What is it?

A lung (V/Q) scan is also known as a lung ventilation and perfusion scan. This test is used to detect blood clots in the lungs. These blood clots are called pulmonary embolisms.


What do I need to do before the procedure?

Make sure you remember to bring any previous films or reports to the appointment. Wear warm comfortable clothing. You will also need to:

  • Medications - take your medications as normal
  • Advise of pregnancy or breastfeeding - let the service know if you are pregnant or breastfeeding


What will happen?

There is two parts to the test. First you will be asked to breathe a small amount of a radioactive gas through a special mouth-piece. It usually takes about ten breaths to breathe in all the gas. They then take pictures of the gas in your lungs using a special camera. This takes about 15 minutes and you will need to lie still and breath normally.

Then you will be given a small injection of a radioactive tracer into a vein. Pictures of the blood supply in your lungs are taken using the camera. This takes another 15 minutes and you will be required to lie still and breathe normally.


What can I expect after?

There are no after-effects from having a lung (V/Q) scan. The small doses of radiation in the gas and tracer is about the same as you would get from a chest X-ray.

Once it is finished, you can go home. You are able to drive immediately after the test. Your results will be sent to your GP or specialist.