An angiogram is an X-ray test that uses dye and a camera to take pictures of the blood flow in an artery or a vein. An angiogram can be used to look at the arteries or veins in the head, arms, legs, chest, back, or belly. This test is done to look for problems in the arteries or veins.
An angiogram is done for many reasons. For example, you may have this test to find the source of bleeding, such as an ulcer. Or it may be done to look for blocked blood vessels in your lungs.
During an angiogram, the doctor will put a thin, flexible tube into a blood vessel in your groin or arm. This tube is called a catheter. The doctor guides the tube to the blood vessel that will be studied. Then a dye is injected through the tube to make the area easier to see. X-rays or pictures are taken of the area.
You will be given medicine to make you sleepy and comfortable during the test. You may or may not need to stay in the hospital overnight. You will stay in a room for at least a few hours to make sure the catheter site starts to heal.
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Why It Is Done
An angiogram is done to:
- Detect problems with blood vessels that affect blood flow. Examples of such problems include a tear in a blood vessel (which can cause blockage or internal bleeding), aneurysms (which are weaknesses in the blood vessel wall), and narrowed areas.
- Look for changes in the blood vessels of injured or damaged organs.
- Show the pattern of blood flow to a tumor. This can not only help show how much the tumor has spread but also guide treatment.
- Show the condition, number, and location of renal arteries before a kidney transplant.
- Look for a source of bleeding, such as an ulcer.
- Prepare for surgery on diseased blood vessels of the legs (peripheral arterial disease) in people who have severe leg pain when walking.
- Check how bad atherosclerosis is in the coronary arteries.
In some cases, a method called interventional radiology may be used during an angiogram to treat diseases. For example, a catheter can be used to open a blocked blood vessel, deliver medicine to a tumor, or stop intestinal bleeding caused by diverticular hemorrhage. To stop intestinal bleeding, the catheter is moved into the small artery where the bleeding is occurring, and medicine that narrows the artery or causes the blood to clot is injected through the catheter.
How To Prepare
Procedures can be stressful. This information will help you understand what you can expect. And it will help you safely prepare for your procedure.
Preparing for the procedure
- Do not eat or drink for 4 to 8 hours before the angiogram.
- Be sure you have someone to take you home. Anesthesia and pain medicine will make it unsafe for you to drive or get home on your own.
- Understand exactly what procedure is planned, along with the risks, benefits, and other options.
- Tell your doctor ALL the medicines, vitamins, supplements, and herbal remedies you take. Some may increase the risk of problems during your procedure. Your doctor will tell you if you should stop taking any of them before the procedure and how soon to do it.
- If you take a medicine that prevents blood clots, your doctor may tell you to stop taking it before your procedure. Or your doctor may tell you to keep taking it. (These medicines include aspirin and other blood thinners.) Make sure that you understand exactly what your doctor wants you to do.
- Make sure your doctor and the hospital have a copy of your advance directive. If you don't have one, you may want to prepare one. It lets others know your health care wishes. It's a good thing to have before any type of surgery or procedure.
How It Is Done
You will need to take off any jewelry. You may need to take off all or most of your clothes. You will be given a gown to wear during the test.
During the test
You will likely have an intravenous (IV) line in a vein in your arm so your doctor can give you medicine or fluids if needed. Small pads or patches (electrodes) are placed on your arms, chest, or legs to record your heart rate and rhythm.
You will lie on your back on an X-ray table. A strap, tape, or sandbags may be used to hold your body still. A lead apron may be placed under your genital and pelvic areas to protect them from X-ray exposure.
A round cylinder or rectangular box that takes the pictures during fluoroscopy will be moved above you. The fluoroscope will move under you during the test.
The place where the catheter will be inserted (in the groin or above the elbow) will be shaved and cleaned. Your doctor will numb the area with a local anesthetic. Then the doctor will put a needle into the blood vessel. A guide wire will be put through the needle into the blood vessel and the needle will be removed. The catheter will be placed over the guide wire and moved into the blood vessel. The catheter then will be guided through the blood vessels until the tip is in the area to be studied. Your doctor will use the fluoroscope to watch the movement of the catheter in the blood vessels.
When the catheter is in place, the dye is injected through it. You may be asked to take a breath and hold it for several seconds. Several X-ray pictures will be taken one after another. These will be available right away for your doctor to look at. You need to lie very still so the pictures are clear. More pictures may be taken.
After the test
The catheter is taken out after the angiogram, and pressure is put on the needle site for 10 to 15 minutes to stop any bleeding. A bandage or compression device is put on the site. This will prevent bleeding. You will be given pain medicine if you need it.
If the catheter was put in your groin, you will need to lie still and keep your leg straight for several hours. The nurse may put a weighted bag on your leg to keep it still. If the catheter was put in your arm, you may be able to sit up and get out of bed right away. But you will need to keep your arm still for at least 1 hour.
How long the test takes
An angiogram takes 1 to 3 hours.
How It Feels
You may feel a brief sting or pinch from the numbing medicine. Most people don't have pain when the catheter is in the blood vessel.
You may feel pressure in the blood vessel as the catheter is moved. Let your doctor know if you are having pain.
You will probably feel some warmth when the dye is put in. This feeling lasts only a few seconds. For some people, the feeling of heat is strong. For others it is very mild.
You may have a headache, flushing of the face, or a salty or metallic taste in your mouth after the dye is used. These feelings don't last long. Some people may feel sick to their stomach or may vomit, but this isn't common.
After the test, you may have some tenderness and bruising at the site where the catheter was inserted.
The chance of any major problem from an angiogram is very small, but some problems can occur. In most cases, the problems occur within 2 hours after the test when you are in the recovery room. If the problem occurs during the angiogram, the test may not be completed. You may need urgent treatment that could include surgery.
- There is a chance of an allergic reaction to the iodine dye. The reaction can be mild (itching, rash) or severe (trouble breathing or sudden shock). Most reactions can be treated with medicines. Be sure to tell your doctor if you have hay fever, asthma, or iodine allergy or food allergies.
- There is a small chance that the catheter may damage a blood vessel or dislodge a piece of clotted blood or fat from the vessel wall. The clot or fat can block blood flow to the brain, arm, leg, or intestine (bowel).
- Bleeding from the needle site may occur. Also, a blood clot can form where the catheter was inserted. This may cause some blockage of the blood flow in the arm or leg.
- The iodine dye used for the test can cause water loss or direct damage to the kidneys. This is a special concern for people who have kidney problems or diabetes or who are dehydrated. Special measures are used during the test to prevent problems for people who need an angiogram and have these conditions.
- There is always a small chance of damage to cells or tissue from being exposed to any radiation, even the low level used for this test.
Your doctor may tell you some results right after the test. Full results are usually ready the same day.
The blood vessels are normal in shape, size, location, and number.
The dye flows evenly through the blood vessels.
No narrowing, blockage, bulging, or other problem of the blood vessels is seen.
Blood vessels that are not in their normal position may mean that a tumor or other growth is pushing against them.
A narrow spot in an artery may mean that a fat deposit, calcium deposit, or clot is reducing blood flow through the blood vessel.
A bulge in a blood vessel may mean a weakness in the blood vessel wall (aneurysm).
Dye that leaks out of a blood vessel may mean a hole in the blood vessel.
There is abnormal branching of blood vessels present since birth (congenital).
An abnormal pattern of blood vessels may mean that a tumor is present.
Current as of: April 5, 2022
Author: Healthwise Staff
Rakesh K. Pai MD, FACC - Cardiology, Electrophysiology
Adam Husney MD - Family Medicine
Martin J. Gabica MD - Family Medicine
E. Gregory Thompson MD - Internal Medicine
Howard Schaff MD - Diagnostic Radiology