====== White matter ======
The [[commissural fiber]]s or transverse fibers are coherent [[white matter]] structures that connect the two hemispheres of the brain.

{{ ::whitematter.png?500|}}

see [[White matter changes]].

see [[White matter hyperintensity]].

see [[White matter dissection]].

see [[White matter infarct]].

see [[White matter lesion]].

see [[White matter tract]].

Is a component of the [[central nervous system]], in the [[brain]] and superficial [[spinal cord]], and consists mostly of [[glial cell]]s and [[myelin]]ated [[axon]]s that transmit [[signal]]s from one region of the [[cerebrum]] to another and between the cerebrum and lower brain centers.

White matter [[tissue]] of the freshly cut [[brain]] appears pinkish white to the naked eye because myelin is composed largely of lipid tissue veined with capillaries. Its white color in prepared specimens is due to its usual preservation in [[formaldehyde]].

White matter, long thought to be passive tissue, actively affects how the brain learns and functions. While [[grey matter]] is primarily associated with processing and [[cognition]], white matter modulates the distribution of [[action potential]]s, acting as a relay and coordinating communication between different brain regions.

The white matter, located in each hemisphere between the [[cerebral cortex]] and [[nuclei]], as a whole has a semioval shape. It consists of cortical [[projection fiber]]s, association fibers and cortical fibers. It continues ventrally as the [[corona radiata]].

Conventional white matter (WM) imaging approaches, such as [[diffusion tensor imaging]] (DTI), have been used to preoperatively identify the location of affected WM [[tract]]s in patients with [[intracranial tumor]]s in order to maximize the extent of resection and potentially reduce postoperative morbidity.
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A better comprehension of the superficial white matter organization is important in order to minimize potential and avoidable damage to long or intermediate association fibre bundles during every step of a surgical approach.
====Atlas====
Two- and three-dimensional (3D) white matter atlases were created based on high-spatial-resolution diffusion tensor magnetic resonance (MR) imaging and 3D tract reconstruction. The 3D trajectories of 17 prominent white matter tracts could be reconstructed and depicted. Tracts were superimposed on coregistered anatomic MR images to parcel the white matter. These parcellation maps were then compared with coregistered diffusion tensor imaging color maps to assign visible structures. The results showed (a). which anatomic structures can be identified on diffusion tensor images and (b). where these anatomic units are located at each section level and orientation. The atlas may prove useful for educational and clinical purposes
((Wakana S, Jiang H, Nagae-Poetscher LM, van Zijl PC, Mori S. Fiber tract-based 
atlas of human white matter anatomy. Radiology. 2004 Jan;230(1):77-87. Epub 2003 
Nov 26. PubMed PMID: 14645885.
)).

=== White Matter Disconnection ===
[[White Matter Disconnection]]