Usually the provider will recommend this scan based on the results of a chest x-ray. Small defects may not be visible on the scan. For this reason, this test is not often done anymore.
Lung gallium scan is a type of nuclear scan that uses radioactive gallium to identify swelling (inflammation) in the lungs.
How the Test is Performed
During the test, you lie on a table that moves underneath a scanner called a gamma camera. The camera detects the radiation produced by the gallium. Images display on a computer screen.
During the scan, it is important that you keep still to get a clear image. The technician can help make you comfortable before the scan begins. The test takes about 30 to 60 minutes.
How the Test will Feel
The injection of gallium will sting, and the puncture site may hurt for several hours or days when touched.
The scan is painless, but you must stay still. This may cause discomfort for some people.
How to Prepare for the Test
Several hours to 1 day before the scan, you will get an injection of gallium at the place where the testing will be done.
Just before the scan, remove jewelry, dentures, or other metal objects that can affect the scan. Take off the clothing on the upper half of your body and put on a hospital gown.
The lungs should appear of normal size and texture, and should take up very little gallium.
There is some risk to children or unborn babies. Because a pregnant or nursing woman may pass on radiation, special precautions will be made.
For women who are not pregnant or nursing and for men, there is very little risk from the radiation in gallium, because the amount is very small. There are increased risks if you are exposed to radiation (such as x-rays, and scans) many times. Discuss any concerns you have about radiation with the health care provider who recommends the test.
What Abnormal Results Mean
If a large amount of gallium is seen in the lungs, it may mean any of the following problems:
- Sarcoidosis (disease in which inflammation occurs in the lungs and other tissues of the body)
- Other respiratory infections, most often a type of pneumonia caused by the fungus Pneumocystis jirovecii
Why the Test is Performed
This test is usually done when you have signs of inflammation in the lungs. This is most often due to sarcoidosis or a certain type of pneumonia.
Gotway MB, Panse PM, Gruden JF, Elicker BM. Thoracic radiology. In: Broaddus VC, Mason RJ, Ernst JD, et al, eds. Murray and Nadel's Textbook of Respiratory Medicine. 6th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 18.
Mettler FA, Guiberteau MJ. Inflammation and infection imaging. In: Mettler FA, Guiberteau MJ, eds. Essentials of Nuclear Medicine Imaging. 6th ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 12.