How It Is Done continued...
Afterward, the radioactive
gas or mist will clear from your lungs as you breathe.
ventilation scan takes about 15 to 30 minutes.
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. The
camera may be repositioned around your chest to get different views. You need to
remain very still during the scans to avoid blurring the pictures.
The perfusion scan takes about 5 to 10 minutes.
How It Feels
You may find that breathing through the
mask during the ventilation scan is uncomfortable, especially if you feel very
short of breath. But you will be given plenty of oxygen through the
You may feel nothing at all from the needle puncture when the
tracer is injected, or you may feel a brief sting or pinch as the needle goes
through the skin. Otherwise, a lung scan is usually painless. You may find it
hard to remain still during the scan. 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 be eliminated from 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 following
Occasionally, some soreness or swelling may develop at
the injection site. These symptoms can usually be relieved by applying moist,
warm compresses to your arm.
There is always a slight risk of
damage to cells or tissue from being exposed to any radiation, including the
low level of radiation released by the radioactive tracer used for this test.