A framework for quality control and parameter optimization in diffusion tensor imaging: theoretical analysis and validation

Hasan, Khader M.

doi:10.1016/j.mri.2007.02.011

Cited by 67 publications

(85 citation statements)

References 30 publications

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“…Our DTI data were acquired using high signal-to-noise ratios and high spatial resolution that minimized diffusion tensor estimation biases (Hasan, 2007;Pierpaoli et al, 1996) and partial volume averaging (Alexander et al, 2001;Pfefferbaum et al, 2003). Due to its potential relation with regional functional specificity (Aboitiz et al, 1992;Highley et al, 1999;Witelson, 1985), the callosal subdivision paradigm implemented in this work has been adopted by several conventional MRI ( …”

Section: Discussionmentioning

confidence: 99%

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Diffusion tensor quantification of the human midsagittal corpus callosum subdivisions across the lifespan

et al. 2008

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The midsagittal corpus callosum (CC) cross-sectional area subdivisions have been used as early and sensitive markers of human brain white matter connectivity, development, natural aging and disease. Despite the simplicity and conspicuity of the appearance of the CC on anatomical magnetic resonance imaging (MRI), the published quantitative MRI literature on its regional sex and age trajectories are contradictory. The availability of noninvasive quantitative methods to assess the CC regions across the human lifespan would help clarify its contribution to behavior and cognition. In this report, we extended the utility of a recently described semi-automated diffusion tensor imaging (DTI) tissue segmentation method to utilize the high orientation contrast of the CC on DTI. Using optimized DTI methods on a cohort of 121 right-handed children and adults aged 6-68 years, we examined the CC areas and corresponding DTI metrics of the different functionally specialized sectors of the CC. Both the area and fractional anisotropy metrics followed inverted U-shaped curves, while the mean and radial diffusivities followed U-curve reflecting white matter progressive and regressive myelination dynamics that continue into young adulthood.

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Section: Discussionmentioning

confidence: 99%

“…Spatial coverage matched the conventional MRI sequences described above (e.g., 44 axial sections, 3mm slice thickness and 0 mm gap with identical field-of-view). DTI acquisition time was approximately 7 minutes and resulted in SNR-independent DTI-metric estimation (Hasan, 2007).…”

Section: Mri and Dti Data Acquisition And Processingmentioning

confidence: 99%

Diffusion tensor quantification of the human midsagittal corpus callosum subdivisions across the lifespan

et al. 2008

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“…, repetition time of T R = 6100 msec, echo time of T E = 84 msec, FOV = 240 · 240 mm 2 , and square matrix of 256 · 256 pixels (Hasan, 2007). The encoding scheme used 21 uniformly distributed directions, which was consistent with scanner capabilities at the time of the study and the need to reduce overall time in the scanner for child participants.…”

Section: à2mentioning

confidence: 99%

Structure, Integrity, and Function of the Hypoplastic Corpus Callosum in Spina Bifida Myelomeningocele

et al. 2014

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Although there are many studies of people with complete or partial hypogenesis of the corpus callosum (CC), little is understood about the hypoplastic CC in which all structures are present but thinned. Spina bifida myelomeningocele (SBM) is a model organism for such studies because many have either a hypogenetic or hypoplastic CC. We used diffusion tensor tractography (DTT) to evaluate the hypoplastic CC in SBM and its relation to interhemispheric functions and intelligence quotient (IQ). Participants were individuals with SBM and an intact or hypoplastic CC (n = 28), who were compared to a typically developing comparison group (n = 32). Total and regional DTT volume and integrity measures (fractional anisotropy, axial diffusivity, and radial diffusivity) of the CC were related to measures of intelligence (IQ), bimanual motor functioning, and dichotic auditory performance. As predicted, DTT showed variations in volume and integrity that were maximized in the entire CC and the posterior CC. IQ correlated with entire CC volume, anterior and posterior regional CC volumes, and also with measures of integrity. Bimanual motor functioning correlated with the anterior and posterior volumes of the CC but not with any integrity measures. Axial diffusivity in the posterior CC was negatively correlated with right ear dichotic listening performance. The hypoplastic CC is not macrostructurally or microstructurally intact in SBM, even when it appears radiologically intact. Both volume and integrity of the posterior regions were related to reductions in IQ and to interhemispheric processing. These findings may transfer to other disorders characterized by a hypoplastic CC.

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“…63 The diffusion sensitization of b-factor = 1,000 sec/mm -2 and the encoding scheme used 21 uniformly distributed directions. 64 The DTI-derived rotationally invariant metrics examined in the present study included FA, axial diffusivity, and radial diffusivity.…”

Section: Visuospatial Span Dual-task (Vss-dt)mentioning

confidence: 99%

Working Memory and Corpus Callosum Microstructural Integrity after Pediatric Traumatic Brain Injury: A Diffusion Tensor Tractography Study

Treble

Hasan

Iftikhar

et al. 2013

Journal of Neurotrauma

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Deficits in working memory (WM) are a common consequence of pediatric traumatic brain injury (TBI) and are believed to contribute to difficulties in a range of cognitive and academic domains. Reduced integrity of the corpus callosum (CC) after TBI may disrupt the connectivity between bilateral frontoparietal neural networks underlying WM. In the present investigation, diffusion tensor imaging (DTI) tractography of eight callosal subregions (CC1-CC8) was examined in relation to measures of verbal and visuospatial WM in 74 children sustaining TBI and 49 typically developing comparison children. Relative to the comparison group, children with TBI demonstrated poorer visuospatial WM, but comparable verbal WM. Microstructure of the CC was significantly compromised in brain-injured children, with lower fractional anisotropy (FA) and higher axial and radial diffusivity metrics in all callosal subregions. In both groups of children, lower FA and/or higher radial diffusivity in callosal subregions connecting anterior and posterior parietal cortical regions predicted poorer verbal WM, whereas higher radial diffusivity in callosal subregions connecting anterior and posterior parietal, as well as temporal, cortical regions predicted poorer visuospatial WM. DTI metrics, especially radial diffusivity, in predictive callosal subregions accounted for significant variance in WM over and above remaining callosal subregions. Reduced microstructural integrity of the CC, particularly in subregions connecting parietal and temporal cortices, may act as a neuropathological mechanism contributing to long-term WM deficits. The future clinical use of neuroanatomical biomarkers may allow for the early identification of children at highest risk for WM deficits and earlier provision of interventions for these children.

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A framework for quality control and parameter optimization in diffusion tensor imaging: theoretical analysis and validation

Cited by 67 publications

References 30 publications

Diffusion tensor quantification of the human midsagittal corpus callosum subdivisions across the lifespan

Diffusion tensor quantification of the human midsagittal corpus callosum subdivisions across the lifespan

Structure, Integrity, and Function of the Hypoplastic Corpus Callosum in Spina Bifida Myelomeningocele

Working Memory and Corpus Callosum Microstructural Integrity after Pediatric Traumatic Brain Injury: A Diffusion Tensor Tractography Study

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