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    Lung Scan

    How It Is Done continued...

    Afterward, the radioactive gas or mist will clear from your lungs as you breathe.

    The ventilation scan takes about 15 to 30 minutes.

    Perfusion scan

    For the perfusion scan, a small amount of the radioactive tracer is injected into your arm.

    After the tracer is injected, the camera will take pictures as the tracer moves through your lungs. The camera may be repositioned around your chest to get different views. You need to stay very still during the scans to avoid blurring the pictures.

    The perfusion scan takes about 5 to 10 minutes.

    How It Feels

    Breathing through the mask during the ventilation scan may be uncomfortable, especially if you feel very short of breath. But you will be given plenty of oxygen through the mask.

    If you have a perfusion scan, you may feel nothing at all from the needle, or you may feel a brief sting or pinch. Otherwise, a lung scan is usually painless.

    You may find it hard to stay still. Ask for a pillow or blanket to make yourself as comfortable as possible before the scan begins.


    Allergic reactions to the radioactive tracer are very rare. Most of the tracer will leave your body through your urine or stool within a day. So be sure to promptly flush the toilet and thoroughly wash your hands with soap and water. The amount of radiation is so small that it is not a risk for people to come in contact with you after the test.

    Some people have soreness or swelling at the injection site. A moist, warm compress applied to the arm may help.

    There is always a slight risk of damage to cells or tissue from being exposed to any radiation, even the low level of radiation released by the radioactive tracer used for this test. But the chance of damage is usually very low compared with the benefits of the test.


    A lung scan camera.gif is a type of nuclear scanning test. It is most often used to find a pulmonary embolism. This is a blood clot that prevents normal blood flow in the lung.

    WebMD Medical Reference from Healthwise

    Last Updated: August 21, 2015
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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