Brain imaging technologies provide an unparalleled tool to assess the physiological and pathological changes in the central nervous system. The aim of this work is to review the technical characteristics of widely used imaging technologies, such as magnetic resonance imaging (MRI), positron emission tomography (PET), or single photon emission computed tomography (SPECT), as well as their utility in clinical diagnosis and follow-up of different neurological disorders. High-resolution developments of MRI and PET, as well as the more recent imaging technology, multiphoton microscopy, for small animal imaging are also analyzed, as rodent models offer an enormous opportunity to study not only the underlying mechanisms of Alzheimer's disease, Parkinson's disease, depression, and schizophrenia among others, but also potential new treatments for all these diseases.