Benign, Degenerative and Inflammatory Diseases

18F-FDG PET studies were shown to be quite sensitive to inflammation as well to a variety of benign diseases that induce focal increase in metabolism [1–3]. While in most countries PET imaging of these diseases are not reimbursed, it remains a potential alternative imaging modality for selected cases. FDG-PET remains a sensitive diagnostic modality for detection of infectious diseases and exploring sources of fever of unknown origin. In this chapter several diseases are presented, but also examples of identification and characterization of vascular plaques [4]. While 18F-FDG is being reported as a potential marker of plaque inflammatory process and therefore may help identify unstable plaques and be a predictor of cardiovascular events, alternative PET tracers are also being evaluated for better characterization of vascular plaques [4–6]. Another application domain of PET and therefore could potentially benefit from hybrid PET-MR is the assessment of neurodegenerative diseases and differentiation of diagnostic classification based on anatomical distribution of brain metabolic activity.