EmissioPETkuvantamisessa

EmissioPETkuvantamisessa, often referred to as PET imaging, is a nuclear medicine imaging technique used to visualize and measure metabolic processes in the body. It utilizes small amounts of radioactive tracers, also known as radiopharmaceuticals, which are injected into the patient and travel through the bloodstream. These tracers are designed to accumulate in specific tissues or organs based on their metabolic activity.

The core principle of PET imaging relies on the decay of these radioactive tracers. As they decay, they emit positrons, which are antiparticles 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, equipped with detectors, simultaneously registers these pairs of gamma rays. By analyzing the timing and direction of these photon pairs, the scanner can reconstruct a three-dimensional image showing the distribution and concentration of the radiotracer within the body. Higher concentrations of the tracer indicate areas of increased metabolic activity.

PET imaging is particularly valuable in detecting and characterizing diseases, such as cancer, neurological disorders, and cardiovascular conditions. It can identify changes at the cellular level before structural abnormalities become apparent with other imaging modalities. Common radiotracers include fluorodeoxyglucose (FDG), which mimics glucose and is taken up by metabolically active cells, making it useful for identifying tumors and inflammation. Other tracers are used to assess specific neurotransmitter systems or blood flow. The resulting PET images provide functional information about tissues and organs, complementing anatomical data from other imaging techniques like CT or MRI.