From the early 1970s to mid-1990s, positron emission tomography (PET) as a diagnostic imaging modality had been for the most part used in experimental research. Clinical PET started only a decade ago. 82Rb-RbCl and 18F-Fluorodeoxyglucose were approved by the U.S. Food and Drug administration in 1989 and 1994, respectively, for clinical PET imaging. Reimbursement by Medicare was approved in 1995 for 82Rb-PET myocardial perfusion imaging and for 18F-FDG PET for various oncologic indications in 1999. Currently several more PET procedures are covered for reimbursement. Based on the incentive from reimbursement for PET procedures and accurate and effective diagnosis of various diseases, PET centers are growing in the United States and worldwide. The importance of PET imaging has flourished to such a large extent that the Nuclear Medicine Technology Certification Board (NMTCB) is planning to introduce a PET specialty examination in 2004 for nuclear medicine technologists, as well as an augmented version of the PET specialty examination in 2005 for registered radiographers and radiation therapy technologists. Courses are being offered all over the country to train physicians and technologists in PET technology. Many books on clinical PET have appeared in the market, but no book on the basics of PET imaging is presently available. Obviously, such a book is needed to fulfill the requirements of these courses and certifications