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排序方式: 共有1804条查询结果,搜索用时 15 毫秒
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Keser Tobias Kofler Mario Katzmayr Mariella Schiefecker Alois J. Rass Verena Ianosi Bogdan A. Lindner Anna Gaasch Maxime Beer Ronny Rhomberg Paul Schmutzhard Erich Pfausler Bettina Helbok Raimund 《Neurocritical care》2020,33(1):132-139
Neurocritical Care - Despite the tremendous impact of swallowing disorders on outcome following ischemic stroke, little is known about the incidence of dysphagia after subarachnoid hemorrhage (SAH)... 相似文献
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Francois Rheault Alessandro De Benedictis Alessandro Daducci Chiara Maffei Chantal M. W. Tax David Romascano Eduardo Caverzasi Felix C. Morency Francesco Corrivetti Franco Pestilli Gabriel Girard Guillaume Theaud Ilyess Zemmoura Janice Hau Kelly Glavin Kesshi M. Jordan Kristofer Pomiecko Maxime Chamberland Muhamed Barakovic Nil Goyette Philippe Poulin Quentin Chenot Sandip S. Panesar Silvio Sarubbo Laurent Petit Maxime Descoteaux 《Human brain mapping》2020,41(7):1859-1874
Investigative studies of white matter (WM) brain structures using diffusion MRI (dMRI) tractography frequently require manual WM bundle segmentation, often called “virtual dissection.” Human errors and personal decisions make these manual segmentations hard to reproduce, which have not yet been quantified by the dMRI community. It is our opinion that if the field of dMRI tractography wants to be taken seriously as a widespread clinical tool, it is imperative to harmonize WM bundle segmentations and develop protocols aimed to be used in clinical settings. The EADC‐ADNI Harmonized Hippocampal Protocol achieved such standardization through a series of steps that must be reproduced for every WM bundle. This article is an observation of the problematic. A specific bundle segmentation protocol was used in order to provide a real‐life example, but the contribution of this article is to discuss the need for reproducibility and standardized protocol, as for any measurement tool. This study required the participation of 11 experts and 13 nonexperts in neuroanatomy and “virtual dissection” across various laboratories and hospitals. Intra‐rater agreement (Dice score) was approximately 0.77, while inter‐rater was approximately 0.65. The protocol provided to participants was not necessarily optimal, but its design mimics, in essence, what will be required in future protocols. Reporting tractometry results such as average fractional anisotropy, volume or streamline count of a particular bundle without a sufficient reproducibility score could make the analysis and interpretations more difficult. Coordinated efforts by the diffusion MRI tractography community are needed to quantify and account for reproducibility of WM bundle extraction protocols in this era of open and collaborative science. 相似文献
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Francois Rheault Kurt G. Schilling Alex ValcourtCaron Antoine Thberge Charles Poirier Gabrielle Grenier Guido I. Guberman John Begnoche Jon Haitz Legarreta Leon Y. Cai Maggie Roy Manon Edde Marco Perez Caceres Mario OcampoPineda Noor AlSharif Philippe Karan Pietro Bontempi Sami Obaid Sara Bosticardo Simona Schiavi Viljami Sairanen Alessandro Daducci Laurie E. Cutting Laurent Petit Maxime Descoteaux Bennett A. Landman 《Human brain mapping》2022,43(7):2134
The segmentation of brain structures is a key component of many neuroimaging studies. Consistent anatomical definitions are crucial to ensure consensus on the position and shape of brain structures, but segmentations are prone to variation in their interpretation and execution. White‐matter (WM) pathways are global structures of the brain defined by local landmarks, which leads to anatomical definitions being difficult to convey, learn, or teach. Moreover, the complex shape of WM pathways and their representation using tractography (streamlines) make the design and evaluation of dissection protocols difficult and time‐consuming. The first iteration of Tractostorm quantified the variability of a pyramidal tract dissection protocol and compared results between experts in neuroanatomy and nonexperts. Despite virtual dissection being used for decades, in‐depth investigations of how learning or practicing such protocols impact dissection results are nonexistent. To begin to fill the gap, we evaluate an online educational tractography course and investigate the impact learning and practicing a dissection protocol has on interrater (groupwise) reproducibility. To generate the required data to quantify reproducibility across raters and time, 20 independent raters performed dissections of three bundles of interest on five Human Connectome Project subjects, each with four timepoints. Our investigation shows that the dissection protocol in conjunction with an online course achieves a high level of reproducibility (between 0.85 and 0.90 for the voxel‐based Dice score) for the three bundles of interest and remains stable over time (repetition of the protocol). Suggesting that once raters are familiar with the software and tasks at hand, their interpretation and execution at the group level do not drastically vary. When compared to previous work that used a different method of communication for the protocol, our results show that incorporating a virtual educational session increased reproducibility. Insights from this work may be used to improve the future design of WM pathway dissection protocols and to further inform neuroanatomical definitions. 相似文献
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Maxime Béland Mikaël BédardGuillaume Tremblay Pierre LavigneXavier Roucou 《Neurobiology of aging》2014
Plasma membrane cellular prion protein (PrPC) is a high-affinity receptor for toxic soluble amyloid-β (Aβ) oligomers that mediates synaptic dysfunction. Secreted forms of PrPC resulting from PrPC α-cleavage (PrPN1) or shedding (shed PrPC) display neuroprotective activity in neuronal cultures and in mouse models of Aβ-induced neuronal dysfunction. In vitro, recombinant PrPN1 and PrP inhibit Aβ fibrillization. However, the mechanism by which PrPN1 and shed PrPC neutralize Aβ oligomers is unclear, and evidence of such neuroprotective activity in Alzheimer's disease (AD) patients is lacking. Here, we show that PrPN1 association with Aβ causes a conformational change resulting in the formation of amorphous and insoluble aggregates that are not compatible with the assembly of Aβs. Using postmortem brain tissues of AD patients, we were able to coimmunoprecipitate Aβ with PrPC molecules and observed a coaggregation of Aβ and PrPN1 in the guanidine-extractable fraction presumably representing insoluble amyloid plaques. Furthermore, PrPC α-cleavage is increased in AD brains, and we noticed a significant positive correlation between the levels of α-cleavage and of guanidine-extractable Aβ. These data strongly support the hypothesis that PrPC α-cleavage is an endogenous neuroprotective mechanism in AD and support the development of PrPC-derived peptides as therapeutic molecules for AD. 相似文献