Corpus Callosum Remodeling in Glioma: Constancy of Fibre Density and Anisotropy in MRI

Author(s):  
Vikas Pareek ◽  
Subhadip Paul ◽  
Prasun K. Roy
2017 ◽  
Author(s):  
Sila Genc ◽  
Charles B Malpas ◽  
Gareth Ball ◽  
Timothy J Silk ◽  
Marc L Seal

AbstractPurposeThe corpus callosum is integral to the central nervous system, and continually develops with age by virtue of increasing axon diameter and ongoing myelination. Magnetic resonance imaging (MRI) techniques offer a means to disentangle these two aspects of white matter development. We investigate the profile of microstructural metrics across the corpus callosum, and assess the impact of age, sex and pubertal development on these processes.MethodsThis study made use of two independent paediatric populations. Multi-shell diffusion MRI data were analysed to produce a suite of diffusion tensor imaging (DTI), neurite orientation density and dispersion imaging (NODDI), and apparent fibre density (AFD) metrics. A multivariate profile analysis was performed for each diffusion metric across 10 subdivisions of the corpus callosum.ResultsAll diffusion metrics significantly varied across the length of the corpus callosum. AFD exhibited a strong relationship with age across the corpus callosum (partial η2 = .65), particularly in the posterior body of the corpus callosum (partial η2 = .72). In addition, females had significantly higher AFD compared with males, most markedly in the anterior splenium (partial η2 = .14) and posterior genu (partial η2 = .13). Age-matched pubertal group differences were localised to the splenium.ConclusionWe present evidence of a strong relationship between apparent fibre density and age, sex, and puberty during development. These results are consistent with ex vivo studies of fibre morphology, providing insights into the dynamics of axonal development in childhood and adolescence using diffusion MRI.Target journalsBrain Structure & Function; HBM; NeuroImage; Developmental Cognitive Neuroscience


2017 ◽  
Author(s):  
Sila Genc ◽  
Marc L Seal ◽  
Thijs Dhollander ◽  
Charles B Malpas ◽  
Philip Hazell ◽  
...  

Recent neurodevelopmental research supports the contribution of pubertal stage to local and global grey and white matter remodelling. Little is known, however, about white matter microstructural alterations at pubertal onset. This study investigated differences in white matter properties between pre-pubertal and pubertal children using whole brain fixel-based analysis (FBA) of the microscopic density and macroscopic cross-section of fibre bundles. Diffusion-weighted imaging data were acquired for 74 typically developing children (M=10.4, SD=0.43 years, 31 female) at 3.0T (60 diffusion gradient directions, b-value=2800 s/mm 2 ). Group comparisons of fibre density (FD) and fibre cross-section (FC) were made between age-matched pre-pubertal and pubertal groups, and post-hoc analyses were performed on regions of interest (ROIs) defined in the splenium, body and genu of the corpus callosum. Significant fixel-wise differences in FD were observed between the pubertal groups, where the pubertal group had significantly higher FD compared with age-matched pre-pubertal children, localised to the posterior corpus callosum. Post-hoc analyses on mean FD in the corpus callosum ROIs revealed group differences between the pubertal groups in the splenium, but not body or genu. The observed higher apparent fibre density in the splenium suggests that pubertal onset coincides with white matter differences explained by increasing axon diameter. This may be an important effect to account for over pubertal development, particularly for group studies where age-matched clinical and typical populations may be at various stages of puberty.


2020 ◽  
Author(s):  
Claire E Kelly ◽  
Deanne K Thompson ◽  
Sila Genc ◽  
Jian Chen ◽  
Joseph YM Yang ◽  
...  

AbstractBackgroundIt is well documented that infants born very preterm (VP) are at risk of brain injury and altered brain development in the neonatal period, however there is a lack of long-term, longitudinal studies on the effects of VP birth on white matter development over childhood. Most previous studies were based on voxel-averaged, non-fibre-specific diffusion magnetic resonance imaging (MRI) measures, such as fractional anisotropy. In contrast, the novel diffusion MRI analysis framework, fixel-based analysis (FBA), enables whole-brain analysis of microstructural and macrostructural properties of individual fibre populations at a sub-voxel level. We applied FBA to investigate the long-term implications of VP birth and associated perinatal risk factors on fibre development in childhood and adolescence.MethodsDiffusion images were acquired for a cohort of VP (born <30 weeks’ gestation) and full-term (FT, ≥37 weeks’ gestation) children at two ages: mean (SD) 7.6 (0.2) years (n=138 VP and 32 FT children) and 13.3 (0.4) years (n=130 VP and 45 FT children). 103 VP and 21 FT children had images at both ages for longitudinal analysis. At every fixel (individual fibre population within an image voxel) across the white matter, we compared FBA metrics (fibre density (FD), cross-section (FC) and a combination of these properties (FDC)) between VP and FT groups cross-sectionally at each age, and longitudinally between ages. We also examined associations between perinatal risk factors and FBA metrics in the VP group.ResultsCompared with FT children, VP children had lower FD, FC and FDC throughout the white matter, particularly in the corpus callosum, tapetum, inferior fronto-occipital fasciculus, fornix and cingulum at ages 7 and 13 years, as well as the motor pathways at age 13 years. VP children also had slower FDC development in the corpus callosum and corticospinal tract between ages 7 and 13 years compared with FT children. Within VP children, earlier gestational age at birth, lower birth weight z-score, and neonatal brain abnormalities were associated with lower FD, FC and FDC throughout the white matter at both ages.ConclusionsVP birth and concomitant perinatal risk factors are associated with fibre tract-specific alterations to axonal development in childhood and adolescence.


2000 ◽  
Vol 42 (01) ◽  
pp. 8 ◽  
Author(s):  
S Overmeyer ◽  
A Simmons ◽  
J Santosh ◽  
C Andrew ◽  
S C R Williams ◽  
...  

2000 ◽  
Vol 59 (3) ◽  
pp. 150-158 ◽  
Author(s):  
Nadia Ortiz ◽  
Michael Reicherts ◽  
Alan J. Pegna ◽  
Encarni Garran ◽  
Michel Chofflon ◽  
...  

Patients suffering from Multiple Sclerosis (MS) have frequently been found to suffer from damage to callosal fibers. Investigations have shown that this damage is associated with signs of hemisphere disconnections. The aim of our study was to provide evidence for the first signs of interhemispheric dysfunction in a mildly disabled MS population. Therefore, we explored whether the Interhemispheric Transfer (IT) deficit is multi-modal and sought to differentiate two MS evolution forms, on the basis of an interhemispheric disconnection index. Twenty-two patients with relapsing-remitting form of MS (RRMS) and 14 chronic-progressive (CPMS) were compared with matched controls on four tasks: a tachistoscopic verbal and non-verbal decision task, a dichotic listening test, cross tactile finger localization and motor tapping. No overall impairment was seen. The dichotic listening and lexical decision tasks were the most sensitive to MS. In addition, CPMS patients' IT was more impaired and was related to the severity of neurological impairment. The different sizes of the callosal fibers, which determine their vulnerability, may explain the heterogeneity of transfer through the Corpus Callosum. Therefore, evaluation of IT may be of value as an index of evolution in MS.


2012 ◽  
Vol 43 (01) ◽  
Author(s):  
D Wolf ◽  
FU Fischer ◽  
J Fesenbeckh ◽  
I Yakushey ◽  
I Lelieveld ◽  
...  
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