Various types of positron emission tomography scans, or PET scans, can be used to evaluate a number of systems in a person’s body. Though the mechanism for creating all PET images is the same no matter what the test is for, introducing radioactive materials into different parts of the body can help doctors closely examine the way a particular organ, including or system is working. These scans are often used to detect cancerous growths and to evaluate how effective a patient’s cancer treatment is. They can also be used to monitor the heart and circulatory system, respiratory system, brain, and body functions such as glucose metabolism.
All PET scans begin with the administration of radioactive materials. These materials are usually given intravenously, though they can be swallowed or inhaled as well. Once these materials have reached the target organ or system, the doctor can take images of them through the use of a PET scanner.
Some of the most common PET scans are those used in oncology. With the help of PET scans, doctors can determine the exact size and position of tumors and, if multiple images are taken over the course of a few weeks or months, how that cancer is changing over time. These scans can help doctors figure out whether a treatment is working for a patient. It is also possible to use PET scans to determine whether a cancerous growth found in one organ or system has already spread to other parts of the body.
PET scans can also be used to evaluate the condition of a patient’s heart and circulatory system. Radioactive chemicals in the blood can be used to determine how well blood is flowing and whether a patient would benefit from a bypass surgery. They can also help doctors determine the overall health of the heart by showing how effective the heart is at pumping blood throughout the body. These types of scans usually involve introducing the radioactive chemical into the patient’s bloodstream.
Other types of PET scans may focus entirely on one part of the body, often the brain. These scans can be used to look for abnormalities such as tumors or regions of dead cells that could indicate a previous stroke. They can also be used to help doctors determine the cause of problems with the central nervous system, such as seizures. In medical research, other types of PET scans can be used to help map the healthy brain.