Thyroid Uptake and Scan
(Thyroid Scintiscan; Technetium Thyroid Scan)
by Julie J. Martin, MS
A thyroid uptake and scan is a test that uses a radioactive substance and a scanning tool to evaluate the thyroid gland. The scanner picks up where and how much the radioactive substance was taken up by the thyroid. This helps determine the structure, location, size, and activity of the gland.
Reasons for Test TOP
The scan may be ordered to:
Possible Complications TOP
Thyroid scans are associated with very few risks. Tell your doctor if you:
What to Expect TOP
Prior to Test
Description of Test
The procedure is done by a trained technician in the radiology department of a hospital. You will be given a radioactive substance by mouth. Once the substance has had time to collect in the thyroid, the scan begins. You will lie on your back with your head tilted back. You will be asked to lie very still at certain times. A scanner will take pictures of your thyroid from different angles. The camera is not an x-ray machine. It does not expose you to more radiation. You may need to return to the radiology department after 24 hours for additional pictures.
After Test TOP
You will be able to leave after the test is done.
Because of the very low dose of radioactive substance used, the majority of the radioactive substance will leave your body within a day or two. You are not at risk for exposing other people to radiation. You can interact normally with them.
How Long Will It Take? TOP
The scan itself takes about half an hour. The radioactive substance needs time to be absorbed before the scan. You may need to wait 4-6 hours if you take the substance by mouth.
Will It Hurt? TOP
There is no pain associated with a thyroid scan. There may be times when you find it uncomfortable to lie still with your head tilted backward.
The pictures of the scan take about an hour to develop. A radiologist will examine them. Based on the results of the test, further studies or treatment will be recommended.
Call Your Doctor TOP
Call your doctor if you experience any unusual pain or discomfort.
In case of an emergency, call for medical help right away.
American Thyroid Association, Inc.
Thyroid Foundation of America, Inc.
Public Health Agency of Canada
The Thyroid Foundation of Canada
Beers MH, Fletcher AJ, et al. The Merck Manual of Medical Information: Second Home Edition. Whitehouse Station, NJ: Merck Research Laboratories; 2003.
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Thyroid nodules: symptoms, causes, diagnosis, treatment. American Thyroid Association website. Available at: http://www.thyroid.org/what-are-thyroid-nodules. Accessed August 24, 2005.
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Thyroid scan and uptake. RadiologyInfo.org website. Available at: http://www.radiologyinfo.org/en/info.cfm?pg=thyroiduptake. Updated February 2010. Accessed November 19, 2010.
Last reviewed December 2013 by Kim Carmichael, MD
Last Updated: 1/13/2014