Since the publication of the third edition of Cerebral SPECT Imaging, significant progress has occurred in the field of functional brain imaging. Most significant is the increased use of PET/SPECT and advances in radiopharmaceutical development and instrumentation. The use of SPECT and PET is now approved in additional disease states such as movement disorders (Parkinson disease, multiple sclerosis) and dementia. The editorship of the book will change slightly with Ron Tikovsky taking a smaller role and the addition of Masanori Ichise, formerly of the NIMH. Chapter topics include PET physics and instrumentation, PET radiopharmaceuticals, SPECT radiopharmaceuticals and technical factors. The entire book will be thoroughly revised and all of the chapters will undergo critical review to reflect an appropriate balance between SPECT and PET applications.