Angiography is an imaging test used to detect disease and abnormality of the blood supply in nearly any organ or body part. Angiography produces images of the major blood vessels and allows radiologists to detect blockages, atherosclerosis, or anatomic malformation.
When done using computed tomography (CT), the procedure is done by administering a contrast agent intravenously and then scanning your body to produce images of your heart and blood vessels. The contrast agent “lights up” blood vessels and tissues and the CT scan creates a detailed image of the body part being examined using X-rays and a sophisticated computer system. This gives radiologists and health care providers a visualization of blood flow and supply, allowing them to diagnose issues and plan for surgery.
CT angiography can detect many kinds of arterial disorders and help plan for treatment or surgery. It is used to:
- Detect aneurysms, arterial narrowing, blood clots, congenital abnormalities, tumors, and blood vessel ruptures and tears.
- Map arteries in preparation for arterial bypass, reconstructive surgery, or stent placement.
- Visualize the extent of arterial damage after trauma.
- Establish tumor blood supply for chemoembolization or surgical resection.
- Evaluate blood supply in preparation for organ transplant.
- Angiography may eliminate the need for surgery. If surgery must be done, CT angiography provides information to make the operation safer.
- CT angiography is minimally invasive and painless. Compared to invasive angiograms, CT angiography is a much faster way to visualize major blood vessels.
- Traditional angiograms require placing a catheter deep into the arterial blood supply which can cause artery damage. CT angiography, however, eliminates the risk of artery damage. If contrast is required, it is administered through a small vein in the arm or hand.
- Unlike magnetic resonance imaging studies (MRI), if you have metal in your body (shrapnel, bullets, needles, etc.) or an implanted medical device, you can still have a CT angiography since no magnets are used in the procedure.
- The recovery time for CT angiography is minimal. After the test is completed, you can resume your normal daily activities.
- CT angiography can provide more detailed blood vessel imaging compared to MR angiography.
- 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 angiography alone is unlikely to cause cancer or increase cancer risk significantly.
- If you have a history of allergy to iodine-based contrast, you may need to take a steroid medication up to 12 hours before CT angiography. Inform you doctor if you have any contrast allergies.
- If you have a history of kidney dysfunction or failure, contrast may worsen your kidney function. Consult with your doctor about this risk if you have kidney disease.
- Pregnant women should be aware of the risk of radiation to the developing child. Doctors may recommend a different test instead of CT angiography. For more details, please refer to the section What if I a pregnant? Can I have a CT scan? below.
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 angiography is available at multiple ARA imaging centers and takes a total of about 20 to 30 minutes.
- You may 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.
- After administering a small numbing injection, your paramedic or technologist will place an IV line into your arm or hand to administer the contrast. IV placement may be uncomfortable and may cause bruising later. Contrast may be delivered at a controlled rate by using a special injection pump and a saline solution drip may be used to help keep the IV line clear.
- 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 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.
Coronary CT angiography evaluates the arteries around your heart (coronary arteries), and the procedure differs from other CT exams. With coronary CT angiography, your heart will be monitored during the exam via sticky electrocardiogram (ECG) leads placed on your chest. Also, your paramedic or nurse may need to administer medication to slow your heart rate down to obtain clear images. You will be monitored during and after the CT angiography if any medication is given.
- Wear comfortable, loose fitting clothing. You may want to leave all jewelry, piercings and any other metal objects at home.
- You will be asked not to eat or drink for a few hours prior to the CT scan. In most cases, you will take all your medications as usual. Ask your doctor for specific directions about your daily medications.
- Be sure to tell your health care provider, ARA scheduler, and ARA technologist about any illness or allergies you may have. Health care providers should know if you have asthma, multiple myeloma, heart, kidney, or thyroid issues, or if you have diabetes. Also, provide a list of your current medications.
- Inform your radiologist if you are pregnant. Although the risk of CT angiography 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 CT angiography. Also, pregnant women should not receive IV contrast unless the benefits clearly outweigh the risks. For more details, please refer to the section What if I a pregnant? Can I have a CT scan? above.
- CT angiography 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. Drinking plenty of water will help flush the contrast agent from your system.
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.