Angiography is a minimally invasive medical test that helps physicians diagnose and treat medical conditions. Angiography uses one of three imaging technologies and, in some cases, a contrast material to produce pictures of major blood vessels throughout the body.

         Angiography is performed using:

• X-rays with catheters
• Computed tomography (CT)
• Magnetic resonance imaging (MRI)
• CT imaging uses special x-ray equipment to produce multiple images and a computer to join them together in multidimensional views. In CT angiography (CTA), computed tomography using a contrast material produces detailed images of both blood vessels and tissues.
  
  CT angiography is used to examine blood vessels in key areas of the body, including the:
   
• brain
• kidneys
• pelvis
• legs
• lungs
• heart
• neck

• abdomen
  
  
  Physicians use the procedure to:
  

• Identify disease and aneurysms in the aorta, both in the chest and abdomen, or in other major blood vessels.
• Detect atherosclerosis disease in the carotid artery of the neck, which may limit blood flow to the brain and cause a stroke.
• Identify a small aneurysm or arteriovenous malformation inside the brain.
• detect atherosclerotic disease that has narrowed the arteries to the legs and help prepare for endovascular intervention or surgery.
• Indicate disease in the arteries to the kidneys or visualize blood flow to help prepare for a kidney transplant.
• Guide interventional radiologists and surgeons making repairs to diseased blood vessels, such as implanting stents or evaluating a stent after implantation.
• Detect injury to one of more arteries in the neck, chest, abdomen, pelvis or extremities in trauma patients.
• Evaluate arteries feeding a tumor prior to surgery or other procedures such as chemoembolization or selective internal radiation therapy.
• Identify dissection or splitting in the aorta in the chest or abdomen or its major branches.
• Show the extent and severity of atherosclerosis in the coronary arteries and plan for a surgical operation, such as a coronary bypass.
• Sample blood from specific veins in the body to detect any endocrine disease.
• Examine pulmonary arteries in the lungs to detect pulmonary embolism (blood clots from leg veins).

          Benefits:

• Angiography may eliminate the need for surgery. If surgery remains necessary, it can be performed more accurately.
• CT angiography is able to detect narrowing of blood vessels in time for corrective therapy to be done.
• CT angiography gives more precise anatomical detail of blood vessels than magnetic resonance imaging (MRI).
• Many patients can undergo CT angiography instead of a conventional catheter angiogram.
• Compared to catheter angiography, which involves placing a catheter (plastic tube) and injecting contrast material into a large artery or vein, CT angiography is a much less invasive and more patient-friendly procedure.
• This procedure is a useful way of screening for arterial disease because it is safer and much less time-consuming than catheter angiography and is a cost-effective procedure. There is also less discomfort because contrast material is injected into an arm vein rather than into a large artery in the groin.
  

www.radiologyinfo.org/content/ct-angiography.htm

Nothing by mouth 4 hours prior to the exam.

You should wear comfortable, loose-fitting clothing to your exam. You may be given a gown to wear during the procedure.

Metal objects including jewelry, eyeglasses, dentures and hairpins may affect the CT images and should be left at home or removed prior to your exam. You may also be asked to remove hearing aids and removable dental work.

You may be asked not to eat or drink anything for several hours beforehand, especially if a contrast material will be used in your exam. You should inform your physician of any medications you are taking and if you have any allergies. If you have a known allergy to contrast material, or "dye," your doctor may prescribe medications to reduce the risk of an allergic reaction.

Women should always inform their physician and the CT technologist if there is any possibility that they are pregnant. See the Safety page for more information about pregnancy and x-rays.

If you are breastfeeding at the time of the exam, you should ask your radiologist how to proceed. It may help to pump breast milk ahead of time and keep it on hand for use after contrast material has cleared from your body, about 24 hours after the test.