scholarly journals Is Manual Drawing of Region of Interest to Measure Fractional Anisotropy a Reliable Method of Determining White Matter Integrity? Medial Temporal Epilepsy Model

2022 ◽  
pp. 100040
Author(s):  
Saman Hazany ◽  
Brittany DeClouette
Keyword(s):  
White Matter ◽  
Fractional Anisotropy ◽  
Reliable Method ◽  
Region Of Interest ◽  
White Matter Integrity ◽  
Temporal Epilepsy

Fiber tracking of white matter integrity connecting the mediodorsal nucleus of the thalamus and the prefrontal cortex in schizophrenia: A diffusion tensor imaging study

2009 ◽  
Vol 24 (5) ◽  
pp. 269-274 ◽  
Author(s):  
Shinsuke Kito ◽  
Jiuk Jung ◽  
Tetsuo Kobayashi ◽  
Yoshihiko Koga
Keyword(s):  
Prefrontal Cortex ◽  
Standard Deviation ◽  
White Matter ◽  
Fractional Anisotropy ◽  
Fiber Tracking ◽  
Cross Sectional Area ◽  
White Matter Integrity ◽  
Sectional Area ◽  
Cross Sectional ◽  
The Cross

AbstractThe goal of this study was to detect abnormalities in white matter integrity connecting the mediodorsal nucleus of the thalamus and the prefrontal cortex using fiber-tracking technique. Diffusion tensor imaging was acquired in 20 patients with schizophrenia and 20 normal comparison subjects. Fiber tracking was performed on the anterior thalamic peduncle, and the tractography was used to determine the cross-sectional area, mean fractional anisotropy, and standard deviation of fractional anisotropy for every step separately in the right and left hemispheres. Compared with normal subjects, patients showed a significant reduction in the cross-sectional area of the left anterior thalamic peduncle. There were no significant differences for the mean fractional anisotropy bilaterally between the two groups, but significant differences for the standard deviation of fractional anisotropy in both hemispheres. Reduction in the cross-sectional area of the left anterior thalamic peduncle suggests the presence of the failure of left-hemisphere lateralization. In schizophrenic patients a significant increase of the standard deviation of fractional anisotropy raise the possibility that the inhomogeneity of white matter integrity, which is densely or sparsely distributed by site. These findings might provide further evidence for disruption of white matter integrity between the thalamus and the prefrontal cortex in schizophrenia.

scholarly journals Monocyte depletion attenuates the development of posttraumatic hydrocephalus and preserves white matter integrity after traumatic brain injury

2018 ◽  
Author(s):  
Hadijat M. Makinde ◽  
Talia B. Just ◽  
Carla M. Cuda ◽  
Nicola Bertolino ◽  
Daniele Procissi ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
White Matter ◽  
Fractional Anisotropy ◽  
Diffusion Mri ◽  
Lesion Size ◽  
White Matter Integrity ◽  
Regional Patterns ◽  
Software Program ◽  
Ventricle Volume

AbstractMonocytes are amongst the first cells recruited into the brain after traumatic brain injury (TBI). We have shown monocyte depletion 24 hours prior to TBI reduces brain edema, decreases neutrophil infiltration and improves behavioral outcomes. Additionally, both lesion and ventricle size correlate with poor neurologic outcome after TBI. Therefore, we aimed to determine the association between monocyte infiltration, lesion size, and ventricle volume. We hypothesized that monocyte depletion would attenuate lesion size, decrease ventricle enlargement, and preserve white matter in mice after TBI. C57BL/6 mice underwent pan monocyte depletion via intravenous injection of liposome-encapsulated clodronate. Control mice were injected with liposome-encapsulated PBS. TBI was induced via an open-head, controlled cortical impact. Mice were imaged using magnetic resonance imaging (MRI) at 1, 7, and 14 days post-injury to evaluate progression of lesion and to detect morphological changes associated with injury (3D T1- weighted MRI) including regional alterations in white matter patterns (multi-direction diffusion MRI). Lesion size and ventricle volume were measured using semi-automatic segmentation and active contour methods with the software program ITK-SNAP. Data was analyzed with the statistical software program PRISM. No significant effect of monocyte depletion on lesion size was detected using MRI following TBI (p=0.4). However, progressive ventricle enlargement following TBI was observed to be attenuated in the monocyte-depleted cohort (5.3 ± 0.9mm3) as compared to the sham-depleted cohort (13.2 ± 3.1mm3; p=0.02). Global white matter integrity and regional patterns were evaluated and quantified for each mouse after extracting fractional anisotropy maps from the multi-direction diffusion-MRI data using Siemens Syngo DTI analysis package. Fractional anisotropy values were preserved in the monocyte-depleted cohort (123.0 ± 4.4mm3) as compared to sham-depleted mice (94.9 ± 4.6mm3; p=0.025) by 14 days post-TBI. The MRI derived data suggests that monocyte depletion at the time of injury may be a novel therapeutic strategy in the treatment of TBI. Furthermore, non-invasive longitudinal imaging allows for the evaluation of both TBI progression as well as therapeutic response over the course of injury.

scholarly journals A Diffusion tensor imaging study to compare normative fractional anisotropy values with patients suffering from Parkinson’s disease in the brain grey and white matter

2020 ◽  
Author(s):  
Rahul P Kotian ◽  
K Prakashini ◽  
N Sreekumaran Nair
Keyword(s):  
Parkinson’S Disease ◽  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Substantia Nigra ◽  
Corpus Callosum ◽  
Fractional Anisotropy ◽  
Grey Matter ◽  
Diffusion Tensor ◽  
Region Of Interest ◽  
Healthy Controls

AbstractBackgroundDiffusion tensor imaging (DTI) appears as a sensitive method to study Parkinson’s disease (PD) pathophysiology and severity. Fractional anisotropy (FA) value is one of the scalar derivatives of DTI used to find out anisotropy within a voxel in a tissue and used for determining white matter integrity in aging and neurodegenerative diseases. We studied DTI derived FA in early PD subjects as their routine MRI scans were normal.Methods40 patients with early PD and 40 healthy controls were employed to evaluate changes in microstructural white and grey matter in the brain’s using DTI derived FA values. Comparison of FA values in the brain’s white and grey matter of patients with PD and age matched controls at the corpus callosum, centrum semiovale, pons, putamen, caudate nucleus, substantia nigra, cerebral peduncles and cerebellar peduncles, was done using a region of interest (ROI) technique, with b-value 1000s/mm2 and TE=100 milliseconds using 1.5T MRI system.ResultsPD patients showed differences in FA values in both the grey and white matter areas of the brain’s compared to healthy controls. Our study revealed the presence of damage in the substantia nigra, corpus callosum, putamen and cerebral peduncles mainly in the PD group.ConclusionOur findings indicate that DTI and region of interest (ROI) methods can be used in patients with early PD to study microstructural alterations mainly in the substantia nigra, putamen and corpus callosum.

scholarly journals Structural and functional brain changes following four weeks of unimanual motor training: evidence from fMRI-guided diffusion MRI tractography

2016 ◽  
Author(s):  
Lee B Reid ◽  
Martin V Sale ◽  
Ross Cunnington ◽  
Jason B Mattingley ◽  
Stephen E Rose
Keyword(s):  
White Matter ◽  
Caudate Nucleus ◽  
Fractional Anisotropy ◽  
Diffusion Mri ◽  
Mean Diffusivity ◽  
Region Of Interest ◽  
Motor Training ◽  
Left Hand ◽  
Dorsolateral Prefrontal ◽  
The Right

AbstractWe have reported reliable changes in behaviour, brain structure and function in 24 healthy right-handed adults who practiced a finger-thumb opposition sequence task with their left hand for 10 mins daily, over four weeks. Here we extend these findings by employing diffusion MRI to investigate white-matter changes in the corticospinal tract, basal-ganglia, and connections of the dorsolateral prefrontal cortex. Twenty-three participant datasets were available with pre-training and post-training scans. Task performance improved in all participants (mean: 52.8%, SD: 20.0%; group p<0.01 FWE) and widespread microstructural changes were detected across the motor system of the ‘trained’ hemisphere. Specifically, region-of-interest based analyses of diffusion MRI (n=21) revealed significantly increased fractional anisotropy in the right caudate nucleus (4.9%; p<0.05 FWE), and decreased mean diffusivity in the left nucleus accumbens (-1.3%; p<0.05 FWE). Diffusion MRI tractography (n=22), seeded by sensorimotor cortex fMRI activation, also revealed increased fractional anisotropy in the right corticomotor tract (mean 3.28%; p<0.05 FWE) predominantly reflecting decreased radial diffusivity. These changes were consistent throughout the entire length of the tract. The left corticomotor tract did not show any changes. FA also increased in white matter connections between the right middle frontal gyrus and both right caudate nucleus (17/22 participants; p<0.05 FWE) and right supplementary motor area (18/22 participants; p<0.05 FWE). Equivalent changes in FA were not seen in the left (‘non-trained’) hemisphere. In combination with our functional and structural findings, this study provides detailed, multifocal evidence for widespread neuroplastic changes in the human brain resulting from motor training.

scholarly journals Greater Loss of White Matter Integrity in Postural Instability and Gait Difficulty Subtype of Parkinson's Disease

2014 ◽  
Vol 41 (6) ◽  
pp. 763-768 ◽  
Author(s):  
Quanquan Gu ◽  
Peiyu Huang ◽  
Min Xuan ◽  
Xiaojun Xu ◽  
Dan Li ◽  
...  
Keyword(s):  
White Matter ◽  
Fractional Anisotropy ◽  
Diffusion Tensor ◽  
Critical Role ◽  
Postural Instability ◽  
White Matter Integrity ◽  
Radial Diffusivity ◽  
Superior Longitudinal Fasciculus ◽  
Axial Diffusivity ◽  
White Matter Abnormalities

ABSTRACTBackground: Patients with the postural instability and gait difficulty (PIGD) subtype of Parkinson disease (PD) are at a higher risk of dysfunction and are less responsive to dopamine replacement therapy. The PIGD subtype was found to largely associate with white matter lesions, but details of the diffusion changes within these lesions have not been fully investigated. Voxel-based analysis for diffusion tensor imaging data is one of the preferred measures to compare diffusion changes in each voxel in any part of the brain. Methods: PD patients with the PIGD (n=12) and non-PIGD subtypes (n=12) were recruited to compare diffusion differences in fractional anisotropy, axial diffusivity, and radial diffusivity with voxel-based analysis. Results: Significantly reduced fractional anisotropy in bilateral superior longitudinal fasciculus, bilateral anterior corona radiata, and the left genu of the corpus callosum were shown in the PIGD subtype compared with the non-PIGD subtype. Increased radial diffusivity in the left superior longitudinal fasciculus was found in the PIGD subtype with no statistical differences in axial diffusivity found. Conclusions: Our study confirms previous findings that white matter abnormalities were greater in the PIGD subtype than in the non-PIGD subtype. Additionally, our findings suggested: (1) compared with the non-PIGD subtype, loss of white matter integrity was greater in the PIGD subtype; (2) bilateral superior longitudinal fasciculus may play a critical role in microstructural white matter abnormalities in the PIGD subtype; and (3) reduced white matter integrity in the PIGD subtype could be mainly attributed to demyelination rather than axonal loss.

A Diffusion tensor imaging study to compare normative fractional anisotropy values with patients suffering from Parkinsons disease in the brain grey and white matter (Preprint)

2020 ◽  
Author(s):  
Dr. RAHUL P KOTIAN ◽  
Dr Prakashini K ◽  
Dr Sreekumaran Nair
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Substantia Nigra ◽  
Corpus Callosum ◽  
Fractional Anisotropy ◽  
Grey Matter ◽  
Diffusion Tensor ◽  
Region Of Interest ◽  
Healthy Controls ◽  
Parkinsons Disease

BACKGROUND Diffusion tensor imaging (DTI) appears as a sensitive method to study Parkinsons disease (PD) pathophysiology and severity. Fractional anisotropy (FA) value is one of the scalar derivatives of DTI used to find out anisotropy within a voxel in a tissue and used for determining white matter integrity in aging and neurodegenerative diseases. We studied DTI derived FA in early PD subjects as their routine MRI scans were normal. OBJECTIVE To compare FA values between normative and subjects with early Parkinson’s disease METHODS 40 patients with early PD and 40 healthy controls were employed to evaluate changes in microstructural white and grey matter in the brains using DTI derived FA values. Comparison of FA values in the brains white and grey matter of patients with PD and age matched controls at the corpus callosum, centrum semiovale, pons, putamen, caudate nucleus, substantia nigra, cerebral peduncles and cerebellar peduncles, was done using a region of interest (ROI) technique, with b-value 1000s/mm2 and TE=100 milliseconds using 1.5T MRI system. RESULTS PD patients showed differences in FA values in both the grey and white matter areas of the brains compared to healthy controls. Our study revealed the presence of damage in the substantia nigra, corpus callosum, putamen and cerebral peduncles mainly in the PD group. CONCLUSIONS Our findings indicate that DTI and region of interest (ROI) methods can be used in patients with early PD to study microstructural alterations mainly in the substantia nigra, putamen and corpus callosum. Keywords: Fractional anisotropy, diffusion tensor imaging, Parkinsons disease, magnetic resonance imaging, neuroimaging. CLINICALTRIAL NA

scholarly journals Diffusion tensor imaging of brain white matter in Huntington gene mutation individuals

2017 ◽  
Vol 75 (8) ◽  
pp. 503-508 ◽  
Author(s):  
Roberta Arb Saba ◽  
James H. Yared ◽  
Thomas M. Doring ◽  
Med Phys ◽  
Vanderci Borges ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Gene Mutation ◽  
Fractional Anisotropy ◽  
Diffusion Tensor ◽  
Brain Magnetic Resonance Imaging ◽  
White Matter Integrity ◽  
Brain White Matter ◽  
Potential Biomarker ◽  
Significant Difference

ABSTRACT Objective To evaluate the role of the involvement of white matter tracts in huntingtin gene mutation patients as a potential biomarker of the progression of the disease. Methods We evaluated 34 participants (11 symptomatic huntingtin gene mutation, 12 presymptomatic huntingtin gene mutation, and 11 controls). We performed brain magnetic resonance imaging to assess white matter integrity using diffusion tensor imaging, with measurement of fractional anisotropy. Results We observed a significant decrease of fractional anisotropy in the cortical spinal tracts, corona radiate, corpus callosum, external capsule, thalamic radiations, superior and inferior longitudinal fasciculus, and inferior frontal-occipital fasciculus in the Huntington disease group compared to the control and presymptomatic groups. Reduction of fractional anisotropy is indicative of a degenerative process and axonal loss. There was no statistically significant difference between the presymptomatic and control groups. Conclusion White matter integrity is affected in huntingtin gene mutation symptomatic individuals, but other studies with larger samples are required to assess its usefulness in the progression of the neurodegenerative process.

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