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https://www.readbyqxmd.com/read/28433947/maximum-likelihood-estimation-of-cardiac-fiber-bundle-orientation-from-arbitrarily-spaced-diffusion-weighted-images
#1
Andreas Nagler, Cristóbal Bertoglio, Christian T Stoeck, Sebastian Kozerke, Wolfgang A Wall
We propose an estimation scheme for local fiber bundle direction in the left ventricle directly from gray values of arbitrarily spaced cardiac diffusion weighted images (DWI). The approach is based on a parametric and space-dependent mathematical representation of the myocardial fiber bundle orientation and hence the diffusion tensor (DT) for the ventricular geometry. By solving a nonlinear inverse problem derived from a maximum likelihood estimator, the degrees of freedom of the fiber and DT model can be estimated from the measured gray values of the DWIs...
April 4, 2017: Medical Image Analysis
https://www.readbyqxmd.com/read/28433624/temporal-slice-registration-and-robust-diffusion-tensor-reconstruction-for-improved-fetal-brain-structural-connectivity-analysis
#2
Bahram Marami, Seyed Sadegh Mohseni Salehi, Onur Afacan, Benoit Scherrer, Caitlin K Rollins, Edward Yang, Judy A Estroff, Simon K Warfield, Ali Gholipour
Diffusion weighted magnetic resonance imaging, or DWI, is one of the most promising tools for the analysis of neural microstructure and the structural connectome of the human brain. The application of DWI to map early development of the human connectome in-utero, however, is challenged by intermittent fetal and maternal motion that disrupts the spatial correspondence of data acquired in the relatively long DWI acquisitions. Fetuses move continuously during DWI scans. Reliable and accurate analysis of the fetal brain structural connectome requires careful compensation of motion effects and robust reconstruction to avoid introducing bias based on the degree of fetal motion...
April 19, 2017: NeuroImage
https://www.readbyqxmd.com/read/28433414/diffusion-tensor-imaging-findings-and-cognitive-function-following-hospitalised-mixed-mechanism-mild-traumatic-brain-injury-a-systematic-review-and-meta-analysis
#3
REVIEW
Lucy Oehr, Jacqueline Anderson
OBJECTIVE: To undertake a systematic review and meta-analysis of the relationship between microstructural damage and cognitive function following hospitalised mixed-mechanism (HMM) mild traumatic brain injury (mTBI). DATA SOURCES: PsycInfo, Embase, and Medline were used to find relevant empirical papers published between January 2002 to January 2016. STUDY SELECTION: Studies that examined the specific relationship between diffusion tensor imaging (DTI) and cognitive test performance were included...
April 19, 2017: Archives of Physical Medicine and Rehabilitation
https://www.readbyqxmd.com/read/28433388/magnetic-resonance-and-diffusion-tensor-imaging-analyses-indicate-heterogeneous-strains-along-human-medial-gastrocnemius-fascicles-caused-by-submaximal-plantar-flexion-activity
#4
Agah Karakuzu, Uluç Pamuk, Cengizhan Ozturk, Burak Acar, Can A Yucesoy
Sarcomere length changes are central to force production and excursion of skeletal muscle. Previous modeling indicates non-uniformity of that if mechanical interaction of muscle with its surrounding muscular and connective tissues is taken into account. Hence, quantifying length changes along the fascicles of activated human muscle in vivo is crucial, but this is lacking due to technical complexities. Combining magnetic resonance imaging deformation analyses and diffusion tensor imaging tractography, the aim was to test the hypothesis that submaximal plantar flexion activity at 15% MVC causes heterogeneous length changes along the fascicles of human medial gastrocnemius (GM) muscle...
April 9, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/28432987/multimodal-imaging-of-language-reorganization-in-patients-with-left-temporal-lobe-epilepsy
#5
Yu-Hsuan A Chang, Nobuko Kemmotsu, Kelly M Leyden, N Erkut Kucukboyaci, Vicente J Iragui, Evelyn S Tecoma, Leena Kansal, Marc A Norman, Rachelle Compton, Tobin J Ehrlich, Vedang S Uttarwar, Anny Reyes, Brianna M Paul, Carrie R McDonald
This study explored the relationships among multimodal imaging, clinical features, and language impairment in patients with left temporal lobe epilepsy (LTLE). Fourteen patients with LTLE and 26 controls underwent structural MRI, functional MRI, diffusion tensor imaging, and neuropsychological language tasks. Laterality indices were calculated for each imaging modality and a principal component (PC) was derived from language measures. Correlations were performed among imaging measures, as well as to the language PC...
April 19, 2017: Brain and Language
https://www.readbyqxmd.com/read/28432780/single-subject-independent-component-analysis-based-intensity-normalization-in-non-quantitative-multi-modal-structural-mri
#6
Sebastian Papazoglou, Jens Würfel, Friedemann Paul, Alexander U Brandt, Michael Scheel
Non-quantitative MRI is prone to intersubject intensity variation rendering signal intensity level based analyses limited. Here, we propose a method that fuses non-quantitative routine T1-weighted (T1w), T2w, and T2w fluid-saturated inversion recovery sequences using independent component analysis and validate it on age and sex matched healthy controls. The proposed method leads to consistent and independent components with a significantly reduced coefficient-of-variation across subjects, suggesting potential to serve as automatic intensity normalization and thus to enhance the power of intensity based statistical analyses...
April 22, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28432188/magnetic-resonance-neurography-visualizes-abnormalities-in-sciatic-and-tibial-nerves-in-patients-with-type-1-diabetes-and-neuropathy
#7
Michael Vaeggemose, Mirko Pham, Steffen Ringgaard, Hatice Tankisi, Niels Ejskjaer, Sabine Heiland, Per L Poulsen, Henning Andersen
This study evaluates whether diffusion-tensor-imaging MR-Neurography (DTI-MRN), T2-relaxation-time and proton-spin-density can detect and grade neuropathic abnormalities in patients with type 1 diabetes.Forty-nine patients with type 1 diabetes (11 with severe polyneuropathy (sDPN), 13 with mild polyneuropathy (mDPN) and 25 without polyneuropathy (nDPN)) and 30 healthy controls (HC) were included. Clinical examinations, nerve-conduction-studies and vibratory-perception-thresholds determined the presence and severity of DPN...
April 21, 2017: Diabetes
https://www.readbyqxmd.com/read/28431605/global-brain-atrophy-and-metabolic-dysfunction-in-lgi1-encephalitis-a-prospective-multimodal-mri-study
#8
Monika Szots, Morten Blaabjerg, Gergely Orsi, Pernille Iversen, Daniel Kondziella, Camilla G Madsen, Ellen Garde, Peter O Magnusson, Peter Barsi, Ferenc Nagy, Hartwig R Siebner, Zsolt Illes
BACKGROUND: Chronic cognitive deficits are frequent in leucin-rich glioma-inactivated 1 protein (LGI1) encephalitis. We examined structural and metabolic brain abnormalities following LGI1 encephalitis and correlated findings with acute and follow-up clinical outcomes. METHODS: Nine patients underwent prospective multimodal 3 Tesla MRI 33.1±18months after disease onset, including automated volumetry, diffusion tensor imaging (DTI) and magnetic resonance spectroscopy (MRS)...
May 15, 2017: Journal of the Neurological Sciences
https://www.readbyqxmd.com/read/28431323/transcranial-magnetic-stimulation-in-developmental-stuttering-relations-with-previous-neurophysiological-research-and-future-perspectives
#9
REVIEW
P Busan, P P Battaglini, M Sommer
Developmental stuttering (DS) is a disruption of the rhythm of speech, and affected people may be unable to execute fluent voluntary speech. There are still questions about the exact causes of DS. Evidence suggests there are differences in the structure and functioning of motor systems used for preparing, executing, and controlling motor acts, especially when they are speech related. Much research has been obtained using neuroimaging methods, ranging from functional magnetic resonance to diffusion tensor imaging and electroencephalography/magnetoencephalography...
April 3, 2017: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/28429407/spinal-cord-injury-induces-widespread-chronic-changes-in-cerebral-white-matter
#10
Tero Ilvesmäki, Eerika Koskinen, Antti Brander, Teemu Luoto, Juha Öhman, Hannu Eskola
Traumatic spinal cord injuries (SCIs) lead to axonal damage at the trauma site, as well as disconnections within the central nervous system. While the exact mechanisms of the long-term pathophysiological consequences of SCIs are not fully understood, it is known that neuronal damage and degeneration are not limited to the direct proximity of the trauma. Instead, the effects can be detected even in the cerebrum. We examined SCI-induced chronic brain changes with a case-control design using 32 patients and 70 control subjects...
April 21, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28429381/the-structural-connectome-of-children-with-traumatic-brain-injury
#11
Marsh Königs, L W Ernest van Heurn, Roel Bakx, R Jeroen Vermeulen, J Carel Goslings, Bwee Tien Poll-The, Marleen van der Wees, Coriene E Catsman-Berrevoets, Jaap Oosterlaan, Petra J W Pouwels
This study aimed to investigate the impact of mild to severe pediatric TBI on the structural connectome. Children aged 8-14 years with trauma control (TC) injury (n = 27) were compared to children with mild TBI and risk factors for complicated TBI (mild(RF+) , n = 20) or moderate/severe TBI (n = 16) at 2.8 years post-injury. Probabilistic tractography on diffusion tensor imaging data was used in combination with graph theory to study structural connectivity. Functional outcome was measured using neurocognitive tests and parent and teacher questionnaires for behavioral functioning...
April 21, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28428205/measurable-supratentorial-white-matter-volume-changes-in-patients-with-diffuse-intrinsic-pontine-glioma-treated-with-an-anti-vascular-endothelial-growth-factor-agent-steroids-and-radiation
#12
P Svolos, W E Reddick, A Edwards, A Sykes, Y Li, J O Glass, Z Patay
BACKGROUND AND PURPOSE: Assessing the response to treatment in infiltrative brain tumors by using lesion volume-based response criteria is challenging. We hypothesized that in such tumors, volume measurements alone may not accurately capture changes in actual tumor burden during treatment. We longitudinally evaluated volume changes in both normal-appearing supratentorial white matter and the brain stem lesions in patients treated for diffuse intrinsic pontine glioma to determine to what extent adjuvant systemic therapies may skew the accuracy of tumor response assessments based on volumetric analysis...
April 20, 2017: AJNR. American Journal of Neuroradiology
https://www.readbyqxmd.com/read/28425348/integration-of-functional-mri-and-white-matter-tractography-in-cyberknife-radiosurgery
#13
Lu Sun, Baolin Qu, Jinyuan Wang, Zhongjian Ju, Zizhong Zhang, Zhiqiang Cui, Yang Jack, Zhipei Ling, Xinguang Yu, Longsheng Pan
PURPOSE: To investigate the efficacy of the integration of functional magnetic resonance imaging and diffusion-tensor imaging tractography data into CyberKnife radiosurgery for intracranial tumor management. MATERIALS AND METHODS: Functional neuroimaging, anatomical magnetic resonance imaging, and computed tomography images of patients with brain lesions in critical areas were acquired before radiosurgery. The acquired data sets were coregistered using the MIM image fusion software module and then were imported into the CyberKnife Robotic Radiosurgery System (Multiplan 4...
January 1, 2017: Technology in Cancer Research & Treatment
https://www.readbyqxmd.com/read/28424895/risk-and-protective-factors-for-structural-brain-ageing-in-the-eighth-decade-of-life
#14
Stuart J Ritchie, Elliot M Tucker-Drob, Simon R Cox, David Alexander Dickie, Maria Del C Valdés Hernández, Janie Corley, Natalie A Royle, Paul Redmond, Susana Muñoz Maniega, Alison Pattie, Benjamin S Aribisala, Adele M Taylor, Toni-Kim Clarke, Alan J Gow, John M Starr, Mark E Bastin, Joanna M Wardlaw, Ian J Deary
Individuals differ markedly in brain structure, and in how this structure degenerates during ageing. In a large sample of human participants (baseline n = 731 at age 73 years; follow-up n = 488 at age 76 years), we estimated the magnitude of mean change and variability in changes in MRI measures of brain macrostructure (grey matter, white matter, and white matter hyperintensity volumes) and microstructure (fractional anisotropy and mean diffusivity from diffusion tensor MRI). All indices showed significant average change with age, with considerable heterogeneity in those changes...
April 19, 2017: Brain Structure & Function
https://www.readbyqxmd.com/read/28424764/diffusion-tensor-imaging-colour-mapping-threshold-for-identification-of-ventilation-induced-brain-injury-after-intrauterine-inflammation-in-preterm-lambs
#15
Dhafer M Alahmari, Beatrice Skiöld, Samantha K Barton, Ilias Nitsos, Courtney McDonald, Suzanne L Miller, Valerie Zahra, Robert Galinsky, Qizhu Wu, Michael John Farrell, Timothy J Moss, Stuart B Hooper, James T Pearson, Graeme R Polglase
PURPOSE: The aim of this study is to examine whether advanced magnetic resonance imaging (MRI) techniques can detect early brain injury caused by intrauterine inflammation and inappropriate initial respiratory support in preterm lambs. HYPOTHESIS: Neuropathology caused by intrauterine inflammation is exacerbated by mechanical ventilation at birth and is detectable with advanced MRI techniques. METHODS: Pregnant ewes received intra-amniotic lipopolysaccharide (LPS) 7 days prior to delivery at ~125 days of gestation (85% of gestation), whereupon lambs were delivered and randomised to receive an injurious (LPS + INJ, n = 6) or protective (LPS + PROT, n = 6) ventilation strategy...
2017: Frontiers in Pediatrics
https://www.readbyqxmd.com/read/28424656/empirical-comparison-of-diffusion-kurtosis-imaging-and-diffusion-basis-spectrum-imaging-using-the-same-acquisition-in-healthy-young-adults
#16
Sijia Wang, Daniel J Peterson, Yong Wang, Qing Wang, Thomas J Grabowski, Wenbin Li, Tara M Madhyastha
As diffusion tensor imaging gains widespread use, many researchers have been motivated to go beyond the tensor model and fit more complex diffusion models, to gain a more complete description of white matter microstructure and associated pathology. Two such models are diffusion kurtosis imaging (DKI) and diffusion basis spectrum imaging (DBSI). It is not clear which DKI parameters are most closely related to DBSI parameters, so in the interest of enabling comparisons between DKI and DBSI studies, we conducted an empirical survey of the interrelation of these models in 12 healthy volunteers using the same diffusion acquisition...
2017: Frontiers in Neurology
https://www.readbyqxmd.com/read/28424595/gray-matter-atrophy-is-primarily-related-to-demyelination-of-lesions-in-multiple-sclerosis-a-diffusion-tensor-imaging-mri-study
#17
Eszter Tóth, Nikoletta Szabó, Gergõ Csete, András Király, Péter Faragó, Tamás Spisák, Krisztina Bencsik, László Vécsei, Zsigmond T Kincses
Objective: Cortical pathology, periventricular demyelination, and lesion formation in multiple sclerosis (MS) are related (Hypothesis 1). Factors in the cerebrospinal fluid close to these compartments could possibly drive the parallel processes. Alternatively, the cortical atrophy could be caused by remote axonal transection (Hypothesis 2). Since MRI can differentiate between demyelination and axon loss, we used this imaging modality to investigate the correlation between the pattern of diffusion parameter changes in the periventricular- and deep white matter and the gray matter atrophy...
2017: Frontiers in Neuroanatomy
https://www.readbyqxmd.com/read/28424004/segmental-diffusion-properties-of-the-corticospinal-tract-and-motor-outcome-in-hemiparetic-children-with-perinatal-stroke
#18
Jacquie Hodge, Bradley Goodyear, Helen Carlson, Xing-Chang Wei, Adam Kirton
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...
May 2017: Journal of Child Neurology
https://www.readbyqxmd.com/read/28422895/diffusion-tensor-tractography-for-detection-of-concomitant-traumatic-brain-injury-in-patients-with-traumatic-spinal-cord-injury
#19
Sung Ho Jang, Sang Ho Ahn, Yun Woo Cho, Ji Woon Lim, Ik Tae Cho
OBJECTIVES: We investigated concomitant traumatic brain injury in patients with traumatic spinal cord injury (TSCI) who had head trauma history, using diffusion tensor tractography (DTT). DESIGN: Retrospective survey. PARTICIPANTS: We recruited 14 consecutive patients with TSCI and coexisting head trauma history at the time of TSCI and 30 control subjects. METHODS: The corticospinal tract (CST), corticoreticulospinal tract (CRT), cingulum, and fornix were reconstructed using DTT, and DTT parameters (fractional anisotropy and fiber volume) and configuration were estimated...
January 18, 2017: Journal of Head Trauma Rehabilitation
https://www.readbyqxmd.com/read/28420955/hemispheric-differences-in-white-matter-microstructure-between-two-profiles-of-children-with-high-intelligence-quotient-vs-controls-a-tract-based-spatial-statistics-study
#20
Fanny Nusbaum, Salem Hannoun, Gabriel Kocevar, Claudio Stamile, Pierre Fourneret, Olivier Revol, Dominique Sappey-Marinier
Objectives: The main goal of this study was to investigate and compare the neural substrate of two children's profiles of high intelligence quotient (HIQ). Methods: Two groups of HIQ children were included with either a homogeneous (Hom-HIQ: n = 20) or a heterogeneous IQ profile (Het-HIQ: n = 24) as defined by a significant difference between verbal comprehension index and perceptual reasoning index. Diffusion tensor imaging was used to assess white matter (WM) microstructure while tract-based spatial statistics (TBSS) analysis was performed to detect and localize WM regional differences in fractional anisotropy (FA), mean diffusivity, axial (AD), and radial diffusivities...
2017: Frontiers in Neuroscience
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