Neuroimaging, particularly positron emission tomography (PET), plays a crucial role in diagnosing and managing brain disorders by providing insights into diverse neuropathologies such as vascular issues, infections, inflammation, degenerative diseases, and tumors. In dementia, [18F]FDG-PET helps predict Alzheimer’s disease (AD) development from mild cognitive impairment, revealing metabolic reductions in specific brain regions. PET’s evolution with novel radiotracers and advanced imaging techniques addresses diagnostic challenges and enhances disease monitoring. Despite limitations like off-target binding, PET remains indispensable in clinical neurology, offering noninvasive insights into brain functions, disease progression, and treatment responses.