Radioactive Iodine Test
Uptake of tracer doses of radioactive iodine is an essential test in thyroid disease. It is injected into a vein and then binds to receptors on the thyroid cells. This therefore allows the thyroid gland to be imaged on X-ray scanning. There may be a low uptake, a diffuse uniform uptake, a patchy uptake or a solitary hot spot.
A low uptake or no uptake in the thyroid occurs in:
- Post partum thyroiditis
- Iodine-induced thyrotoxicosis
- Factitious hyperthyroidism (self administered or over replacement of thyroid)
A diffuse uniform uptake in the thyroid occurs in:
A patchy uptake in the thyroid occurs in:
Toxic nodular goitre.
A solitary hot spot in the thyroid occurs in:
Various different pictures maybe seen with thyroid cancers.