Microscopic Fractional Anisotropy Detects Cognitive Training-Induced Microstructural Brain Changes

Cognitive training-induced neuroplastic brain changes have been reported. This prospective study evaluated whether microscopic fractional anisotropy (μFA) derived from double diffusion encoding (DDE) MRI could detect brain changes following a 4 week cognitive training. Twenty-nine healthy volunteers were recruited and randomly assigned into the training (n = 21) and control (n = 8) groups. Both groups underwent brain MRI including DDE MRI and 3D-T1-weighted imaging twice at an interval of 4–6 weeks, during which the former underwent the training. The training consisted of hour-long dual N-back and attention network tasks conducted five days per week. Training and time-related changes of DDE MRI indices (μFA, fractional anisotropy (FA), and mean diffusivity (MD)) and the gray and white matter volume were evaluated using mixed-design analysis of variance. In addition, any significant imaging indices were tested for correlation with cognitive training-induced task performance changes, using partial correlation analyses. μFA in the left middle frontal gyrus decreased upon the training (53 voxels, uncorrected p < 0.001), which correlated moderately with response time changes in the orienting component of attention (r = −0.521, uncorrected p = 0.032). No significant training and time-related changes were observed for other imaging indices. Thus, μFA can become a sensitive index to detect cognitive training-induced neuroplastic changes.

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Neural Changes Induced by a Speech Motor Treatment in Childhood Apraxia of Speech: A Case Series

Journal of Child Neurology ◽

10.1177/08830738211015800 ◽

2021 ◽

pp. 088307382110158

Author(s):

Simona Fiori ◽

Kerstin Pannek ◽

Irina Podda ◽

Paola Cipriani ◽

V. Lorenzoni ◽

...

Keyword(s):

Fractional Anisotropy ◽

Brain Mri ◽

Case Series ◽

Mean Diffusivity ◽

Treated Group ◽

Apraxia Of Speech ◽

Childhood Apraxia Of Speech ◽

Motor Speech ◽

Corticobulbar Tract ◽

Speech Motor

We report a case series of children with childhood apraxia of speech, by describing behavioral and white matter microstructural changes following 2 different treatment approaches. Five children with childhood apraxia of speech were assigned to a motor speech treatment (PROMPT) and 5 to a language, nonspeech oral motor treatment. Speech assessment and brain MRI were performed pre- and post-treatment. The ventral (tongue/larynx) and dorsal (lips) corticobulbar tracts were reconstructed in each subject. Mean fractional anisotropy and mean diffusivity were extracted. The hand corticospinal tract was assessed as a control pathway. In both groups speech improvements paralleled changes in the left ventral corticobulbar tract fractional anisotropy. The PROMPT treated group also showed fractional anisotropy increase and mean diffusivity decrease in the left dorsal corticobulbar tract. No changes were detected in the hand tract. Our results may provide preliminary support to the possible neurobiologic effect of a multimodal speech motor treatment in childhood apraxia of speech.

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Breast milk exposure is associated with cortical maturation in preterm infants

10.1101/2022.01.04.22268723 ◽

2022 ◽

Author(s):

Gemma Sullivan ◽

Kadi Vaher ◽

Manuel Blesa ◽

Paola Galdi ◽

David Q Stoye ◽

...

Keyword(s):

Preterm Birth ◽

Breast Milk ◽

Fractional Anisotropy ◽

Preterm Infants ◽

Gestational Age ◽

Brain Mri ◽

Mean Diffusivity ◽

Brain Morphology ◽

Radial Diffusivity ◽

Nutritional Data

Breast milk exposure is associated with improved neurocognitive outcomes following preterm birth but the neural substrates linking nutrition with outcome are uncertain. By combining nutritional data with brain MRI, we tested the hypothesis that high versus low breast milk exposure in preterm infants during neonatal care results in a cortical morphology that more closely resembles that of infants born at term. We studied 135 preterm (mean gestational age 30+2 weeks, range 22+1 to 32+6) and 77 term-born infants (mean gestational age 39+4 weeks, range 36+3 to 42+1). Nutritional data was collected from birth until hospital discharge to identify the proportion of days preterm infants received exclusive breast milk. Structural and diffusion MRI were performed at term-equivalent age. Cortical indices (volume, thickness, surface area, gyrification index, sulcal depth, curvature) and water diffusion parameters (fractional anisotropy, mean diffusivity, radial diffusivity, axial diffusivity, neurite density index, orientation dispersion index) were compared between preterm infants who received exclusive breast milk for <75% of inpatient days (n=68), preterm infants who received exclusive breast milk for ≥75% of inpatient days (n=67) and term-born controls (n=77). High breast milk exposure was associated with reduced cortical gray matter volume (d=0.47, p=0.014), thickness (d=0.42, p=0.039) and radial diffusivity (d=0.38, p=0.039), and increased fractional anisotropy (d=0.38, p=0.037) after adjustment for age at MRI. High versus low breast milk exposure in the weeks following preterm birth is associated with a cortical imaging phenotype that more closely resembles the brain morphology of healthy infants born at term.

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Persistently higher serum sCD40L levels are associated with outcome in septic patients

BMC Anesthesiology ◽

10.1186/s12871-021-01241-9 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Yingjian Liang ◽

Chengrui Zhu ◽

Yini Sun ◽

Zhiliang Li ◽

Liang Wang ◽

...

Keyword(s):

Intensive Care Unit ◽

Septic Shock ◽

Odds Ratio ◽

Cd40 Ligand ◽

Surgical Patients ◽

Soluble Cd40 Ligand ◽

Icu Admission ◽

Time Changes ◽

And Control ◽

Type Of Surgery

Abstract Background Soluble CD40 ligand (sCD40L) exhibits proinflammatory and procoagulant effects. Recent data indicated that sCD40L plays a significant role in septic patients. The aim of the present study was to determine sCD40L changes in surgical patients without sepsis (SWS) and surgical sepsis patients (SS) during the first 3 days after intensive care unit (ICU) admission and to observe the association between sCD40L and mortality. Methods Time changes in sCD40L levels were assessed for 3 days after ICU admission in 49 patients with SS and compared with those in 19 SWS patients. Serum sCD40L concentration was detected by ELISA. Survival at 28 days served as the endpoint. Results SS had significantly higher sCD40L levels than SWS and control patients. We observed an association between sCD40L levels ≥1028.75 pg/mL at day 2 and 28-day mortality (odds ratio = 7.888; 95% confidence interval = 1.758 to 35.395; P = 0.007). We could not discover any significant differences in sex, presence of septic shock, site of infection, length of stay in the ICU, PaO2/FiO2 ratio, incidence of AKI, ARDS, or type of surgery between nonsurvivors and survivors. Conclusions Septic patients show persistently higher circulating sCD40L levels in the first 3 days after ICU admission, and serum sCD40L levels are associated with the mortality of patients with sepsis. Thus, serum sCD40L may be used as a reliable biomarker and therapeutic target in sepsis.

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Abstract T P234: Multiparametric Assessment of Longitudinal Changes in Tissue Microstructure in Normal and Abnormal Brain Tissue in Patients with Small Vessel Disease

Stroke ◽

10.1161/str.46.suppl_1.tp234 ◽

2015 ◽

Vol 46 (suppl_1) ◽

Author(s):

Maria D Valdes-Hernandez ◽

Paul A Armitage ◽

Eleni Sakka ◽

Susana Munoz Maniega ◽

Natalie A Royle ◽

...

Keyword(s):

White Matter ◽

Brain Tissue ◽

Small Vessel Disease ◽

Brain Mri ◽

Mean Diffusivity ◽

Tissue Loss ◽

Minor Stroke ◽

Normal Brain ◽

Limited Information ◽

Time Points

Background: Volume measures of normal brain tissue and white matter hyperintensities (WMH) between two time points gives limited information about the complex dynamics of tissue change. We evaluated two quantitative parameters that characterise the microstructure of normal-appearing white matter (NAWM), deep grey matter (DGM) and WMH on brain images obtained at presentation with minor stroke and at 1 year to investigate the microstructural changes. Methods: From 182 brain MRI datasets of patients with minor stroke obtained at baseline and 1 year, we extracted the WMH, DGM and NAWM, and separated WMH into less-intense and intense WMH, using validated semi-automatic methods and validated criteria. We registered the binary structural masks to diffusion space and performed a voxel-wise subtraction of the combined masks at both time points. Then we measured fractional anisotropy (FA) and mean diffusivity (MD)(valuex10 -9 m 2 /s) in each tissue mask at baseline and 1 year. Results: WMH volume median increase was 1.4ml (IQR 6.98) mainly due to changes in less-intense WMH: 0.94ml (7.13). WMH that were visible at both time points, ie damage that remained after a year, had the lowest FA= 0.21(0.06) and highest MD=1.05(0.12) at baseline, and were mainly intense WMH at baseline (FA=0.12(0.03), MD=1.55(0.27)). WMH seen only at follow-up, ie that were NAWM at baseline, had the highest FA=0.30(0.06) and lowest MD=0.85 (0.06) at baseline. WMH that were observed only at baseline had intermediate FA=0.26(0.08) and MD=0.90(0.10). NAWM FA=0.26(0.03), MD=0.78(0.04) and DGM FA=0.23(0.03), MD=0.79(0.06) did not change between time points. Conclusions: WMH at baseline can partially evolve to normal-appearing tissues, remain or precede tissue loss. Differentiation between severe and subtle damage and spatial analysis are necessary to characterise the dynamic of WMH evolution.

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A Correlational Study between Microstructural White Matter Properties and Macrostructural Gray Matter Volume Across Normal Ageing: Conjoint DTI and VBM Analysis

Magnetic Resonance Insights ◽

10.1177/1178623x18799926 ◽

2018 ◽

Vol 11 ◽

pp. 1178623X1879992 ◽

Cited By ~ 4

Author(s):

Vikas Pareek ◽

VP Subramanyam Rallabandi ◽

Prasun K Roy

Keyword(s):

White Matter ◽

Life Span ◽

Fractional Anisotropy ◽

Gray Matter ◽

Healthy Aging ◽

Gray Matter Volume ◽

Mean Diffusivity ◽

Radial Diffusivity ◽

Axial Diffusivity ◽

Matter Volume

We investigate the relationship between Gray matter’s volume vis-a-vis White matter’s integrity indices, such Axial diffusivity, Radial diffusivity, Mean diffusivity, and Fractional anisotropy, in individuals undergoing healthy aging. We investigated MRI scans of 177 adults across 20 to 85 years. We used Voxel-based morphometry, and FDT-FSL analysis for estimation of Gray matter volume and White matter’s diffusion indices respectively. Across the life span, we observed an inter-relationship between the Gray matter and White matter, namely that both Axial diffusivity and Mean Diffusivity show strong correlation with Gray matter volume, along the aging process. Furthermore, across all ages the Fractional anisotropy and Mean diffusivity are found to be significantly reduced in females when compared to males, but there are no significant gender differences in Axial Diffusivity and Radial diffusivity. We conclude that for both genders across all ages, the Gray matter’s Volume is strongly correlated with White matter’s Axial Diffusivity and Mean Diffusivity, while being weakly correlated with Fractional Anisotropy. Our study clarifies the multi-scale relationship in brain tissue, by elucidating how the White matter’s micro-structural parameters influences the Gray matter’s macro-structural characteristics, during healthy aging across the life-span.

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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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Experimental Study on the Recirculation of Homogeneous and Stratified Fluid Layers in the Advanced Solar Pond

Journal of Solar Energy Engineering ◽

10.1115/1.2930501 ◽

1994 ◽

Vol 116 (2) ◽

pp. 74-78 ◽

Cited By ~ 1

Author(s):

Y. Keren ◽

H. Rubin ◽

G. A. Bemporad

Keyword(s):

Double Diffusion ◽

Stratified Fluid ◽

Experimental Investigations ◽

Laboratory Setup ◽

Solar Pond ◽

Fluid Layers ◽

Data Density ◽

And Control ◽

Stable Flow ◽

Transient And Steady State

The practical possibilities of constructing and operating a stable flow of homogeneous and stratified fluid layers in a solar pond were investigated in this study. A laboratory setup was prepared to carry out the experimental investigations. Transient and steady-state conditions were analyzed. A numerical model was developed to simulate heat, salt, and momentum transfer in the water body. The model was calibrated with the experimental data. Density and temperature measurements along the laboratory setup showed the configuration to be stable in all of the conditions which were analyzed. These experimental results indicated that through a proper multiselective injection and withdrawal procedure it was possible to create and control the double-diffusion stratified fluid layers, which characterizes the advanced solar pond.

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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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TRANSCORTICAL SENSORY APHASIA AS A MANIFESTATION OF ISCHEMIC STROKE WITH INTRACARDIAC THROMBUS

10.36106/ijar/4021269 ◽

2021 ◽

pp. 86-86

Author(s):

Aziz Ahizoune ◽

Ahmed Bourazza

Keyword(s):

Language Impairment ◽

Brain Mri ◽

Semantic Knowledge ◽

Sudden Onset ◽

Left Middle Cerebral Artery ◽

Intracardiac Thrombus ◽

Auditory Comprehension ◽

Sensory Aphasia ◽

History Of ◽

Left Middle

Transcortical sensory aphasia is characterized by impaired auditory comprehension, with intact repetition and uent speech. A 44-year-old right-handed patient with a history of hypertension on amlodipine and ischemic heart disease on aspirin was admitted to the neurology department for sudden onset of language impairment that started 2 days ago. The patient had features of transcortical sensory aphasia. Brain MRI showed an infarct in the territory of the left middle cerebral artery involving the tempo-parietal region. An apical thrombus was observed in the left ventricle on transthoracic echocardiography. This language impairment is thought to be caused by a disconnection between sensory language processes and semantic knowledge of objects. The prognosis is generally guarded and depends on the etiology and severity of the presentation

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