Form: D-5567

Thyroid Scan with I–123

Read this information to learn: • what a thyroid scan with I–123 is • how to prepare • what to expect • who to call if you have any questions

Your thyroid scan with I–123 has been scheduled for:

Day 1: Date

Time

Day 2: Date

Time

Location: Toronto General Hospital 585 University Avenue Medical Imaging Reception Peter Munk Building – 1st floor What is a thyroid scan with I – 123? A thyroid scan with I – 123 is a nuclear test. It lets your doctor see what your thyroid gland looks like and how well it is working.

How do tests work? Nuclear medicine tests are different from x-rays. X-rays show what your body looks like. Nuclear medicine tests show how your body and organs are working. They can help find problems that other tests can’t find.

Before a nuclear medicine test, you are given a medicine called a (also called radioactive tracer). A radiopharmaceutical is radioactive. This means it gives off energy.

The radioactive tracer is usually given through an intravenous (IV) line placed in a vein. But it can also be swallowed or breathed in through the lungs.

The tracer travels to the part of the body that your doctor wants to see. When it reaches the right area, we take pictures. We use a special machine called a . It takes pictures of the energy coming from the tracer.

Why do I need this test? A thyroid scan is done to:

• look for abnormal thyroid tissue

• look for tumours or cancer cells in the neck area

• assess any thyroid diseases you may have from birth

• see if you have an underactive, normal or overactive thyroid

2 How do I prepare for the test?

• Stop taking your thyroid before the test. Check the chart below to find out when to stop taking certain medicines:

When to stop taking the medicine Medicine before your test Seaweed Kelp 2 weeks Cough medicines 2 weeks S. S.KI 2 weeks Lugol’s Solution 2 weeks Antithyroid medicines PTU 1 week Tapazole 1 week Methimazole 1 week Thyroid medicines Thyroxine (T4) 4 weeks Triiodothyronime (T3) 2 weeks Contrast (CT) 6 weeks Antihistamines 1 week Corticosteroids 1 week Betadine/Surgery 3 weeks Amiodarone 6 months (Anti-arrhythmic)

It’s OK to eat seafood and/or take multivitamins and minerals before your test.

• Bring a list of all your medicines to your appointment.

• Check in at the Medical Imaging reception area (University Avenue entrance, across from the pharmacy) 15 minutes before your appointment.

• Remember to bring your health card (OHIP). If you do not have an OHIP card, please bring another form of government-issued photo ID (such as a driver’s license, passport, or other provincial health card).

3 If you haven’t registered, come to Toronto General Hospital 30 minutes before your appointment. Go to Patient Registration on the Ground floor near the Elizabeth Street entrance.

Important: If there is any chance you are pregnant, tell the technologist before they give you the radioactive tracer.

What can I expect?

Day 1: • You fill out a thyroid questionnaire about the medicines you take and your contact with iodinated contrast. • We give you some radioactive liquid to drink.

Day 2: • The technologist takes pictures of your thyroid using a gamma camera.

Are there any side effects? There are no known side effects from this test. You can go back to your normal activities once the test is over. We will send a report to your doctor.

Who can I call if I have any questions? If you have any questions or concerns or if you need to cancel or reschedule your appointment, please contact the nuclear medicine department at 416 340 3311.

The nuclear medicine department is on the 1st Floor of Toronto General Hospital, EB1 – 408, near the Eaton elevators.

Visit www.uhnpatienteducation.ca for more health information. Contact [email protected] to request this brochure in a different format, such as large print or electronic formats.

© 2021 University Health Network. All rights reserved. Use this material for your information only. It does not replace advice from your doctor or other health care professional. Do not use this information for diagnosis or treatment. Ask your health care provider for advice about a specific medical condition. You may print 1 copy of this brochure for non-commercial and personal use only.

Form: D-5567 | Author: JDMI Nuclear Medicine | Revised: 04/2021