positronemissiotomografiaa

Positronemissiótomografiaa (PEAT) is the Portuguese term for positron emission tomography (PET), a powerful nuclear medicine imaging technique that provides functional information about biological processes in the body. The method involves injecting a radiopharmaceutical that emits positrons; when a positron encounters an electron, the two annihilate and release a pair of gamma photons traveling in opposite directions. PET scanners detect these photons, reconstructing the distribution of the radiotracer within the tissues to create a three‑dimensional image that reflects metabolic, chemical, or molecular activity.

PET was first developed in the 1970s and rapidly gained clinical relevance by the 1990s as a diagnostic tool for oncology, cardiology, and neurology. In oncology, fluorodeoxyglucose (FDG) PET is routinely used to locate malignant tumors, assess treatment response, and detect metastases. In cardiology, PET can quantify myocardial perfusion and viability, assisting in decision‑making for revascularization procedures. Neurologically, PET provides insights into brain metabolism, amyloid deposition, and neurotransmitter system function, playing a crucial role in Alzheimer’s disease and Parkinson’s disease research.

The principal advantages of PET include its high sensitivity for detecting metabolic changes before anatomical alterations become apparent, and its ability to use various tracers for different pathological processes. However, PET has limitations such as relatively high cost, limited spatial resolution compared to CT or MRI, and exposure to ionizing radiation from the radiotracer. Recent technological advancements, including hybrid PET/CT and PET/MRI systems, have improved anatomical correlation and reduced scan time. Researchers continue to develop new tracers targeting specific proteins and receptors, expanding PET’s diagnostic and therapeutic monitoring scope.