What Is Pulmonary Angiography?

Medically Reviewed by Paul Boyce, MD on March 01, 2024
3 min read

Pulmonary angiography is an X-ray procedure that looks at the blood vessels leading to and from your lungs. The X-rays produced are called pulmonary angiograms, which may show blood clots in and around your lungs — called pulmonary embolisms

A special dye stains your blood vessels, so they appear bright white under X-rays. This contrast allows doctors to see any blood clots and other blood vessel-related conditions. 

Pulmonary angiography is often used to look for blood clots in the artery that leads from your heart to your lungs.

Your doctor may order the procedure if you’re showing common symptoms of a blood clot, including: 

  • Chest pain
  • High blood pressure specific to areas around the lungs and heart
  • A history of other blood clots or deep vein thrombosis

Pulmonary angiography can help identify several other conditions in the lung region, including: 

  • Aneurysms, when there are bulges in your blood vessels
  • Abnormal connections between your blood vessels, such as between arteries and veins
  • Birth conditions that affected the development of your blood vessels
  • Stenosis, when the openings in your blood vessels have narrowed

Pulmonary angiography can also monitor blood flow into the lungs.

How Is Pulmonary Angiography Done?

Before the pulmonary angiography, be sure to tell your doctor if: 

  • You’re pregnant
  • Have any known allergies
  • Have a history of allergic reactions

Your doctor will have specific instructions about whether or not you need to stop eating or drinking for a few hours before the procedure. Your doctor may also order a blood test to check the amount of time your blood takes to clot. 

The procedure follows these steps: 

  • You may need to put on a hospital gown, so wear loose, comfortable clothing. You’ll need to remove all metal objects, including jewelry. 
  • A thin, intravenous (IV) line is inserted into your arm, and devices to monitor your heart rate, blood pressure, and breathing are attached to your chest. This is so your doctors can track these vital signs throughout the procedure. 
  • You lie on your back, and a catheter — a flexible tube — is inserted into either your arm or groin. It is moved through your vein to the right side of your heart.
  • A contrast dye is inserted into your veins with the IV.   
  • X-ray pictures are taken until there are enough high-quality images. This could involve a second round of dye injection and X-ray imaging. 
  • The catheter and IV are removed and the openings covered. 
  • You’ll need to recover by lying flat for up to two hours while your doctors monitor your vital signs. 
  • This can be an outpatient surgery for some people, so you’ll be able to leave later on the same day. Sometimes, though, your doctor will want to keep you overnight for observation.

There are few risks associated with pulmonary angiography. They include: 

  • Radiation exposure. All X-rays expose your tissues to radiation, which increases your risk of developing cancer later in your life.
  • Allergic reactions to the dye. 
  • Infection. You run a risk of infection at the sites of all of the surgical openings.

Computed tomography angiography (CTA) has almost completely replaced traditional pulmonary angiography to become the new standard for viewing blood vessels near the lungs. Like pulmonary angiography, CTA: 

  • Use X-rays to examine blood vessels
  • Use a type of dye to make your blood vessels stand out in X-rays
  • Can be easy outpatient procedures

CTA is used to examine blood vessels all over — from your brain to your legs — while a pulmonary angiogram focuses on the lungs. CTA can also be helpful to look at the way that blood vessels connect to tumors.

A difference between CTA and traditional pulmonary angiography is in the number of X-ray sources and detectors aimed at you. In traditional pulmonary angiography, there is a single source of X-rays and a single detector. From this, your doctor can form a two-dimensional image of your blood vessels. 

In CTA, there are multiple X-ray sources and detectors in a donut-shaped machine that your body is moved in and out of. This device sends out X-rays from many different angles. It uses a computer to construct a 3D image of your blood vessels in the areas where clots are suspected. 

There are also procedures called CT pulmonary angiograms. This is when the CT technology is used to look near your lungs.