

When the contrast material is injected, you may feel a quick sensation of warmth as it flows throughout your body. You may also experience a brief metallic taste in your mouth. Once the contrast dye is in your body, you will be moved into the scanner, which will start taking images.

How Long Does a CT Angiogram Take?

CT angiogram: doctor checking a patient

Generally, a CT angiogram is quick and can gather the necessary images in as little as 15 minutes depending on which body area is being scanned. But it can take longer if more images are needed. For instance, during a CT coronary angiogram, sometimes a person’s heart rate can affect the quality of the CT images. As a result, medications such as beta-blockers may be needed to slow the heart rate down to improve the quality of the images.

What’s the Difference Between a CT Scan and a CT Angiogram?

As discussed, a CT angiogram focuses on blood vessels using a contrast dye and can diagnose many vascular conditions. A coronary calcium computed tomography scan is a CT scan that produces images of the heart without the use of contrast dye. It’s a screening test for people who may have a family history of coronary artery disease, or heart disease but don’t have any symptoms themselves.

A low-dose cardiac CT with coronary artery calcium scoring may be indicated in someone who is seeking more information about their heart health. It’s not a recommended test for someone with a known history of heart disease.

How Does a Coronary Calcium Scan Compare to a CT Coronary Angiogram?

While coronary CT angiography can diagnose a wide range of conditions, it can also be beneficial in preventing life-threatening episodes such as a heart attack or stroke. For example, if a CT coronary angiography reveals narrowing in certain blood vessels supplying the heart, preventive action can be taken that can be potentially lifesaving. Such measures could include lifestyle changes, medications, and surgical procedures.

On the other hand, a coronary calcium scan, or CT with CAC scoring, can detect calcium deposits in the blood vessels of the heart, which may help predict the future risk of a heart attack. It can also help you and your cardiologist decide if medications such as statins would significantly decrease your risk of heart disease. It’s also a preventive action that can be potentially lifesaving. 

CAC scoring has repeatedly been shown to be beneficial in identifying those who are at high risk of heart disease and who don’t yet have any signs or symptoms. Another key difference between a CT coronary angiography and a CT with CAC scoring is that a CT with CAC scoring usually only has a fraction of the radiation exposure of a CT angiography. 

Can You Get a Coronary Calcium Score Plus a Full Body MRI?

CT angiogram: man riding a bike

Yes, with Ezra’s Full Body Plus scan, you can get a low-dose chest CT with CAC scoring to assess your heart disease risk, plus an MRI scan of the entire body, which can detect a wide range of conditions. The Full Body MRI only takes one hour of your time and the low-dose CT can take just five minutes. 

Be Proactive About Your Heart Health

CT angiography can be very helpful in diagnosing vascular conditions like cardiovascular disease while CT with CAC scoring can help identify people at high risk of heart disease before symptoms even develop. Take charge of your health and get your scans done with Ezra — with early detection for over 500 conditions in up to 13 organs, it may be your key to better outcomes.