The foreword discusses the updates made in the fourth edition of the textbook "Nuclear Medicine: The Requisites". It notes that the fields of nuclear medicine have continued advancing, with SPECT evolving into SPECT/CT and the increased use of PET and PET/CT. New radiopharmaceuticals have also been developed. These updates have injected new vitality into the specialty of nuclear medicine. The foreword hopes that this edition of the textbook will serve as a concise introduction and review text for residents, fellows, and specialists in nuclear medicine and radiology.

1. vii
Foreword
The fourth edition of Nuclear Medicine: The Requisites con­
tinues to follow the philosophy and format of the first three
editions. The basic science chapters are designed to pre­
sent important principles of physics, instrumentation, and
nuclear pharmacy in the context of how they help shape
clinical practice. The clinical chapters continue to follow a
logical progression from basic principles of tracer distribu­
tion and localization to practical clinical applications. The
authors believe that understanding tracer mechanisms is
fundamental to nuclear medicine practice and that knowl­
edge of how radiopharmaceuticals localize temporally and
spatially in normal and diseased tissues is the best deduc­
tive tool available for analyzing images and is superior to
simply memorizing representative illustrations.
In the time between the publication of the third and
fourth editions of this title, the field of nuclear medicine has
continued its remarkable development. Single-photon
emission computed tomography (SPECT) has morphed in­
creasingly into SPECT/computed tomography (CT), and
an increasing number of scanner designs have been devel­
oped, primarily for specialized cardiac imaging. Positron
emission tomography (PET) has become much more wide­
spread, with larger institutions acquiring their own cyclo­
trons. It can now be said with confidence that PET/CT has
proved to be a substantial advancement, especially in body
imaging. PET/magnetic resonance imaging (MRI) is still in
its infancy, but enough data are in hand to predict that this
integrated method will also become important, although the
scale of applications is still unknown. The other revolution
in PET is the clinical availability of new radiopharmaceuti­
cals, including agents aimed at Alzheimer disease diagnosis,
and literally dozens more tracers are in the pipeline.
Adding new SPECT, PET, PET/CT, and PET/MRI ap­
plications to the nuclear medicine armamentarium has in­
jected new, even unprecedented, vitality into the special­
ty. Readers of Nuclear Medicine: The Requisites will feel this
vitality almost palpably as they work their way through the
book. Among other challenges, the integrated methods of
PET/CT and PET/MRI require higher levels of knowl­
edge of anatomic cross-sectional imaging than ever before,
as well as more knowledge of the respective technologies.
Some of this is beyond the scope of the current book but
can be found elsewhere in the Requisites series.
The Requisites in Radiology titles have become old
friends to generations of radiologists. The original intent
of the series was to provide the resident or fellow with a
text that might be reasonably read within several days at
the beginning of each subspecialty rotation and perhaps
reread several times during subsequent rotations or during
board preparation. The series is not intended to be ex­
haustive but rather to provide the basic conceptual, factu­
al, and interpretive material required for clinical practice.
After more than 20 years of experience with the series, it is
now clear that the books are also sought out by practicing
imaging specialists for the efficiency of their presentation
format and the quality of their material. With more people
reaching the point of requiring re-certification, the Requi­
sites books should again prove helpful.
Each book in the Requisites series is written by nation­
ally recognized authorities in their respective subspecialty
areas. Each author is challenged to present material in the
context of today’s practice of radiology rather than grafting
information about new imaging modalities onto old, out-of-
date material. It is our hope in adopting this strategy that
readers will find the Requisites titles to be a very efficient
way of accessing the most important material.
The first three editions of Nuclear Medicine: The Requisites
were well received in the radiology and nuclear medicine
community. Dr. Ziessman and his colleagues have again
done a terrific job in putting together a new and updated
edition, and we expect that this edition will be deemed to
be as outstanding as its predecessors. We hope that Nuclear
Medicine: The Requisites will serve residents in radiology as a
concise and useful introduction to the subject and will also
serve as a very manageable text for review by fellows and
practicing nuclear medicine specialists and radiologists.
James H. Thrall, MD
Radiologist-in-Chief
Massachusetts General Hospital
Juan M. Taveras Professor of Radiology
Harvard Medical School
Boston, Massachusetts