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.
The scan may be ordered to:
Thyroid scans are associated with very few risks. Tell your doctor if you:
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.
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 in 1-2 days. You are not at risk for exposing other people to radiation. You can interact normally with them.
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.
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.
American Thyroid Association
Hormone Health Network—Endocrine Society
Public Health Agency of Canada
The Thyroid Foundation of Canada
Hyperthyroidism. Johns Hopkins University website. Available at: http://www.hopkinsmedicine.org/healthlibrary/conditions/adult/endocrinology/hyperthyroidism_85,P00408. Accessed November 28, 2017.
Hyperthyroidism and thyrotoxicosis. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T116479/Hyperthyroidism-and-other-causes-of-thyrotoxicosis. Accessed July 27, 2017. Accessed November 28, 2017.
Thyroid nodule. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T115781/Thyroid-nodule. Updated December 11, 2015. Accessed November 28, 2017.
Thyroid nodules. American Thyroid Association website. Available at: http://www.thyroid.org/thyroid-nodules. Accessed November 28, 2017.
Thyroid scan and uptake. Radiological Society of North America Radiology Info website. Available at: http://www.radiologyinfo.org/en/info.cfm?pg=thyroiduptake. Updated February 1, 2017. Accessed November 28, 2017.
Last reviewed November 28, 2017 by EBSCO Medical Review Board James Cornell, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.