Lung Scan

What is a lung scan?

A lung scan is a procedure that uses a radioactive chemical to look at your lungs. The chemical is called a radionuclide or tracer. Although the thought of radioactive material in the body may be scary, this substance is very safe. The amount of radiation it gives off is slight. It is less than the amount used for a standard chest X-ray.

When is it used?

This procedure is done to check for a blood clot in your lung (a pulmonary embolism).

How do I prepare for a lung scan?

Follow your healthcare provider's instructions. Be sure to tell your provider if you think you might be pregnant.

What happens during the procedure?

There are 2 types of lung scans. For one type called a perfusion scan, the X-ray technologist injects a small amount of the tracer into a vein in your hand or arm. As the chemical moves through your bloodstream, a camera records how the blood flows into your lungs. The information creates a picture your healthcare provider can use to see if any parts of the lung are not getting enough blood.

The other type of lung scan is called a ventilation scan. For this test you will breathe in a small amount of the tracer mixed with oxygen through a face mask. You will be asked to breathe in and out and hold your breath. The camera records where the air is going inside your lungs. It may show parts of the lung that are not getting enough air or parts that are getting too much air.

What happens after the procedure?

The radiologist sends the complete report to your healthcare provider. If you do have a blood clot in your lung, you may need to stay in the hospital to have blood thinner medicine (an anticoagulant).

The small amount of radioactivity is not considered dangerous. It will be completely gone from your body within hours to days.

If your test is negative, which means it did not find any clots, you should ask your provider if you need more tests. Also ask what symptoms you need to come back for right away and when you need to come back for a checkup.

What are the benefits of this procedure?

This procedure will not cure the problem, but it may help your healthcare provider make a more accurate diagnosis.

What are the risks associated with this procedure?

Reactions to the tracer happen rarely. You should ask your provider how this risk applies to you.

When should I call my healthcare provider?

Call your healthcare provider right away if:

• You develop a fever.
• You become short of breath.
• You develop chest pain.

Call your healthcare provider during office hours if:

• You have questions about the procedure or its result.
• You want to make another appointment.