scholarly journals White matter microstructural alterations in amblyopic adults revealed by diffusion spectrum imaging with systematic tract-based automatic analysis

2018 ◽  
Vol 103 (4) ◽  
pp. 511-516 ◽  
Author(s):  
Tzu-Hsun Tsai ◽  
Hsien-Te Su ◽  
Yung-Chin Hsu ◽  
Yao-Chia Shih ◽  
Chien-Chung Chen ◽  
...  
Keyword(s):  
White Matter ◽  
Visual Processing ◽  
Audiovisual Integration ◽  
Automatic Analysis ◽  
Middle Temporal Gyrus ◽  
Whole Brain ◽  
White Matter Tracts ◽  
Microstructural Alterations ◽  
Diffusion Spectrum Imaging ◽  
Spectrum Imaging

Background/aimWe investigated the microstructural changes in white matter of adults with amblyopia using diffusion spectrum imaging with systematic tract-based automatic analysis of the whole brain.MethodsTen adults with amblyopia (six women and four men, 33.6±10.6 years old on average) and 20 age- and sex-matched normal-sighted controls were enrolled. The mean generalised fractional anisotropy (GFA) was measured in 76 white matter tracts and compared between the experimental and control groups using a threshold-free cluster-weighted method and t-test. A 2-percentile cut-off was used to identify segments with the greatest differences between the two groups.ResultsParticipants with amblyopia had significantly lower GFA values than the controls in 11 segments located in nine white matter tracts, which included the following: left arcuate fasciculus, left frontal aslant tract, left fornix and left inferior fronto-occipital fasciculus of the association fibres; left thalamic radiations of the auditory nerve and bilateral optic radiations of the projection fibres; and genu and middle temporal gyrus of the callosal fibres. Amblyopic participants had statistically higher GFA values in the bilateral uncinate fasciculus than those of the controls.ConclusionThis preliminary study using whole-brain tractographic analysis of white matter reveals association between abnormal early visual processing and alterations in brain architecture, which may be related to various higher-level deficits, such as audiovisual integration and hand−eye coordination in patients with amblyopia.

Different neural substrates for executive functions in youths with ADHD: a diffusion spectrum imaging tractography study

2016 ◽  
Vol 46 (6) ◽  
pp. 1225-1238 ◽  
Author(s):  
H.-L. Chiang ◽  
Y.-J. Chen ◽  
C.-Y. Shang ◽  
W.-Y. I. Tseng ◽  
S. S.-F. Gau
Keyword(s):  
White Matter ◽  
Executive Functions ◽  
White Matter Tracts ◽  
Fibre Tract ◽  
Diffusion Spectrum Imaging ◽  
Cingulum Bundle ◽  
Microstructural Property ◽  
Wide Range ◽  
Spectrum Imaging ◽  
Microstructural Integrity

BackgroundThe relationship between white-matter tracts and executive functions (EF) in attention deficit hyperactivity disorder (ADHD) has not been well studied and previous studies mainly focused on frontostriatal (FS) tracts. The authors explored the microstructural property of several fibre tracts hypothesized to be involved in EF, to correlate their microstructural property with EF, and to explore whether such associations differ between ADHD and typically developing (TD) youths.MethodWe assessed 45 youths with ADHD and 45 individually matched TD youths with a computerized test battery for multiple dimensions of EF. From magnetic resonance imaging, FS tract, superior longitudinal fasciculus (SLF), arcuate fasciculus (AF) and cingulum bundle (CB) were reconstructed by diffusion spectrum imaging tractography. The generalized fractional anisotropy (GFA) values of white-matter tracts were computed to present microstructural property of each tract.ResultsWe found lower GFA in the left FS tract, left SLF, left AF and right CB, and poorer performance in set-shifting, sustained attention, cognitive inhibition and visuospatial planning in ADHD than TD. The ADHD and TD groups demonstrated different association patterns between EF and fibre tract microstructural property. Most of the EF were associated with microstructural integrity of the FS tract and CB in TD youths, while with that of the FS tract, SLF and AF in youths with ADHD.ConclusionsOur findings support that the SLF, AF and CB also involve in a wide range of EF and that the main fibre tracts involved in EF are different in youths with ADHD.

WHITE MATTER TRACTS IN FRONTO-STRIATO-THALAMIC CIRCUIT IN THE HUMAN BRAIN: A DIFFUSION SPECTRUM IMAGING STUDY

2011 ◽  
Vol 23 (03) ◽  
pp. 215-222
Author(s):  
Yu-Chun Lo ◽  
Fu-Shan Jaw ◽  
Su-Chun Huang ◽  
Yu-Yang Yeh ◽  
Wen-Yih Isaac Tseng
Keyword(s):  
White Matter ◽  
Water Molecule ◽  
Imaging Study ◽  
Brain Structures ◽  
White Matter Tract ◽  
White Matter Tracts ◽  
Diffusion Mr ◽  
Diffusion Spectrum Imaging ◽  
Significant Difference ◽  
Spectrum Imaging

Gender and handedness differences in cognitive functions and brain structures are well recognized. Recent research has reported different white matter structures between male and female subjects. Yet it is unknown whether the gender and handedness effects on different white matter tracts are comparable or disparate. In this study, we focus on three main tracts in the fronto-striato-thalamic circuit, namely, the cingulum bundles (CG), fornices (FXs) and anterior thalamic radiations (ATR). These are the primary connections among the frontal lobe, the limbic system, and the thalamus, integrating functions of emotion control, memory, and decision-making. A total of 40 healthy adults were recruited in this study. There was no significant difference in demographic variables between males and females. Images were acquired on a 3-T Magnetic resonance imaging (MRI) system with an eight-channel head coil. The diffusion spectrum imaging (DSI) experiment was performed by applying 203 diffusion gradient vectors. DSI maps the angular distribution of water molecule displacement by acquiring diffusion MR signals in a more comprehensive way. The theory of DSI is based on the Fourier transform relationship between diffusion MR signals and the average propagator of water molecule displacement. Isotropic spatial resolution was obtained by setting both in-plane and through-plane resolutions as 2.7 mm. A total of 45 trans-axial slices were acquired encompassing the whole brain. DSI analysis was computed based on the Fourier relationship between diffusion echo signals and the probability density function (PDF). Fiber tracking was used to define the targeted tracts. All fiber orientations of the nearest voxels were used to decide the proceeding orientation for the next step. Tracking stopped if there was no coinciding orientation in the nearest voxels. Mean path analysis, a method that projected the anisotropy of PDF [generalized fractional anisotropy (GFA)] onto a single mean path of the specific white matter tract bundle, was used to analyze subtle changes in microstructure coherence along individual tract bundles. The asymmetric differences of targeted tracts were assessed statistically by calculating GFA values and lateralization indices (LIs). The handedness factor of the LI values in CG and ATR showed a trend for significance. The gender factor of the LI values was investigated in FX also. Different white matter tract bundles manifested different degrees of gender effect on GFA distributions. Our results suggest that the gender and handedness factors should be considered when one evaluates the impairment of the fronto-striato-thalamic circuit.

scholarly journals Connectivity and tissue microstructural alterations in right and left temporal lobe epilepsy revealed by diffusion spectrum imaging

2014 ◽  
Vol 5 ◽  
pp. 349-358 ◽  
Author(s):  
Alia Lemkaddem ◽  
Alessandro Daducci ◽  
Nicolas Kunz ◽  
François Lazeyras ◽  
Margitta Seeck ◽  
...  
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Left Temporal Lobe ◽  
Microstructural Alterations ◽  
Diffusion Spectrum Imaging ◽  
Spectrum Imaging

scholarly journals Recovery of White Matter Tracts in Regions of Peritumoral FLAIR Hyperintensity with Use of Restriction Spectrum Imaging

2012 ◽  
Vol 34 (6) ◽  
pp. 1157-1163 ◽  
Author(s):  
C.R. McDonald ◽  
N.S. White ◽  
N. Farid ◽  
G. Lai ◽  
J.M. Kuperman ◽  
...  
Keyword(s):  
White Matter ◽  
White Matter Tracts ◽  
Spectrum Imaging

scholarly journals Automatic whole brain tract-based analysis using predefined tracts in a diffusion spectrum imaging template and an accurate registration strategy

2015 ◽  
Vol 36 (9) ◽  
pp. 3441-3458 ◽  
Author(s):  
Yu-Jen Chen ◽  
Yu-Chun Lo ◽  
Yung-Chin Hsu ◽  
Chun-Chieh Fan ◽  
Tzung-Jeng Hwang ◽  
...  
Keyword(s):  
Whole Brain ◽  
Diffusion Spectrum Imaging ◽  
Spectrum Imaging

scholarly journals Microstructure of Strategic White Matter Tracts and Cognition in Memory Clinic Patients with Vascular Brain Injury

2017 ◽  
Vol 44 (5-6) ◽  
pp. 268-282 ◽  
Author(s):  
J. Matthijs Biesbroek ◽  
Alexander Leemans ◽  
Hanna den Bakker ◽  
Marco Duering ◽  
Benno Gesierich ◽  
...  
Keyword(s):  
Brain Injury ◽  
White Matter ◽  
Executive Functioning ◽  
Diffusion Tensor ◽  
Added Value ◽  
Memory Clinic ◽  
Whole Brain ◽  
White Matter Tracts ◽  
Conventional Mri ◽  
Brain White Matter

Background: White matter injury is an important factor for cognitive impairment in memory clinic patients. We determined the added value of diffusion tensor imaging (DTI) of strategic white matter tracts in explaining variance in cognition in memory clinic patients with vascular brain injury. Methods: We included 159 patients. Conventional MRI markers (white matter hyperintensity volume, lacunes, nonlacunar infarcts, brain atrophy, and microbleeds), and fractional anisotropy and mean diffusivity (MD) of the whole brain white matter and of 18 white matter tracts were related to cognition using linear regression and Bayesian network analysis. Results: On top of all conventional MRI markers combined, MD of the whole brain white matter explained an additional 3.4% (p = 0.014), 7.8% (p < 0.001), and 1.2% (p = 0.119) variance in executive functioning, speed, and memory, respectively. The Bayesian analyses of regional DTI measures identified strategic tracts for executive functioning (right superior longitudinal fasciculus), speed (left corticospinal tract), and memory (left uncinate fasciculus). MD within these tracts explained an additional 3.4% (p = 0.012), 3.8% (p = 0.007), and 2.1% (p = 0.041) variance in executive functioning, speed, and memory, respectively, on top of all conventional MRI and global DTI markers combined. Conclusion: In memory clinic patients with vascular brain injury, DTI of strategic white matter tracts has a significant added value in explaining variance in cognitive functioning.

White matter endophenotype candidates for ADHD: a diffusion imaging tractography study with sibling design

2019 ◽  
Vol 50 (7) ◽  
pp. 1203-1213 ◽  
Author(s):  
Huey-Ling Chiang ◽  
Yung-Chin Hsu ◽  
Chi-Yuan Shang ◽  
Wen-Yih Isaac Tseng ◽  
Susan Shur-Fen Gau
Keyword(s):  
White Matter ◽  
Fractional Anisotropy ◽  
Diffusion Imaging ◽  
Familial Risk ◽  
Mean Diffusivity ◽  
Control Group ◽  
White Matter Tracts ◽  
Spatial Span ◽  
Diffusion Spectrum Imaging ◽  
The Right

AbstractBackgroundBrain structural alterations are frequently observed in probands with attention-deficit/hyperactivity disorder (ADHD). Here we examined the microstructural integrity of 76 white matter tracts among unaffected siblings of patients with ADHD to evaluate the potential familial risk and its association with clinical and neuropsychological manifestations.MethodsThe comparison groups included medication-naïve ADHD probands (n = 50), their unaffected siblings (n = 50) and typically developing controls (n = 50, age-and-sex matched with ADHD probands). Whole brain tractography was reconstructed automatically by tract-based analysis of diffusion spectrum imaging (DSI). Microstructural properties of white matter tracts were represented by the values of generalized fractional anisotropy (GFA), fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD) and axial diffusivity (AD).ResultsCompared to the control group, ADHD probands showed higher AD values in the perpendicular fasciculus, superior longitudinal fasciculus I, corticospinal tract, and corpus callosum. The AD values of unaffected siblings were in the intermediate position between those of the ADHD and control groups. These AD values were significantly associated with ADHD symptoms, sustained attention and working memory, for all white matter tracks evaluated except for the perpendicular fasciculus. Higher FA and lower RD values in the right frontostriatal tract connecting ventrolateral prefrontal cortex (FS-VLPFC) were associated with better performance in spatial span only in the unaffected sibling group.ConclusionsAbnormal AD values of specific white matter tracts among unaffected siblings of ADHD probands suggest the presence of familial risk in this population. The right FS-VLPFC may have a role in preventing the expression of the ADHD-related behavioral phenotype.ClinicalTrials.gov numberNCT01682915

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