scholarly journals Analyses of the Disruption of White Matter Integrity in Schizophrenia Using Diffusion Tensor Fiber Tracking with Automatic Construction of Region of Interest

2013 ◽  
Vol 2 (0) ◽  
pp. 1-10
Author(s):  
Utako YAMAMOTO ◽  
Akifumi HISADA ◽  
Tetsuo KOBAYASHI ◽  
Shinsuke KITO ◽  
Yoshihiko KOGA
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Region Of Interest ◽  
Fiber Tracking ◽  
White Matter Integrity ◽  
Automatic Construction

Preoperative and Intraoperative Diffusion Tensor Imaging-based Fiber Tracking in Glioma Surgery

Neurosurgery ◽  
2005 ◽  
Vol 56 (1) ◽  
pp. 130-138 ◽  
Author(s):  
Christopher Nimsky ◽  
Oliver Ganslandt ◽  
Peter Hastreiter ◽  
Ruopeng Wang ◽  
Thomas Benner ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Fractional Anisotropy ◽  
Diffusion Tensor ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Region Of Interest ◽  
Fiber Tracking ◽  
Glioma Surgery ◽  
White Matter Tracts

Abstract OBJECTIVE: To investigate the intraoperative displacement of major white matter tracts during glioma resection by comparing preoperative and intraoperative diffusion tensor imaging-based fiber tracking. METHODS: In 37 patients undergoing glioma surgery, preoperative and intraoperative diffusion tensor imaging was performed with a 1.5-T magnetic resonance scanner applying an echo-planar imaging sequence with six diffusion directions. For three-dimensional tractography, we implemented a knowledge-based multiple-region-of-interest approach applying user-defined seed regions in the color-coded maps of fractional anisotropy. Tracking was initiated in both the retrograde and orthograde directions according to the direction of the principal eigenvector in each voxel of the region of interest. The tractography results were also assigned color, applying the convention used in color-coded fractional anisotropy maps. RESULTS: Preoperative and intraoperative fiber tracking was technically feasible in all patients. Fiber tract visualization gave a quick and intuitive overview of the displaced course of white matter tracts in three-dimensional space. Comparison of preoperative and intraoperative tractography depicted a marked shifting of major white matter tracts during glioma removal. Maximum white matter tract shifting ranged from −8 to +15 mm (+2.7 ± 6.0 mm; mean ± standard deviation); in 29.7%, an inward and in 62.2%, an outward shifting was detected. CONCLUSION: Comparing preoperative and intraoperative fiber tracking visualizes a marked shifting and deformation of major white matter tracts because of tumor removal. This shifting emphasizes the need for an intraoperative update of navigation systems during resection of deep-seated tumor portions near eloquent brain areas. Fiber tracking is a method not only for preoperative neurosurgical visualization but also for further intraoperative planning.

Accuracy of diffusion tensor magnetic resonance imaging tractography assessed using intraoperative subcortical stimulation mapping and magnetic source imaging

2007 ◽  
Vol 107 (3) ◽  
pp. 488-494 ◽  
Author(s):  
Jeffrey I. Berman ◽  
Mitchel S. Berger ◽  
Sungwon Chung ◽  
Srikantan S. Nagarajan ◽  
Roland G. Henry
Keyword(s):  
White Matter ◽  
Magnetic Resonance ◽  
Diffusion Tensor ◽  
Fiber Tracking ◽  
Bipolar Electrode ◽  
Source Imaging ◽  
Magnetic Source Imaging ◽  
Motor Pathway ◽  
Magnetic Source ◽  
Subcortical Stimulation

Object Resecting brain tumors involves the risk of damaging the descending motor pathway. Diffusion tensor (DT)–imaged fiber tracking is a noninvasive magnetic resonance (MR) technique that can delineate the subcortical course of the motor pathway. The goal of this study was to use intraoperative subcortical stimulation mapping of the motor tract and magnetic source imaging to validate the utility of DT-imaged fiber tracking as a tool for presurgical planning. Methods Diffusion tensor-imaged fiber tracks of the motor tract were generated preoperatively in nine patients with gliomas. A mask of the resultant fiber tracks was overlaid on high-resolution T1- and T2-weighted anatomical MR images and used for stereotactic surgical navigation. Magnetic source imaging was performed in seven of the patients to identify functional somatosensory cortices. During resection, subcortical stimulation mapping of the motor pathway was performed within the white matter using a bipolar electrode. Results A total of 16 subcortical motor stimulations were stereotactically identified in nine patients. The mean distance between the stimulation sites and the DT-imaged fiber tracks was 8.7 ±3.1 mm (±standard deviation). The measured distance between subcortical stimulation sites and DT-imaged fiber tracks combines tracking technique errors and all errors encountered with stereotactic navigation. Conclusions Fiber tracks delineated using DT imaging can be used to identify the motor tract in deep white matter and define a safety margin around the tract.

Arterial Stiffness Is Associated with White Matter Disruption and Cognitive Impairment: A Community-Based Cohort Study

2021 ◽  
Vol 80 (2) ◽  
pp. 567-576
Author(s):  
Fei Han ◽  
Fei-Fei Zhai ◽  
Ming-Li Li ◽  
Li-Xin Zhou ◽  
Jun Ni ◽  
...  
Keyword(s):  
Cognitive Function ◽  
White Matter ◽  
Arterial Stiffness ◽  
Cognitive Decline ◽  
Sex Education ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
White Matter Injury ◽  
White Matter Integrity ◽  
Cross Sectional

Background: Mechanisms through which arterial stiffness impacts cognitive function are crucial for devising better strategies to prevent cognitive decline. Objective: To examine the associations of arterial stiffness with white matter integrity and cognition in community dwellings, and to investigate whether white matter injury was the intermediate of the associations between arterial stiffness and cognition. Methods: This study was a cross-sectional analysis on 952 subjects (aged 55.5±9.1 years) who underwent diffusion tensor imaging and measurement of brachial-ankle pulse wave velocity (baPWV). Both linear regression and tract-based spatial statistics were used to investigate the association between baPWV and white matter integrity. The association between baPWV and global cognitive function, measured as the mini-mental state examination (MMSE) was evaluated. Mediation analysis was performed to assess the influence of white matter integrity on the association of baPWV with MMSE. Results: Increased baPWV was significantly associated with lower mean global fractional anisotropy (β= –0.118, p < 0.001), higher mean diffusivity (β= 0.161, p < 0.001), axial diffusivity (β= 0.160, p < 0.001), and radial diffusivity (β= 0.147, p < 0.001) after adjustment of age, sex, and hypertension, which were measures having a direct effect on arterial stiffness and white matter integrity. After adjustment of age, sex, education, apolipoprotein E ɛ4, cardiovascular risk factors, and brain atrophy, we found an association of increased baPWV with worse performance on MMSE (β= –0.093, p = 0.011). White matter disruption partially mediated the effect of baPWV on MMSE. Conclusion: Arterial stiffness is associated with white matter disruption and cognitive decline. Reduced white matter integrity partially explained the effect of arterial stiffness on cognition.

Diffusion tensor imaging analysis in scrub typhus meningoencephalitis to determine the alteration of microstructural subcortical white-matter integrity

2020 ◽  
pp. 197140092098031
Author(s):  
Pranjal Phukan ◽  
Kalyan Sarma ◽  
Aman Yusuf Khan ◽  
Bhupen Barman ◽  
Md Jamil ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Scrub Typhus ◽  
Diffusion Tensor ◽  
Neuronal Degeneration ◽  
Central Nervous System Involvement ◽  
Subcortical White Matter ◽  
White Matter Integrity ◽  
Conventional Mri ◽  
Significant Difference

Background and purpose Magnetic resonance imaging (MRI) of the brain in scrub typhus meningoencephalitis is non-specific, and in the majority of the cases, conventional MRI fails to detect any abnormality. However, autopsy reports depict central nervous system involvement in almost all patients. There is therefore a need for research on the quantitative assessment of brain parenchyma that can detect microstructural abnormalities. The study aimed to assess the microstructural integrity changes of scrub typhus meningoencephalitis by using different diffusion tensor imaging (DTI) parameters. Methods This was a retrospective analysis of scrub typhus meningoencephalitis. Seven patients and seven age- and sex-matched healthy controls were included. Different DTI parameters such as apparent diffusion coefficient (ADC), fractional anisotropy (FA), relative anisotropy (RA), trace, volume ratio (VR) and geodesic anisotropy (GA) were obtained from six different regions of subcortical white matter at the level of the centrum semiovale. Intergroup significant difference was determined by one-way analysis of variance followed by Tukey’s post hoc test. Receiver operating characteristic curves were constructed to determine the accuracy of the DTI matrices. Results There was a significant decrease in FA, RA and GA as well as an increase in ADC and VR in the subcortical white matter in patients with scrub typhus meningoencephalitis compared to controls ( p < 0.001). The maximum sensitivity of the DTI parameters was 85.7%, and the maximum specificity was 81%. Conclusion There was an alteration of subcortical white-matter integrity in scrub typhus meningoencephalitis that represents the axonal degeneration, myelin breakdown and neuronal degeneration. DTI may be a useful tool to detect white-matter abnormalities in scrub typhus meningoencephalitis in clinical practice, particularly in patients with negative conventional MRI.

Age-related changes in white matter integrity: A diffusion tensor imaging study

NeuroImage ◽  
2009 ◽  
Vol 47 ◽  
pp. S128
Author(s):  
H Lemaitre ◽  
S Marenco ◽  
M Emery ◽  
T Alam ◽  
M Geramita ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Diffusion Tensor ◽  
Imaging Study ◽  
White Matter Integrity ◽  
Age Related ◽  
Diffusion Tensor Imaging Study ◽  
Age Related Changes

Diffusion tensor tractography of the temporal stem on the inferior limiting sulcus

2008 ◽  
Vol 108 (4) ◽  
pp. 775-781 ◽  
Author(s):  
Feng Wang ◽  
Tao Sun ◽  
Xing-Gang Li ◽  
Na-Jia Liu
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Anterior Commissure ◽  
Region Of Interest ◽  
Diffusion Tensor Tractography ◽  
Optic Radiation ◽  
Uncinate Fasciculus ◽  
White Matter Tracts ◽  
Temporal Horn ◽  
Temporal Stem

Object The aim of this study was to use diffusion tensor tractography (DTT) to define the 3D relationships of the uncinate fasciculus, anterior commissure, inferior occipitofrontal fasciculus, inferior thalamic peduncle, and optic radiation and to determine the positioning landmarks of these white matter tracts. Methods The anatomy was studied in 10 adult human brain specimens. Brain DTT was performed in 10 healthy volunteers. Diffusion tensor tractography images of the white matter tracts in the temporal stem were obtained using the simple single region of interest (ROI) and multi-ROIs based on the anatomical knowledge. Results The posteroinferior insular point is the anterior extremity of intersection of the Heschl gyrus and the inferior limiting sulcus. On the inferior limiting sulcus, this point is the posterior limit of the optic radiation, and the temporal stem begins at the limen insulae and ends at the posteroinferior insular point. The distance from the limen insulae to the tip of the temporal horn is just one third the length of the temporal stem. The uncinate fasciculus comprises the core of the anterior temporal stem, behind which the anterior commissure and the inferior thalamic peduncle are located, and they occupy the anterior third of the temporal stem. The inferior occipitofrontal fasciculus passes through the entire temporal stem. The most anterior extent of the Meyer loop is located between the anterior tip of the temporal horn and the limen insulae. Most of the optic radiation crosses the postmedian two thirds of the temporal stem. Conclusions On the inferior limiting sulcus, the posteroinferior insular point is a reliable landmark of the posterior limit of the optic radiations. The limen insulae, anterior tip of the temporal horn, and posteroinferior insular point may be used to localize the white matter fibers of the temporal stem in analyzing magnetic resonance imaging or during surgery.

scholarly journals Relationship between white matter integrity and serum cortisol levels in drug-naive patients with major depressive disorder: Diffusion tensor imaging study using tract-based spatial statistics

2016 ◽  
Vol 208 (6) ◽  
pp. 585-590 ◽  
Author(s):  
Xiaodan Liu ◽  
Keita Watanabe ◽  
Shingo Kakeda ◽  
Reiji Yoshimura ◽  
Osamu Abe ◽  
...  
Keyword(s):  
Major Depressive Disorder ◽  
White Matter ◽  
Diffusion Tensor ◽  
Serum Cortisol ◽  
White Matter Integrity ◽  
Uncinate Fasciculus ◽  
Major Depressive ◽  
Drug Naïve ◽  
Cortisol Levels ◽  
Anterior Thalamic Radiation

BackgroundHigher daytime cortisol levels because of a hyperactive hypothalamic–pituitary–adrenal axis have been reported in patients with major depressive disorder (MDD). The elevated glucocorticoids inhibit the proliferation of the oligodendrocytes that are responsible for myelinating the axons of white matter fibre tracts.AimsTo evaluate the relationship between white matter integrity and serum cortisol levels during a first depressive episode in drug-naive patients with MDD (MDD group) using a tract-based spatial statistics (TBSS) method.MethodThe MDD group (n = 29) and a healthy control group (n = 47) underwent diffusion tensor imaging (DTI) scans and an analysis was conducted using TBSS. Morning blood samples were obtained from both groups for cortisol measurement.ResultsCompared with the controls, the MDD group had significantly reduced fractional anisotropy values (P<0.05, family-wise error (FWE)-corrected) in the inferior fronto-occipital fasciculus, uncinate fasciculus and anterior thalamic radiation. The fractional anisotropy values of the inferior fronto-occipital fasciculus, uncinate fasciculus and anterior thalamic radiation had significantly negative correlations with the serum cortisol levels in the MDD group (P<0.05, FWE-corrected).ConclusionsOur findings indicate that the elevated cortisol levels in the MDD group may injure the white matter integrity in the frontal–subcortical and frontal–limbic circuits.

Olfactory Function and Diffusion Tensor Imaging as Markers of Mild Cognitive Impairment in Early Stages of Parkinson's Disease

2021 ◽  
pp. 155005942110582
Author(s):  
Sophie A. Stewart ◽  
Laura Pimer ◽  
John D. Fisk ◽  
Benjamin Rusak ◽  
Ron A. Leslie ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cognitive Impairment ◽  
Diffusion Tensor Imaging ◽  
Mild Cognitive Impairment ◽  
White Matter ◽  
Neurodegenerative Disorder ◽  
Diffusion Tensor ◽  
Early Stage ◽  
White Matter Integrity

Parkinson's disease (PD) is a neurodegenerative disorder that is typified by motor signs and symptoms but can also lead to significant cognitive impairment and dementia Parkinson's Disease Dementia (PDD). While dementia is considered a nonmotor feature of PD that typically occurs later, individuals with PD may experience mild cognitive impairment (PD-MCI) earlier in the disease course. Olfactory deficit (OD) is considered another nonmotor symptom of PD and often presents even before the motor signs and diagnosis of PD. We examined potential links among cognitive impairment, olfactory functioning, and white matter integrity of olfactory brain regions in persons with early-stage PD. Cognitive tests were used to established groups with PD-MCI and with normal cognition (PD-NC). Olfactory functioning was examined using the University of Pennsylvania Smell Identification Test (UPSIT) while the white matter integrity of the anterior olfactory structures (AOS) was examined using magnetic resonance imaging (MRI) diffusion tensor imaging (DTI) analysis. Those with PD-MCI demonstrated poorer olfactory functioning and abnormalities based on all DTI parameters in the AOS, relative to PD-NC individuals. OD and microstructural changes in the AOS of individuals with PD may serve as additional biological markers of PD-MCI.

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