scholarly journals Midbrain injury in patients with subarachnoid hemorrhage: a diffusion tensor imaging study

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Sung Ho Jang ◽  
Young Hyeon Kwon
Keyword(s):  
Diffusion Tensor Imaging ◽  
Subarachnoid Hemorrhage ◽  
Patient Group ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Control Group ◽  
Pathophysiological Mechanism ◽  
Ventral Midbrain ◽  
Midbrain Tegmentum ◽  
The Mean

AbstractWe investigated the characteristics of midbrain injuries in patients with spontaneous subarachnoid hemorrhage (SAH) by using diffusion tensor imaging (DTI). Twenty-seven patients with SAH and 25 healthy control subjects were recruited for this study. Fractional anisotropy (FA) and mean diffusivity (MD) data were obtained for four regions of the midbrain (the anterior ventral midbrain, posterior ventral midbrain, tegmentum area, and tectum) in 27 hemispheres that did not show any pathology other than SAH. The mean FA and MD values of the four regions of the midbrain (anterior ventral midbrain, posterior ventral midbrain, tegmentum, and tectum) of the patient group were significantly lower and higher than those of the control group, respectively (p < 0.05). The mean FA values of the patient group were significantly different among the anterior ventral midbrain, posterior ventral midbrain, tegmentum, and tectum regions (ANOVA; F = 3.22, p < 0.05). Post hoc testing showed that the mean FA value of the anterior ventral midbrain was significantly lower than those of the posterior ventral midbrain, tegmentum, and tectum (p < 0.05); in contrast, there were no differences in mean FA values of the posterior ventral midbrain, tegmentum, and tectum (p > 0.05). However, differences were not observed among four regions of the midbrain (anterior ventral midbrain, posterior ventral midbrain, tegmentum, and tectum) in the mean MD values. We detected evidence of neural injury in all four regions of the midbrain of patients with SAH, and the anterior ventral midbrain was the most severely injured among four regions of the midbrain. Our results suggest that a pathophysiological mechanism of these neural injuries might be related to the occurrence of a subarachnoid hematoma.

scholarly journals Midbrain Injury in Patients With Subarachnoid Hemorrhage: A Diffusion Tensor Imaging Study

2021 ◽  
Author(s):  
Sung Ho Jang ◽  
Young Hyeon Kwon
Keyword(s):  
Diffusion Tensor Imaging ◽  
Subarachnoid Hemorrhage ◽  
Patient Group ◽  
Diffusion Tensor ◽  
Imaging Study ◽  
Control Group ◽  
Pathophysiological Mechanism ◽  
Ventral Midbrain ◽  
Midbrain Tegmentum ◽  
The Mean

Abstract We investigated the characteristics of midbrain injuries in patients with spontaneous subarachnoid hemorrhage (SAH) by using diffusion tensor imaging (DTI). Twenty-seven patients with SAH and 25 healthy control subjects were recruited for this study. Fractional anisotropy (FA) data were obtained for four regions of the midbrain (the anterior ventral midbrain, posterior ventral midbrain, tegmentum area, and tectum) in 27 hemispheres that did not show any pathology other than SAH. The mean FA values of the four regions of the midbrain (anterior ventral midbrain, posterior ventral midbrain, tegmentum, and tectum) of the patient group were significantly lower than those of the control group (p < 0.05). The mean FA values of the patient group were significantly different among the anterior ventral midbrain, posterior ventral midbrain, tegmentum, and tectum regions (ANOVA; F = 3.22, p < 0.05). Post hoc testing showed that the mean FA value of the anterior ventral midbrain was significantly lower than those of the posterior ventral midbrain, tegmentum, and tectum (p < 0.05); in contrast, there were no differences in mean FA values of the posterior ventral midbrain, tegmentum, and tectum (p > 0.05). We detected evidence of neural injury in all four regions of the midbrain of patients with SAH, and the anterior ventral midbrain was the most severely injured among four regions of the midbrain. Our results suggest that a pathophysiological mechanism of these neural injuries might be related to the occurrence of a subarachnoid hematoma.

Diffusion Tensor Imaging in Patients With Adult Chronic Idiopathic Hydrocephalus

Neurosurgery ◽  
2010 ◽  
Vol 66 (5) ◽  
pp. 917-924 ◽  
Author(s):  
Elke Hattingen ◽  
Alina Jurcoane ◽  
Julia Melber ◽  
Stella Blasel ◽  
Friedhelm E. Zanella ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Normal Pressure ◽  
Clinical Findings ◽  
Control Group ◽  
Microstructural Changes ◽  
Automated Method ◽  
Definition Of ◽  
Lumbar Cerebrospinal Fluid

Abstract OBJECTIVE Diffusion tensor imaging (DTI) parameters were investigated in patients with chronic idiopathic hydrocephalus to evaluate microstructural changes of brain tissue caused by chronic ventricular dilatation. METHODS Eleven patients fulfilling the criteria for possible or probable idiopathic normal pressure hydrocephalus and 10 healthy control subjects underwent MRI at 3 Tesla, including DTI with 12 gradient directions. Patients were scanned before lumbar cerebrospinal fluid (CSF) withdrawal tests. Differences in fractional anisotropy (FA) and mean diffusivity (MD) between patients and controls were assessed using 2 different methods: manual definition of regions of interest and a fully automated method, TBSS (Tract-Based Spatial Statistics). DTI parameters were correlated with clinical findings. RESULTS Compared with the control group, patients with chronic idiopathic hydrocephalus had significantly higher MD values in both the periventricular corticospinal tract (CST) and the corpus callosum (CC), whereas FA values were significantly higher in the CST but lower in the CC. DTI parameters of the CST correlated with the severity of gait disturbances. CONCLUSION Microstructural changes in periventricular functionally relevant white matter structures (CSF, CC) in chronic idiopathic hydrocephalus can be visualized using DTI. Further studies should investigate the change of DTI parameters after CSF shunting and its relation to neurologic outcome.

Characterization of abnormal diffusion properties of supratentorial brain tumors: a preliminary diffusion tensor imaging study

2008 ◽  
Vol 1 (4) ◽  
pp. 263-269 ◽  
Author(s):  
Weihong Yuan ◽  
Scott K. Holland ◽  
Blaise V. Jones ◽  
Kerry Crone ◽  
Francesco T. Mangano
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Imaging Study ◽  
Low Grade ◽  
High Grade ◽  
The Mean ◽  
Supratentorial Tumors ◽  
Diffusion Properties

Object Diffusion tensor (DT) imaging was used in children with supratentorial tumors to evaluate the anisotropic diffusion properties between different tumor grades and between tumors and adjacent and contralateral white matter. Methods In this retrospective review, the authors review the cases of 16 children (age range 1–18 years) who presented to their institution with supratentorial tumors and were treated between 2004 and 2007. Eleven patients had low-grade and 5 had high-grade tumors. Fractional anisotropy (FA), mean diffusivity, and axial (λ∥) and radial (λ⊥) eigenvalues within selected regions were studied. Mitotic index, necrosis, and vascularity of the tumors were compared with DT imaging parameters. Results The mean diffusivity was significantly higher in low-grade than in high-grade tumors (p = 0.04); the 2 tumor grades also significantly differed for both λ∥ (p < 0.05) and λ⊥ (p < 0.05). Mean diffusivity values in low-grade tumors were significantly higher than in adjacent normal-appearing white matter (NAWM; p = 0.0004) and contralateral NAWM (p = 0.0001). In both low- and high-grade tumors, the FA was significantly lower than in NAWM (p < 0.0001 and p < 0.03, respectively) and contralateral NAWM (p < 0.0001 and p < 0.003, respectively). Tumor cellularity highly correlated with mean diffusivity and λ∥and λ⊥. Conclusions Diffusion tensor imaging is a useful tool in the evaluation of supratentorial tumors in children. The mean diffusivity appears to be a significant marker in differentiating tumors grades. Findings related to λ∥ and λ⊥ within tumor groups and between tumors and NAWM may be an indirect manifestation of the combined effects of axonal injury, demyelination, and tumor mass within the cranial compartment.

scholarly journals Diffusion tensor imaging of dorsal stream language areas in patients with post-stroke aphasia

2022 ◽  
Vol 53 (1) ◽  
Author(s):  
Azza Elmongui ◽  
Ahmed AbdelRazek ◽  
Tamer Abou-Elsaad ◽  
Tamer Belal ◽  
Noha Ibrahim ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Dorsal Stream ◽  
Functional Independence ◽  
Post Stroke ◽  
Non Invasive ◽  
The Mean ◽  
Sensitivity Specificity ◽  
Language Areas

Abstract Background Aphasia complicating stroke occurs due to language deficits that decrease communication abilities and functional independence. Our study aims to assess fractional anisotropy (FA) and mean diffusivity (MD) parameters of diffusion tensor imaging (DTI) of the dorsal stream language areas in patients with post-stroke aphasia. It was conducted on 27 patients with post-stroke aphasia and 27 age- and sex-matched controls who underwent DTI of the brain. FA and MD values of Broca's area (BA), Wernick's area (WA), superior longitudinal fasciculus (SLF), and arcuate fasciculus (AF), and number of tract fibers (TF) of AF and SLF were calculated. Results were correlated with National Institutes of Health Stroke Scale (NIHSS), Arabic version of Comprehensive Aphasia Test (Arabic CAT), and Mansoura Arabic Screening Aphasia Test (MASAT). Results FA of AF and SLF in patients was significantly lower (P = 0.001) than controls. MD of AF and SLF in patients was significantly higher (P = 0.001) than controls. The mean volume TF of AF and SLF in patients was significantly (P = 0.001) lower than the mean volume in controls for AF and SLF. FA cutoff for AF was 0.34 and for SLF, it was 0.35 with sensitivity, specificity, and accuracy (85.2%, 62.1%, 73.2%) for AF, (74.1%, 69%, 71.4%) for SLF, respectively. MD cutoff value for AF was 0.87, and 0.84 for SLF with sensitivity, specificity, and accuracy (63%, 72.4%, 67.8%) for AF, (81.5%, 79.3%, 80.4%) for SLF, respectively. Cutoff TF of AF was 1728 and for SLF it was 601 with sensitivity, specificity, and accuracy (88.9%, 72.4%, 80.4%) for AF and (85.2%, 85.2%, 78.6%) for SLF, respectively. Conclusions DTI is a non-invasive promising method that can be used to assess language areas in patients with post-stroke aphasia.

scholarly journals High-Resolution 3D in vivo Brain Diffusion Tensor Imaging at Ultrahigh Fields: Following Maturation on Juvenile and Adult Mice

2020 ◽  
Vol 14 ◽  
Author(s):  
Maxime Yon ◽  
Qingjia Bao ◽  
Odélia Jacqueline Chitrit ◽  
Rafael Neto Henriques ◽  
Noam Shemesh ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
High Resolution ◽  
Olfactory Bulb ◽  
Diffusion Tensor ◽  
Post Partum ◽  
Mean Diffusivity ◽  
Planar Imaging ◽  
The Mean ◽  
Ultrahigh Fields

Diffusion tensor imaging (DTI) is a well-established technique for mapping brain microstructure and white matter tracts in vivo. High resolution DTI, however, is usually associated with low intrinsic sensitivity and therefore long acquisition times. By increasing sensitivity, high magnetic fields can alleviate these demands, yet high fields are also typically associated with significant susceptibility-induced image distortions. This study explores the potential arising from employing new pulse sequences and emerging hardware at ultrahigh fields, to overcome these limitations. To this end, a 15.2 T MRI instrument equipped with a cryocooled surface transceiver coil was employed, and DTI experiments were compared between SPatiotemporal ENcoding (SPEN), a technique that tolerates well susceptibility-induced image distortions, and double-sampled Spin-Echo Echo-Planar Imaging (SE-EPI) methods. Following optimization, SE-EPI afforded whole brain DTI maps at 135 μm isotropic resolution that possessed higher signal-to-noise ratios (SNRs) than SPEN counterparts. SPEN, however, was a better alternative to SE-EPI when focusing on challenging regions of the mouse brain –including the olfactory bulb and the cerebellum. In these instances, the higher robustness of fully refocused SPEN acquisitions coupled to its built-in zooming abilities, provided in vivo DTI maps with 75 μm nominal isotropic spatial resolution. These DTI maps, and in particular the mean diffusion direction (MDD) details, exhibited variations that matched very well the anatomical features known from histological brain Atlases. Using these capabilities, the development of the olfactory bulb (OB) in live mice was followed from week 1 post-partum, until adulthood. The diffusivity of this organ showed a systematic decrease in its overall isotropic value and increase in its fractional anisotropy with age; this maturation was observed for all regions used in the OB's segmentation but was most evident for the lobules' centers, in particular for the granular cell layer. The complexity of the OB neuronal connections also increased during maturation, as evidenced by the growth in directionalities arising in the mean diffusivity direction maps.

Quantitative Diffusion Tensor Imaging (DTI) Analysis Reveals Different Infiltrative Patterns of Oligodendrogliomas and Astrocytomas in Peri-Tumour White Matter

Neurosurgery ◽  
2019 ◽  
Vol 84 (5) ◽  
pp. E273-E273
Author(s):  
Christopher Murphy ◽  
Erjon Agushi ◽  
Zhangjie Su ◽  
Rainer Hinz ◽  
Federico Roncaroli ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Control Group ◽  
Control Data ◽  
Primary Brain Tumours ◽  
Diffusion Parameters ◽  
Grade Ii ◽  
Diffusion Tensor Imaging Dti

Abstract INTRODUCTION Gliomas are highly infiltrative primary brain tumours. Glioma infiltration is difficult to identify clinically using conventional diagnostic imaging. We used diffusion tensor imaging (DTI) to identify glioma infiltration in peritumour white matter (WM) and characterized differences between histological subtypes. METHODS We recruited 8 patients with a histological diagnosis of grade II or III glioma and 10 healthy controls. We compared fractional anisotropy (FA) maps of each patient against the control group using SPM8 (Matlab 2014a) to identify regions of glioma infiltration. The FA and mean diffusivity (MD) of formerly WM matter tumour regions, infiltrated WM and normal appearing WM were compared with a 2-sample t-test and characterized with respect to normal control data. RESULTS Our results have identified radiological evidence of infiltration in the peri-tumour WM of glioma patients. The infiltrated region of oligodendrogliomas extended further than that of astrocytomas. Oligodendrogliomas preferentially infiltrated larger WM tracts, whereas astrocytomas infiltrated more peripheral WM. In all grades, the 3 regions had significantly different diffusion parameters and there were significant differences between oligodendrogliomas and astrocytomas. CONCLUSION We identified previously unrecognized study wide significant changes in the peri-tumour WM of gliomas. Despite the known propensity of these tumours to infiltrate WM we found no significant DTI changes distant to the tumour. Our DTI results suggest oligodendrogliomas and astrocytomas demonstrate different infiltrative patterns, which highlights the need for astrocytomas and oligodendrogliomas to be studied separately.

scholarly journals Use of diffusion-weighted imaging and diffusion tensor imaging in assessment of myometrial invasion in patients of endometrial carcinoma and its correlation with histopathological grading (Prospective study)

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Mahmoud Abdel-Latif ◽  
Hebatullah Safwat Mosaad
Keyword(s):  
Diffusion Tensor Imaging ◽  
Endometrial Carcinoma ◽  
Diffusion Tensor ◽  
Histological Grade ◽  
Mean Diffusivity ◽  
Myometrial Invasion ◽  
Endometrioid Adenocarcinoma ◽  
Diffusion Weighted ◽  
The Mean ◽  
And Diffusion

Abstract Background Endometrial cancer (EMC) is considered one of the most common gynecological cancers worldwide. In particular, the depth of myometrial invasion and histological grade of endometrial cancers (EMCs) are strong prognostic factors. Diffusion tensor measurements as mean diffusivity (MD) and fractional anisotropy (FA) values could be useful for assessing the depth of tumor invasion and its histological grade. The study aimed to evaluate the role of diffusion-weighted imaging (DWI) and diffusion tensor imaging in the detection of myometrial invasion in cases of endometrial carcinoma and prediction of its grade in vivo. Results This study included 50 female patients with pathologically proved endometrial carcinoma, and their ages ranged from 38 to 67 years; the mean age was 56.15 years (± 8.229 standard deviation “SD”). There was a significant statistical difference regarding the mean values of diffusion tensor fractional anisotropy (DT-FA), diffusion tensor mean diffusivity (DT-MD) and diffusion-weighted apparent diffusion coefficient(DW-ADC) values in differentiating between intact and infiltrated myometrium with (P value ≤ 0.001). The accuracy of DT-MD, DT-FA and DWI-ADC was 98%, 90% and 86%, respectively, in the detection of myometrial invasion. There was a statistically significant difference in the mean values of DT-FA, DT-MD and DW-ADC for differentiating endometrioid adenocarcinoma grades with the overall P values (˂0.001). The accuracy of DT-FA, DT- MD and DWI-ADC for differentiating grade 3 from grade 1 or 2 endometrioid adenocarcinoma was 94.9%, 84.6% and 74.4%, respectively. For differentiating grade 1 from grade 2 or 3 endometrioid adenocarcinoma, the accuracy of DT-FA, DT-MD and DWI-ADC was 90%, 89.7% and 84.6%, respectively. Mean DT-FA, DT-MD and DW-ADC values were inversely proportional to the degree of pathological grading with r =  − 0.867, − 0.762 and − 0.706, respectively. Conclusion Diffusion tensor imaging and DWI are helpful in the assessment of myometrial invasion and have a high negative correlation with histopathological grading in patients with endometrial cancer.

Diffusion tensor imaging in hyperthyroidism: assessment of microstructural white matter abnormality with a tract-based spatial statistical analysis

2020 ◽  
Vol 61 (12) ◽  
pp. 1677-1683 ◽  
Author(s):  
Kerim Aslan ◽  
Hediye Pinar Gunbey ◽  
Sumeyra Cortcu ◽  
Onur Ozyurt ◽  
Ugur Avci ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Corpus Callosum ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Imaging Study ◽  
Internal Capsule ◽  
Control Group ◽  
Corona Radiata ◽  
Microstructural Alterations

Background Metabolic, morphological, and functional brain changes associated with a neurological deficit in hyperthyroidism have been observed. However, changes in microstructural white matter (WM), which can explain the underlying pathophysiology of brain dysfunctions, have not been researched. Purpose To assess microstructural WM abnormality in patients with untreated or newly diagnosed hyperthyroidism using tract-based spatial statistics (TBSS). Material and Methods Eighteen patients with hyperthyroidism and 14 age- and sex-matched healthy controls were included in this study. TBSS were used in this diffusion tensor imaging study for a whole-brain voxel-wise analysis of fractional anisotropy, mean diffusivity, axial diffusivity (AD), and radial diffusivity (RD) of WM. Results When compared to the control group, TBSS showed a significant increase in the RD of the corpus callosum, anterior and posterior corona radiata, posterior thalamic radiation, cingulum, superior longitudinal fasciculus, and the retrolenticular region of the internal capsule in patients with hyperthyroidism ( P < 0.05), as well as a significant decrease in AD in the anterior corona radiata and the genu of corpus callosum ( P < 0.05). Conclusion This study showed that more regions are affected by the RD increase than the AD decrease in the WM tracts of patients with hyperthyroidism. These preliminary results suggest that demyelination is the main mechanism of microstructural alterations in the WM of hyperthyroid patients.

scholarly journals Diffusion tensor imaging revealed different pathological processes of white matter hyperintensities

BMC Neurology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Zhi-gang Min ◽  
Hai-rong Shan ◽  
Long Xu ◽  
Dai-hai Yuan ◽  
Xue-xia Sheng ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Frontal Lobe ◽  
Effect Size ◽  
White Matter Hyperintensities ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Control Group ◽  
Diffusion Weighted Images ◽  
Fazekas Scale

Abstract Background Although increasing evidence showed the correlations between white matter hyperintensities (WMHs) and cognitive impairment, the relationship between them is still modest. Many researchers began to focus on the variation caused by the heterogeneity of WMH. We tried to explore the pathological heterogeneity in WMH by using diffusion tensor imaging (DTI), so as to provide a new insight into the future research. Methods Diffusion weighted images (DWIs) of the brain were acquired from 73 patients with WMH and 18 healthy controls, which were then modeled by DTI. We measured fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) of white matter of the periventricular frontal lobe (pFL), periventricular occipital lobe (pOL), periventricular parietal lobe (pPL) and deep centrum ovales (dCO), and grouped these measures according to the Fazekas scale. Then we compared the DTI metrics of different regions with the same Fazekas scale grade. Results Significantly lower FA values (all p < 0.001), and higher MD (all p < 0.001) and RD values (all p < 0.001) were associated with WMH observed in the periventricular frontal lobe (pFL) compared to all other regions with the same Fazekas grades. The AD of WMH in the pFL was higher than that of pPL and dCO, but the differences between groups was not as high as of MD and RD, as indicated by the effect size. In the normal control group, DTI metrics between pFL and other regions were not significantly different or less significant different. The difference of DTI metrics of WMH between pPL, pOL and dCO was lower than that of normal white matter, as indicated by the effect size. Conclusion Distinct pathological processes can be revealed by DTI between frontal periventricular WMH and other regions. These processes may represent the effects of severe demyelination within the frontal periventricular WMH.

scholarly journals Demyelination and remyelination detected in an alternative cuprizone mouse model of multiple sclerosis with 7.0 T multiparameter magnetic resonance imaging

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shuang Ding ◽  
Yu Guo ◽  
Xiaoya Chen ◽  
Silin Du ◽  
Yongliang Han ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Multiple Sclerosis ◽  
Magnetic Resonance ◽  
Mouse Model ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Blue Staining ◽  
Resonance Imaging ◽  
The Mean ◽  
Underlying Mechanisms

AbstractThe aim of this study was to investigate the mechanisms underlying demyelination and remyelination with 7.0 T multiparameter magnetic resonance imaging (MRI) in an alternative cuprizone (CPZ) mouse model of multiple sclerosis (MS). Sixty mice were divided into six groups (n = 10, each), and these groups were imaged with 7.0 T multiparameter MRI and treated with an alternative CPZ administration schedule. T2-weighted imaging (T2WI), susceptibility-weighted imaging (SWI), and diffusion tensor imaging (DTI) were used to compare the splenium of the corpus callosum (sCC) among the groups. Prussian blue and Luxol fast blue staining were performed to assess pathology. The correlations of the mean grayscale value (mGSV) of the pathology results and the MRI metrics were analyzed to evaluate the multiparameter MRI results. One-way ANOVA and post hoc comparison showed that the normalized T2WI (T2-nor), fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) values were significantly different among the six groups, while the mean phase (Φ) value of SWI was not significantly different among the groups. Correlation analysis showed that the correlation between the T2-nor and mGSV was higher than that among the other values. The correlations among the FA, RD, MD, and mGSV remained instructive. In conclusion, ultrahigh-field multiparameter MRI can reflect the pathological changes associated with and the underlying mechanisms of demyelination and remyelination in MS after the successful establishment of an acute CPZ-induced model.

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