PET and PET/MRI Methods

The goal of this chapter is to provide the reader with a basic understanding of Positron Emission Tomography (PET) imaging and simultaneous PET and magnetic resonance (or PET/MR) imaging. These topics are presented with particular emphasis on PET as a molecular imaging tool and MRI as a structural and functional imaging tool. The chapter begins with an introduction to the underlying PET physics and a brief review of how data are acquired and reconstructed into 3D images. This includes common corrections that are applied to minimize image artifacts and improve accuracy, as well as a brief discussion of key advantages and limitations of PET and MRI and the benefits of combined PET/MR imaging. The strengths of PET as a molecular imaging technology are then presented in the context of in vivo imaging of protein targets that are relevant to schizophrenia and other neuropsychiatric disorders. This includes a basic review of PET pharmacokinetic methods used to evaluate radioligand-protein binding interactions and simpler and more feasible methods used for routine PET assessments. The final section presents a discussion of future directions and recent advances in PET/MR imaging applications.