Publications by authors named "Kim-Han Thung"

Despite the cerebellum's crucial role in brain functions, its early development, particularly in relation to the cerebrum, remains poorly understood. Here, we examine cerebellocortical connectivity using over 1,000 high-quality resting-state functional MRI scans of children from birth to 60 months. By mapping cerebellar topography with fine temporal detail for the first time, we show the hierarchical and contralateral organization of cerebellocortical connectivity from birth.

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Recent evidence indicates that the organization of the human neocortex is underpinned by smooth spatial gradients of functional connectivity (FC). These gradients provide crucial insight into the relationship between the brain's topographic organization and the texture of human cognition. However, no studies to date have charted how intrinsic FC gradient architecture develops across the entire human lifespan.

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Brain atlases are spatial references for integrating, processing, and analyzing brain features gathered from different individuals, sources, and scales. Here we introduce a collection of joint surface-volume atlases that chart postnatal development of the human brain in a spatiotemporally dense manner from two weeks to two years of age. Our month-specific atlases chart normative patterns and capture key traits of early brain development and are therefore conducive to identifying aberrations from normal developmental trajectories.

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Article Synopsis
  • Cephalometric analysis involves identifying specific facial landmarks from cone-beam CT scans, which is complicated due to the complex bone structures involved.
  • This paper presents a deep learning framework that uses an enhanced version of Mask R-CNN to accurately identify 105 facial landmarks by learning both global and local geometric relationships.
  • The proposed method demonstrated an impressive average detection accuracy of 1.38± 0.95mm on patients with various jaw deformities, surpassing existing methodologies.
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  • Researchers propose a new framework called cluster-based multi-view high-order functional connectivity network (Ho-FCN) to better understand brain connectivity in disorders like autism.
  • The framework groups functional connectivity data into clusters and computes higher-order statistics to capture complex interactions among brain regions.
  • Results show that this method enhances diagnostic accuracy for autism, addresses phase mismatch issues in traditional analyses, and achieves an impressive accuracy of 86.2% using different functional connectivity approaches.
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Most brain microstructure models are dedicated to the quantification of white matter microstructure, using for example sticks, cylinders, and zeppelins to model intra- and extra-axonal environments. Gray matter presents unique micro-architecture with cell bodies (somas) exhibiting diffusion characteristics that differ from axons in white matter. In this paper, we introduce a method to quantify soma microstructure, giving measures such as volume fraction, diffusivity, and kurtosis.

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Antisocial behavior (ASB) is believed to have neural substrates; however, the association between ASB and functional brain networks remains unclear. The temporal variability of the functional connectivity (or dynamic FC) derived from resting-state functional MRI has been suggested as a useful metric for studying abnormal behaviors including ASB. This is the first study using low-frequency fluctuations of the dynamic FC to unravel potential system-level neural correlates with ASB.

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In this article, we study a novel problem: "automatic prescription recommendation for PD patients." To realize this goal, we first build a dataset by collecting 1) symptoms of PD patients, and 2) their prescription drug provided by neurologists. Then, we build a novel computer-aided prescription model by learning the relation between observed symptoms and prescription drug.

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Fast and automated image quality assessment (IQA) of diffusion MR images is crucial for making timely decisions for rescans. However, learning a model for this task is challenging as the number of annotated data is limited and the annotation labels might not always be correct. As a remedy, we will introduce in this paper an automatic image quality assessment (IQA) method based on hierarchical non-local residual networks for pediatric diffusion MR images.

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During the first years of life, the human brain undergoes dynamic spatially-heterogeneous changes, invo- lving differentiation of neuronal types, dendritic arbori- zation, axonal ingrowth, outgrowth and retraction, synaptogenesis, and myelination. To better quantify these changes, this article presents a method for probing tissue microarchitecture by characterizing water diffusion in a spectrum of length scales, factoring out the effects of intra-voxel orientation heterogeneity. Our method is based on the spherical means of the diffusion signal, computed over gradient directions for a set of diffusion weightings (i.

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In this paper, we introduce an image quality assessment (IQA) method for pediatric T1- and T2-weighted MR images. IQA is first performed slice-wise using a nonlocal residual neural network (NR-Net) and then volume-wise by agglomerating the slice QA results using random forest. Our method requires only a small amount of quality-annotated images for training and is designed to be robust to annotation noise that might occur due to rater errors and the inevitable mix of good and bad slices in an image volume.

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Objective: To estimate a patient-specific reference bone shape model for a patient with craniomaxillofacial (CMF) defects due to facial trauma.

Methods: We proposed an automatic facial bone shape estimation framework using pre-traumatic conventional portrait photos and post-traumatic head computed tomography (CT) scans via a 3D face reconstruction and a deformable shape model. Specifically, a three-dimensional (3D) face was first reconstructed from the patient's pre-traumatic portrait photos.

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Accurate segmentation of organs at risk (OARs) from head and neck (H&N) CT images is crucial for effective H&N cancer radiotherapy. However, the existing deep learning methods are often not trained in an end-to-end fashion, i.e.

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Article Synopsis
  • Fusing multi-modality data is essential for accurately diagnosing brain disorders like Alzheimer's disease since different data types provide unique insights into complex neurodegenerative conditions.
  • Existing fusion methods have issues, including simply combining features without analyzing correlations, relying on single classifiers that may not capture the variability of disease progression, and treating feature selection and classifier training as separate steps.
  • The paper proposes a new framework for early Alzheimer's diagnosis using a multi-modality approach that incorporates both complete and incomplete datasets, leveraging a latent space model and ensemble classifiers to improve accuracy over current methods.
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Diffusion MRI (dMRI) is typically time consuming as it involves acquiring a series of 3D volumes, each associated with a wave-vector in q-space that determines the diffusion direction and strength. The acquisition time is further increased when "blip-up blip-down" scans are acquired with opposite phase encoding directions (PEDs) to facilitate distortion correction. In this work, we show that geometric distortions can be corrected without acquiring with opposite PEDs for each wave-vector, and hence the acquisition time can be halved.

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In this paper, we introduce a method for estimating patient-specific reference bony shape models for planning of reconstructive surgery for patients with acquired craniomaxillofacial (CMF) trauma. We propose an automatic bony shape estimation framework using pre-traumatic portrait photographs and post-traumatic head computed tomography (CT) scans. A 3D facial surface is first reconstructed from the patient's pre-traumatic photographs.

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  • MRI is preferred over CT for imaging craniomaxillofacial structures because it avoids harmful radiation, but MRI images are less clear.
  • The authors propose a model that uses mostly unpaired MRI and CT data, along with a single paired set, to improve MRI segmentation of bony structures.
  • Their method consists of two trained sub-networks and includes innovative strategies to enhance image quality and segmentation accuracy, outperforming existing methods in tests.
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The fusion of complementary information contained in multi-modality data [e.g., magnetic resonance imaging (MRI), positron emission tomography (PET), and genetic data] has advanced the progress of automated Alzheimer's disease (AD) diagnosis.

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Accurate segmentation of infant brain magnetic resonance (MR) images into white matter (WM), gray matter (GM), and cerebrospinal fluid (CSF) is an indispensable foundation for early studying of brain growth patterns and morphological changes in neurodevelopmental disorders. Nevertheless, in the isointense phase (approximately 6-9 months of age), due to inherent myelination and maturation process, WM and GM exhibit similar levels of intensity in both T1-weighted (T1w) and T2-weighted (T2w) MR images, making tissue segmentation very challenging. Despite many efforts were devoted to brain segmentation, only few studies have focused on the segmentation of 6-month infant brain images.

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Recent studies have shown that fusing multi-modal neuroimaging data can improve the performance of Alzheimer's Disease (AD) diagnosis. However, most existing methods simply concatenate features from each modality without appropriate consideration of the correlations among multi-modalities. Besides, existing methods often employ feature selection (or fusion) and classifier training in two independent steps without consideration of the fact that the two pipelined steps are highly related to each other.

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Complex tissue microstructure involving various types of cells and their membranes can deviate the movement of water molecules from the typical Gaussian diffusion. This deviation can be quantified using excess kurtosis to characterize tissue structural complexity. However, true kurtosis measurements can be obscured by complex white matter configurations such as fiber crossing, bending, and branching, which are ubiquitous in the brain.

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Precise quantification of brain tissue micro-architecture using diffusion MRI is hampered by the conflation of diffusion-attenuated signals from micro-environments that can be orientationally heterogeneous due to complex fiber configurations, such as crossing, fanning, and bending, and compartmentally heterogeneous due to variability in tissue organization. In this paper, we introduce a method, called Spherical Mean Spectrum Imaging (SMSI), for quantification of tissue microstructure. SMSI does not assume a fixed number of compartments, but characterizes the signal as a of fine- to coarse-scale diffusion processes.

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Fast and automated image quality assessment (IQA) for diffusion MR images is crucial so that a rescan decision can be made swiftly during or after the scanning session. However, learning this task is challenging as the number of annotated data is limited and the annotated label is not always perfect. To this end, we introduce an automatic multistage IQA method for pediatric diffusion MR images.

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Article Synopsis
  • The authors explore using a combination of multimodal neuroimaging (like MRI and PET) and genetic data to better identify Alzheimer's disease (AD) and Mild Cognitive Impairment (MCI) in patients compared to normal aging subjects.
  • They propose a three-stage deep learning framework that processes these heterogeneous data sources to improve diagnostic accuracy by learning high-level features from each modality and combining them effectively.
  • Evaluation on the Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset demonstrates that this new approach outperforms existing methods in diagnosing AD.
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Discriminative methods commonly produce models with relatively good generalization abilities. However, this advantage is challenged in real-world applications (e.g.

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