keyword
MENU ▼
Read by QxMD icon Read
search

Diffusion tensor

keyword
https://www.readbyqxmd.com/read/28231395/functional-connectivity-in-amygdalar-sensory-pre-motor-networks-at-rest-new-evidence-from-the-human-connectome-project
#1
Nicola Toschi, Andrea Duggento, Luca Passamonti
The word "e-motion" derives from the Latin word "ex-moveo" which literally means "moving away from something / somebody". Emotions are thus fundamental to prime action and goal-directed behavior with obvious implications for individual's survival. However, the brain mechanisms underlying the interactions between emotional and motor cortical systems remain poorly understood. A recent diffusion tensor imaging study in humans has reported the existence of direct anatomical connections between the amygdala and sensory/(pre)motor cortices, corroborating an initial observation in animal research...
February 23, 2017: European Journal of Neuroscience
https://www.readbyqxmd.com/read/28229840/-magnetic-resonance-imaging-conversion-predictors-of-clinically-isolated-syndrome-to-multiple-sclerosis
#2
REVIEW
Sara Peixoto, Pedro Abreu
INTRODUCTION: Clinically isolated syndrome may be the first manifestation of multiple sclerosis, a chronic demyelinating disease of the central nervous system, and it is defined by a single clinical episode suggestive of demyelination. However, patients with this syndrome, even with long term follow up, may not develop new symptoms or demyelinating lesions that fulfils multiple sclerosis diagnostic criteria. We reviewed, in clinically isolated syndrome, what are the best magnetic resonance imaging findings that may predict its conversion to multiple sclerosis...
November 2016: Acta Médica Portuguesa
https://www.readbyqxmd.com/read/28227795/simplified-realistic-human-head-model-for-simulating-tumor-treating-fields-ttfields
#3
Cornelia Wenger, Ze'ev Bomzon, Ricardo Salvador, Peter J Basser, Pedro C Miranda, Cornelia Wenger, Ze'ev Bomzon, Ricardo Salvador, Peter J Basser, Pedro C Miranda, Peter J Basser, Pedro C Miranda, Cornelia Wenger, Ricardo Salvador, Ze'ev Bomzon
Tumor Treating Fields (TTFields) are alternating electric fields in the intermediate frequency range (100-300 kHz) of low-intensity (1-3 V/cm). TTFields are an anti-mitotic treatment against solid tumors, which are approved for Glioblastoma Multiforme (GBM) patients. These electric fields are induced non-invasively by transducer arrays placed directly on the patient's scalp. Cell culture experiments showed that treatment efficacy is dependent on the induced field intensity. In clinical practice, a software called NovoTal(TM) uses head measurements to estimate the optimal array placement to maximize the electric field delivery to the tumor...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227765/distribution-aware-estimation-of-the-minimum-achievable-uncertainty-in-diffusion-tensor-imaging-dti
#4
Andrea Duggento, Marco Giannelli, Carlo Tessa, Simona Lanzafame, Maria Guerrisi, Nicola Toschi, Andrea Duggento, Marco Giannelli, Carlo Tessa, Simona Lanzafame, Maria Guerrisi, Nicola Toschi, Nicola Toschi, Maria Guerrisi, Marco Giannelli, Carlo Tessa, Simona Lanzafame, Andrea Duggento
Diffusion tensor imaging (DTI) provides exquisite sensitivity to structural and microstructural characteristics of brain tissue, and is routinely employed in advanced neuroimaging applications. DTI is commonly performed using intrinsically noisy echo-planar imaging techniques and poses high demands both on scanner performance and on in-scanner subject time, which in turn is directly related to the number of diffusion-weighting direction one requires. While DTI-derived indices such as fractional anisotropy (FA), diffusion tensor trace and anisotropy mode have proven extremely useful in characterizing disease-related aberrations, their estimation is commonly performed using fitting routines that do not properly take into account MRI noise distribution...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227763/network-effects-and-pathways-in-deep-brain-stimulation-in-parkinson-s-disease
#5
N Koirala, V Fleischer, O Granert, G Deuschl, M Muthuraman, S Groppa, N Koirala, V Fleischer, O Granert, G Deuschl, M Muthuraman, S Groppa
Deep brain stimulation of subthalamic nucleus (STN-DBS) became a standard therapeutic option in Parkinson's disease (PD), even though the underlying modulated network of STN-DBS is still poorly described. Probabilistic tractography and connectivity analysis as derived from diffusion tensor imaging (DTI) were performed together with modelling of implanted electrode positions and linked postoperative clinical outcome. Fifteen patients with idiopathic PD without dementia were selected for DBS treatment. After pre-processing, probabilistic tractography was run from cortical and subcortical seeds of the hypothesized network to targets represented by the positions of the active DBS contacts...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227761/application-of-dti-connectivity-in-lateralization-of-mtle
#6
Mohammad R Nazem-Zadeh, Susan M Bowyer, John E Moran, Esmaeil Davoodi-Bojd, Andrew Zillgitt, Hassan Bagher-Ebadian, Fariborz Mahmoudi, Kost V Elisevich, Hamid Soltanian-Zadeh, Mohammad R Nazem-Zadeh, Susan M Bowyer, John E Moran, Esmaeil Davoodi-Bojd, Andrew Zillgitt, Hassan Bagher-Ebadian, Fariborz Mahmoudi, Kost V Elisevich, Hamid Soltanian-Zadeh, Susan M Bowyer, Hassan Bagher-Ebadian, Esmaeil Davoodi-Bojd, Andrew Zillgitt, Fariborz Mahmoudi, John E Moran, Hamid Soltanian-Zadeh, Kost V Elisevich, Mohammad R Nazem-Zadeh
Diffusion tensor imaging (DTI) is a noninvasive imaging method for measuring the diffusion properties of the underlying white matter tracts through which epileptiform activity is propagated. This study investigates the structural abnormalities quantified by DTI in mesial temporal lobe epilepsy (mTLE). Fiber tracts passing through 54 anatomical sites in 12 adult mTLE patients and 12 age- and gender-matched controls were identified using DTI tractography. DTI nodal degree (ND) and laterality index were then calculated...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226696/divergence-map-from-diffusion-tensor-imaging-concepts-and-application-to-corpus-callosum
#7
Gustavo R Pinheiro, Guilherme S Soares, Andre Luis Costa, Roberto A Lotufo, Leticia Rittner, Gustavo R Pinheiro, Guilherme S Soares, Andre Luis Costa, Roberto A Lotufo, Leticia Rittner, Leticia Rittner, Gustavo R Pinheiro, Roberto A Lotufo, Andre Luis Costa, Guilherme S Soares
This work proposes a novel approach to the analysis of Diffusion Tensor Imaging (DTI) by applying the mathematical concept of divergence, used in vector analysis. This is achieved by choosing an arbitrary direction of analysis and using this direction to transform the diffusion tensor field into an oriented vector field. The method was inspired by the idea of imposing a liquid flow inside the biological tissues, oriented in the direction of analysis, and watching the direction it would be expected to take as it flows through the paths created by the fibers...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226694/multi-output-gaussian-processes-for-enhancing-resolution-of-diffusion-tensor-fields
#8
Hernan Dario Vargas Cardona, Alvaro A Orozco, Mauricio A Alvarez, Hernan Dario Vargas Cardona, Alvaro A Orozco, Mauricio A Alvarez, Hernan Dario Vargas Cardona, Mauricio A Alvarez, Alvaro A Orozco
Second order diffusion tensor (DT) fields are widely used in several clinical applications: brain fibers connections, diagnosis of neuro-degenerative diseases, image registration, brain conductivity models, etc. However, due to current acquisition protocols and hardware limitations in MRI machines, the diffusion magnetic resonance imaging (dMRI) data is obtained with low spatial resolution (1 or 2 mm(3) for each voxel). This issue can be significant, because tissue fibers are much smaller than voxel size. Interpolation has become in a successful methodology for enhancing spatial resolution of DT fields...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226410/patient-specific-computational-modeling-of-cortical-spreading-depression-via-diffusion-tensor-imaging
#9
Julia M Kroos, Isabella Marinelli, Ibai Diez, Jesus M Cortes, Sebastiano Stramaglia, Luca Gerardo-Giorda
Cortical Spreading Depression (CSD), a depolarization wave originating in the visual cortex and traveling towards the frontal lobe, is commonly accepted as a correlate of migraine visual aura. As of today, little is known about the mechanisms that can trigger or stop such phenomenon. However, the complex and highly individual characteristics of the brain cortex suggest that the geometry might have a significant impact in supporting or contrasting the propagation of CSD. Accurate patient-specific computational models are fundamental to cope with the high variability in cortical geometries among individuals, but also with the conduction anisotropy induced in a given cortex by the complex neuronal organisation in the grey matter...
February 22, 2017: International Journal for Numerical Methods in Biomedical Engineering
https://www.readbyqxmd.com/read/28223932/cerebrospinal-fluid-levels-of-amyloid-beta-1-43-mirror-1-42-in-relation-to-imaging-biomarkers-of-alzheimer-s-disease
#10
Ina S Almdahl, Camilla Lauridsen, Per Selnes, Lisa F Kalheim, Christopher Coello, Beata Gajdzik, Ina Møller, Marianne Wettergreen, Ramune Grambaite, Atle Bjørnerud, Geir Bråthen, Sigrid B Sando, Linda R White, Tormod Fladby
Introduction: Amyloid beta 1-43 (Aβ43), with its additional C-terminal threonine residue, is hypothesized to play a role in early Alzheimer's disease pathology possibly different from that of amyloid beta 1-42 (Aβ42). Cerebrospinal fluid (CSF) Aβ43 has been suggested as a potential novel biomarker for predicting conversion from mild cognitive impairment (MCI) to dementia in Alzheimer's disease. However, the relationship between CSF Aβ43 and established imaging biomarkers of Alzheimer's disease has never been assessed...
2017: Frontiers in Aging Neuroscience
https://www.readbyqxmd.com/read/28223713/reduced-white-matter-integrity-in-antisocial-personality-disorder-a-diffusion-tensor-imaging-study
#11
Weixiong Jiang, Feng Shi, Huasheng Liu, Gang Li, Zhongxiang Ding, Hui Shen, Celina Shen, Seong-Whan Lee, Dewen Hu, Wei Wang, Dinggang Shen
Emerging neuroimaging research suggests that antisocial personality disorder (ASPD) may be linked to abnormal brain anatomy, but little is known about possible impairments of white matter microstructure in ASPD, as well as their relationship with impulsivity or risky behaviors. In this study, we systematically investigated white matter abnormalities of ASPD using diffusion tensor imaging (DTI) measures: fractional anisotropy (FA), axial diffusivity (AD), and radial diffusivity (RD). Then, we further investigated their correlations with the scores of impulsivity or risky behaviors...
February 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28223484/rhythmic-brain-stimulation-reduces-anxiety-related-behavior-in-a-mouse-model-based-on-meditation-training
#12
Aldis P Weible, Denise M Piscopo, Mary K Rothbart, Michael I Posner, Cristopher M Niell
Meditation training induces changes at both the behavioral and neural levels. A month of meditation training can reduce self-reported anxiety and other dimensions of negative affect. It also can change white matter as measured by diffusion tensor imaging and increase resting-state midline frontal theta activity. The current study tests the hypothesis that imposing rhythms in the mouse anterior cingulate cortex (ACC), by using optogenetics to induce oscillations in activity, can produce behavioral changes. Mice were randomly assigned to groups and were given twenty 30-min sessions of light pulses delivered at 1, 8, or 40 Hz over 4 wk or were assigned to a no-laser control condition...
February 21, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28223037/asymmetric-dopaminergic-degeneration-and-levodopa-alter-functional-corticostriatal-connectivity-bilaterally-in-experimental-parkinsonism
#13
Cyril Monnot, Xiaoqun Zhang, Sahar Nikkhou-Aski, Peter Damberg, Per Svenningsson
Asymmetric dopamine loss is commonly found in early Parkinson's disease (PD), but its effects on functional networks have been difficult to delineate in PD patients because of variations in age, disease duration and therapy. Here we used unilateral 6-hydroxydopamine-lesioned (6-OHDA) rats and controls and treated them with a single intraperitoneal injection of levodopa (L-DOPA) before performing diffusion weighted MRI and resting state functional MRI (rs-fMRI). In accordance with a neurodegeneration of the nigrostriatal dopaminergic pathway, diffusion tensor imaging showed increased radial diffusivity and decreased fractional anisotropy in the lesioned substantia nigra...
February 18, 2017: Experimental Neurology
https://www.readbyqxmd.com/read/28222523/anomalous-white-matter-structure-and-the-effect-of-age-in-down-syndrome-patients
#14
Raquel Fenoll, Jesus Pujol, Susanna Esteba-Castillo, Susana de Sola, Núria Ribas-Vidal, Javier García-Alba, Gonzalo Sánchez-Benavides, Gerard Martínez-Vilavella, Joan Deus, Mara Dierssen, Ramón Novell-Alsina, Rafael de la Torre
BACKGROUND: Neural tissue alterations in Down syndrome are fully expressed at relatively late developmental stages. In addition, there is an early presence of neurodegenerative changes in the late life stages. OBJECTIVE: The aims of this study were both to characterize white matter abnormalities in the brain of adult Down syndrome patients using diffusion tensor imaging (DTI) and to investigate whether degenerative alterations in white matter structure are detectable before dementia is clinically evident...
February 7, 2017: Journal of Alzheimer's Disease: JAD
https://www.readbyqxmd.com/read/28220654/longitudinal-study-examining-abnormal-white-matter-integrity-using-a-tract-specific-analysis-in-individuals-with-a-high-risk-for-psychosis
#15
Junichi Saito, Masaaki Hori, Takahiro Nemoto, Naoyuki Katagiri, Keigo Shimoji, Shinya Ito, Naohisa Tsujino, Taiju Yamaguchi, Nobuyuki Shiraga, Shigeki Aoki, Masafumi Mizuno
AIM: Although volume reductions in the grey matter have been previously observed in individuals with an at-risk mental state (ARMS) for psychosis, the features of white matter integrity and their correlation with psychiatric symptoms remain unclear. METHODS: Forty-six ARMS subjects were examined using magnetic resonance imaging (MRI) to acquire diffusion tensor imaging (DTI) images; the subjects were also evaluated using the Scale of Prodromal Symptoms at baseline and at 52 weeks...
February 20, 2017: Psychiatry and Clinical Neurosciences
https://www.readbyqxmd.com/read/28219492/microstructural-white-matter-alterations-in-the-corpus-callosum-of-girls-with-conduct-disorder
#16
Willeke Martine Menks, Reto Furger, Claudia Lenz, Lynn Valérie Fehlbaum, Christina Stadler, Nora Maria Raschle
OBJECTIVE: Diffusion tensor imaging (DTI) studies in adolescent conduct disorder (CD) have demonstrated white matter alterations of tracts connecting functionally distinct fronto-limbic regions, but only in boys or mixed-gender samples. So far, no study has investigated white matter integrity in girls with CD on a whole-brain level. Therefore, our aim was to investigate white matter alterations in adolescent girls with CD. METHOD: We collected high-resolution DTI data from 24 girls with CD and 20 typically developing control girls using a 3T magnetic resonance imaging system...
March 2017: Journal of the American Academy of Child and Adolescent Psychiatry
https://www.readbyqxmd.com/read/28219191/-study-of-optic-radiations-in-patients-with-primary-open-angle-glaucoma-with-diffusion-tensor-imaging
#17
T Li, W Miao, H G He, J F Xian
Objective: To study the alteration of the optic radiations in patients with primary open-angle glaucoma (POAG) by diffusion tensor imaging (DTI) and tractography, and to reveal the correlation between the DTI derived parameters and the severity of the disease. Methods: A total of 24 patients with POAG and 20 age- and gender-matched healthy controls were enrolled in this study from January 2011 to June 2013.All subjects underwent ophthalmoscopy, standard automatic perimetry, intraocular pressure measurement and MRI scanning...
February 7, 2017: Zhonghua Yi Xue za Zhi [Chinese medical journal]
https://www.readbyqxmd.com/read/28218643/diffusion-assessment-of-cortical-changes-induced-by-traumatic-spinal-cord-injury
#18
Peng Sun, Rory K J Murphy, Paul Gamble, Ajit George, Sheng-Kwei Song, Wilson Z Ray
Promising treatments are being developed to promote functional recovery after spinal cord injury (SCI). Magnetic resonance imaging, specifically Diffusion Tensor Imaging (DTI) has been shown to non-invasively measure both axonal and myelin integrity following traumatic brain and SCI. A novel data-driven model-selection algorithm known as Diffusion Basis Spectrum Imaging (DBSI) has been proposed to more accurately delineate white matter injury. The objective of this study was to investigate whether DTI/DBSI changes that extend to level of the cerebral peduncle and internal capsule following a SCI could be correlated with clinical function...
February 17, 2017: Brain Sciences
https://www.readbyqxmd.com/read/28214960/axonal-disruption-in-white-matter-underlying-cortical-sulcus-tau-pathology-in-chronic-traumatic-encephalopathy
#19
Laurena Holleran, Joong Hee Kim, Mihika Gangolli, Thor Stein, Victor Alvarez, Ann McKee, David L Brody
Chronic traumatic encephalopathy (CTE) is a progressive degenerative disorder associated with repetitive traumatic brain injury. One of the primary defining neuropathological lesions in CTE, based on the first consensus conference, is the accumulation of hyperphosphorylated tau in gray matter sulcal depths. Post-mortem CTE studies have also reported myelin loss, axonal injury and white matter degeneration. Currently, the diagnosis of CTE is restricted to post-mortem neuropathological analysis. We hypothesized that high spatial resolution advanced diffusion MRI might be useful for detecting white matter microstructural changes directly adjacent to gray matter tau pathology...
February 18, 2017: Acta Neuropathologica
https://www.readbyqxmd.com/read/28214420/prevention-of-radiotherapy-induced-neurocognitive-dysfunction-in-survivors-of-paediatric-brain-tumours-the-potential-role-of-modern-imaging-and-radiotherapy-techniques
#20
REVIEW
Thankamma Ajithkumar, Stephen Price, Gail Horan, Amos Burke, Sarah Jefferies
Neurocognitive dysfunction is the leading cause of reduced quality of life in long-term survivors of paediatric brain tumours. Radiotherapy is one of the main contributors to neurocognitive sequelae. Current approaches for prevention and reduction of neurocognitive dysfunction include avoidance of radiotherapy in young children and reduction of the radiotherapy dose and volume of brain irradiated. Substantial advances have been made in brain imaging, especially with functional imaging and fibre tracking with the use of diffusion tensor imaging...
February 2017: Lancet Oncology
keyword
keyword
105871
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"