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White fibers

Thitaphat Ngernsutivorakul, Cynthia M Cipolla, Colleen E Dugan, Shi Jin, Michael D Morris, Robert T Kennedy, Francis W L Esmonde-White
Fiber optics coupled to components such as lenses and mirrors have seen extensive use as probes for Raman and fluorescence measurements. Probes can be placed directly on or into a sample to allow for simplified and remote application of these optical techniques. The size and complexity of such probes however limits their application. We have used microfabrication in polydimethylsiloxane (PDMS) to create compact probes that are 0.5 mm thick by 1 mm wide. The miniature probes incorporate pre-aligned mirrors, lenses, and two fiber optic guides to allow separate input and output optical paths suitable for Raman and fluorescence spectroscopy measurements...
October 20, 2016: Analytical and Bioanalytical Chemistry
Emmanuel Mandonnet, Juan Martino, Silvio Sarubbo, Francesco Corrivetti, Schahraed Bouazza, Damien Bresson, Hugues Duffau, Sebastien Froelich
BACKGROUND: Advances in the oncological and functional results of insular surgery have been reported recently. Such successes have been made possible by the advent of the transopercular approach under awake monitoring and by the improved anatomical and functional knowledge of the white matter pathways surrounding the insula. Nonetheless, given the rarity of insular tumors, it is difficult to get familiar with the complex 3D anatomy of the different neuronal and vascular structures encountered during a transopercular insular resection...
October 17, 2016: World Neurosurgery
Chinglin Wu, Suyu Zhong, Hsuehchih Chen
Remote association is a core ability that influences creative output. In contrast to close association, remote association is commonly agreed to be connected with more original and unique concepts. However, although existing studies have discovered that creativity is closely related to the white-matter structure of the brain, there are no studies that examine the relevance between the connectivity efficiencies and creativity of the brain regions from the perspective of networks. Consequently, this study constructed a brain white matter network structure that consisted of cerebral tissues and nerve fibers and used graph theory to analyze the connection efficiencies among the network nodes, further illuminating the differences between remote and close association in relation to the connectivity of the brain network...
2016: PloS One
Jianfei Yang, Dirk H J Poot, Matthan W A Caan, Tanja Su, Charles B L M Majoie, Lucas J van Vliet, Frans M Vos
PURPOSE: This paper presents and studies a framework for reliable modeling of diffusion MRI using a data-acquisition adaptive prior. METHODS: Automated relevance determination estimates the mean of the posterior distribution of a rank-2 dual tensor model exploiting Jeffreys prior (JARD). This data-acquisition prior is based on the Fisher information matrix and enables the assessment whether two tensors are mandatory to describe the data. The method is compared to Maximum Likelihood Estimation (MLE) of the dual tensor model and to FSL's ball-and-stick approach...
2016: PloS One
Christoph Scherfler, Alois Josef Schiefecker, Margarete Delazer, Ronny Beer, Thomas Bodner, Georg Spinka, Mario Kofler, Bettina Pfausler, Christian Kremser, Michael Schocke, Thomas Benke, Elke R Gizewski, Erich Schmutzhard, Raimund Helbok
OBJECTIVE: MRI parameters of iron concentration (R2*, transverse relaxation rate), microstructural integrity (mean diffusivity and fractional anisotropy), as well as gray and white matter volumes were analyzed in patients with subarachnoid hemorrhage (SAH) and uncomplicated clinical course to detect the evolution of brain tissue changes 3 weeks and 12 months after ictus. METHODS: MRI scans of 14 SAH patients (aneurysm of the anterior communicating artery, n = 5; no aneurysm n = 9) were compared with 14 age-matched healthy control subjects...
October 2016: Annals of Clinical and Translational Neurology
Shi-Fa Zhang, Yan Zhou, Kai-Jing Zhang, Jia-Jie Luan, Shi-Mei Qi
OBJECTIVE: To investigate the effect of Nogo-66 receptor (NgR) silencing with specific small interfering RNA (siRNA) on brain injury repair in preterm rats with brain injury caused by intrauterine infection and related mechanism of action. METHODS: The pregnant Sprague-Dawley rats (with a gestational age of 15 days) were selected, and premature delivery was induced by RU486 or lipopolysaccharide (LPS). The preterm rats delivered by those treated with RU486 were selected as the control group...
October 2016: Zhongguo Dang Dai Er Ke za Zhi, Chinese Journal of Contemporary Pediatrics
Alexander U Brandt, Elena Meinert-Bohn, Jan Leo Rinnenthal, Hanna Zimmermann, Janine Mikolajczak, Timm Oberwahrenbrock, Sebastian Papazoglou, Caspar F Pfüller, Johann Schinzel, Björn Tackenberg, Friedemann Paul, Katrin Hahn, Judith Bellmann-Strobl
BACKGROUND: The PMP22 gene encodes a protein integral to peripheral myelin. Its deletion leads to hereditary neuropathy with liability to pressure palsies (HNPP). PMP22 is not expressed in the adult central nervous system, but previous studies suggest a role in CNS myelin development. The objective of this study was to identify potential structural and functional alterations in the afferent visual system in HNPP patients. METHODS: Twenty HNPP patients and 18 matched healthy controls (HC) were recruited in a cross-sectional study...
2016: PloS One
Jingjin Jiang, Qian Shen, Wei Ding, Jianying Zhou
Primary pulmonary chondrosarcoma is a rare neoplasm that usually grows slowly, metastasizes late, and responds well to excision when localized. Herein, we present a 59-year-old man who manifested with hemoptysis, cough and dyspnea with a hemithorax mass. A chest computed tomography scan demonstrated a fast-growing mass in the right upper lobe, and the enhancement was partially heterogeneous. Bronchoscopy revealed a hemorrhagic neoplasm in the right upper bronchus. A bronchoscopy biopsy specimen revealed a variety of tissues, including mucoid cartilage, fibers, respiratory epithelium and squamous epithelium...
September 2016: Journal of Thoracic Disease
RaviK Shastri, GaurangV Shah, Page Wang, Patricia Cagnoli, Tobias Schmidt-Wilcke, Joseph McCune, Richard Harris, PiaC Sundgren
PURPOSE: Systemic lupus erythematosus (SLE) is a predominantly female autoimmune disease that can affect the central nervous system. Neuropsychiatric symptoms are found in 25-70% of SLE patients. Using diffusion tensor imaging, various studies have reported changes in white matter integrity in SLE patients with neuropsychiatric symptoms (NPSLE patients). The purpose of this study was to investigate if changes can be detected in the individual white matter tracts in SLE patients regardless if neuropsychiatric symptoms are present or not...
October 13, 2016: Academic Radiology
Yi-Bin Xi, Fan Guo, Hua Li, Xiao Chang, Jin-Bo Sun, Yuan-Qiang Zhu, Wen-Ming Liu, Long-Biao Cui, Gang Chen, Hua-Ning Wang, Hong Yin
Heterogeneous findings across studies of structural abnormality in schizophrenia (SZ) have impeded the development a unified theory of white matter pathology. As a cardinal symptom of SZ, auditory verbal hallucination (AVH) has been suspected to be associated with improper communication among several brain regions, which might indicated white matter pathology. Participants comprised 25 first-episode (FE) patients with AVH, 25 patients without AVH and 25 healthy subjects. Diffusion tensor imaging (DTI) measures were calculated using the TBSS of FSL...
September 28, 2016: Psychiatry Research
Farid Ahmed Sid, Karim Abed-Meraim, Rachid Harba, Fatima Oulebsir-Boumghar
PURPOSE: To examine the effects of MR acquisition parameters on brain white matter fiber orientation estimation and parameter of clinical interest in crossing fiber areas based on the Multi-Tensor Model (MTM). MATERIAL AND METHODS: We compute the Cramér-Rao Bound (CRB) for the MTM and the parameter of clinical interest such as the Fractional Anisotropy (FA) and the dominant fiber orientations, assuming that the diffusion MRI data are recorded by a multi-coil, multi-shell acquisition system...
October 12, 2016: Magnetic Resonance Imaging
Neda Sadeghi, John H Gilmore, Guido Gerig
Twin studies provide valuable insights into the analysis of genetic and environmental factors influencing human brain development. However, these findings may not generalize to singletons due to differences in pre- and postnatal environments. One would expect the effect of these differences to be greater during the early years of life. To address this concern, we compare longitudinal diffusion data of white matter regions for 26 singletons and 76 twins (monozygotic and dizygotic) from birth to 2 years of age...
October 14, 2016: Human Brain Mapping
Richard Q Loi, Kelly M Leyden, Akshara Balachandra, Vedang Uttarwar, Donald J Hagler, Brianna M Paul, Anders M Dale, Nathan S White, Carrie R McDonald
OBJECTIVE: Diffusion tensor imaging (DTI) has become a popular tool for delineating the location and extent of white matter injury in temporal lobe epilepsy (TLE). However, DTI yields nonspecific measures that are confounded by changes occurring within both the intracellular and extracellular environments. This study investigated whether an advanced diffusion method, restriction spectrum imaging (RSI) could provide a more robust measure of white matter injury in TLE relative to DTI due to RSI's ability to separate intraaxonal diffusion (i...
October 13, 2016: Epilepsia
Jidan Zhong, David Q Chen, Matthew Walker, Adam Waspe, Thomas Looi, Karolina Piorkowska, James M Drake, Mojgan Hodaie
An increasing number of applications use the postnatal piglet model in neuroimaging studies, however, these are based primarily on T1 weighted image templates. There is a growing need for a multimodal structural brain template for a comprehensive depiction of the piglet brain, particularly given the growing applications of diffusion weighted imaging for characterizing tissue microstructures and white matter organization. In this study, we present the first multimodal piglet structural brain template which includes a T1 weighted image with tissue segmentation probability maps, diffusion weighted metric templates with multiple diffusivity maps, and population-based whole-brain fiber tracts for postnatal piglets...
2016: Frontiers in Neuroanatomy
Chao J Liu, Kristen E Williams, Harry T Orr, Taner Akkin
We present the visualization of the mouse cerebellum and adjacent brainstem using a serial optical coherence scanner, which integrates a vibratome slicer and polarization-sensitive optical coherence tomography for ex vivo imaging. The scanner provides intrinsic optical contrasts to distinguish the cerebellar cortical layers and white matter. Images from serial scans reveal the large-scale anatomy in detail and map the nerve fiber pathways in the cerebellum and brainstem. By incorporating a water-immersion microscope objective, we also present high-resolution tiled images that delineate fine structures in the cerebellum and brainstem...
January 2017: Neurophotonics
Carlo Serra, Uğur Türe, Niklaus Krayenbühl, Gülgün Şengül, Dianne C H Yaşargil, M Gazi Yaşargil
OBJECT: To describe the topographic anatomy of the surgically accessible surfaces of the human thalamus as a guide to surgical exploration of this sensitive area. METHODS: Using the operating microscope, we applied the fiber microdissection technique to study 10 brain specimens. Step by step dissections in superior-inferior, medial-lateral and posterior-anterior directions were conducted in order to expose the surfaces and nuclei of the thalamus and to investigate the relevant anatomic relationships and visible connections...
October 7, 2016: World Neurosurgery
Catarina Guise, Margarida M Fernandes, Sudhir Pathak, Walter Schneider, Raul Fangueiro
Current brain imaging methods largely fail to provide detailed information about the location and severity of axonal injuries, and do not anticipate recovery of the patients with traumatic brain injury. High-Definition Fiber Tractography appears as a novel imaging modality based on water motion in the brain that allows for direct visualization and quantification of the degree of axons damage, thus predicting the functional deficits due to traumatic axonal injury and loss of cortical projections. This neuroimaging modality still faces major challenges because it lacks a "gold standard" for the technique validation and respective quality control...
October 10, 2016: ACS Applied Materials & Interfaces
Weihong Yuan, Artur Meller, Joshua S Shimony, Tiffany Nash, Blaise V Jones, Scott K Holland, Mekibib Altaye, Holly Barnard, Jannel Phillips, Stephanie Powell, Robert C McKinstry, David D Limbrick, Akila Rajagopal, Francesco T Mangano
Neuroimaging research in surgically treated pediatric hydrocephalus patients remains challenging due to the artifact caused by programmable shunt. Our previous study has demonstrated significant alterations in the whole brain white matter structural connectivity based on diffusion tensor imaging (DTI) and graph theoretical analysis in children with hydrocephalus prior to surgery or in surgically treated children without programmable shunts. This study seeks to investigate the impact of brain injury on the topological features in the left hemisphere, contratelateral to the shunt placement, which will avoid the influence of shunt artifacts and makes further group comparisons feasible for children with programmable shunt valves...
2016: NeuroImage: Clinical
Laurie M Baker, Ryan P Cabeen, Sarah Cooley, David H Laidlaw, Robert H Paul
This paper reviews basic methods and recent applications of length-based fiber bundle analysis of cerebral white matter using diffusion magnetic resonance imaging (dMRI). Diffusion weighted imaging (DWI) is a dMRI technique that uses the random motion of water to probe tissue microstructure in the brain. Diffusion tensor imaging (DTI) is an extension of DWI that measures the magnitude and direction of water diffusion in cerebral white matter, using either voxel-based scalar metrics or tractography-based analyses...
April 2016: Technology and Innovation
Lauren Marussich, Kun-Han Lu, Haiguang Wen, Zhongming Liu
Despite wide applications of functional magnetic resonance imaging (fMRI) to mapping brain activation and connectivity in cortical gray matter, it has rarely been utilized to study white-matter functions. In this study, we investigated the spatiotemporal characteristics of fMRI data within the white matter acquired from humans in the resting state or watching a naturalistic movie. By using independent component analysis and hierarchical clustering, resting-state fMRI data in the white matter were denoised and decomposed into spatially independent components, further assembled into hierarchically organized axonal fiber bundles...
October 5, 2016: NeuroImage
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