How It Is Done
A lung scan is usually done by a nuclear medicine technologist. The
scan pictures are usually interpreted by a
radiologist or
nuclear medicine specialist.
You will need to remove any jewellery that might interfere with the
scan. You may need to take off all or most of your clothes, depending on which
area is being examined (you may be allowed to keep on your underwear if it does
not interfere with the test). You will be given a cloth or paper covering to
use during the test.
During the scan, you will either lie on your back with the scanning
camera positioned over your chest or you will sit with the camera positioned
next to your chest. The camera does not produce any radiation, so you are not
exposed to any additional radiation while the scan is being done.
Ventilation scan
For the ventilation scan, a mask will be placed over your mouth
and nose. You will inhale the tracer gas or mist through the mask by taking a
deep breath and then holding it. The camera will scan for radiation released by
the tracer and produce pictures as the tracer moves through your lungs. You may
be asked to breathe the gas or mist in and out through your mouth into a bag
for several minutes. You may then be asked to hold your breath for short
periods (about 10 seconds) and to change positions so your lungs can be viewed
from other angles. The camera may move to take pictures from different angles.
You need to remain very still during the scans to avoid blurring the
pictures.
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, the technologist cleans the site on your
arm where the radioactive tracer will be injected. A small amount of the
radioactive tracer is then injected.
After the radioactive tracer is injected, the camera will scan
for radiation released by the tracer and produce pictures as the tracer moves
through your lungs. You may be asked to move into different positions (onto
your side and stomach) so your lungs can be viewed from other angles, or the
camera may be repositioned around your chest to obtain other views. You need to
remain very still during the scans to avoid blurring the pictures.
The perfusion scan takes about 15 to 30 minutes.