Cingulum bundle connectivity considering the double-layered cingulate cortex using diffusion-weighted MRI - PubMed (original) (raw)
Cingulum bundle connectivity considering the double-layered cingulate cortex using diffusion-weighted MRI
Sang-Han Choi et al. Neuroimage Rep. 2021.
Abstract
The cingulum bundle (CB) is a fasciculus in the white matter surrounded by the cingulate cortex, which is generally subdivided into the anterior, middle, and posterior parts based on their function and cytology. Interestingly, the cingulate cortex can also be divided into inner and outer layers based on their gross anatomy. Herein, we analyzed the CB pathway by considering the double-layered cingulate cortex using magnetic resonance (MR) tractography data. We used 7.0T diffusion-weighted MRI data from the Human Connectome Project dataset, from which 32 individual datasets were selected. Anatomical MR images in each dataset were parcellated into the cortical subdivisions automatically using the FreeSurfer software. The seed positions in both layers of the cingulate white matter (CWM) for fiber tracking were determined based on the parcellated MR image data. The cingulate cortex with double layers was found in 46.5% of the coronal section in the cingulate cortex's dorsal part, with many individual differences in the outer-layered CWM. Fiber extraction from each determined seed position in both layers of the CWM was carried out using the MRtrix software. The fiber tracking results indicated that the anterior and posterior areas demonstrate major cortical connectivity through the inner-layered CB and the superior area of the brain through the outer-layered CB. From the results, we designed a new CB connectivity model considering the double-layered cingulate cortex to provide a more organized insight into the function of CB function and its connectivity with the cerebral cortex.
Keywords: Cingulum bundle; Double-layered cingulate cortex; Paracingulate sulcus; Tractography.
© 2021 The Authors.
Figures
Fig. 1
Ch2 template brain MRI images showing the DLCC of each axis. The coronal and sagittal images in (a) and (b) show the DLCC in the anterior and posterior parts of the brain, respectively. The red axis in (a) and (b) indicate the corresponding axis of each view. Extended views of the coronal image in (a) and (b) are shown in (c) and (d), respectively. The green circles in (c) and (d) indicate the cingulate cortex area. CWM, cingulate white matter; DLCC, double-layered cingulate cortex; ILCG, inner-layered cingulate gyrus; OLCG, outer-layered cingulate gyrus.
Fig. 2
The procedure of determining the inner- and outer-layered CWM on the dataset HCP 201816. (a) Parcellated area of the entire CWM (cyan area). (b) The dorsal part of the CWM (magenta area). (c) The dorsal part of the CWM with the corpus callosum removed (yellow area). (d) The finally determined inner- (red) and outer-layered (blue) CWM. The overlaid image of the determined area from (a) to (d) along the sagittal and coronal axes are shown in (e) and (f), respectively. The left-side, middle, and right-side images in (f) are the coronal images of the selected CB in (b), (c), and (d), respectively. The coronal section’s position in (f) is indicate in (e) by the dashed white line, while (g) and (h) are the coronal cut slice in frontal and posterior dashed lines in (b), respectively, and the dashed circle is the corpus callosum area. CWM, cingulate white matter; CWM, cingulate white matter; HCP, Human Connectome Project.
Fig. 3
Fiber tracking results of the double-layered CB from 8 HCP dataset (a–h). The full projected fiber tracking results of inner- and outer-layered CB are displayed in the first and second columns, according to the directional color. The combined fiber tracking results of the inner- and outer-layered CB are shown in the third and fourth columns labeled according to color (inner-layered CB = blue, outer-layered CB = red) in the sagittal and coronal views, respectively. The sagittal and coronal images show the full projected and corresponding-slice projected results, respectively. The coronal images in the fourth column are from the center slice of the anterior and posterior commissure. CB, cingulum bundle; HCP, Human Connectome Project.
Fig. 4
The constructed average connectivity matrix from the 32 subjects for inner-layered CB (a) and outer-layered CB (b). The intensity scale in the matrixes indicates the number of the connectivity fibers. The X and Y-axis in each matrix indicate the label number of the brain area in FreeSurfer. Of the 35 labeled cortex areas by FreeSurfer, the main label numbers from these results are as follows: 2_caudalanteriorcingulate, 10_isthmuscingulate, 14_medialorbitofrontal, 17_paracentral, 23_posteriorcingulate, 25_precuneus, 26_rostralanteriorcingulate, and 28_superiorfrontal.
Fig. 5
Composed CB connectivity model considering the DLCC. (a) Simplified composed CB connectivity model on the sagittal MRI image. (b) Proposed model with the conceptual diagram. The red and blue lines in each image indicate the outer and inner-layered CB, respectively. (c) Graph that represents the distribution-density of the outer-layered CWM. The X-axis shows the normalized position for the dorsal part of the cingulate cortex from the anterior (0) to the posterior region (100). The Y-axis shows the mean voxel size (1 mm3) for outer-layered CWM from 32 subjects. DLCC, double-layered cingulate cortex; MCC, middle cingulate cortex; PCC, posterior cingulate cortex; CWM, cingulate white matter.
References
- Brodmann K. Barth; Leipzig: 1909. Vergleichende Lokalisationslehre der Grosshirnrinde in ihren Prinzipien dargestellt auf Grund des Zellenbaues.
- Budisavljevic S., Kawadler J.M., Dell’Acqua F., Rijsdijk F.V., Kane F., Picchioni M., McGuire P., Toulopoulou T., Georgiades A., Kalidindi S., Kravariti E., Murray R.M., Murphy D.G., Craig M.C., Catani M. Heritability of the limbic networks. Soc. Cognit. Affect Neurosci. 2016;11:746–757. -PMC -PubMed
LinkOut - more resources
Full Text Sources