What Is a Thallium Exercise Scan?
The thallium exercise scan is also called a thallium stress test. For the test, a technician injects radioactive thallium into the bloodstream and takes pictures with a scanning camera. The test reveals how adequate the blood flow is through the coronary arteries of the heart. The thallium stress test is combined with an exercise stress test that uses a treadmill or bicycle. Test results show that the blood flow to the heart muscle is either normal, limited, or blocked. The thallium stress test begins with the exercise test. The patient exercises until reaching his or her maximum level of exercise. Then the exercise is stopped and a very small amount of thallium is injected into a vein. The scanning camera measures the flow of thallium into the heart muscle. The first series of pictures is taken when the heart has been “stressed” by the exercise test. A second series of pictures is taken after the patient has rested for 2 to 3 hours, so the pictures will show blood flow to the heart mu
