Microstructural Parcellation Of The Human Cerebral Cortex

Unraveling the functional properties of structural elements in the brain is one of the fundamental goals of neuroscientific research. In the cerebral cortex this is no mean feat, since cortical areas are defined microstructurally in post-mortem brains but functionally in living brains with electrophysiological or neuroimaging techniques – and cortical areas vary in their topographical properties across individual brains. Being able to map both microstructure and function in the same brains noninvasively in vivo would represent a huge leap forward. In recent years, high-field magnetic resonance imaging (MRI) technologies with spatial resolution below 0.5 mm have set the stage for this by detecting structural differences within the human cerebral cortex, beyond the Stria of Gennari. This provides the basis for an in vivo microanatomical brain map, with the enormous potential to make direct correlations between microstructure and function in living human brains. This book starts with Brodmann’s post-mortem map published in the early 20th century, moves on to the almost forgotten microstructural maps of von Economo and Koskinas and the Vogt-Vogt school, sheds some light on more recent approaches that aim at mapping cortical areas noninvasively in living human brains, and culminates with the concept of “in vivo Brodmann mapping” using high-field MRI, which was introduced in the early 21st century.

The macro connectome elucidates the pathways through which brain regions are structurally connected or functionally coupled to perform cognitive functions. It embodies the notion of representing, analysing, and understanding all connections within the brain as a network, while the subdivision of the brain into interacting cortical units is inherent in its architecture. As a result, the definition of network nodes is one of the most critical steps in connectivity network analysis. Parcellations derived from anatomical brain atlases or random parcellations are traditionally used for node identification, however these approaches do not always fully reflect the functional/structural organisation of the brain. Connectivity-driven methods have arisen only recently, aiming to delineate parcellations that are more faithful to the underlying connectivity. Such parcellation methods face several challenges, including but not limited to poor signal-to-noise ratio, the curse of dimensionality, and functional/structural variations inherent in individual brains, which are only limitedly addressed by the current state of the art. In this thesis, we present robust and fully-automated methods for the subdivision of the entire human cerebral cortex based on connectivity information. Our contributions are four-fold: First, we propose a clustering approach to delineate a cortical parcellation that provides a reliable abstraction of the brain's functional organisation. Second, we cast the parcellation problem as a feature reduction problem and make use of manifold learning and image segmentation techniques to identify cortical regions with distinct structural connectivity patterns. Third, we present a multi-layer graphical model that combines within- and between-subject connectivity, which is then decomposed into a cortical parcellation that can represent the whole population, while accounting for the variability across subjects. Finally, we conduct a large-scale, systematic comparison of existing parcellation methods, with a focus on providing some insight into the reliability of brain parcellations in terms of reflecting the underlying connectivity, as well as, revealing their impact on network analysis. We evaluate the proposed parcellation methods on publicly available data from the Human Connectome Project and a plethora of quantitative and qualitative evaluation techniques investigated in the literature. Experiments across multiple resolutions demonstrate the accuracy of the presented methods at both subject and group levels with regards to reproducibility and fidelity to the data. The neuro-biological interpretation of the proposed parcellations is also investigated by comparing parcel boundaries with well-structured properties of the cerebral cortex. Results show the advantage of connectivity-driven parcellations over traditional approaches in terms of better fitting the underlying connectivity. However, the benefit of using connectivity to parcellate the brain is not always as clear regarding the agreement with other modalities and simple network analysis tasks carried out across healthy subjects. Nonetheless, we believe the proposed methods, along with the systematic evaluation of existing techniques, offer an important contribution to the field of brain parcellation, advancing our understanding of how the human cerebral cortex is organised at the macroscale.

Brain Mapping: A Comprehensive Reference offers foundational information for students and researchers across neuroscience. With over 300 articles and a media rich environment, this resource provides exhaustive coverage of the methods and systems involved in brain mapping, fully links the data to disease (presenting side by side maps of healthy and diseased brains for direct comparisons), and offers data sets and fully annotated color images. Each entry is built on a layered approach of the content – basic information for those new to the area and more detailed material for experienced readers. Edited and authored by the leading experts in the field, this work offers the most reputable, easily searchable content with cross referencing across articles, a one-stop reference for students, researchers and teaching faculty. Broad overview of neuroimaging concepts with applications across the neurosciences and biomedical research Fully annotated color images and videos for best comprehension of concepts Layered content for readers of different levels of expertise Easily searchable entries for quick access of reputable information Live reference links to ScienceDirect, Scopus and PubMed

Diffusion MRI is a magnetic resonance imaging (MRI) method that produces in vivo images of biological tissues weighted with the local microstructural characteristics of water diffusion, providing an effective means of visualizing functional connectivities in the nervous system. This book is the first comprehensive reference promoting the understanding of this rapidly evolving and powerful technology and providing the essential handbook for designing, analyzing or interpreting diffusion MR experiments. The book presents diffusion imaging in the context of well-established, classical experimental techniques, so that readers will be able to assess the scope and limitations of the new imaging technology with respect to techniques available previously. All chapters are written by leading international experts and cover methodology, validation of the imaging technology, application of diffusion imaging to the study of variation and development of normal brain anatomy, and disruption to the white matter in neurological disease or psychiatric disorder. • Discusses all aspects of a diffusion MRI study from acquisition, through analysis, to interpretation, providing an essential reference text for scientists designing or interpreting diffusion MR experiments • Practical advice on running an experiment • Full color throughout

The three-volume set LNCS 8149, 8150, and 8151 constitutes the refereed proceedings of the 16th International Conference on Medical Image Computing and Computer-Assisted Intervention, MICCAI 2013, held in Nagoya, Japan, in September 2013. Based on rigorous peer reviews, the program committee carefully selected 262 revised papers from 789 submissions for presentation in three volumes. The 86 papers included in the second volume have been organized in the following topical sections: registration and atlas construction; microscopy, histology, and computer-aided diagnosis; motion modeling and compensation; segmentation; machine learning, statistical modeling, and atlases; computer-aided diagnosis and imaging biomarkers; physiological modeling, simulation, and planning; microscope, optical imaging, and histology; cardiology; vasculatures and tubular structures; brain segmentation and atlases; and functional MRI and neuroscience applications.

The book comprises biographical notes, of about 1000 words each, with a portrait photo, of 90 influential figures of the famous prewar Viennese school of neuropsychiatry, appearing together for the first time in a single volume. The entries focus on the academic lives and scientific contributions of pioneers in the neurological sciences viewed from a modern perspective. These updated profiles are based on substantial new research. The book includes a wide range of people, some famous Nobel laureates, and others less well known, from the era when Vienna was the epicenter of brain research. Despite the tragic circumstances of two World Wars, these pioneers remained resilient, willing to help others with an admirable dignity against adversity that leaves an indelible lesson to the later generations. Some fell victim of the Holocaust. Others overcame the constraints of National Socialism and ultimately settled overseas to nurture their ambitions and pursue their intellectual goals as physicians, researchers, and teachers. The monograph is a useful source for scholars interested in the evolution of ideas in basic neuroscience, clinical neurology, and neuropsychiatry, and the investigators who effected them.

The Encyclopedia of the Neurological Sciences, Second Edition, Four Volume Set develops from the first edition, covering all areas of neurological sciences through over 1000 entries focused on a wide variety of topics in neurology, neurosurgery, psychiatry and other related areas of neuroscience. The contributing authors represent all aspects of neurology from many viewpoints and disciplines to provide a complete overview of the field. Entries are designed to be understandable without detailed background knowledge in the subject matter, and cross-referencing and suggested further reading lead the reader from a basic knowledge of the subject to more advanced understanding. The easy-to-use 'encyclopedic-dictionary' format of the Encyclopedia of the Neurological Sciences, Second Edition features alphabetic entries, extensive cross-referencing, and a thorough index for quick reference. The wealth of information provided by these four volumes makes this reference work a trusted source of valuable information for a wide range of researchers, from undergraduate students to academic researchers. Provides comprehensive coverage of the field of neurological science in over 1,000 entries in 4 volumes "Encyclopedic-dictionary" format provides for concise, readable entries and easy searching Presents complete, up-to-date information on 32 separate areas of neurology Entries are supplemented with extensive cross-referencing, useful references to primary research articles, and an extensive index