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Da Li, Yu-Ming Jiao, Liang Wang, Fu-Xin Lin, Jun Wu, Xian-Zeng Tong, Shuo Wang, Yong Cao
OBJECTIVE Surgical management of brainstem lesions is challenging due to the highly compact, eloquent anatomy of the brainstem. This study aimed to evaluate the safety and efficacy of preoperative diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) in brainstem cavernous malformations (CMs). METHODS A prospective randomized controlled clinical trial was performed by using stratified blocked randomization. The primary eligibility criterion of the study was being a surgical candidate for brainstem CMs (with informed consent)...
March 16, 2018: Journal of Neurosurgery
Xiao-Ling Yang, Yolandi van der Merwe, Jeffrey Sims, Carlos Parra, Leon C Ho, Joel S Schuman, Gadi Wollstein, Kira L Lathrop, Kevin C Chan
Although elevated intraocular pressure (IOP) and age are major risk factors for glaucoma, their effects on glaucoma pathogenesis remain unclear. This study examined the onset and progression of glaucomatous changes to ocular anatomy and physiology, structural and physiological brain integrity, and visuomotor behavior in the DBA/2J mice via non-invasive tonometry, multi-parametric magnetic resonance imaging (MRI) and optokinetic assessments from 5 to 12 months of age. Using T2-weighted MRI, diffusion tensor MRI, and manganese-enhanced MRI, increasing IOP elevation at 9 and 12 months old coincided with anterior chamber deepening, altered fractional anisotropy and radial diffusivity of the optic nerve and optic tract, as well as reduced anterograde manganese transport along the visual pathway respectively in the DBA/2J mice...
March 15, 2018: Scientific Reports
Heather T Whittaker, Shenghua Zhu, Domenico L Di Curzio, Richard Buist, Xin-Min Li, Suzanna Noy, Frances K Wiseman, Jonathan D Thiessen, Melanie Martin
Alzheimer's disease (AD) pathology causes microstructural changes in the brain. These changes, if quantified with magnetic resonance imaging (MRI), could be studied for use as an early biomarker for AD. The aim of our study was to determine if T1 relaxation, diffusion tensor imaging (DTI), and quantitative magnetization transfer imaging (qMTI) metrics could reveal changes within the hippocampus and surrounding white matter structures in ex vivo transgenic mouse brains overexpressing human amyloid precursor protein with the Swedish mutation...
March 12, 2018: Magnetic Resonance Imaging
Ankit Raj, Hiro-O Hamaguchi, Henryk A Witek
We report an exhaustive compilation of wavelength-dependent matrix elements over the mean polarizability (α¯) and polarizability anisotropy (γ) operators for the rovibrational states of the H2 , HD, and D2 molecules together with an accompanying computer program for their evaluation. The matrix elements can be readily evaluated using the provided codes for rovibrational states with J = 0-15 and v = 0-4 and for any laser wavelengths in the interval 182.25-1320.6 nm corresponding to popular, commercially available lasers...
March 14, 2018: Journal of Chemical Physics
Lintao Peng, Spencer A Wells, Christopher R Ryder, Mark C Hersam, Matthew Grayson
The crystal orientation of an exfoliated black phosphorous flake is determined by purely electrical means. A sequence of three resistance measurements on an arbitrarily shaped flake with five contacts determines the three independent components of the anisotropic in-plane resistivity tensor, thereby revealing the crystal axes. The resistivity anisotropy ratio decreases linearly with increasing temperature T and carrier density reaching a maximum ratio of 3.0 at low temperatures and densities, while mobility indicates impurity scattering at low T and acoustic phonon scattering at high T...
February 23, 2018: Physical Review Letters
Esther M C van Leijsen, H Bea Kuiperij, Iris Kersten, Mayra I Bergkamp, Ingeborg W M van Uden, Hugo Vanderstichele, Erik Stoops, Jurgen A H R Claassen, Ewoud J van Dijk, Frank-Erik de Leeuw, Marcel M Verbeek
BACKGROUND AND PURPOSE: Cerebral small vessel disease (SVD) is a frequent pathology in aging and contributor to the development of dementia. Plasma Aβ (amyloid β) levels may be useful as early biomarker, but the role of plasma Aβ in SVD remains to be elucidated. We investigated the association of plasma Aβ levels with severity and progression of SVD markers. METHODS: We studied 487 participants from the RUN DMC study (Radboud University Nijmegen Diffusion Tensor and Magnetic Resonance Imaging Cohort) of whom 258 participants underwent 3 MRI assessments during 9 years...
March 14, 2018: Stroke; a Journal of Cerebral Circulation
Dorothee Boehm, Konstantin Bergmeister, Emre Gazyakan, Thomas Kremer, Ulrich Kneser, Volker J Schmidt
AIMS: Reconstruction of breasts and chest wall deformities in female patients after severe burn injury is a challenge for reconstructive surgeons. In these patients, neither implant-based procedures nor standard free flaps are sometimes applicable because of limited skin quality and unavailability of donor sites at the abdomen, back, buttock, or medial thigh. METHODS: We present a case of a young female patient with a history of 80 % total body surface area burn after electric high-voltage injury...
March 13, 2018: Annals of Plastic Surgery
G Oriolo, E Egmond, Z Mariño, M Cavero, R Navines, L Zamarrenho, R Solà, J Pujol, N Bargallo, X Forns, R Martin-Santos
BACKGROUND: Chronic hepatitis C is considered a systemic disease because of extra-hepatic manifestations. Neuroimaging has been employed in hepatitis C virus-infected patients to find in vivo evidence of central nervous system alterations. AIMS: Systematic review and meta-analysis of neuroimaging research in chronic hepatitis C treatment naive patients, or patients previously treated without sustained viral response, to study structural and functional brain impact of hepatitis C...
March 14, 2018: Alimentary Pharmacology & Therapeutics
Pawel J Winklewski, Agnieszka Sabisz, Patrycja Naumczyk, Krzysztof Jodzio, Edyta Szurowska, Arkadiusz Szarmach
The use of the diffusion tensor imaging (DTI) is rapidly growing in the neuroimaging field. Nevertheless, rigorously performed quantitative validation of DTI pathologic metrics remains very limited owing to the difficulty in co-registering quantitative histology findings with magnetic resonance imaging. The aim of this review is to summarize the existing state-of-the-art knowledge with respect to axial (λ║ ) and radial (λ┴ ) diffusivity as DTI markers of axonal and myelin damage, respectively. First, we provide technical background for DTI and briefly discuss the specific organization of white matter in bundles of axonal fibers running in parallel; this is the natural target for imaging based on diffusion anisotropy...
2018: Frontiers in Neurology
Evan P Pasha, Alex C Birdsill, Stephanie Oleson, Hirofumi Tanaka, Andreana P Haley
Sex differences in cerebral white matter (WM) aging have been debated extensively over the past 2 decades without unequivocal resolution. We aimed to determine if the effects of age and arterial stiffness on WM microstructure differ between sexes. Artery elasticity via carotid artery compliance (CAC) and WM diffusion metrics via diffusion tensor image-derived fractional anisotropy (FA) and mean diffusivity (MD) were measured in 155 (87 females) middle-aged (40-62 years) adults. Males demonstrated poorer water diffusion metrics in WM than women in the corpus callosum body, cingulum, and cingulum (hippocampal)...
February 17, 2018: Neurobiology of Aging
Vishwesh Nath, Kurt G Schilling, Prasanna Parvathaneni, Justin Blaber, Allison E Hainline, Zhaohua Ding, Adam Anderson, Bennett A Landman
The diffusion tensor model is nonspecific in regions where micrometer structural patterns are inconsistent at the millimeter scale (i.e., brain regions with pathways that cross, bend, branch, fan, etc.). Numerous models have been proposed to represent crossing fibers and complex intravoxel structure from in vivo diffusion weighted magnetic resonance imaging (e.g., high angular resolution diffusion imaging-HARDI). Here, we present an empirical comparison of two HARDI approaches-persistent angular structure MRI (PAS-MRI) and Q-ball-using a newly acquired reproducibility dataset...
January 2018: Journal of Medical Imaging
Panlong Li, Han Shan, Shengxiang Liang, Binbin Nie, Shaofeng Duan, Qi Huang, Tianhao Zhang, Xi Sun, Ting Feng, Lin Ma, Baoci Shan, Demin Li, Hua Liu
Retrosplenial cortex (RSC) plays a key role in various cognitive functions. The fiber connectivity of RSC had been reported in rodent and primate studies by tracer injection methods To explore structural and functional connectivity of two sub-regions of RSC, Brodmann area (BA)29 and BA30, we constructed fiber connectivity networks of two sub-regions by diffusion tensor imaging (DTI) tractography based on diffusion magnetic resonance imaging (MRI) and functional connectivity networks by resting-state functional MRI...
March 9, 2018: Neuroscience Letters
Shuailong Zhang, Adele Nikitina, Yujie Chen, Yanfeng Zhang, Lin Liu, Andrew G Flood, Joan Juvert, M Dean Chamberlain, Nazir P Kherani, Steven L Neale, Aaron R Wheeler
Optoelectronic tweezers (OET) are a microsystem actuation technology capable of moving microparticles at mm s-1 velocities with nN forces. In this work, we analyze the behavior of particles manipulated by negative dielectrophoresis (DEP) forces in an OET trap. A user-friendly computer interface was developed to generate a circular rotating light pattern to control the movement of the particles, allowing their force profiles to be conveniently measured. Three-dimensional simulations were carried out to clarify the experimental results, and the DEP forces acting on the particles were simulated by integrating the Maxwell stress tensor...
March 5, 2018: Optics Express
Avinash Rao, Hesham Soliman, Mayank Kaushal, Oleysa Motovylak, Aditya Vedantam, Matthew D Budde, Brian Schmit, Marjorie Wang, Shekar N Kurpad
BACKGROUND: Fractional anisotropy (FA) of the high cervical cord correlates with upper limb function in acute cervical cord injury. We investigated the correlation between preoperative FA at the level of maximal compression and functional recovery in a group of patients after decompressive surgery for cervical spondylotic myelopathy (CSM). OBJECTIVE: To determine the usefulness of FA as a biomarker for severity of CSM and as a prognostic biomarker for improvement after surgery...
February 23, 2018: Neurosurgery
Carla Andreani, Giovanni Romanelli, Roberto Senesi
No abstract text is available yet for this article.
March 12, 2018: Journal of Physical Chemistry Letters
Evangelia Tsolaki, Angela Downes, William Speier, W Jeff Elias, Nader Pouratian
Magnetic Resonance-guided Focused UltraSound (MRgFUS) offers an incisionless approach to treat essential tremor (ET). Due to lack of evident internal anatomy on traditional structural imaging, indirect targeting must still be used to localize the lesion. Here, we investigate the potential predictive value of probabilistic tractography guided thalamic targeting by defining how tractography-defined targets, lesion size and location, and clinical outcomes interrelate. MR imaging and clinical outcomes from 12 ET patients that underwent MRgFUS thalamotomy in a pilot study at the University of Virginia were evaluated in this analysis...
2018: NeuroImage: Clinical
Sanuji Gajamange, David Raffelt, Thijs Dhollander, Elaine Lui, Anneke van der Walt, Trevor Kilpatrick, Joanne Fielding, Alan Connelly, Scott Kolbe
Long term irreversible disability in multiple sclerosis (MS) is thought to be primarily driven by axonal degeneration. Axonal degeneration leads to degenerative atrophy, therefore early markers of axonal degeneration are required to predict clinical disability and treatment efficacy. Given that additional pathologies such as inflammation, demyelination and oedema are also present in MS, it is essential to develop axonal markers that are not confounded by these processes. The present study investigated a novel method for measuring axonal degeneration in MS based on high angular resolution diffusion magnetic resonance imaging...
2018: NeuroImage: Clinical
Cheima Bouziane, Matthan W A Caan, Hyke G H Tamminga, Anouk Schrantee, Marco A Bottelier, Michiel B de Ruiter, Sandra J J Kooij, Liesbeth Reneman
Several diffusion tensor imaging (DTI) studies in attention deficit hyperactivity disorder (ADHD) have shown a delay in brain white matter (WM) development. Because these studies were mainly conducted in children and adolescents, these WM abnormalities have been assumed, but not proven to progress into adulthood. To provide further insight in the natural history of WM maturation delay in ADHD, we here investigated the modulating effect of age on WM in children and adults. 120 stimulant-treatment naive male ADHD children (10-12 years of age) and adults (23-40 years of age) with ADHD (according to DSM-IV; all subtypes) were included, along with 23 age and gender matched controls...
2018: NeuroImage: Clinical
Alexandre Lewalle, Sander Land, Eric Carruth, Lawrence R Frank, Pablo Lamata, Jeffrey H Omens, Andrew D McCulloch, Steven A Niederer, Nicolas P Smith
The cardiac system compensates for variations in physiological and pathophysiological conditions through a dynamic remodeling at the organ, tissue, and intracellular levels in order to maintain function. However, on longer time scales following the onset of ventricular pressure overload, such remodeling may begin to inhibit physiological function and ultimately lead to heart failure. This progression from compensatory to decompensatory behavior is poorly understood, in particular owing to the absence of a unified perspective of the concomitantly remodeling subsystems...
2018: Frontiers in Physiology
Gang Liu, Kangqiang Peng, Chao Dang, Shuangquan Tan, Hongbing Chen, Chuanmiao Xie, Shihui Xing, Jinsheng Zeng
BACKGROUND: Secondary degeneration of the fiber tract of the motor pathway below infarct foci and functional recovery after stroke have been well demonstrated, but the role of the fiber tract above stroke foci remains unclear. OBJECTIVE: This study aimed to investigate diffusion changes in motor fibers above the lesion and identify predictors of motor improvement within 12 weeks after subcortical infarction. METHODS: Diffusion tensor imaging and the Fugl-Meyer (FM) scale were conducted 1, 4, and 12 weeks (W) after a subcortical infarct...
2018: Restorative Neurology and Neuroscience
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