open access

Vol 76, No 4 (2017)
ORIGINAL ARTICLES
Published online: 2017-04-26
Submitted: 2017-01-15
Accepted: 2017-03-11
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Frontal aslant tract projections to the inferior frontal gyrus

T. Szmuda, M. Rogowska, P. Słoniewski, A. Abuhaimed, M. Szmuda, J. Springer, A. Sabisz, J. Dzierżanowski, A. Starzyńska, T. Przewoźny
DOI: 10.5603/FM.a2017.0039
·
Pubmed: 28553860
·
Folia Morphol 2017;76(4):574-581.

open access

Vol 76, No 4 (2017)
ORIGINAL ARTICLES
Published online: 2017-04-26
Submitted: 2017-01-15
Accepted: 2017-03-11

Abstract

Background: Frontal aslant tract (FAT) is a white matter bundle connecting the pre-supplementary motor area (pre-SMA) and the supplementary motor area (SMA) with the inferior frontal gyrus (IFG). The purpose of the present study was to evaluate the anatomical variability of FAT.

Materials and methods: Total number of fibres and the lateralisation index (LI) were calculated. We attempted to find factors contributing to the diversity of FAT regarding IFG terminations to the pars opercularis (IFG-Op) and to the pars triangularis (IFG-Tr). Magnetic resonance imaging of adult patients with diffusion tensor imaging (DTI) with total number of 98 hemispheres composed a cohort. V-shaped operculum was the most common (60.5%).

Results: Total number of FAT fibres had widespread and unimodal distribution (6 to 1765; median: 160). Left lateralisation was noted in 64.3% of cases and was positively correlated with total number of FAT fibres and the bundle projecting to IFG-Op (p < 0.01). LI correlated with total number of FAT fibres (r = 0.43, p < 0.01). FAT projected predominantly to IFG-Op (88.9%; 88 of 99). Only in 3 (3.1%) cases more fibres terminated in IFG-Tr than in IFG-Op. Total number of FAT fibres and number of fibres terminating at IFG-Op did not correlate with the ratio of fibre numbers: FAT/IFG-Op, FAT/IFG-Tr and IFG-Op/IFG-Tr (p > 0.05). The greater total number of fibres to IFG-Tr was, the higher were the ratios of IFG-Tr/ /FAT (r = 0.57, p < 0.01) and IFG-Tr/IFG-Op (r = 0.32, p = 0.04).

Conclusions: Among the IFG, the major termination of FAT is IFG-Op. Whereas the IFG-Tr projection seems to be related to the expansion of the entire FAT bundle regardless of side, domination and handedness. Nevertheless, FAT features a significant anatomical variability which cannot be explained in terms of DTI findings.

Abstract

Background: Frontal aslant tract (FAT) is a white matter bundle connecting the pre-supplementary motor area (pre-SMA) and the supplementary motor area (SMA) with the inferior frontal gyrus (IFG). The purpose of the present study was to evaluate the anatomical variability of FAT.

Materials and methods: Total number of fibres and the lateralisation index (LI) were calculated. We attempted to find factors contributing to the diversity of FAT regarding IFG terminations to the pars opercularis (IFG-Op) and to the pars triangularis (IFG-Tr). Magnetic resonance imaging of adult patients with diffusion tensor imaging (DTI) with total number of 98 hemispheres composed a cohort. V-shaped operculum was the most common (60.5%).

Results: Total number of FAT fibres had widespread and unimodal distribution (6 to 1765; median: 160). Left lateralisation was noted in 64.3% of cases and was positively correlated with total number of FAT fibres and the bundle projecting to IFG-Op (p < 0.01). LI correlated with total number of FAT fibres (r = 0.43, p < 0.01). FAT projected predominantly to IFG-Op (88.9%; 88 of 99). Only in 3 (3.1%) cases more fibres terminated in IFG-Tr than in IFG-Op. Total number of FAT fibres and number of fibres terminating at IFG-Op did not correlate with the ratio of fibre numbers: FAT/IFG-Op, FAT/IFG-Tr and IFG-Op/IFG-Tr (p > 0.05). The greater total number of fibres to IFG-Tr was, the higher were the ratios of IFG-Tr/ /FAT (r = 0.57, p < 0.01) and IFG-Tr/IFG-Op (r = 0.32, p = 0.04).

Conclusions: Among the IFG, the major termination of FAT is IFG-Op. Whereas the IFG-Tr projection seems to be related to the expansion of the entire FAT bundle regardless of side, domination and handedness. Nevertheless, FAT features a significant anatomical variability which cannot be explained in terms of DTI findings.

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Keywords

white matter, frontal aslant tract, operculum, frontal lobe, diffusion tensor imaging, diffusion tensor tractography

About this article
Title

Frontal aslant tract projections to the inferior frontal gyrus

Journal

Folia Morphologica

Issue

Vol 76, No 4 (2017)

Pages

574-581

Published online

2017-04-26

DOI

10.5603/FM.a2017.0039

Pubmed

28553860

Bibliographic record

Folia Morphol 2017;76(4):574-581.

Keywords

white matter
frontal aslant tract
operculum
frontal lobe
diffusion tensor imaging
diffusion tensor tractography

Authors

T. Szmuda
M. Rogowska
P. Słoniewski
A. Abuhaimed
M. Szmuda
J. Springer
A. Sabisz
J. Dzierżanowski
A. Starzyńska
T. Przewoźny

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