St Vincent's Clinic Medical Imaging & Nuclear Medicine

Thallium Scan

A Thallium Myocardial Viability Scan localises and evaluates viable heart tissue.

What will happen when you have your Thallium Scan

There are 2 parts to your scan:

  1. The Nuclear Medicine Technologist will place a small cannula into a vein in your arm. You will be connected to an ECG machine and a blood pressure monitor whilst on the treadmill. You begin walking at a slow pace and every 3 minutes the speed and inclination of the treadmill will increase. If for any reason you cannot exercise, the test can be done using a medication to simulate exercise. This medication is called Adenosine and is given as an injection. Most people have minimal side effects from this medication, usually a slight headache, flushing and sometimes angina. 1 minute before you finish exercising, or after the medication, the doctor will give an injection of a ‘tracer’ through the cannula in your arm. The stress procedure should take approximately 30 minutes to complete. After the stress procedure is finished images will be taken of your heart for approximately 20-30minutes.
  2. You will then be allowed to leave the department but must return for more imaging 4 hours later. In the break you must continue fasting but you may have water. When you return for imaging it will take approximately 20-30minutes.

Occasionally it may be necessary to bring you back 24 hours after the injection for more images of your heart, the Nuclear Medicine Technologist will discuss this with you.

What you need to do and how to prepare for the test

You may be required to wear a gown for the scan. The scan is performed with the Gamma Camera close to your body but you do not go through a “tunnel”.

  • You will need a referral from your doctor and continue taking medications as prescribed
  • You will need an appointment
  • If you are or think you may be pregnant or are breastfeeding please inform the booking staff
  • You will be in the department for approximately 60 minutes for the stress test and the first scan, and approximately 30 minutes for the second part of the test
  • Please bring any previous relevant X-rays or scans to your appointment
  • You will need to cease ALL caffeine products which include tea, coffee, chocolate, soft drinks for 24 hours before the test and be fasting from midnight
  • Non diabetic patients: Fast from midnight the night prior to the scan. You may have water.
  • Insulin dependant diabetic patients : Light breakfast (toast+juice) with half your insulin dose then fast for 4hrs prior to the scan. You may have water.
  • Non insulin dependant diabetic patients: Fast from midnight the night prior to the scan and withhold diabetic medications on the morning of the test. You may have water.
Your Practice Online
Follow us on: