Radioactive Iodine Scan Information Sheet

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What is a diagnostic scan using Radioactive Iodine?

This scan may also be called a whole body Iodine scan. This scan can be used to identify thyroid tissue and assess the function of any such tissue. The radioactive tracer is introduced into the body and then will be absorbed by functioning thyroid tissue if it is present.

What preparation is required?

Fasting - You will be required to fast from midnight on the morning of your appointment and for 2 hours after swallowing the capsule. Small sips of water are permitted. If you are diabetic you may take half your normal morning insulin / tablet.

Medications - Consult with your doctor about which medications to continue and stop. It is important that you inform your referring doctor if you are taking any vitamin or mineral supplements as you may be required to stop taking these supplements.

Low- Iodine Diet - A low iodine diet before your appointment may be recommended. Please discuss this with your doctor. Some low iodine recipes can be found at

What happens during the test?

There are two parts to this scan.

PART 1: You will be given a tablet/capsule to swallow. This capsule contains a radioactive tracer which will take a few days to be absorbed by your body. After swallowing the capsule you must continue fasting for another 2 hours.

PART 2: During the second appointment (several days later) diagnostic imaging of the whole body will be performed as well as additional 3D imaging. This process generally takes at least 1-2 hours.

Are there any side effects?

Please inform nuclear medicine if you have an Iodine allergy. There should be no other side effects from the capsule and no restrictions following the test. You will be able to continue with your usual daily activities. The amount of radiation used is quite small.

Can I have this test while I am pregnant or breast feeding?

Your doctors may have requested that you undergo this examination while you are pregnant or breastfeeding. Your doctors will have considered and discussed the risks and benefits of having the scan to the health of both you and your baby.

As part of the procedure you will be given the opportunity to further discuss any concerns that you may have including the potential risks and benefits with one of our staff members.

This examination may have been deemed suitable for you to undergo while you are breastfeeding. It is recommended that you cease breastfeeding following the administration of the radiotracer.


If you are / could be pregnant OR are breast-feeding please call us to discuss your options.

It is important to bring any previous test results and your Medicare card with you. 

Please feel free to call us on 6244 2439 if you have any questions or to reschedule.