Segmental Diffusion Properties of the Corticospinal Tract and Motor Outcome in Hemiparetic Children With Perinatal Stroke

Perinatal stroke injures developing motor systems, resulting in hemiparetic cerebral palsy. Diffusion tensor imaging can explore structural connectivity. We used diffusion tensor imaging to assess corticospinal tract diffusion in hemiparetic children with perinatal stroke. Twenty-eight children (6-18 years) with unilateral stroke underwent diffusion tensor imaging. Four corticospinal tract assessments included full tract, partial tract, minitract and region of interest. Diffusion characteristics (fractional anisotropy, mean, axial, and radial diffusivity) were calculated. Ratios (lesioned/nonlesioned) were compared across segments and to validated long-term motor outcomes (Pediatric Stroke Outcome Measure, Assisting Hand Assessment, Melbourne Assessment). Fractional anisotropy and radial diffusivity ratios decreased as tract size decreased, while mean diffusivity showed consistent symmetry. Poor motor outcomes were associated with lower fractional anisotropy in all segments and radial diffusivity correlated with both Assisting Hand Assessment and Melbourne Assessment. Diffusion imaging of segmented corticospinal tracts is feasible in hemiparetic children with perinatal stroke. Correlations with disability support clinical relevance and utility in model development for personalized rehabilitation.

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Brain Connectivity Affecting Gait Function after Unilateral Supratentorial Stroke

Brain Sciences ◽

10.3390/brainsci11070870 ◽

2021 ◽

Vol 11 (7) ◽

pp. 870

Author(s):

Hyun-Ah Lee ◽

Dae-Hyun Kim

Keyword(s):

Diffusion Tensor Imaging ◽

Corpus Callosum ◽

Fractional Anisotropy ◽

Motor Coordination ◽

Diffusion Tensor ◽

Brain Connectivity ◽

Structural Connectivity ◽

Mean Diffusivity ◽

Medial Lemniscus ◽

Gait Function

Gait dysfunction is a leading cause of long-term disability after stroke. The mechanisms underlying recovery of gait function are unknown. We retrospectively evaluated the association between structural connectivity and gait function in 127 patients with unilateral supratentorial stroke (>1 month after stroke). All patients underwent T1-weighted, diffusion tensor imaging and functional ambulation categorization. Voxel-wise linear regression analyses of the images were conducted using fractional anisotropy, mean diffusivity, and mode of anisotropy mapping as dependent variables, while the functional ambulation category was used as an independent variable with age and days after stroke as covariates. The functional ambulation category was positively associated with increased fractional anisotropy in the lesioned cortico-ponto-cerebellar system, corona radiata of the non-lesioned corticospinal tract pathway, bilateral medial lemniscus in the brainstem, and the corpus callosum. The functional ambulation category was also positively associated with increased mode of anisotropy in the lesioned posterior corpus callosum. In conclusion, structural connectivity associated with motor coordination and feedback affects gait function after stroke. Diffusion tensor imaging for evaluating structural connectivity can help to predict gait recovery and target rehabilitation goals after stroke.

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Quantitative diffusion tensor imaging analysis does not distinguish pediatric canines with mucopolysaccharidosis I from control canines

The Neuroradiology Journal ◽

10.1177/1971400917718844 ◽

2017 ◽

Vol 30 (5) ◽

pp. 454-460

Author(s):

Dana M Middleton ◽

Jonathan Y Li ◽

Steven D Chen ◽

Leonard E White ◽

Patricia I Dickson ◽

...

Keyword(s):

Diffusion Tensor Imaging ◽

White Matter ◽

Fractional Anisotropy ◽

Imaging System ◽

Diffusion Tensor ◽

Brain Regions ◽

Magnetic Resonance Imaging System ◽

Radial Diffusivity ◽

Mucopolysaccharidosis I ◽

Diffusivity Measurements

Purpose We compared fractional anisotropy and radial diffusivity measurements between pediatric canines affected with mucopolysaccharidosis I and pediatric control canines. We hypothesized that lower fractional anisotropy and higher radial diffusivity values, consistent with dysmyelination, would be present in the mucopolysaccharidosis I cohort. Methods Six canine brains, three affected with mucopolysaccharidosis I and three unaffected, were euthanized at 7 weeks and imaged using a 7T small-animal magnetic resonance imaging system. Average fractional anisotropy and radial diffusivity values were calculated for four white-matter regions based on 100 regions of interest per region per specimen. A 95% confidence interval was calculated for each mean value. Results No difference was seen in fractional anisotropy or radial diffusivity values between mucopolysaccharidosis affected and unaffected brains in any region. In particular, the 95% confidence intervals for mucopolysaccharidosis affected and unaffected canines frequently overlapped for both fractional anisotropy and radial diffusivity measurements. In addition, in some brain regions a large range of fractional anisotropy and radial diffusivity values were seen within the same cohort. Conclusion The fractional anisotropy and radial diffusivity values of white matter did not differ between pediatric mucopolysaccharidosis affected canines and pediatric control canines. Possible explanations include: (a) a lack of white matter tissue differences between mucopolysaccharidosis affected and unaffected brains at early disease stages; (b) diffusion tensor imaging does not detect any existing differences; (c) inflammatory processes such as astrogliosis produce changes that offset the decreased fractional anisotropy values and increased radial diffusivity values that are expected in dysmyelination; and (d) our sample size was insufficient to detect differences. Further studies correlating diffusion tensor imaging findings to histology are warranted.

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White matter differences between essential tremor and Parkinson disease

Neurology ◽

10.1212/wnl.0000000000006694 ◽

2018 ◽

Vol 92 (1) ◽

pp. e30-e39 ◽

Cited By ~ 5

Author(s):

Meher R. Juttukonda ◽

Giulia Franco ◽

Dario J. Englot ◽

Ya-Chen Lin ◽

Kalen J. Petersen ◽

...

Keyword(s):

White Matter ◽

Parkinson Disease ◽

Essential Tremor ◽

Fractional Anisotropy ◽

Diffusion Tensor ◽

Mean Diffusivity ◽

Superior Cerebellar Peduncle ◽

Radial Diffusivity ◽

Cerebellar Peduncles ◽

Cerebellar Peduncle

ObjectiveTo assess white matter integrity in patients with essential tremor (ET) and Parkinson disease (PD) with moderate to severe motor impairment.MethodsSedated participants with ET (n = 57) or PD (n = 99) underwent diffusion tensor imaging (DTI) and fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity values were computed. White matter tracts were defined using 3 well-described atlases. To determine candidate white matter regions that differ between ET and PD groups, a bootstrapping analysis was applied using the least absolute shrinkage and selection operator. Linear regression was applied to assess magnitude and direction of differences in DTI metrics between ET and PD populations in the candidate regions.ResultsFractional anisotropy values that differentiate ET from PD localize primarily to thalamic and visual-related pathways, while diffusivity differences localized to the cerebellar peduncles. Patients with ET exhibited lower fractional anisotropy values than patients with PD in the lateral geniculate body (p < 0.01), sagittal stratum (p = 0.01), forceps major (p = 0.02), pontine crossing tract (p = 0.03), and retrolenticular internal capsule (p = 0.04). Patients with ET exhibited greater radial diffusivity values than patients with PD in the superior cerebellar peduncle (p < 0.01), middle cerebellar peduncle (p = 0.05), and inferior cerebellar peduncle (p = 0.05).ConclusionsRegionally, distinctive white matter microstructural values in patients with ET localize to the cerebellar peduncles and thalamo-cortical visual pathways. These findings complement recent functional imaging studies in ET but also extend our understanding of putative physiologic features that account for distinctions between ET and PD.

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Discrimination of epileptogenic lesions and perilesional white matter using diffusion tensor magnetic resonance imaging

The Neuroradiology Journal ◽

10.1177/1971400918813991 ◽

2018 ◽

Vol 32 (1) ◽

pp. 10-16

Author(s):

Alexander Rau ◽

Elias Kellner ◽

Niels A Foit ◽

Niklas Lützen ◽

Dieter H Heiland ◽

...

Keyword(s):

White Matter ◽

Fractional Anisotropy ◽

Diffusion Tensor ◽

Focal Cortical Dysplasia ◽

Mean Diffusivity ◽

Area Under The Curve ◽

P Value ◽

Radial Diffusivity ◽

Normal Appearing White Matter ◽

Diffusion Parameters

The aim of this study was to evaluate whether ganglioglioma (GGL), dysembryoplastic neuroepithelial tumour (DNET) and FCD (focal cortical dysplasia) are distinguishable through diffusion tensor imaging. Additionally, it was investigated whether the diffusion measures differed in the perilesional (pNAWM) and in the contralateral normal appearing white matter (cNAWM). Six GGLs, eight DNETs and seven FCDs were included in this study. Quantitative diffusion measures, that is, axial, radial and mean diffusivity and fractional anisotropy, were determined in the lesion identified on isotropic T2 or FLAIR-weighted images and in pNAWM and cNAWM, respectively. DNET differed from FCD in mean diffusivity, and GGL from FCD in radial diffusivity. Both types of glioneuronal tumours were different from pNAWM in fractional anisotropy and radial diffusivity. For identifying the tumour edges, threshold values for tumour-free tissue were investigated with receiver operating characteristic analyses: tumour could be separated from pNAWM at a threshold ≤ 0.32 (fractional anisotropy) or ≥ 0.56 (radial diffusivity) *10–3 mm2/s (area under the curve 0.995 and 0.990 respectively). While diffusion parameters of FCDs differed from cNAWM (radial diffusivity (*10–3 mm/s2): 0.74 ± 0.19 vs. 0.43 ± 0.05; corrected p-value < 0.001), the pNAWM could not be differentiated from the FCD.

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Diffusion Tensor Imaging of the Kidneys: Influence of b-Value and Number of Encoding Directions on Image Quality and Diffusion Tensor Parameters

Journal of Clinical Imaging Science ◽

10.4103/2156-7514.122323 ◽

2013 ◽

Vol 3 ◽

pp. 53 ◽

Cited By ~ 14

Author(s):

Natalie C. Chuck ◽

Günther Steidle ◽

Iris Blume ◽

Michael A. Fischer ◽

Daniel Nanz ◽

...

Keyword(s):

Diffusion Tensor Imaging ◽

Image Quality ◽

Fractional Anisotropy ◽

Diffusion Tensor ◽

Mean Diffusivity ◽

Renal Medulla ◽

Whole Body ◽

Acquisition Time ◽

Data Sets ◽

B Values

Objectives: The purpose of this study was to evaluate to which degree investment of acquisition time in more encoding directions leads to better image quality (IQ) and what influence the number of encoding directions and the choice of b-values have on renal diffusion tensor imaging (DTI) parameters. Material and Methods: Eight healthy volunteers (32.3 y ± 5.1 y) consented to an examination in a 1.5T whole-body MR scanner. Coronal DTI data sets of the kidneys were acquired with systematic variation of b-values (50, 150, 300, 500, and 700 s/mm2) and number of diffusion-encoding directions (6, 15, and 32) using a respiratory-triggered echo-planar sequence (TR/TE 1500 ms/67 ms, matrix size 128 × 128). Additionally, two data sets with more than two b-values were acquired (0, 150, and 300 s/mm2 and all six b-values). Parametrical maps were calculated on a pixel-by-pixel basis. Image quality was determined with a reader score. Results: Best IQ was visually assessed for images acquired with 15 and 32 encoding directions, whereas images acquired with six directions had significantly lower IQ ratings. Image quality, fractional anisotropy, and mean diffusivity only varied insignificantly for b-values between 300 and 500 s/mm2. In the renal medulla fractional anisotropy (FA) values between 0.43 and 0.46 and mean diffusivity (MD) values between 1.8-2.1 × 10-3 mm2/s were observed. In the renal cortex, the corresponding ranges were 0.24-0.25 (FA) and 2.2-2.8 × 10-3 mm2/s (MD). Including b-values below 300 s/mm2, notably higher MD values were observed, while FA remained constant. Susceptibility artifacts were more prominent in FA maps than in MD maps. Conclusion: In DTI of the kidneys at 1.5T, the best compromise between acquisition time and resulting image quality seems the application of 15 encoding directions with b-values between 300 and 500 s/mm2. Including lower b-values allows for assessment of fast diffusing spin components.

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Diffusion Tensor Imaging Evaluation of Corticospinal Tract Hyperintensity in Upper Motor Neuron-Predominant ALS Patients

Journal of Aging Research ◽

10.4061/2011/481745 ◽

2011 ◽

Vol 2011 ◽

pp. 1-9 ◽

Cited By ~ 8

Author(s):

Venkateswaran Rajagopalan ◽

Didier Allexandre ◽

Guang H. Yue ◽

Erik P. Pioro

Keyword(s):

Diffusion Tensor Imaging ◽

Motor Neuron ◽

Corticospinal Tract ◽

Diffusion Tensor ◽

Mean Diffusivity ◽

Internal Capsule ◽

Proton Density ◽

Imaging Evaluation ◽

Axonal Pathology ◽

Als Patients

Amyotrophic lateral sclerosis (ALS) patients with predominant upper motor neuron (UMN) signs occasionally have hyperintensity of corticospinal tract (CST) on T2- and proton-density-(PD-) weighted brain images. Diffusion tensor imaging (DTI) was used to assess whether diffusion parameters along intracranial CST differ in presence or absence of hyperintensity and correspond to UMN dysfunction. DTI brain scans were acquired in 47 UMN-predominant ALS patients with (n=21) or without (n=26) CST hyperintensity and in 10 control subjects. Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were measured in four regions of interests (ROIs) along CST. Abnormalities (P<0.05) were observed in FA, AD, or RD in CST primarily at internal capsule (IC) level in ALS patients, especially those with CST hyperintensity. Clinical measures corresponded well with DTI changes at IC level. The IC abnormalities suggest a prominent axonopathy in UMN-predominant ALS and that tissue changes underlying CST hyperintensity have specific DTI changes, suggestive of unique axonal pathology.

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Migraine affects white-matter tract integrity: A diffusion-tensor imaging study

Cephalalgia ◽

10.1177/0333102415573513 ◽

2015 ◽

Vol 35 (13) ◽

pp. 1162-1171 ◽

Cited By ~ 26

Author(s):

Catherine D Chong ◽

Todd J Schwedt

Keyword(s):

Diffusion Tensor Imaging ◽

White Matter ◽

Corticospinal Tract ◽

Diffusion Tensor ◽

Mean Diffusivity ◽

Imaging Study ◽

White Matter Tract ◽

Inferior Longitudinal Fasciculus ◽

Left And Right ◽

The Right

Background Specific white-matter tract alterations in migraine remain to be elucidated. Using diffusion tensor imaging (DTI), this study investigated whether the integrity of white-matter tracts that underlie regions of the “pain matrix” is altered in migraine and interrogated whether the number of years lived with migraine modifies fibertract structure. Methods Global probabilistic tractography was used to assess the anterior thalamic radiations, the corticospinal tracts and the inferior longitudinal fasciculi in 23 adults with migraine and 18 healthy controls. Results Migraine patients show greater mean diffusivity (MD) in the left and right anterior thalamic radiations, the left corticospinal tract, and the right inferior longitudinal fasciculus tract. Migraine patients also show greater radial diffusivity (RD) in the left anterior thalamic radiations, the left corticospinal tract as well as the left and right inferior longitudinal fasciculus tracts. No group fractional anisotropy (FA) differences were identified for any tracts. Migraineurs showed a positive correlation between years lived with migraine and MD in the right anterior thalamic radiations ( r = 0.517; p = 0.012) and the left corticospinal tract ( r = 0.468; p = 0.024). Conclusion Results indicate that white-matter integrity is altered in migraine and that longer migraine history is positively correlated with greater alterations in tract integrity.

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DIFFUSION TENSOR TRACTOGRAPHY

Neurosurgery ◽

10.1227/01.neu.0000325259.95571.20 ◽

2008 ◽

Vol 63 (3) ◽

pp. 452-459 ◽

Cited By ~ 6

Author(s):

Wai Hoe Ng ◽

Dennis Lai-Hong Cheong ◽

Kathleen Joy Khu ◽

Govidasamy Venkatesh ◽

Yee Kong Ng ◽

...

Keyword(s):

Diffusion Tensor Imaging ◽

Magnetic Resonance ◽

Fractional Anisotropy ◽

Corticospinal Tract ◽

Tumor Volume ◽

Diffusion Tensor ◽

Diffusion Tensor Tractography ◽

Significant Difference ◽

Fiber Number ◽

And Diffusion

ABSTRACT OBJECTIVE Benign extracerebral lesions such as meningiomas may cause hemiparesis by compression and deviation without infiltrating the white matter. We used magnetic resonance diffusion tensor imaging and diffusion tensor tractography to investigate the effects of benign extracerebral lesions on the corticospinal tract (CST). METHODS Thirteen patients with extracerebral lesions (11 benign meningiomas and 2 benign cysts) underwent magnetic resonance diffusion tensor imaging and diffusion tensor tractography of the CST using fiber assignment by continuous tractography. The CST was reconstructed and assessed by comparing the ipsilateral and unaffected contralateral fibers. The tumor volume, relative fractional anisotropy, fiber deviation, relative fiber number, and relative fiber per voxel were compared between patients without and with temporary presurgical hemiparesis. RESULTS Seven patients without hemiparesis and five patients with temporary hemiparesis were analyzed; one patient had permanent weakness and was excluded from analysis. There was no significant difference in the tumor volume, relative fractional anisotropy, presence of cerebral edema, or CST deviation between groups. In patients with temporary hemiparesis, the median relative fiber number (mean, 0.35 ± 0.32) and relative fiber per voxel (mean, 0.49 ± 0.14) were significantly reduced compared with patients without hemiparesis (0.92 ± 0.55, P = 0.04; and 0.96 ± 0.28, P < 0.01, respectively). CONCLUSION In patients with benign extracerebral lesions, reduction in fiber number and fiber per voxel, but not fiber deviation, correlated with temporary hemiparesis. Clinical recovery was possible even if the CST fibers detected by diffusion tensor tractography were reduced by benign extracerebral lesions.

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