This book aims to summarize the research progress of integrated PET/MR brain function and molecular imaging, and more importantly, clinical application and research status of PET/MR of brain imaging from brain diseases to brain science. Starting from the overviews of brain function imaging technology, following chapters introduces clinical application of integrated PET/MR specific brain diseases in details, such as Alzheimer's disease, Parkinson's disease, epilepsy, and brain tumor, etc., which are hot issues of brain science research. It will be a useful reference to residents and practitioners in nuclear medicine, radiology, and neurology, as well as those interested in molecular imaging of brain.