Positroniemissiossa

Positroniemissiossa, commonly known as Positron Emission Tomography (PET) in English, is a nuclear medicine imaging technique used to observe metabolic processes in the body non-invasively. It works by injecting a small amount of a radioactive tracer into the bloodstream, which then accumulates in specific organs or tissues. The tracer emits positrons, which are antimatter particles of electrons. When a positron encounters an electron in the body, they annihilate each other, producing two gamma rays that travel in opposite directions. The PET scanner detects these gamma rays and uses a sophisticated computer algorithm to reconstruct a three-dimensional image of the tracer's distribution.

The distribution of the tracer reveals information about physiological processes. For example, tracers that are taken up by metabolically active cells, such as cancer cells, will show up as "hot spots" in the PET scan. This allows for the detection and staging of various cancers, as well as monitoring treatment response. PET scans are also used to study brain function, diagnose neurological disorders like Alzheimer's disease and Parkinson's disease, and assess heart conditions. The specific tracer used determines what physiological process is being visualized. Different tracers are designed to target specific molecules or metabolic pathways. PET imaging provides functional information that can complement anatomical imaging techniques like MRI or CT scans, offering a more comprehensive understanding of a patient's condition.