The modern era of radionuclide imaging and therapy is well into its seventh decade. During this era, many national and international textbooks have been published in an attempt to educate not only the practitioners of our medical discipline, but also referring physicians and medical students. Some of the more recent large multic- tural texts, such as those by Ell and Ghambir, Sandler et al. and Henkin et al. , provide us with very comprehensive reference sources while some of the smaller texts totally writtenbytwo or threeindividuals,e. g. Mettler &Guiberteauand Ziessman,OβM- ley & Thrall, have achieved popularity with radiology residents and other physicians in training. The concept of Clinical Nuclear Medicine arose 3 years ago from a conversation between the editors, who have been close friends for many years. We have always felt that our relationship epitomizes one of the major strengths of nuclear medicine, which is the very close ties and spirit of educational cooperation that exist between international colleagues. We all share the same aim of doing whatever we can to op- mize patient care whether it be by introducing new pharmaceuticals and inst- ments or by developing new techniques or approaches to performing our broad spectrum of clinical procedures. Nuclear medicine physicians have almost uniformly been willing to share their expertise at national and international meetings. The - ternational nuclear medicine community, unlike many other larger specialty areas, has remained relatively small. It was within this spirit that Clinical Nuclear Medicine was born.