The Experts below are selected from a list of 3852 Experts worldwide ranked by ideXlab platform

Olivier Coulon - One of the best experts on this subject based on the ideXlab platform.

  • U-shape short-range extrinsic connectivity organisation around the human Central Sulcus
    bioRxiv, 2020
    Co-Authors: Alexandre Pron, Christine Deruelle, Olivier Coulon
    Abstract:

    The Central Sulcus is probably one of the most studied folds in the human brain, owing to its clear relationship with primary sensory-motor functional areas. However, due to the difficulty of estimating the trajectories of the U-shape fibres from diffusion MRI, the short structural connectivity of this Sulcus remains relatively unknown. In this context, we studied the spatial organization of these U-shape fibres along the Central Sulcus. Based on high quality diffusion MRI data of 100 right-handed subjects and state-of-the-art pre-processing pipeline, we first define a connectivity space that provide a comprehensive and continuous description of the short-range anatomical connectivity around the Central Sulcus at both the individual and group levels. We then infer the presence of five major U-shape fibre bundles at the group level in both hemispheres by applying unsupervised clustering in the connectivity space. We propose a quantitative investigation of their position and number of streamlines as a function of phenotypic traits such as sex and hemispheres and functional scores such as handedness and manual dexterity. Main findings of this study are twofold: a description of U-shape short-range connectivity along the Central Sulcus at group level and the evidence of a significant relationship between the position of three hand related U-shape fibre bundles and the handedness score of subjects.

  • handedness in monkeys reflects hemispheric specialization within the Central Sulcus an in vivo mri study in right and left handed olive baboons
    Cortex, 2019
    Co-Authors: Olivier Coulon, Konstantina Margiotoudi, Damien Marie, Nicolas Claidiere, Muriel Roth, Bruno Nazarian, Romain Lacoste
    Abstract:

    Abstract Handedness, one of the most prominent expressions of laterality, has been historically considered unique to human. This noteworthy feature relates to contralateral inter-hemispheric asymmetries in the motor hand area following the mid-portion of the Central Sulcus. However, within an evolutionary approach, it remains debatable whether hand preferences in nonhuman primates are associated with similar patterns of hemispheric specialization. In the present study conducted in Old world monkeys, we investigate anatomical asymmetries of the Central Sulcus in a sample of 86 olive baboons (Papio anubis) from in vivo T1 anatomical magnetic resonance images (MRI). Out of this sample, 35 individuals were classified as right-handed and 28 as left-handed according to their hand use responses elicited by a bimanual coordinated tube task. Here we report that the direction and degree of hand preference (left or right), as measured by this manual task, relates to and correlates with contralateral hemispheric Sulcus depth asymmetry, within a mid-portion of the Central Sulcus. This neuroanatomical manifestation of handedness in baboons located in a region, which may correspond to the motor hand area, questions the phylogenetic origins of human handedness that may date back to their common ancestor, 25–40 millions years ago.

  • Dense and structured representations of U-shape fiber connectivity in the Central Sulcus
    2018 IEEE 15th International Symposium on Biomedical Imaging (ISBI 2018), 2018
    Co-Authors: Alexandre Pron, Christine Deruelle, Lucile Brun, Olivier Coulon
    Abstract:

    U-shape fibers are superficial white matter fibers connecting adjacent gyri. In this paper, we present a method to characterize the connectivity of U-shape fibers coursing around the Central Sulcus. Pre- and post-Central gyral crests are semi-automatically drawn and used to build a connectivity space that is identical between subjects. This group space provides a dense representation of the short-range connectivity between the two gyri, as well as a structured representation after clustering.

  • Dense and structured representations of U-Shape fibers connectivity in the Central Sulcus
    2018
    Co-Authors: Alexandre Pron, Christine Deruelle, Lucile Brun, Olivier Coulon
    Abstract:

    U-shape fibers are superficial white matter fibers connecting adjacent gyri. In this paper, we present a method to characterize the connectivity of U-shape fibers coursing around the Central Sulcus. Pre-and post-Central gyral crests are semi-automatically drawn and used to build a connectivity space that is identical between subjects. This group space provides a dense representation of the short-range connectivity between the two gyri, as well as a structured representation after clustering.

  • ISBI - Dense and structured representations of U-shape fiber connectivity in the Central Sulcus
    2018 IEEE 15th International Symposium on Biomedical Imaging (ISBI 2018), 2018
    Co-Authors: Alexandre Pron, Christine Deruelle, Lucile Brun, Olivier Coulon
    Abstract:

    U-shape fibers are superficial white matter fibers connecting adjacent gyri. In this paper, we present a method to characterize the connectivity of U-shape fibers coursing around the Central Sulcus. Pre- and post-Central gyral crests are semi-automatically drawn and used to build a connectivity space that is identical between subjects. This group space provides a dense representation of the short-range connectivity between the two gyri, as well as a structured representation after clustering.

Jean-françois Mangin - One of the best experts on this subject based on the ideXlab platform.

  • a longitudinal study of the evolution of the Central Sulcus shape in preterm infants using manifold learning
    Smart Ultrasound Imaging and Perinatal Preterm and Paediatric Image Analysis - 1st International Workshop SUSI 2019 and 4th International Workshop PIP, 2019
    Co-Authors: Heloise De Vareilles, Denis Riviere, Zhong Yi Sun, Manon J N L Benders, Clara Fischer, Francois Leroy, Linda S De Vries, Floris Groenendaal, Jessica Dubois, Jean-françois Mangin
    Abstract:

    Cortical folding in humans is different for every individual, and is associated with functional specificities. It forms mainly during the last trimester of pregnancy, hence its development lacks description, especially in a longitudinal way. To cope with this issue, this study focused on the evolution of the Central Sulcus’ variability of 71 preterm infants studied longitudinally with MRI at 30 and 40 weeks (w) postmenstrual age (PMA). Our aim was to investigate the main shape characteristics and whether they are encoded early on or appear closer to term birth. We captured shape dissimilarity between the sulci using a distance matrix after pairwise co-registration using an Iterative Closest Point algorithm. We applied non-linear dimensionality reduction to this matrix using the Isomap algorithm in order to capture the most discriminative shape features among the Central sulci. We characterized the three most discriminative features over the group, and found that the sulci evolved consistently from a given feature at 30w PMA to the 40w PMA equivalent feature. We incidentally captured a feature that could coincide with the most discriminative adult feature, both visually and by its asymmetry in left and right sulcal distribution. These results captured the main shape features of the Central Sulcus in preterm infants and suggest that they are already encoded at 30w PMA.

  • SUSI/PIPPI@MICCAI - A longitudinal study of the evolution of the Central Sulcus’ shape in preterm infants using manifold learning
    Smart Ultrasound Imaging and Perinatal Preterm and Paediatric Image Analysis, 2019
    Co-Authors: Heloise De Vareilles, Denis Riviere, Zhong Yi Sun, Manon J N L Benders, Clara Fischer, Francois Leroy, Linda S De Vries, Floris Groenendaal, Jessica Dubois, Jean-françois Mangin
    Abstract:

    Cortical folding in humans is different for every individual, and is associated with functional specificities. It forms mainly during the last trimester of pregnancy, hence its development lacks description, especially in a longitudinal way. To cope with this issue, this study focused on the evolution of the Central Sulcus’ variability of 71 preterm infants studied longitudinally with MRI at 30 and 40 weeks (w) postmenstrual age (PMA). Our aim was to investigate the main shape characteristics and whether they are encoded early on or appear closer to term birth. We captured shape dissimilarity between the sulci using a distance matrix after pairwise co-registration using an Iterative Closest Point algorithm. We applied non-linear dimensionality reduction to this matrix using the Isomap algorithm in order to capture the most discriminative shape features among the Central sulci. We characterized the three most discriminative features over the group, and found that the sulci evolved consistently from a given feature at 30w PMA to the 40w PMA equivalent feature. We incidentally captured a feature that could coincide with the most discriminative adult feature, both visually and by its asymmetry in left and right sulcal distribution. These results captured the main shape features of the Central Sulcus in preterm infants and suggest that they are already encoded at 30w PMA.

  • Shape of the Central Sulcus and Disability After Subcortical Stroke A Motor Reserve Hypothesis
    Stroke, 2016
    Co-Authors: Eric Jouvent, Jean-françois Mangin, François De Guio, Edouard Duchesnay, Marco Duering, Stefan Ropele, Martin Dichgans, Hugues Chabriat
    Abstract:

    Background and Purpose—Both brain and cognitive reserves modulate the clinical impact of chronic brain diseases. Whether a motor reserve also modulates the relationships between stroke and disability is unknown. We aimed to determine whether the shape of the Central Sulcus, a marker of the development of underlying motor connections, is independently associated with disability in patients with a positive history of small subcortical ischemic stroke. Methods—Shapes of Central sulci were reconstructed from high-resolution magnetic resonance imaging and ordered without supervision according to a validated algorithm in 166 patients with a positive history of small subcortical ischemic stroke caused by CADASIL (Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy), a severe monogenic cerebral small vessel disease affecting young patients. Ordinal logistic regression modeling was used to test the relationships between modified Rankin scale, a disability scale strongly weigh...

  • Concomitant variability of the Central Sulcus morphology and adjacent connectivity patterns
    2015 IEEE 12th International Symposium on Biomedical Imaging (ISBI), 2015
    Co-Authors: Sebastien Lefranc, P. Roca, Le D Bihan, Cyril Poupon, Jean-françois Mangin, Denis Riviere
    Abstract:

    Coupling the morphological characteristics of sulcal anatomy with connectivity patterns established from diffusion MRI remains a major challenge. Individual results from a group-wise connectivity-based parcellation of the cortex in the brain Central region are compared with cortical folding. This comparison uses an original approach wich allows to represent the main inter-individual variability bringing closer subjects with similar Central Sulcus shape. Data stemming from several modalities - here connectivity and morphology - can thus be compared with a restrained inter-subject variability on similar subjects. Our approach demonstrates that the lowest position of the hand knob of the Central Sulcus, known to be related to the hand motor region, is correlated with the structural parcellations of adjacent gyri. These results strenghten the validity of our connectivity-based parcellation, and opens the way to multimodal neuroscientific validation.

  • ISBI - Concomitant variability of the Central Sulcus morphology and adjacent connectivity patterns
    2015 IEEE 12th International Symposium on Biomedical Imaging (ISBI), 2015
    Co-Authors: Sebastien Lefranc, P. Roca, Cyril Poupon, Jean-françois Mangin, Zhong Yi Sun, D. Le Bihan, Denis Riviere
    Abstract:

    Coupling the morphological characteristics of sulcal anatomy with connectivity patterns established from diffusion MRI remains a major challenge. Individual results from a group-wise connectivity-based parcellation of the cortex in the brain Central region are compared with cortical folding. This comparison uses an original approach wich allows to represent the main inter-individual variability bringing closer subjects with similar Central Sulcus shape. Data stemming from several modalities — here connectivity and morphology — can thus be compared with a restrained inter-subject variability on similar subjects. Our approach demonstrates that the lowest position of the hand knob of the Central Sulcus, known to be related to the hand motor region, is correlated with the structural parcellations of adjacent gyri. These results strenghten the validity of our connectivity-based parcellation, and opens the way to multimodal neuroscientific validation.

Alexandre Pron - One of the best experts on this subject based on the ideXlab platform.

  • U-shape short-range extrinsic connectivity organisation around the human Central Sulcus
    bioRxiv, 2020
    Co-Authors: Alexandre Pron, Christine Deruelle, Olivier Coulon
    Abstract:

    The Central Sulcus is probably one of the most studied folds in the human brain, owing to its clear relationship with primary sensory-motor functional areas. However, due to the difficulty of estimating the trajectories of the U-shape fibres from diffusion MRI, the short structural connectivity of this Sulcus remains relatively unknown. In this context, we studied the spatial organization of these U-shape fibres along the Central Sulcus. Based on high quality diffusion MRI data of 100 right-handed subjects and state-of-the-art pre-processing pipeline, we first define a connectivity space that provide a comprehensive and continuous description of the short-range anatomical connectivity around the Central Sulcus at both the individual and group levels. We then infer the presence of five major U-shape fibre bundles at the group level in both hemispheres by applying unsupervised clustering in the connectivity space. We propose a quantitative investigation of their position and number of streamlines as a function of phenotypic traits such as sex and hemispheres and functional scores such as handedness and manual dexterity. Main findings of this study are twofold: a description of U-shape short-range connectivity along the Central Sulcus at group level and the evidence of a significant relationship between the position of three hand related U-shape fibre bundles and the handedness score of subjects.

  • Dense and structured representations of U-shape fiber connectivity in the Central Sulcus
    2018 IEEE 15th International Symposium on Biomedical Imaging (ISBI 2018), 2018
    Co-Authors: Alexandre Pron, Christine Deruelle, Lucile Brun, Olivier Coulon
    Abstract:

    U-shape fibers are superficial white matter fibers connecting adjacent gyri. In this paper, we present a method to characterize the connectivity of U-shape fibers coursing around the Central Sulcus. Pre- and post-Central gyral crests are semi-automatically drawn and used to build a connectivity space that is identical between subjects. This group space provides a dense representation of the short-range connectivity between the two gyri, as well as a structured representation after clustering.

  • Dense and structured representations of U-Shape fibers connectivity in the Central Sulcus
    2018
    Co-Authors: Alexandre Pron, Christine Deruelle, Lucile Brun, Olivier Coulon
    Abstract:

    U-shape fibers are superficial white matter fibers connecting adjacent gyri. In this paper, we present a method to characterize the connectivity of U-shape fibers coursing around the Central Sulcus. Pre-and post-Central gyral crests are semi-automatically drawn and used to build a connectivity space that is identical between subjects. This group space provides a dense representation of the short-range connectivity between the two gyri, as well as a structured representation after clustering.

  • ISBI - Dense and structured representations of U-shape fiber connectivity in the Central Sulcus
    2018 IEEE 15th International Symposium on Biomedical Imaging (ISBI 2018), 2018
    Co-Authors: Alexandre Pron, Christine Deruelle, Lucile Brun, Olivier Coulon
    Abstract:

    U-shape fibers are superficial white matter fibers connecting adjacent gyri. In this paper, we present a method to characterize the connectivity of U-shape fibers coursing around the Central Sulcus. Pre- and post-Central gyral crests are semi-automatically drawn and used to build a connectivity space that is identical between subjects. This group space provides a dense representation of the short-range connectivity between the two gyri, as well as a structured representation after clustering.

Jens Frahm - One of the best experts on this subject based on the ideXlab platform.

  • Revisiting a historic human brain with magnetic resonance imaging – the first description of a divided Central Sulcus
    Frontiers in Neuroanatomy, 2014
    Co-Authors: Renate Schweizer, Gunther Helms, Jens Frahm
    Abstract:

    In 1860 and 1862, the German physiologist Wagner published two studies, in which he compared the cortical surfaces of brain specimens. This provided the first account of a rare anatomical variation – bridges across the Central sulci in both hemispheres connecting the forward and backward facing Central convolutions in one of the brains. The serendipitous rediscovery of the preserved historic brain specimen in the collections at Gottingen University, being mistaken as the brain of the mathematician C.F. Gauss, allowed us to further investigate the morphology of the bridges Wagner had described with magnetic resonance imaging (MRI). On the historic lithograph, current photographs and MRI surface reconstructions of the brain, a connection across the Central Sulcus can only be seen in the left hemisphere. In the right hemisphere, contrary to the description of Wagner, a connecting structure is only present across the postCentral Sulcus. MRI reveals that the left-hemispheric bridge extends into the depth of the Sulcus, forming a transverse connection between the two opposing gyri. This rare anatomical variation, generally not associated with neurological symptoms, would nowadays be categorized as a divided Central Sulcus. The left-hemispheric connection seen across the postCentral Sulcus, represents the very common case of a segmented postCentral Sulcus. MRI further disclosed a connection across the right-hemispheric Central Sulcus, which terminates just below the surface of the brain and is therefore not depicted on the historical lithography. This explains the apparent inconsistency between the bilateral description of bridges across the Central sulci and the unilateral appearance on the brain surface. The results are discussed based on the detailed knowledge of anatomists of the late 19th century, who already recognized the divided Central Sulcus as an extreme variation of a deep convolution within the Central Sulcus.

  • revisiting a historic human brain with magnetic resonance imaging the first description of a divided Central Sulcus
    Frontiers in Neuroanatomy, 2014
    Co-Authors: Renate Schweizer, Gunther Helms, Jens Frahm
    Abstract:

    In 1860 and 1862, the German physiologist Wagner published two studies, in which he compared the cortical surfaces of brain specimens. This provided the first account of a rare anatomical variation – bridges across the Central sulci in both hemispheres connecting the forward and backward facing Central convolutions in one of the brains. The serendipitous rediscovery of the preserved historic brain specimen in the collections at Gottingen University, being mistaken as the brain of the mathematician C.F. Gauss, allowed us to further investigate the morphology of the bridges Wagner had described with magnetic resonance imaging (MRI). On the historic lithograph, current photographs and MRI surface reconstructions of the brain, a connection across the Central Sulcus can only be seen in the left hemisphere. In the right hemisphere, contrary to the description of Wagner, a connecting structure is only present across the postCentral Sulcus. MRI reveals that the left-hemispheric bridge extends into the depth of the Sulcus, forming a transverse connection between the two opposing gyri. This rare anatomical variation, generally not associated with neurological symptoms, would nowadays be categorized as a divided Central Sulcus. The left-hemispheric connection seen across the postCentral Sulcus, represents the very common case of a segmented postCentral Sulcus. MRI further disclosed a connection across the right-hemispheric Central Sulcus, which terminates just below the surface of the brain and is therefore not depicted on the historical lithography. This explains the apparent inconsistency between the bilateral description of bridges across the Central sulci and the unilateral appearance on the brain surface. The results are discussed based on the detailed knowledge of anatomists of the late 19th century, who already recognized the divided Central Sulcus as an extreme variation of a deep convolution within the Central Sulcus.

Christine Deruelle - One of the best experts on this subject based on the ideXlab platform.

  • U-shape short-range extrinsic connectivity organisation around the human Central Sulcus
    bioRxiv, 2020
    Co-Authors: Alexandre Pron, Christine Deruelle, Olivier Coulon
    Abstract:

    The Central Sulcus is probably one of the most studied folds in the human brain, owing to its clear relationship with primary sensory-motor functional areas. However, due to the difficulty of estimating the trajectories of the U-shape fibres from diffusion MRI, the short structural connectivity of this Sulcus remains relatively unknown. In this context, we studied the spatial organization of these U-shape fibres along the Central Sulcus. Based on high quality diffusion MRI data of 100 right-handed subjects and state-of-the-art pre-processing pipeline, we first define a connectivity space that provide a comprehensive and continuous description of the short-range anatomical connectivity around the Central Sulcus at both the individual and group levels. We then infer the presence of five major U-shape fibre bundles at the group level in both hemispheres by applying unsupervised clustering in the connectivity space. We propose a quantitative investigation of their position and number of streamlines as a function of phenotypic traits such as sex and hemispheres and functional scores such as handedness and manual dexterity. Main findings of this study are twofold: a description of U-shape short-range connectivity along the Central Sulcus at group level and the evidence of a significant relationship between the position of three hand related U-shape fibre bundles and the handedness score of subjects.

  • Dense and structured representations of U-shape fiber connectivity in the Central Sulcus
    2018 IEEE 15th International Symposium on Biomedical Imaging (ISBI 2018), 2018
    Co-Authors: Alexandre Pron, Christine Deruelle, Lucile Brun, Olivier Coulon
    Abstract:

    U-shape fibers are superficial white matter fibers connecting adjacent gyri. In this paper, we present a method to characterize the connectivity of U-shape fibers coursing around the Central Sulcus. Pre- and post-Central gyral crests are semi-automatically drawn and used to build a connectivity space that is identical between subjects. This group space provides a dense representation of the short-range connectivity between the two gyri, as well as a structured representation after clustering.

  • Dense and structured representations of U-Shape fibers connectivity in the Central Sulcus
    2018
    Co-Authors: Alexandre Pron, Christine Deruelle, Lucile Brun, Olivier Coulon
    Abstract:

    U-shape fibers are superficial white matter fibers connecting adjacent gyri. In this paper, we present a method to characterize the connectivity of U-shape fibers coursing around the Central Sulcus. Pre-and post-Central gyral crests are semi-automatically drawn and used to build a connectivity space that is identical between subjects. This group space provides a dense representation of the short-range connectivity between the two gyri, as well as a structured representation after clustering.

  • ISBI - Dense and structured representations of U-shape fiber connectivity in the Central Sulcus
    2018 IEEE 15th International Symposium on Biomedical Imaging (ISBI 2018), 2018
    Co-Authors: Alexandre Pron, Christine Deruelle, Lucile Brun, Olivier Coulon
    Abstract:

    U-shape fibers are superficial white matter fibers connecting adjacent gyri. In this paper, we present a method to characterize the connectivity of U-shape fibers coursing around the Central Sulcus. Pre- and post-Central gyral crests are semi-automatically drawn and used to build a connectivity space that is identical between subjects. This group space provides a dense representation of the short-range connectivity between the two gyri, as well as a structured representation after clustering.