For the first time, in this atlas nuclear physicians and radiologists cover the entire hybrid nuclear medicine (PET/CT, SPECT/CT and PET/MRI), based on their own case studies. The structure in three volumes represents an user friendly guide for interpreting PET and SPECT in relation to co-registered CT and/or MRI. Three companion volumes with a practical structure in two-page unit offer to the reader a navigational tool, based on anatomical districts, with labeled and explained low-dose multiplanar CT or MRI views merged with PET fusion imaging on the right hand and contrast enhanced CT or MRI on the other side. This new format enables rapid identification of hybrid nuclear medicine findings which are now routine at leading medical centers. Volume 1 is focused on brain and neck PET imaging, with emphasis on PET/MRI; Volume 2 concerns thorax, abdomen and pelvis, with particular attention on lung and liver segmental anatomy and evaluation of peritoneum. Special chapters on heart, lymph nodes and musculoskeletal system, are collected in the Volume 3. Each chapter begins with three-dimensional CT and/or MRI views of the evaluated anatomical region, bringing forward sectional tables. Clinical cases, tricks and pitfalls linked to several PET or SPECT radiopharmaceuticals help to introduce the reader to peculiar molecular pathways and to improve confidence in cross-sectional imaging, that is vital for the accurate diagnosis and treatment of diseases.