Lung gallium scan

Definition

Lung gallium scan is a type of nuclear scan that uses radioactive gallium (Ga) to identify swelling (inflammation) in the lungs.

Alternative Names

Gallium 67 lung scan; Lung scan; Gallium scan - lung; Scan - lung

How the test is performed

Gallium is injected into a vein. The scan will be taken 6 - 24 hours after the gallium is injected. (Test time depends on whether your condition is acute or chronic.)

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 will take about 30 - 60 minutes.

How to prepare for the test

You must sign an informed consent form. 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.

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. However, you must stay still. This may cause discomfort for some patients. The wait between the injection and scan can cause some patients to become agitated.

Why the test is performed

This test is most often done when you have signs of inflammation in the lungs (sarcoidosis).

Normal Values

The lungs should appear of normal size and texture, and should take up very little gallium.

What abnormal results mean

• Sarcoidosis
• Other respiratory infections, most often pneumocystis jirovecii pneumonia

Other conditions under which the test may be performed:

• Primary pulmonary hypertension
• Pulmonary embolus
• Tumors in the lung
• Scleroderma of the lung

What the risks are

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.

Special considerations

Usually the health care provider will recommend this scan based on the results of a chest x-ray. Small defects may not be visible on the scan.

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References

Weinberger SE. Sarcoidosis. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 95.