scientists with backgrounds from various physical, biological, and medical specialty areas. Each chapter presents material in a straightforward man­ ner that is well illustrated and explained. Because of the diverse audience for the book, certain chapters or sections of chapters will be of more interest than oth­ ers to certain segments of the readership. Chapter 1 introduces the fundamental physics upon which PET imaging sys­ tems is based and discusses in detail the technologies and methods used to pro­ duce PET images. The chapter starts out by reviewing the physics of positron emission and annihilation and explains how positron range and photon non­ colinearity in coincidence detection place certain limits on spatial resolution.