CTPA (CT Pulmonary Angiogram)

A CT pulmonary angiogram is used to diagnose a blood clot in the lung.

What is a CT pulmonary angiogram?
Why do I need a CT pulmonary angiogram?
What are the risks of having a CT pulmonary angiogram?
How do I prepare for a CT pulmonary angiogram?
What happens during a CT pulmonary angiogram?
What happens after a CT pulmonary angiogram?

What is a CT pulmonary angiogram?

A CT pulmonary angiogram (or CTPA) is a CT scan that looks for blood clots in the lungs (also known as pulmonary embolism or PE). A CT pulmonary angiogram takes pictures of the blood vessels that run from the heart to the lungs (the pulmonary arteries).

During the test, dye will be injected into a vein in your arm which travels to your pulmonary arteries. This dye makes the arteries appear bright and white on the scan pictures. Your doctor can then see if there are any blockages or blood clots.

Why do I need a CT pulmonary angiogram?

Your doctor might have asked you to get a CT pulmonary angiogram to:

  • Check for a bulging blood vessel
  • Check for an artery abnormally connected to a vein
  • Check for and treat a blood clot
  • Identify narrowing of a blood vessel wall
  • See how well blood is flowing to the lungs.

A CT pulmonary angiogram may be recommended for you if you have symptoms of a blood clot, such as:

  • A history of deep vein thrombosis (DVT)
  • Chest pain
  • Pulmonary hypertension, which is high blood pressure that affects arteries in the lungs and heart.

 Below, you can watch a short video from one of our doctors explaining more about CTPA.

 

 

Below, you can watch an animation explaining what happens during a CTPA.

What are the risks of having a CT pulmonary angiogram?

Severe reactions to CTPA are rare, but some risks do exist, including:

  • Allergy to the X-ray dye (tell your doctor if you have a history of allergies)
  • Headache from medication given during the procedure    
  • In rare cases, dye may leak into the veins in surrounding tissues
  • Kidney problems as a result of the X-ray dye (in people with a history of kidney problems).

In this test, the radiation exposure is very minimal. The benefits of diagnosing a blood clot – a life-threatening condition – far outweigh any of the risks of radiation exposure.

How do I prepare for a CT pulmonary angiogram?

You don’t have to do anything to prepare for your CT pulmonary angiogram. During the scan, you may be given a gown to wear. You’ll also need to remove metal objects, such as necklaces and bra fastenings, as these can affect the CT images.

You can eat and drink normally before and after the scan unless your doctor tells you otherwise.

What happens during a CT pulmonary angiogram?

To begin, you’ll be taken into the CT scanning room at the hospital. The nurse or radiographer will explain the procedure and answer any questions you have. You will be given a questionnaire to fill out to check other details such as allergies.

During the scan:

  • The radiographer will place a cannula (very thin tube) in a vein in your arm
  • You will lie on the CT bed on your back with your arms above your head
  • X-ray dye will be injected into the cannula in your arm
  • When the dye is injected into your arm, you may feel a ‘hot flush’ across your neck and chest or throughout your body – this feeling is normal and doesn’t last long
  • You might also notice a slight metallic taste in your mouth, but this goes away quickly
  • The CT bed will move inside the CT scanner
  • You’ll hear slight buzzing, clicking and whirring sounds as the scanner takes images of your chest
  • The CT bed will move in and out of the machine a few times
  • You will be asked to hold your breath for a few seconds during each scan
  • During the scan, you’ll be able to talk to the radiographers over an intercom and the radiographers will be able to see you throughout the scan
  • The scanning process takes around 10 minutes.

What happens after a CT pulmonary angiogram?

After your CT pulmonary angiogram, you’ll be asked to wait while your doctor checks the scan images.If any blockages are identified, your doctor will discuss the next steps with you - including when you need to make a follow-up appointment.

You shouldn’t feel any different after the scan. But, if you’re still not feeling quite right after a few days, call your doctor.