The dogma that brain function relied on the cortex has dominated clinical neurology, neurosurgery and psychiatry for the last 100 years. Since the start of the 2000s, it has become evident that brain function is orchestrated as a network through white matter connections. This framework provides an understanding of brain function and dysfunction, and has radically changed how neurosurgical resections are performed. There is currently no manual for clinicians to visualize this functional anatomy in a fast, easy and user-friendly way. This is particularly important for senior clinicians who may have an understanding of cortical anatomy but may struggle with newly described white matter connections as they may now be visualized with MRI, and also for trainees who are learning the subject of applied neuro-anatomy. With this book, we aim to bridge this gap.

In 1995 Jackson and Duncan produced "MRI Neuroanatomy: a new angle on the brain" using the best clinical MRI available at the time and did not demonstrate white matter tracts. This was very well received, and it is time now to produce an atlas that shows the 3D anatomy of gray and white matter to contemporary standards.

This atlas is based on a high-quality MRI of a healthy subject which resembles the type of imaging is regularly available to clinicians. It is structured in sections (cortical anatomy, subcortical anatomy, and network anatomy) that are intended to guide clinicians from the classical cortical paradigms into a network neuroscience perspective. The 2D orthogonal slices are organized in two orientations:

(A) following the plane of the anterior and posterior commissure, as has been traditionally used in stereotactic atlases

(B) following the plane of the hippocampus, as is commonly used in clinical epilepsy practice.

The first part shows the 3D anatomy of the cerebral hemisphere, deep nuclei, brainstem and cerebellum.

The second part shows the same brain cut in 2D orthogonal slices (axial, coronal, sagittal) with a raw T1-weighted image, accompanied by a labelled image showing the gross anatomy of the brain and grey matter structures and, also, the labelled white matter tracts in that slice. This is particularly relevant for neurosurgeons, who will be able to appreciate before planning a resection the relationship between each tract's trajectory and the gray matter. This will also benefit neurologists, enabling clarity as to how single lesions can cause multiple disconnection and impact on different functions and behaviours.

The third part demonstrates the 3D anatomy of the major white matter tracts in the brain, to indicate how distant lesions can impact the same function.