FDG-PET AND PET/CT - Part I

Abstract Positron emission tomography (PET) with 18 F fluoro-deoxyglucose (FDG) is now an established functional imaging modality predominantly used in the work-up of several neoplastic diseases. It also has several neurological and cardiac applications in routine clinical practice. However, the radiopharmaceutical, 18 F-FDG, most commonly used for clinical PET studies today is also taken up by inflammatory and infectious cells and it also has a potential role in inflammation imaging in the future. Since this technique provides a map of glucose metabolism in the body, it is extremely important to understand the bio-distribution of FDG in the human body and factors that alter it. Accordingly, the technique used and several patient factors have a significant impact on the quality of images obtained. Hence, it becomes critical to perform this highly sophisticated exam with adequate patient preparation, following an accepted technique and interpret the images with the knowledge of normal and physiologic bio-distribution of FDG in several body organs and tissues. With this objective, this two-series review article will review the current principles and practice of clinical FDG-PET. The first section of this article deals mostly with basic aspects of FDG-PET and PET/CT including properties of FDG, PET instrumentation and technique and normal variants.