This book focuses on advances in imaging and mapping strategies to study the brain's structure, function and the relationship between both, from the whole brain to the molecular and cellular tissue level in order to improve the understanding of normal and disease processes. Studies of intact living organisms may be at the human, animal, cellular or molecular level, which advance our understanding of biological events in living systems and how these events relate to normal and pathological processes. Imaging modalities include nuclear medicine techniques (SPECT and PET) and non-nuclear techniques such as MRI, MRS, CT, ultrasound, intravital microscopy, optical imaging, diffuse optical tomography, electromagnetic tomography and other methods which elucidate molecular and cellular mechanisms, accelerate the understanding of biology, test the efficacy of therapeutic interventions in intact living systems and assess the therapeutic outcomes.