Diffusion Tensor Imaging Analysis for Psychiatric Disorders

Shizukuishi, Takashi; Abe, Osamu; Aoki, Shigeki

doi:10.2463/mrms.2012-0082

Cited by 55 publications

(38 citation statements)

References 46 publications

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“…The formation of anomalous tracts after developmental insults has been inferred by many authors out of subtle changes documented in the white matter of human subjects with different neuropsychological disorders (22), such as schizophrenia, autism, and epilepsy. To our knowledge, however, this is the first time they are morphologically described, proved functional, and associated with specific cognitive abilities.…”

Section: Discussionmentioning

confidence: 99%

Structural and functional brain rewiring clarifies preserved interhemispheric transfer in humans born without the corpus callosum

Tovar‐Moll

Monteiro

Andrade

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

107

109

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Why do humans born without the corpus callosum, the major interhemispheric commissure, lack the disconnection syndrome classically described in callosotomized patients? This paradox was discovered by Nobel laureate Roger Sperry in 1968, and has remained unsolved since then. To tackle the hypothesis that alternative neural pathways could explain this puzzle, we investigated patients with callosal dysgenesis using structural and functional neuroimaging, as well as neuropsychological assessments. We identified two anomalous white-matter tracts by deterministic and probabilistic tractography, and provide supporting resting-state functional neuroimaging and neuropsychological evidence for their functional role in preserved interhemispheric transfer of complex tactile information, such as object recognition. These compensatory pathways connect the homotopic posterior parietal cortical areas (Brodmann areas 39 and surroundings) via the posterior and anterior commissures. We propose that anomalous brain circuitry of callosal dysgenesis is determined by long-distance plasticity, a set of hardware changes occurring in the developing brain after pathological interference. So far unknown, these pathological changes somehow divert growing axons away from the dorsal midline, creating alternative tracts through the ventral forebrain and the dorsal midbrain midline, with partial compensatory effects to the interhemispheric transfer of cortical function.callosal agenesis | callosal plasticity | human connectome

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Section: Discussionmentioning

confidence: 99%

Structural and functional brain rewiring clarifies preserved interhemispheric transfer in humans born without the corpus callosum

Tovar‐Moll

Monteiro

Andrade

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

107

109

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“…Diffusion kurtosis imaging (DKI) characterizes the degree of non-Gaussian water diffusion by estimating the kurtosis, i.e., peakedness, in deviation from a Gaussian distribution. [1][2][3][4][5][6][7][8] DKI has been reported to provide additional information that cannot be obtained by conventional diffusion-weighted imaging (DWI) and diffusion tensor imaging (DTI), 9 both of which assume a Gaussian distribution of water diffusion. Compared with DTI, DKI can readily detect subtle alterations of the cerebral white matter (WM), such as demyelination and axonal damage, as well as those of gray matter (GM), such as neuronal loss.…”

Section: Introductionmentioning

confidence: 99%

Optimization of Scan Parameters to Reduce Acquisition Time for Diffusion Kurtosis Imaging at 1.5T

et al. 2016

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Purpose: To shorten acquisition of diffusion kurtosis imaging (DKI) in 1.5-tesla magnetic resonance (MR) imaging, we investigated the effects of the number of b-values, diffusion direction, and number of signal averages (NSA) on the accuracy of DKI metrics.Methods: We obtained 2 image datasets with 30 gradient directions, 6 b-values up to 2500 s/mm 2 , and 2 signal averages from 5 healthy volunteers and generated DKI metrics, i.e., mean, axial, and radial kurtosis (MK, K ¬ , and K ¦ ) maps, from various combinations of the datasets. These maps were estimated by using the intraclass correlation coefficient (ICC) with those from the full datasets.Results: The MK and K ¦ maps generated from the datasets including only the b-value of 2500 s/mm 2 showed excellent agreement (ICC, 0.96 to 0.99). Under the same acquisition time and diffusion directions, agreement was better of MK, K ¬ , and K ¦ maps obtained with 3 b-values (0, 1000, and 2500 s/mm 2 ) and 4 signal averages than maps obtained with any other combination of numbers of b-value and varied NSA. Good agreement (ICC > 0.6) required at least 20 diffusion directions in all the metrics.Conclusion: MK and K ¦ maps with ICC greater than 0.95 can be obtained at 1.5T within 10 min (b-value = 0, 1000, and 2500 s/mm 2 ; 20 diffusion directions; 4 signal averages; slice thickness, 6 mm with no interslice gap; number of slices, 12).

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“…The advent of diffusion tensor imaging (DTI), an MRI methodology that allows for the examination and quantification of white matter integrity, has allowed for a closer inspection of this tissue in BD. The evidence to date suggests that white matter integrity, commonly indexed as fractional anisotropy, appears to be altered in BD (9) as well as in schizophrenia (10), unipolar depression (11), and many other neuropsychiatric disorders (12).…”

Section: Structural Brain Alterationsmentioning

confidence: 99%

The Neurobiology of Bipolar Disorder: Neuroimaging and Genetics Update

Mahon¹,

Russo²,

Perez‐Rodriguez³

et al. 2015

FOC

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disorder is a heterogeneous, complex, multidimensional neuropsychiatric condition characterized by episodes of (hypo)mania and depression. The neurobiology of bipolar disorder is undoubtedly complicated, and much remains to be discovered regarding the neural and genetic correlates of this disorder. In the present work, we present an update on what is currently known regarding the neurobiology of bipolar disorder with a focus on data from neuroimaging and genetic studies. Magnetic resonance imaging studies suggest alterations in both the structure and function of prefrontal and cortical regions implicated in emotion regulation and cognition. Genetic studies have identified several risk variants for the disorder, yet the functional relevance of these variants remains to be clarified. Future studies that take into account the phenotypic heterogeneity of bipolar disorder are likely to advance our understanding of the neurobiology of this complicated neuropsychiatric illness.

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Diffusion Tensor Imaging Analysis for Psychiatric Disorders

Cited by 55 publications

References 46 publications

Structural and functional brain rewiring clarifies preserved interhemispheric transfer in humans born without the corpus callosum

Structural and functional brain rewiring clarifies preserved interhemispheric transfer in humans born without the corpus callosum

Optimization of Scan Parameters to Reduce Acquisition Time for Diffusion Kurtosis Imaging at 1.5T

The Neurobiology of Bipolar Disorder: Neuroimaging and Genetics Update

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