Exam: Thyroid Scan and Uptake

Thyroid Scan and Uptake Description

Duration: This is done over 2 days and is less than 1 hour each day.

A thyroid scan is a type of “nuclear medicine” imaging. The thyroid uptake test is also known as a radioactive iodine uptake test (RAIU). It is a measurement of thyroid function, but does not involve imaging.

What is Nuclear Medicine?

Nuclear medicine is a type of diagnostic exam whereby images are acquired by tracking the distribution of radioactive material in the body.  The radioactive isotope is injected at the start of the test.  A Gamma camera is used to detect the rays emitted by the radioactive material.  Most of the radioactive isotopes injected into the patient’s body is eliminated via urine and the intensity of radioactivity diminishes over time.

An appointment is necessary for all Nuclear Medicine/Nuclear Cardiac examinations.


  1. No Thyroid medication 4 weeks prior to examination in consultation with your referring physician.
  2. No iodinated contrast injection (angiography, CT, IVP) 6 weeks prior to the exam.
  3. Please bring a list of all medications.
  4. Day 1 - Nothing to eat or drink 1 hour prior to test.
  5. Day 2 - No restrictions, resume regular diet.