Book excerpt: A basic knowledge of physics, instrumentation, and radiobiology is essential for nuclear physicians and technologists in the practice of nuclear medicine. The nuclear medicine specialty has matured over the past three decades to the extent that there is an increasing need for certification of physicians and technologists to practice nuclear medicine. Each year many medical residents take the American Board of Nuclear Medicine examination and the Ameri can Board of Radiology examination with special competency in Nuclear Radiology, and many technologists take the Registry examination in Nuclear Medicine. All these tests include a good portion of physics, instrumenta tion, and radiobiology in nuclear medicine. It is mandatory that radiology residents pass the physics section of the American Board of Radiology examination. This book is primarily addressed to this audience. In addition, anyone in terested in the basics of physics, instrumentation, and radiobiology in nuclear medicine should find this book useful.