Search results for " tractography"

Insight into Disrupted Spatial Patterns of Human Connectome in Alzheimer’s Disease via Subgraph Mining

2012

Alzheimer’s disease (AD) is the most common cause of age-related dementia, which prominently affects the human connectome. In this paper, the authors focus on the question how they can identify disrupted spatial patterns of the human connectome in AD based on a data mining framework. Using diffusion tractography, the human connectomes for each individual subject were constructed based on two diffusion derived attributes: fiber density and fractional anisotropy, to represent the structural brain connectivity patterns. After frequent subgraph mining, the abnormal score was finally defined to identify disrupted subgraph patterns in patients. Experiments demonstrated that our data-driven approa…

Discovering Aberrant Patterns of Human Connectome in Alzheimer's Disease via Subgraph Mining

2012

Alzheimer's disease (AD) is the most common cause of age-related dementia, which prominently affects the human connectome. Diffusion weighted imaging (DWI) provides a promising way to explore the organization of white matter fiber tracts in the human brain in a non-invasive way. However, the immense amount of data from millions of voxels of a raw diffusion map prevent an easy way to utilizable knowledge. In this paper, we focus on the question how we can identify disrupted spatial patterns of the human connectome in AD based on a data mining framework. Using diffusion tractography, the human connectomes for each individual subject were constructed based on two diffusion derived attributes: …

In vivo definition of parieto-motor connections involved in planning of grasping movements

2010

We combined bifocal transcranial magnetic stimulation (TMS) and diffusion tensor imaging (DTI) tractography to investigate in humans the contribution of connections originating from different parietal areas in planning of different reaching to grasp movements. TMS experiments revealed that in the left hemisphere functional connectivity between the primary motor cortex (M1) and a portion of the angular gyrus (AG) close to the caudal intraparietal sulcus was activated during early preparation of reaching and grasping movements only when the movement was made with a whole hand grasp (WHG) towards objects in contralateral space. In contrast, a different pathway, linking M1 with a part of the su…

Thalamic parcellation for target identification in trans-cranial MR-guided Focused UltraSound (tcMRgFUS) thalamotomies: a preliminary probabilistc tr…

2018

Background: Trans-cranial MR-guided Focused UltraSound (tcMRgFUS) allows a neurofunctional exploration of thalamic nuclei to confirm and optimize the target before inducing a permanent brain lesion. However, the choice of the target is based on stereotactic coordinates that do not take into account the anatomical variability of each single patient. Thus, the optimization of the treatment target is based on the patient's feedback during lower power sonications. The aim of this work is to retrospectively evaluate the possible role of thalamic parcellation for the identification of the intermediate ventral nucleus (VIM) in patients undergoing tcMRgFUS. Materials and Methods: A 1.5T MR scanner …

Thalamic parcellation for target identification in trans-cranial MR-guided Focused UltraSound (tcMRgFUS) thalamotomies: A preliminary probabilistic t…

2020

Identification of proprioceptive thalamocortical tracts in children: comparison of fMRI, MEG, and manual seeding of probabilistic tractography

2022

Publisher Copyright: © The Author(s) 2022. Published by Oxford University Press. Studying white matter connections with tractography is a promising approach to understand the development of different brain processes, such as proprioception. An emerging method is to use functional brain imaging to select the cortical seed points for tractography, which is considered to improve the functional relevance and validity of the studied connections. However, it is unknown whether different functional seeding methods affect the spatial and microstructural properties of the given white matter connection. Here, we compared functional magnetic resonance imaging, magnetoencephalography, and manual seedin…

Diagnostic potential of the diffusion tensor tractography with fractional anisotropy in the diagnosis and treatment of cervical spondylotic and postt…

2016

Background: Diffusion tensor imaging (DTI) is a magnetic resonance imaging (MRI)-based methodology widely used for the evaluation of microstructural integrity of the central nervous system (CNS), particularly of brain white matter fibers and bundles. Methods: The most common parameters evaluated in a DTI study are the fractional anisotropy (FA) and mean diffusivity (MD). Combining FA and MD analyses is commonly used in the evaluation of various types of brain pathologies, such as brain tumors, where a combined analysis allows an accurate tumor characterization. Results: Recent studies have shown that FA and MD could be of value in non-oncologic spinal pathology. In this regard, it has been …