CT angiography combines a CT scan with the injection of dye. This technique is able to create pictures of the blood vessels in your belly (abdomen) or pelvis area. CT stands for computed tomography.
You will lie on a narrow table that slides into the center of the CT scanner. Most often, you will lie on your back with your arms raised above your head.
Once you are inside the scanner, the machine's x-ray beam rotates around you. Modern "spiral" scanners can perform the exam without stopping.
A computer creates separate images of the belly area, called slices. These images can be stored, viewed on a monitor, or printed on film. Three-dimensional models of the belly area can be made by stacking the slices together.
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 scan should take less than 30 minutes.
You need to have a special dye, called contrast, put into your body before some exams. Contrast helps certain areas show up better on the x-rays.
The contrast can worsen kidney function problems in patients with poorly functioning kidneys. Talk to your provider if you have a history of kidney problems.
Too much weight can damage the scanner. If you weigh more than 300 pounds (135 kilograms), talk to your provider about the weight limit before the test.
You will need to take off your jewelry and wear a hospital gown during the study.
Lying on the hard table may be a little bit uncomfortable.
If you have contrast through a vein, you may have a:
These feelings are normal and go away within a few seconds.
A CT angiography scan quickly makes detailed pictures of the blood vessels inside your belly or pelvis.
This test may be used to look for:
The test also may be used before:
Results are considered normal if no problems are seen.
The abnormal results may show:
Risks of CT scans include:
CT scans expose you to more radiation than regular x-rays. Many x-rays or CT scans over time may increase your risk for cancer. However, the risk from any one scan is small. Talk to your health care provider about this risk and the benefit of the test for getting a correct diagnosis of your medical problem. Most modern scanners use techniques to use less radiation.
Some people have allergies to contrast dye. Let your provider know if you have ever had an allergic reaction to injected contrast dye.
The most common type of contrast given into a vein contains iodine. If you have an iodine allergy, you may have nausea or vomiting, sneezing, itching, or hives if you get this type of contrast.
If you must be given such contrast, your provider may give you antihistamines (such as Benadryl) or steroids before the test.
Your kidneys help remove iodine out of the body. You may need extra fluids after the test to help flush the iodine out of your body if you have kidney disease or diabetes.
Rarely, the dye may cause a life-threatening allergic response called anaphylaxis. Tell the scanner operator right away if you have any trouble breathing during the test. Scanners come with an intercom and speakers, so the operator can hear you at all times.
Reviewed By: Deepak Sudheendra, MD, FSIR, RPVI, Assistant Professor of Interventional Radiology & Surgery at the University of Pennsylvania Perelman School of Medicine, with an expertise in Vascular Interventional Radiology & Surgical Critical Care, Philadelphia, PA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.