Angiogram of the Lung

Test Overview

An angiogram of the lung is an X-ray test that uses a special dye and camera ( fluoroscopy ) to take pictures of the blood flow in the blood vessels of the lung.

During an angiogram, a thin tube called a catheter is placed into a femoral blood vessel in the groin (femoral vein) or just above the elbow (brachial vein). The catheter is guided to the area to be studied. Then an iodine dye ( contrast material ) is injected into the vessel to make the area show clearly on the X-ray pictures. The angiogram pictures can be made into regular X-ray films or stored as digital pictures in a computer.

A lung (pulmonary) angiogram is used to check the arteries that lead to the lungs (pulmonary arteries) and the blood vessels in the lungs. It can also find narrowing or a blockage in a blood vessel that slows or stops blood flow. See an image of an angiogram showing the blood flow of the lungs .

Why It Is Done

A lung angiogram is often done to find a pulmonary embolism (PE) . A PE is a blockage in the pulmonary artery that suddenly reduces blood flow to the lungs. A PE is often caused by a blood clot. It may also be caused by fat particles, air, or a tumor. A PE can be a very serious condition. A PE may be treated with blood thinners.

A lung angiogram may also be done to measure the pressure in the blood vessels carrying blood to the lungs, to look for lung problems, or to find other causes of blockage or narrowing of the vessels.

How To Prepare

Before an angiogram, tell your doctor if you:

• Are or might be pregnant.
• Are breast-feeding. Use formula (throw out your breast milk) for 1 to 2 days after the angiogram until the dye has passed from your body. This generally takes 24 hours.
• Are allergic to iodine dye used in the test.
• Have ever had a serious allergic reaction ( anaphylaxis ) from any substance, such as the venom from a bee sting or from eating shellfish.
• Have asthma .
• Are allergic to any medicines.
• Have any bleeding problems or are taking blood-thinning medicines.
• Have left heart block or a pacemaker .
• Have a history of kidney problems or diabetes , especially if you take metformin (such as Glucophage) to control your diabetes. The dye used during an angiogram can cause kidney damage in people who have poor kidney function.

Do not eat or drink for 4 to 8 hours before the angiogram. You may be asked to not take aspirin, aspirin products, or blood thinners for several days before the test and for 1 day after the test. If you take these medicines, talk with your doctor.

An angiogram can be done as an inpatient or outpatient. If you are an outpatient, you will stay in a recovery room for several hours before you go home. You may want to bring something to do or read to pass the time. Arrange to have someone take you home because you may get a sedative before the test. If you stay overnight in the hospital, you will probably go home the next day.

The test may take several hours, so you will empty your bladder just before it begins.

Also before the angiogram you may have other blood tests, such as blood clotting (coagulation) studies, blood urea nitrogen (BUN), and creatinine.

You will need to sign a consent form that says you understand the risks of an angiogram and agree to have the test done. Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this test, fill out the medical test information form (What is a PDF document?) .

How It Is Done

An angiogram is done by a radiologist . The radiologist may be helped by another doctor, a radiology technologist, or a nurse.

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.

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. A device called a pulse oximeter, which measures oxygen levels in your blood, may be clipped to your finger or ear. Small discs (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. Ask for a pad or blanket to make yourself comfortable. 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 he or she 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 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 developed right away for your doctor to look at. You need to lie very still so the pictures are clear. Sometimes only one lung is studied, or the process may be repeated more than once for each lung. See a picture of how an angiogram is done .

An angiogram takes 1 to 2 hours. 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 small sandbag or clamp may be put on the site to hold pressure. A bandage is put on the site. You will be given pain medicine if you need it.

The place in your hands and feet where your heartbeat (peripheral pulse) can be felt may be marked with a pen. Your pulse may be checked before and after the angiogram.

How It Feels

You may feel a brief sting or pinch from the numbing medicine. Most people do not 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 and for others it is very mild.

You may feel a need to cough but try to keep holding your breath until you are told to breathe.

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 do not last long. Some people may feel sick to their stomach or may vomit, but this is not common.

After the test, you may have some tenderness and bruising at the site where the catheter was inserted.

You can drink extra fluids to pass the dye from your body unless your doctor has told you not to.

Risks

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 small chance of developing an abnormal heartbeat . This usually lasts only a few seconds and goes away without any other treatment.
• There is a chance of an allergic reaction to the iodine dye. The reaction can be mild (itching, rash) or severe (difficulty 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.
• 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 from 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, 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.

After the test

After the test, call 911 or other emergency services immediately if you have:

• Chest pain.
• Moderate to severe difficulty breathing.
• Vision problems or slurred speech.
• Weakness in the muscles of your face or in your arms or legs.
• Severe pain in your belly or back.

After the test, call your doctor immediately if you:

• Have shortness of breath.
• Have dizziness.
• Have numbness, tingling, pain, swelling, loss of color, coolness, or loss of function in the arm or leg where the catheter was inserted.
• Develop a fever.
• Develop signs of infection at the catheter site. These signs may include:
  • Increased pain, swelling, redness, or warmth around the area.
  • Red streaks spreading from the area.
  • Drainage of pus from the area.
  • Swollen lymph nodes in the neck, armpit, or groin.
  • Fever or chills.

Results

An angiogram of the lung is an X-ray test that uses a special dye and camera ( fluoroscopy ) to take pictures of the blood flow in the blood vessels of the lung. Your doctor may tell you some results right after the test. Full results are ready in 2 days.

What Affects the Test

Reasons you may not be able to have the test or why the results may not be helpful include:

• Being pregnant. An angiogram is not usually done during pregnancy because the radiation could damage the developing baby ( fetus ).
• Having a blocked blood vessel or another blood vessel problem.
• Having high blood pressure in the blood vessels that carry blood to the lungs ( pulmonary hypertension ).
• Not being able to lie still during the test.
• Having an abnormal heart rhythm. Your doctor will talk to you about this.

What To Think About

• A computed tomography pulmonary angiogram (CTPA) or a magnetic resonance angiogram (MRA) may be an option instead of an angiogram. Each of these tests is less invasive than a standard angiogram. Some MRA tests and all CTA tests require an injection of dye. A CTA also involves radiation exposure. For more information, see the medical tests Magnetic Resonance Angiogram (MRA) and CT Scan of the Body. Some doctors may want results from a standard angiogram before doing surgery to treat a damaged or abnormal blood vessel.
• For people with kidney problems, diabetes , or dehydration , steps are taken to prevent kidney damage. Less dye may be used or more fluids may be given before, during, and after the test. If you have a history of kidney problems, other blood tests (creatinine, blood urea nitrogen) may be done before an angiogram to make sure that your kidneys are working well. For more information, see the medical tests Creatinine and Creatinine Clearance and Blood Urea Nitrogen.
• In rare cases, surgery may be needed to repair a hole in the blood vessel where the catheter was placed. There is also a substance (called Angio-Seal) that can be used to help plug the hole in the vessel and stop the bleeding. The substance used to plug the hole in the vessel is normally absorbed by the body over several months.

References

Other Works Consulted

• Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis: Saunders.
• Pagana KD, Pagana TJ (2006). Mosby’s Manual of Diagnostic and Laboratory Tests, 3rd ed. St. Louis: Mosby.

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