Lung Scan (V/Q scan)

A lung scan gives us a set of pictures which shows the air supply and the blood supply to your lungs.

Information about your scan

A lung scan gives us a set of pictures which shows the air supply and the blood supply to your lungs.

Is there any preparation and can I eat and drink?

There is no preparation before this scan – you can eat and drink normally and keep taking your medication.

What happens at the scan?

The scan is in two parts. In the first part we look at the air supply to your lungs and in the second part we look at the blood supply.

To look at the air supply to your lungs you will be asked to breathe through a mouthpiece and a clip will be placed on your nose. You will be asked to breathe in a small amount of odourless radioactive gas which will show the air passages in your lungs. This will not put you to sleep, does not taste or smell or have any side effects. A scan is then performed to see where this gas is in your lungs.

The second part of the scan is to look at the blood supply to your lungs.  We give you an injection into a vein in either your arm or hand which contains a small amount of radioactivity. This will have no effect on you and is similar to the dose of radiation you would get from an x-ray of your spine. We then do the scan again to see where this injection has gone in your lungs. The whole test takes about 45 minutes. You do not need to undress for your test but please remove any metal objects from around your chest area. 

There will be someone in the room with you all the time.

Will it hurt?

The injection may only feel like a small scratch.

Will I be able to drive?


Is there anything I should tell the staff before the scan?

Yes. If you are pregnant or think you may be pregnant, please inform us. We also need to know if you are breastfeeding as you will need to refrain from breastfeeding for several hours following the scan.

Do I need to do anything after the scan?

No special precautions are needed after the scan.

How will I get the results of the scan?

You will be asked to return to Same Day Emergency Care (SDEC) after your scan where you will receive the results. There may be occasions when your results are delayed. You will be informed of this at the time.


There is a very small risk of a reaction to the injection, e.g. a rash on the skin in patients who tend to be hypersensitive.  The amount of radiation your body receives is similar to the radiation you would receive if having an x-ray of the spine.

You will be given a radioactive substance for this procedure. The risks involved are low and a licensed doctor has judged that the benefits of doing the test outweigh the risks; if you wish to know more please see; if you still have questions regarding radiation risk please get in touch with us.

Alternatives to the procedure

You may have a CT (computerised tomography) scan instead of this scan depending upon the results of your chest x-ray. If you do not wish to have this test you must discuss this with the Doctor who referred, you.

Any other questions?

We want your visit to be as pleasant as possible. If you have any questions, please ask the staff in the Medical Physics Department. You can telephone or ask before the scan starts.

Contact numbers for advice

Medical Physics Tel: 0191 445 2710 Monday to Friday 8.30am to 4.30pm

Physicist/Head of Physics Tel: 0191 445 2476 or 0191 445 5516 Monday to Friday 9am to 5pm