Fiber tract

The fiber tracts of the cerebrum may be a more important determinant of resection limits than the cortex. Better knowledge of the 3 dimensional (3D) anatomic organization of the fiber pathways is important in planning safe and accurate surgery for lesions within the cerebrum.

Different strategies have been used to study fiber tract anatomy of the human brain in vivo and ex vivo. Nevertheless, the ideal method to study white matter anatomy is yet to be determined, since it should integrate information obtained from multiple sources.

See Fiber dissection technique.

Twenty-five formalin-fixed human brains and 4 whole cadaveric heads were examined by fiber dissection technique and ×6 to ×40 magnification. The fiber tracts and central core structures, including the insula and basal ganglia, were examined and their relationships captured in 3D photography. The depth between the surface of the cortical gyri and selected fiber tracts was measured.

The topographic relationships of the important association, projection, and commissural fiber tract within the cerebrum and superficial cortical landmarks were identified. Important landmarks with consistent relationships to the fiber tracts were the cortical gyri and sulci, limiting sulci of the insula, nuclear masses in the central core, and lateral ventricles. The fiber tracts were also organized in a consistent pattern in relation to each other. The anatomic findings are briefly compared with functional data from clinicoradiological analysis and intraoperative stimulation of fiber tracts.

An understanding of the 3D anatomic organization of the fiber tracts of the brain is essential in planning safe and accurate cerebral surgery ¹⁾.

The correlation of high-definition 7T MRI and the white matter dissection technique with neuronavigation significantly improves the understanding of the structural connections in complex areas of the human cerebrum ²⁾.