84 research outputs found

    DĂ©tection et suivi des sillons corticaux

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    L'étiquetage et l'identification automatique des structures cérébrales, en particulier des sillons corticaux, ont des applications dans le domaine de la neurologie. Nous proposons une méthode de détection du fond des sillons du cortex cérébral dans le but d'obtenir la surface médiane 3D des sillons et une modélisation paramétrique de cette surface. La méthode est basée sur un calcul des caractéristiques différentielles appliqué sur le volume IRM complet. L'extraction du fond des sillons se fait par suivi pseudo-continu (précision sub-voxel). Les déplacements successifs s'effectuent en direction des vecteurs courbure minimum en chaque point. Les caractéristiques différentielles nécessaires au suivi sont calculées à partir des dérivées partielles du volume traité. Le suivi du fond des sillons, correctement détecté, ne nécessite pas de segmentation fine du cortex cérébral

    Joint inversion of EM and magnetic data for near?surface studies

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    International audienceMagnetic and electromagnetic measurements are influenced by magnetic susceptibility and, thus, are widely used in geophysical surveys for archeology or pedology. To date, the data inversion is performed separately. A filtering process incorporating both types of data is presented here. After testing the algorithm with synthetic data, the algorithm is used in several case studies in archeological prospecting. This approach presents two advantages: establishing the presence of remanent mag-netizations (viscous or thermoremanent), and achieving more refined depth analysis of the anomaly

    Cortical sulci detection and tracking

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    International audienceAutomatic labelling and identification of cerebral structure, like cortical sulci, are useful in neurology, surgery planning, etc... We propose a cortical sulci valley detection. The aim of the method is to achieve the sulci medial surface. The method applied on MRI data, is based on geometrical features (curvature) which doesn't require the accurate segmentation of the cerebral cortex. We use a sub-voxel precision tracking. The minimum curvature vector in each point allows successive displacement along the valley of sulci. Partial derivatives provide the differential characteristics

    3D curves tracking and its application to cortical sulci detection

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    International audienceAutomatic labelling and identification of cerebral structure, such as cortical sulci, are useful in neurology, surgery planning, etc... In this paper, a method to detect the valley of the cortical sulci is presented. The aim of the method is to achieve the sulci medial surface. The method applied on MRI data, is based on geometrical features (curvature) which doesn't require the accurate segmentation of the cerebral cortex. We use a sub-voxel precision tracking. The minimum curvature vector in each point allows successive displacement along the valley of sulci. Partial derivatives provide the differential characteristics

    Suivi de courbes 3D. Application à la détection des sillons corticaux

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    International audienceL'étiquetage et l'identification automatique des structures cérébrales, en particulier des sillons corticaux, ont des applications dans le domaine de la neurologie. Nous proposons une méthode de détection du fond des sillons du cortex cérébral dans le but d'obtenir la surface médiane 3D des sillons et une modélisation paramétrique de cette surface. La méthode est basée sur un calcul des caractéristiques différentielles appliqué sur le volume IRM complet. L'extraction du fond des sillons se fait par suivi pseudo-continu (précision sub-voxel). Les déplacements successifs s'effectuent en direction des vecteurs courbure minimum en chaque point. Les caractéristiques différentielles nécessaires au suivi sont calculées à partir des dérivées partielles du volume traité. Le suivi du fond des sillons, correctement détecté, ne nécessite pas de segmentation fine du cortex cérébral

    Joint inversion of EM and magnetic data for near?surface studies

    No full text
    International audienceMagnetic and electromagnetic measurements are influenced by magnetic susceptibility and, thus, are widely used in geophysical surveys for archeology or pedology. To date, the data inversion is performed separately. A filtering process incorporating both types of data is presented here. After testing the algorithm with synthetic data, the algorithm is used in several case studies in archeological prospecting. This approach presents two advantages: establishing the presence of remanent mag-netizations (viscous or thermoremanent), and achieving more refined depth analysis of the anomaly

    Sulci and curvature: detection of the roof

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    International audienceAutomatic labelling and identification of cortical sulci which can be used as landmarks in registration between patients or between different modalities. Methods used to achieve this goal are the segmentation of the brain, the detection of sulci using classification and threshold or morphologic tool, the statistical or structural recognition techniques. Our previous work proceeds with segmentation of the brain by thresholding the LCR, and skeletonisation of the LCR. We present here a method based on geometrical feature (curvature) which doesn't require the fine segmentation of the LCR-Grey Matter or of the Grey Matter-White Matter interface. Although our previous work [1] used the superficial trace of sulci, we detect the roof of the sulci, which presents less intersection between sulci than the superficial trace of sulci

    DĂ©tection et suivi de sillons corticaux

    No full text
    National audienceL'étiquetage et l'identification automatique des structures cérébrales, en particulier des sillons corticaux, ont des applications dans le domaine de la neurologie. Nous proposons une méthode de détection du fond des sillons du cortex cérébral dans le but d'obtenir la surface médiane 3D des sillons et une modélisation paramétrique de cette surface. La méthode est basée sur un calcul des caractéristiques différentielles appliqué sur le volume IRM complet. L'extraction du fond des sillons se fait par suivi pseudo- continu (précision sub-voxel). Les déplacements successifs s'effectuent en direction des vecteurs courbure minimum en chaque point. Les caractéristiques différentielles nécessaires au suivi sont calculées à partir des dérivées partielles du volume traité. Le suivi du fond des sillons, correctement détecté, ne nécessite pas de segmentation fine du cortex cérébral

    How to Identify Pathogenic Mutations among All Those Variations: Variant Annotation and Filtration in the Genome Sequencing Era

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    International audienceHigh-throughput sequencing technologies have become fundamental for the identification of disease-causing mutations in human genetic diseases both in research and clinical testing contexts. The cumulative number of genes linked to rare diseases is now close to 3,500 with more than 1,000 genes identified between 2010 and 2014 because of the early adoption of Exome Sequencing technologies. However, despite these encouraging figures, the success rate of clinical exome diagnosis remains low due to several factors including wrong variant annotation and nonoptimal filtration practices, which may lead to misinterpretation of disease-causing mutations. In this review, we describe the critical steps of variant annotation and filtration processes to highlight a handful of potential disease-causing mutations for downstream analysis. We report the key annotation elements to gather at multiple levels for each mutation, and which systems are designed to help in collecting this mandatory information. We describe the filtration options, their efficiency, and limits and provide a generic filtration workflow and highlight potential pitfalls through a use case. (C) 2016 Wiley Periodicals, Inc
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