An Iodine-131 whole-body scan is a procedure that is performed in nuclear medicine to check for recurrence of thyroid cancer in the body following a complete thyroidectomy (removal of the thyroid).


For 1 week prior to the test, you are required to follow a low iodine diet. You will also be required to be off your thyroid medications for 3 weeks prior to the test OR to receive Thyrogen injections for 2 days prior to the test.

Blood work for Thyroglobulin and Thyroglobulin Antibodies is typically done before the Thyrogen injections and/or receiving the Iodine-131.

GE Hawkeye Infinia
Equipment used for this test: GE Hawkeye Infinia



Check-in at the Diagnostic Imaging Department at the Sault Area Hospital for your appointment.

Upon arrival to the Nuclear Medicine department, you will be required to drink a small volume (approx. 10 mL) of radioactive iodine (Iodine-131).  There should be no odd tastes or feelings from drinking the Iodine and it should only take a few minutes.  Over the course of a couple of days, the iodine will get taken into any thyroid tissue you may have.  You will then be required to return to the Nuclear Medicine department 2 days after drinking the Iodine for imaging.

When you return for the images make sure you wear comfortable clothing that doesn’t contain metal.  For the images, you will be positioned flat on your back under our camera and a whole-body scan will be acquired.  Following the whole body scan, a three-dimensional image of your thyroid bed known as a SPECT (Single-Photon Emission Computed Tomography) will be acquired to get a closer look at the thyroid bed area.  The images take 90 to 120 minutes to acquire and we will make you as comfortable as we can.

After your scan, you will typically have another blood test done to examine the Thyroglobulin levels in your blood.

Following your test, there are no restrictions and you will be able to drive as you normally would.  If you are planning on going into the United States of America you will set off the radiation detectors for approximately 2-3 months.  We can provide a letter explaining why you are setting off the detectors however you will still be stopped.

Once your scan is complete it will be examined by a radiologist and a report will be sent to the ordering doctor within a week.  Follow up your test with the ordering physician or your family doctor.

The Camera

For an Iodine-131 whole-body scan, we acquire the images using a gamma camera.  A gamma camera is a type of radiation detector that is used to show us how the radioactive iodine is distributed throughout your body.  Our cameras do not emit radiation or loud noises and are not a hazard to anyone in the vicinity while acquiring. 

The cameras we use have 2 detectors: one above you and one below you.  Dual camera heads allow for two views to be acquired at the same time, and for SPECT imaging to be acquired in half the time.