We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.
Health

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

What is a Thallium Scan?

By Emma Lloyd
Updated: May 17, 2024
Views: 23,014
Share

A thallium scan involves the injection of a very small amount of radioactive thallium into the vein of the patient undergoing the test. The amount used is so tiny that it does not produce a harmful amount of radiation for the patient. Although the radiation is not harmful for an adult, a pregnant woman must notify her doctor before undergoing this test to ensure the safety of the fetus. As the test proceeds, monitors are used to follow the radioactive thallium as it travels through the bloodstream.

During a thallium scan, a small amount of radioactive substance is used to create images of a particular area of the body. This test is typically used to examine the heart or brain and determine whether these areas are receiving enough blood. The thallium scan is often combined with an exercise test to determine how well the heart functions under stress.

The thallium scan is often combined with an exercise test. In this kind of test, the initial thallium injection is administered while the patient is walking on a treadmill. A further injection is given at another time, when the heart is at rest. By comparing the two sets of results, a doctor can determine if any areas of the heart are receiving an inadequate blood supply either at rest or after exercise.

At the beginning of the test, the patient begins by exercising on the treadmill for several minutes. His heart rate and blood pressure are monitored throughout. A minute or so before he stops exercising, the thallium is injected into a vein. During the remaining minute of the exercise portion of the test, the radioactive thallium travels through the bloodstream and reaches the heart. Once it enters the heart, the thallium accumulates in locations which have an adequate blood supply.

At the end of the exercise period, the patient is immediately scanned using an imaging camera, so that the location of the radioactive thallium can be pinpointed. Areas of the heart that have accumulated thallium are judged to have good access to the blood supply. Any areas of the heart that have less thallium, or none at all, have a limited blood supply.

The thallium scan therefore pinpoints areas of the heart that do not have an adequate supply of blood and oxygen. In people who have had a heart attack, it is common for certain areas of the heart to have suffered damage that reduces blood flow both at rest and during exercise. People who are at risk of a heart attack often show signs of reduced thallium accumulation only after exercise. The test therefore helps doctors pinpoint people who are at risk of heart attack and other cardiac issues.

Share
WiseGeek is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.

Editors' Picks

Discussion Comments
By Diwrecktor — On Oct 19, 2014

Thallium tests show black spots on the areas of the heart that are not getting enough oxygen, so it is a good test for anyone who is having unexplained chest pain. If your doctor says to have one, don't hesitate.

My husband waited until it was too late. He had a heart attack, but had a thallium scan after his surgery to make sure the surgery worked. I think if he'd had it before, he wouldn't have had the heart attack.

Share
https://www.wisegeek.net/what-is-a-thallium-scan.htm
Copy this link
WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.

WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.