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Thyroid uptake and scan
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A radioactive iodine uptake test is used to evaluate how well the thyroid, the gland in the neck, is working. What it measures is simple: how much radioactive iodine the gland picks up.
It is done with a pill that contains a very small amount of radioactive iodine. You swallow it and wait for it to collect in the thyroid. The tagged iodine acts as ink, and the thyroid picks it up. A gamma probe, a device that detects the rays this iodine gives off, is then placed over the neck.
A thyroid scan uses a radioactive iodine tracer to create an image of the structure and function of the gland. On that image, nodules, which are lumps inside the thyroid, usually look lighter if they took up no iodine and darker if they took up more.
In brief
A radioactive iodine uptake test evaluates thyroid function by measuring how much iodine the gland takes up.
You swallow a pill containing a very small amount of radioactive iodine, and once it has collected in the thyroid, a gamma probe over the neck detects its rays.
The tagged iodine acts as ink, and the thyroid picks it up.
The scan uses a radioactive iodine tracer to show structure and function; a nodule usually looks lighter if it took up no iodine and darker if it took up more.
Sources (2)
- MedlinePlus, U.S. National Library of MedicineRadioactive iodine uptake, MedlinePlus Medical EncyclopediaPublished
- MedlinePlus, U.S. National Library of MedicineThyroid scan, MedlinePlus Medical EncyclopediaPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
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