A Connectomic Atlas of the Human Cerebrum-Chapter 18: The Connectional Anatomy of Human Brain Networks

Abstract

Background: It is widely understood that cortical functions are mediated by complex, interdependent brain networks. These networks have been identified and studied using novel technologies such as functional magnetic resonance imaging under both resting-state and task-based conditions. However, no one has attempted to describe these networks in terms of their cortical parcellations.

Objective: To describe our approach to network modeling and discuss its significance for the future of neuronavigation in brain surgery using the cortical parcellation scheme detailed within this supplement.

Methods: Using network models previously elucidated by our group using coordinate-based meta-analytic techniques, we show the anatomic position and underlying white matter tracts of the cortical regions comprising 8 functional networks of the human cerebrum. These network models are displayed using Synaptive's clinically available BrightMatter tractography software (Synaptive Medical, Toronto, Canada).

Results: The relevant cortical parcellations of 8 different cerebral networks have been identified. The fiber tracts between these regions were used to construct anatomically precise models of the networks. Models are described for the dorsal attention, ventral attention, semantic, auditory, supplementary motor, ventral premotor, default mode, and salience networks.

Conclusion: Our goal is to move towards more precise, anatomically specific models of brain networks that can be constructed for individual patients and utilized in navigational platforms during brain surgery. We believe network modeling and future advances in navigation technology can provide a foundation for improving neurosurgical outcomes by allowing us to preserve complex brain networks.

FIGURE 1.

The dorsal attention network is displayed using Synaptive's BrightMatter fiber tracking software. Individual parcellations are labeled and identified with arrows in A. The dorsal attention network is shown in the left cerebral hemisphere on a 3D-rendered brain mask inA, medial-lateral view, B, anterior-posterior view, andC, superior-inferior view. The fiber tracts of the network are readily identified in the sagittal plane. Corresponding T1-weighted MR images in theD, sagittal, E, coronal, andF, axial planes show the fiber connections of the network in this particular patient.

FIGURE 2.

The ventral attention network is displayed using Synaptive's BrightMatter fiber tracking software. Individual parcellations are labeled and identified with arrows in A. The ventral attention network is shown in the right cerebral hemisphere on a 3D-rendered brain mask in multiple views inA, medial-lateral view, B, anterior-posterior view, C, superior-inferior view, and D, axial view.

FIGURE 3.

The semantic network is displayed using Synaptive's BrightMatter fiber tracking software. Individual parcellations are labeled and identified with arrows in A. The semantic network is shown in the left cerebral hemisphere on a 3D-rendered brain mask in multiple views:A, medial-lateral view, B, anterior-posterior view, andC, superior-inferior view. The fiber tracts of the network are readily identified in the sagittal plane.

FIGURE 4.

The auditory network is displayed using Synaptive's BrightMatter fiber tracking software. Individual parcellations are labeled and identified with arrows in A. The auditory is shown in the left cerebral hemisphere on a 3D-rendered brain mask in multiple views:A, medial-lateral view. Corresponding T1-weighted MR images in theB, sagittal, andC, axial planes show the fiber connections of the network for this particular patient.

FIGURE 5.

A and B, Composite images of the supplementary motor and ventral premotor networks. The supplementary motor network is shown isolated inC, and includes four parcellations: 6ma, 6mp, SFL, and SCEF (arrows). The ventral premotor network is shown isolated inD, E, andFand includes four parcellations: 3a, 3b, 4, and 6v (arrows). Motor network tractography is displayed using Synaptive's BrightMatter fiber tracking software on a 3D-rendered brain mask.

FIGURE 6.

The default mode network is displayed using Synaptive's BrightMatter fiber tracking software. The default mode network is shown in the left cerebral hemisphere on a 3D-rendered brain mask in multiple views: A, medial-lateral view andB, superior-inferior view. The fiber tracts of the network are readily identified in the sagittal plane.C, Corresponding T1-weighted MR imaging in the sagittal plane demonstrates the fiber connections of the network for this particular patient.

FIGURE 7.

The salience network is displayed using Synaptive's BrightMatter fiber tracking software. Individual parcellations are labeled and identified with arrows in A. The salience network is shown in the left cerebral hemisphere on a 3D-rendered brain mask in multiple views:A, medial-lateral view andB, anterior-posterior view. The fiber tracts of the network are readily identified in the sagittal and coronal planes.C, Corresponding T1-weighted MR imaging in the coronal plane shows the fiber connections of the network for this particular patient.