Principles of PET Imaging
PET scans rely on the detection of gamma rays emitted by a radioactive tracer, or radiotracer.
Radiotracer Injection: A small amount of radiotracer is injected into the patient's bloodstream.
Radiotracer Uptake: The radiotracer accumulates in tissues with high metabolic activity, such as cancer cells.
Positron Emission: The radiotracer emits positrons, which collide with electrons in the body.
Gamma Ray Detection: The collisions produce gamma rays, which are detected by the PET scanner.
Image Reconstruction: A computer reconstructs the gamma ray data to create images of metabolic activity.
The PET scan process typically involves:
Preparation: Patients may be asked to fast or avoid certain activities before the scan.
Radiotracer Administration: The radiotracer is injected.
Waiting Period: Time is allowed for the radiotracer to distribute throughout the body.
Scanning: The patient lies on a table that slides into the PET scanner.
Image Interpretation: A radiologist interprets the images.
Clinical Applications of PET Scans
PET scans are used for various medical purposes, including:
Cancer Diagnosis and Staging: Detecting and monitoring cancer.
Neurological Disorders: Diagnosing Alzheimer's disease, epilepsy, and other brain disorders.
Cardiovascular Disease: Assessing heart function and blood flow.
Infection and Inflammation: Identifying areas of infection or inflammation.
Benefits and Limitations of PET Scans
Provides functional information.
Detects diseases at an early stage.
Helps in treatment planning and monitoring.
This guide has offered a comprehensive overview of Positron Emission Tomography (PET). For more insight into how this concept interacts with others, see our detailed guide on Computed Tomography (CT) Imaging, which further explores a complimentary imaging methodology often used in conjunction with PET, and its implications in greater depth.
