Radioactive iodine uptake

Thyroid uptake; Iodine uptake test; RAIU

Radioactive iodine uptake (RAIU) tests thyroid function. It measures how much radioactive iodine is taken up by your thyroid gland in a certain time period.

A similar test is the thyroid scan. The 2 tests are commonly performed together, but they can be done separately.

Thyroid uptake test

Radioactive iodine uptake test is a type of nuclear test performed to evaluate thyroid function. The patient ingests radioactive iodine (I-123 or I-131) capsules or liquid. After a time (usually 6 and 24-hours later), a gamma probe is placed over the thyroid gland to measure the amount of radioiodine uptake in the thyroid gland. The values are then compared.

How the Test is Performed

How to Prepare for the Test

How the Test will Feel

Why the Test is Performed

Normal Results

What Abnormal Results Mean