Equipment for a Nuclear Thermal Scan Test

A nuclear thermal scan is a series of examinations that scan a human body for red blood cells injected with a radioactive isotope in order to detect irregularities. Most often, these tests are used to check for internal bleeding from the small intestine or the colon. Ventriculograms, a type of nuclear scan test, use this isotope to test problems with the heart.

Radioactive Isotope

• Once the possibility of internal bleeding or irregularities has been determined, the patient will be injected with a radioactive isotope that connects to red blood cells, effectively marking them. As these cells flow through the body, they will emit gamma rays. Should there be any internal bleeding or irregularities, these red blood cells would be detected by the gamma camera. The isotope is administered one of two ways. It is either mixed with red cells that have been separated from both the body and from the plasma. These red blood cells may then be injected back into the bloodstream shortly before testing. Another method is to inject the isotope into the area of the body where testing is desired 15 to 20 minutes before testing will occur.

Gamma Camera

• A gamma camera is used to produce thermal images that detect where in the body that the isotope the patient has been injected with has traveled. A gamma camera can be compared to a sort of x-ray machine, except that it records three-dimensional images of organs, instead a two-dimensional picture of bones. This camera, also called a scintillation camera, picks up gamma waves from the radioactive material and presents a view of the organ onto a computer. Depending on the area being tested, whether the heart, abdomen, or brain, the camera will rotate around the testing site in order to produce a three-dimensional model of blood flow and activity.

Imaging Computer

• Once the series of tests are performed, a digital image will be sent from the camera to a special imaging computer. The doctors will then be able to view a three-dimensional image of the tested organ. This image will show how the blood moves through the organ as well as how the organ is functioning. If there are irregularities or internal bleeding, they would show up on this model and give doctors a warning that action is required to fix the problem. These special, thermal-imaging computers are either located directly in the hospital or in an imaging center, where doctors will perform the series of tests.