Positron Emission Tomography Imaging: An Updated Review for Radiologists

Background: Positron Emission Tomography (PET) is a cornerstone of functional and molecular imaging, enabling the visualization of metabolic and physiological processes in vivo. It utilizes radiotracers that accumulate in tissues with high biochemical activity, providing critical information beyond anatomical imaging. Aim: This updated review aims to synthesize the current applications, technological principles, and clinical significance of PET imaging for radiologists, highlighting its utility across various medical specialties and the emergence of novel radiotracers. Methods: The review consolidates evidence on PET procedures, including radiotracer administration, imaging protocols, and the integration with CT (PET-CT). It evaluates the use of different radiotracers—most notably 18F-FDG for glucose metabolism, 68Ga-DOTA peptides for neuroendocrine tumors, and specialized tracers for neurology and cardiology—across a broad spectrum of diseases. Results: PET imaging demonstrates high diagnostic and prognostic value. In oncology, it is indispensable for tumor staging, treatment response assessment, and detecting recurrence. In neurology, it aids in differentiating dementias and localizing epileptic foci. In cardiology, it accurately assesses myocardial viability. Emerging tracers, such as FAPI for cancer-associated fibroblasts, are expanding its diagnostic and theranostic potential. Key considerations include managing interfering factors like patient diet and medication to ensure image accuracy. Conclusion: PET imaging is a powerful, versatile modality that has revolutionized diagnostic medicine. Its ability to provide quantitative molecular data makes it essential for precision medicine, guiding diagnosis, treatment planning, and therapeutic monitoring across numerous clinical domains.