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2.
Nat Methods ; 21(5): 809-813, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38605111

RESUMEN

Neuroscience is advancing standardization and tool development to support rigor and transparency. Consequently, data pipeline complexity has increased, hindering FAIR (findable, accessible, interoperable and reusable) access. brainlife.io was developed to democratize neuroimaging research. The platform provides data standardization, management, visualization and processing and automatically tracks the provenance history of thousands of data objects. Here, brainlife.io is described and evaluated for validity, reliability, reproducibility, replicability and scientific utility using four data modalities and 3,200 participants.


Asunto(s)
Nube Computacional , Neurociencias , Neurociencias/métodos , Humanos , Neuroimagen/métodos , Reproducibilidad de los Resultados , Programas Informáticos , Encéfalo/fisiología , Encéfalo/diagnóstico por imagen
3.
ArXiv ; 2023 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-37332566

RESUMEN

Neuroscience research has expanded dramatically over the past 30 years by advancing standardization and tool development to support rigor and transparency. Consequently, the complexity of the data pipeline has also increased, hindering access to FAIR data analysis to portions of the worldwide research community. brainlife.io was developed to reduce these burdens and democratize modern neuroscience research across institutions and career levels. Using community software and hardware infrastructure, the platform provides open-source data standardization, management, visualization, and processing and simplifies the data pipeline. brainlife.io automatically tracks the provenance history of thousands of data objects, supporting simplicity, efficiency, and transparency in neuroscience research. Here brainlife.io's technology and data services are described and evaluated for validity, reliability, reproducibility, replicability, and scientific utility. Using data from 4 modalities and 3,200 participants, we demonstrate that brainlife.io's services produce outputs that adhere to best practices in modern neuroscience research.

4.
Sci Data ; 9(1): 300, 2022 06 14.
Artículo en Inglés | MEDLINE | ID: mdl-35701428

RESUMEN

Most psychiatric disorders are chronic, associated with high levels of disability and distress, and present during pediatric development. Scientific innovation increasingly allows researchers to probe brain-behavior relationships in the developing human. As a result, ambitions to (1) establish normative pediatric brain development trajectories akin to growth curves, (2) characterize reliable metrics for distinguishing illness, and (3) develop clinically useful tools to assist in the diagnosis and management of mental health and learning disorders have gained significant momentum. To this end, the NKI-Rockland Sample initiative was created to probe lifespan development as a large-scale multimodal dataset. The NKI-Rockland Sample Longitudinal Discovery of Brain Development Trajectories substudy (N = 369) is a 24- to 30-month multi-cohort longitudinal pediatric investigation (ages 6.0-17.0 at enrollment) carried out in a community-ascertained sample. Data include psychiatric diagnostic, medical, behavioral, and cognitive phenotyping, as well as multimodal brain imaging (resting fMRI, diffusion MRI, morphometric MRI, arterial spin labeling), genetics, and actigraphy. Herein, we present the rationale, design, and implementation of the Longitudinal Discovery of Brain Development Trajectories protocol.


Asunto(s)
Encéfalo , Conectoma , Salud Mental , Adolescente , Encéfalo/diagnóstico por imagen , Encéfalo/fisiología , Niño , Imagen de Difusión por Resonancia Magnética , Humanos
5.
BMC Med Imaging ; 22(1): 5, 2022 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-34986790

RESUMEN

Pancreas volume is reduced in individuals with diabetes and in autoantibody positive individuals at high risk for developing type 1 diabetes (T1D). Studies investigating pancreas volume are underway to assess pancreas volume in large clinical databases and studies, but manual pancreas annotation is time-consuming and subjective, preventing extension to large studies and databases. This study develops deep learning for automated pancreas volume measurement in individuals with diabetes. A convolutional neural network was trained using manual pancreas annotation on 160 abdominal magnetic resonance imaging (MRI) scans from individuals with T1D, controls, or a combination thereof. Models trained using each cohort were then tested on scans of 25 individuals with T1D. Deep learning and manual segmentations of the pancreas displayed high overlap (Dice coefficient = 0.81) and excellent correlation of pancreas volume measurements (R2 = 0.94). Correlation was highest when training data included individuals both with and without T1D. The pancreas of individuals with T1D can be automatically segmented to measure pancreas volume. This algorithm can be applied to large imaging datasets to quantify the spectrum of human pancreas volume.


Asunto(s)
Aprendizaje Profundo , Diabetes Mellitus Tipo 1/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos , Páncreas/diagnóstico por imagen , Adolescente , Algoritmos , Diabetes Mellitus Tipo 1/patología , Humanos , Imagenología Tridimensional/métodos , Masculino , Tamaño de los Órganos , Páncreas/patología , Estudios Retrospectivos
6.
Hum Brain Mapp ; 43(1): 129-148, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-32310331

RESUMEN

The goal of the Enhancing Neuroimaging Genetics through Meta-Analysis (ENIGMA) Stroke Recovery working group is to understand brain and behavior relationships using well-powered meta- and mega-analytic approaches. ENIGMA Stroke Recovery has data from over 2,100 stroke patients collected across 39 research studies and 10 countries around the world, comprising the largest multisite retrospective stroke data collaboration to date. This article outlines the efforts taken by the ENIGMA Stroke Recovery working group to develop neuroinformatics protocols and methods to manage multisite stroke brain magnetic resonance imaging, behavioral and demographics data. Specifically, the processes for scalable data intake and preprocessing, multisite data harmonization, and large-scale stroke lesion analysis are described, and challenges unique to this type of big data collaboration in stroke research are discussed. Finally, future directions and limitations, as well as recommendations for improved data harmonization through prospective data collection and data management, are provided.


Asunto(s)
Imagen por Resonancia Magnética , Neuroimagen , Accidente Cerebrovascular , Humanos , Estudios Multicéntricos como Asunto , Accidente Cerebrovascular/diagnóstico por imagen , Accidente Cerebrovascular/patología , Accidente Cerebrovascular/fisiopatología , Rehabilitación de Accidente Cerebrovascular
7.
Gigascience ; 10(8)2021 08 20.
Artículo en Inglés | MEDLINE | ID: mdl-34414422

RESUMEN

As the global health crisis unfolded, many academic conferences moved online in 2020. This move has been hailed as a positive step towards inclusivity in its attenuation of economic, physical, and legal barriers and effectively enabled many individuals from groups that have traditionally been underrepresented to join and participate. A number of studies have outlined how moving online made it possible to gather a more global community and has increased opportunities for individuals with various constraints, e.g., caregiving responsibilities. Yet, the mere existence of online conferences is no guarantee that everyone can attend and participate meaningfully. In fact, many elements of an online conference are still significant barriers to truly diverse participation: the tools used can be inaccessible for some individuals; the scheduling choices can favour some geographical locations; the set-up of the conference can provide more visibility to well-established researchers and reduce opportunities for early-career researchers. While acknowledging the benefits of an online setting, especially for individuals who have traditionally been underrepresented or excluded, we recognize that fostering social justice requires inclusivity to actively be centered in every aspect of online conference design. Here, we draw from the literature and from our own experiences to identify practices that purposefully encourage a diverse community to attend, participate in, and lead online conferences. Reflecting on how to design more inclusive online events is especially important as multiple scientific organizations have announced that they will continue offering an online version of their event when in-person conferences can resume.

8.
Gigascience ; 10(6)2021 06 21.
Artículo en Inglés | MEDLINE | ID: mdl-34155505

RESUMEN

BACKGROUND: As mobile technologies become ever more sensor-rich, portable, and ubiquitous, data captured by smart devices are lending rich insights into users' daily lives with unprecedented comprehensiveness and ecological validity. A number of human-subject studies have been conducted to examine the use of mobile sensing to uncover individual behavioral patterns and health outcomes, yet minimal attention has been placed on measuring living environments together with other human-centered sensing data. Moreover, the participant sample size in most existing studies falls well below a few hundred, leaving questions open about the reliability of findings on the relations between mobile sensing signals and human outcomes. RESULTS: To address these limitations, we developed a home environment sensor kit for continuous indoor air quality tracking and deployed it in conjunction with smartphones, Fitbits, and ecological momentary assessments in a cohort study of up to 1,584 college student participants per data type for 3 weeks. We propose a conceptual framework that systematically organizes human-centric data modalities by their temporal coverage and spatial freedom. Then we report our study procedure, technologies and methods deployed, and descriptive statistics of the collected data that reflect the participants' mood, sleep, behavior, and living environment. CONCLUSIONS: We were able to collect from a large participant cohort satisfactorily complete multi-modal sensing and survey data in terms of both data continuity and participant adherence. Our novel data and conceptual development provide important guidance for data collection and hypothesis generation in future human-centered sensing studies.


Asunto(s)
Teléfono Inteligente , Estudios de Cohortes , Ambiente en el Hogar , Humanos , Reproducibilidad de los Resultados , Encuestas y Cuestionarios
9.
Neuron ; 109(11): 1769-1775, 2021 06 02.
Artículo en Inglés | MEDLINE | ID: mdl-33932337

RESUMEN

Brainhack is an innovative meeting format that promotes scientific collaboration and education in an open, inclusive environment. This NeuroView describes the myriad benefits for participants and the research community and how Brainhacks complement conventional formats to augment scientific progress.


Asunto(s)
Comunicación , Internet , Neurociencias/organización & administración , Congresos como Asunto , Guías de Práctica Clínica como Asunto
10.
Neuroimage ; 235: 118001, 2021 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-33789137

RESUMEN

Brain extraction (a.k.a. skull stripping) is a fundamental step in the neuroimaging pipeline as it can affect the accuracy of downstream preprocess such as image registration, tissue classification, etc. Most brain extraction tools have been designed for and applied to human data and are often challenged by non-human primates (NHP) data. Amongst recent attempts to improve performance on NHP data, deep learning models appear to outperform the traditional tools. However, given the minimal sample size of most NHP studies and notable variations in data quality, the deep learning models are very rarely applied to multi-site samples in NHP imaging. To overcome this challenge, we used a transfer-learning framework that leverages a large human imaging dataset to pretrain a convolutional neural network (i.e. U-Net Model), and then transferred this to NHP data using a small NHP training sample. The resulting transfer-learning model converged faster and achieved more accurate performance than a similar U-Net Model trained exclusively on NHP samples. We improved the generalizability of the model by upgrading the transfer-learned model using additional training datasets from multiple research sites in the Primate Data-Exchange (PRIME-DE) consortium. Our final model outperformed brain extraction routines from popular MRI packages (AFNI, FSL, and FreeSurfer) across a heterogeneous sample from multiple sites in the PRIME-DE with less computational cost (20 s~10 min). We also demonstrated the transfer-learning process enables the macaque model to be updated for use with scans from chimpanzees, marmosets, and other mammals (e.g. pig). Our model, code, and the skull-stripped mask repository of 136 macaque monkeys are publicly available for unrestricted use by the neuroimaging community at https://github.com/HumanBrainED/NHP-BrainExtraction.


Asunto(s)
Encéfalo/diagnóstico por imagen , Imagen por Resonancia Magnética , Modelos Teóricos , Redes Neurales de la Computación , Neuroimagen/métodos , Adulto , Animales , Conjuntos de Datos como Asunto , Estudios de Factibilidad , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Macaca , Masculino , Persona de Mediana Edad , Adulto Joven
11.
Neuroimage ; 226: 117585, 2021 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-33248256

RESUMEN

New large neuroimaging studies, such as the Adolescent Brain Cognitive Development study (ABCD) and Human Connectome Project (HCP) Development studies are adopting a new T1-weighted imaging sequence with prospective motion correction (PMC) in favor of the more traditional 3-Dimensional Magnetization-Prepared Rapid Gradient-Echo Imaging (MPRAGE) sequence. Here, we used a developmental dataset (ages 5-21, N = 348) from the Healthy Brain Network (HBN) Initiative to directly compare two widely used MRI structural sequences: one based on the Human Connectome Project (MPRAGE) and another based on the ABCD study (MPRAGE+PMC). We aimed to determine if the morphometric measurements obtained from both protocols are equivalent or if one sequence has a clear advantage over the other. The sequences were also compared through quality control measurements. Inter- and intra-sequence reliability were assessed with another set of participants (N = 71) from HBN that performed two MPRAGE and two MPRAGE+PMC sequences within the same imaging session, with one MPRAGE (MPRAGE1) and MPRAGE+PMC (MPRAGE+PMC1) pair at the beginning of the session and another pair (MPRAGE2 and MPRAGE+PMC2) at the end of the session. Intraclass correlation coefficients (ICC) scores for morphometric measurements such as volume and cortical thickness showed that intra-sequence reliability is the highest with the two MPRAGE+PMC sequences and lowest with the two MPRAGE sequences. Regarding inter-sequence reliability, ICC scores were higher for the MPRAGE1 - MPRAGE+PMC1 pair at the beginning of the session than the MPRAGE1 - MPRAGE2 pair, possibly due to the higher motion artifacts in the MPRAGE2 run. Results also indicated that the MPRAGE+PMC sequence is robust, but not impervious, to high head motion. For quality control metrics, the traditional MPRAGE yielded better results than MPRAGE+PMC in 5 of the 8 measurements. In conclusion, morphometric measurements evaluated here showed high inter-sequence reliability between the MPRAGE and MPRAGE+PMC sequences, especially in images with low head motion. We suggest that studies targeting hyperkinetic populations use the MPRAGE+PMC sequence, given its robustness to head motion and higher reliability scores. However, neuroimaging researchers studying non-hyperkinetic participants can choose either MPRAGE or MPRAGE+PMC sequences, but should carefully consider the apparent tradeoff between relatively increased reliability, but reduced quality control metrics when using the MPRAGE+PMC sequence.


Asunto(s)
Encéfalo/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador/métodos , Imagenología Tridimensional/métodos , Imagen por Resonancia Magnética/métodos , Adolescente , Niño , Preescolar , Conectoma , Femenino , Humanos , Masculino , Reproducibilidad de los Resultados , Relación Señal-Ruido , Adulto Joven
12.
Cereb Cortex ; 30(3): 1171-1184, 2020 03 14.
Artículo en Inglés | MEDLINE | ID: mdl-31595961

RESUMEN

The collection of eye gaze information during functional magnetic resonance imaging (fMRI) is important for monitoring variations in attention and task compliance, particularly for naturalistic viewing paradigms (e.g., movies). However, the complexity and setup requirements of current in-scanner eye tracking solutions can preclude many researchers from accessing such information. Predictive eye estimation regression (PEER) is a previously developed support vector regression-based method for retrospectively estimating eye gaze from the fMRI signal in the eye's orbit using a 1.5-min calibration scan. Here, we provide confirmatory validation of the PEER method's ability to infer eye gaze on a TR-by-TR basis during movie viewing, using simultaneously acquired eye tracking data in five individuals (median angular deviation < 2°). Then, we examine variations in the predictive validity of PEER models across individuals in a subset of data (n = 448) from the Child Mind Institute Healthy Brain Network Biobank, identifying head motion as a primary determinant. Finally, we accurately classify which of the two movies is being watched based on the predicted eye gaze patterns (area under the curve = 0.90 ± 0.02) and map the neural correlates of eye movements derived from PEER. PEER is a freely available and easy-to-use tool for determining eye fixations during naturalistic viewing.


Asunto(s)
Encéfalo/fisiología , Medidas del Movimiento Ocular , Fijación Ocular/fisiología , Imagen por Resonancia Magnética , Adulto , Mapeo Encefálico , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Estimulación Luminosa , Análisis de Regresión
13.
Nat Commun ; 9(1): 2818, 2018 07 19.
Artículo en Inglés | MEDLINE | ID: mdl-30026557

RESUMEN

Data sharing is increasingly recommended as a means of accelerating science by facilitating collaboration, transparency, and reproducibility. While few oppose data sharing philosophically, a range of barriers deter most researchers from implementing it in practice. To justify the significant effort required for sharing data, funding agencies, institutions, and investigators need clear evidence of benefit. Here, using the International Neuroimaging Data-sharing Initiative, we present a case study that provides direct evidence of the impact of open sharing on brain imaging data use and resulting peer-reviewed publications. We demonstrate that openly shared data can increase the scale of scientific studies conducted by data contributors, and can recruit scientists from a broader range of disciplines. These findings dispel the myth that scientific findings using shared data cannot be published in high-impact journals, suggest the transformative power of data sharing for accelerating science, and underscore the need for implementing data sharing universally.


Asunto(s)
Bibliometría , Encéfalo/diagnóstico por imagen , Difusión de la Información , Neuroimagen/métodos , Bases de Datos Factuales , Humanos , Neuroimagen/instrumentación , Publicaciones Periódicas como Asunto , Reproducibilidad de los Resultados
14.
Cell Rep ; 23(2): 429-441, 2018 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-29642002

RESUMEN

Complementing long-standing traditions centered on histology, fMRI approaches are rapidly maturing in delineating brain areal organization at the macroscale. The non-human primate (NHP) provides the opportunity to overcome critical barriers in translational research. Here, we establish the data requirements for achieving reproducible and internally valid parcellations in individuals. We demonstrate that functional boundaries serve as a functional fingerprint of the individual animals and can be achieved under anesthesia or awake conditions (rest, naturalistic viewing), though differences between awake and anesthetized states precluded the detection of individual differences across states. Comparison of awake and anesthetized states suggested a more nuanced picture of changes in connectivity for higher-order association areas, as well as visual and motor cortex. These results establish feasibility and data requirements for the generation of reproducible individual-specific parcellations in NHPs, provide insights into the impact of scan state, and motivate efforts toward harmonizing protocols.


Asunto(s)
Corteza Cerebral/fisiología , Anestesia , Animales , Mapeo Encefálico , Corteza Cerebral/anatomía & histología , Corteza Cerebral/diagnóstico por imagen , Femenino , Macaca mulatta , Imagen por Resonancia Magnética , Masculino , Vigilia
15.
Sci Data ; 5: 180011, 2018 02 20.
Artículo en Inglés | MEDLINE | ID: mdl-29461514

RESUMEN

Stroke is the leading cause of adult disability worldwide, with up to two-thirds of individuals experiencing long-term disabilities. Large-scale neuroimaging studies have shown promise in identifying robust biomarkers (e.g., measures of brain structure) of long-term stroke recovery following rehabilitation. However, analyzing large rehabilitation-related datasets is problematic due to barriers in accurate stroke lesion segmentation. Manually-traced lesions are currently the gold standard for lesion segmentation on T1-weighted MRIs, but are labor intensive and require anatomical expertise. While algorithms have been developed to automate this process, the results often lack accuracy. Newer algorithms that employ machine-learning techniques are promising, yet these require large training datasets to optimize performance. Here we present ATLAS (Anatomical Tracings of Lesions After Stroke), an open-source dataset of 304 T1-weighted MRIs with manually segmented lesions and metadata. This large, diverse dataset can be used to train and test lesion segmentation algorithms and provides a standardized dataset for comparing the performance of different segmentation methods. We hope ATLAS release 1.1 will be a useful resource to assess and improve the accuracy of current lesion segmentation methods.


Asunto(s)
Encéfalo/diagnóstico por imagen , Encéfalo/patología , Accidente Cerebrovascular/diagnóstico por imagen , Accidente Cerebrovascular/patología , Adulto , Algoritmos , Humanos , Imagen por Resonancia Magnética , Neuroimagen
16.
Eur Cell Mater ; 35: 34-53, 2018 02 09.
Artículo en Inglés | MEDLINE | ID: mdl-29424418

RESUMEN

Although the composition and structure of cartilaginous tissues is complex, collagen II fibrils and aggrecan are the most abundant assemblies in both articular cartilage (AC) and the nucleus pulposus (NP) of the intervertebral disc (IVD). Whilst structural heterogeneity of intact aggrecan ( containing three globular domains) is well characterised, the extent of aggrecan fragmentation in healthy tissues is poorly defined. Using young, yet skeletally mature (18-30 months), bovine AC and NP tissues, it was shown that, whilst the ultrastructure of intact aggrecan was tissue-dependent, most molecules (AC: 95 %; NP: 99.5 %) were fragmented (lacking one or more globular domains). Fragments were significantly smaller and more structurally heterogeneous in the NP compared with the AC (molecular area; AC: 8543 nm2; NP: 4625 nm2; p < 0.0001). In contrast, fibrillar collagen appeared structurally intact and tissue-invariant. Molecular fragmentation is considered indicative of a pathology; however, these young, skeletally mature tissues were histologically and mechanically (reduced modulus: AC: ≈ 500 kPa; NP: ≈ 80 kPa) comparable to healthy tissues and devoid of notable gelatinase activity (compared with rat dermis). As aggrecan fragmentation was prevalent in neonatal bovine AC (99.5 % fragmented, molecular area: 5137 nm2) as compared with mature AC (95.0 % fragmented, molecular area: 8667 nm2), it was hypothesised that targeted proteolysis might be an adaptive process that modified aggrecan packing (as simulated computationally) and, hence, tissue charge density, mechanical properties and porosity. These observations provided a baseline against which pathological and/or age-related fragmentation of aggrecan could be assessed and suggested that new strategies might be required to engineer constructs that mimic the mechanical properties of native cartilaginous tissues.


Asunto(s)
Cartílago Articular/metabolismo , Matriz Extracelular/metabolismo , Adsorción , Agrecanos/química , Agrecanos/metabolismo , Agrecanos/ultraestructura , Secuencia de Aminoácidos , Animales , Fenómenos Biomecánicos , Bovinos , Colágeno/metabolismo , Fuerza Compresiva , Simulación por Computador , Gelatinasas/metabolismo , Metaloproteinasas de la Matriz/metabolismo , Microscopía de Fuerza Atómica , Nanopartículas , Núcleo Pulposo , Especificidad de Órganos , Propiedades de Superficie
18.
Neuroimage ; 169: 407-418, 2018 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-29278774

RESUMEN

Data quality is increasingly recognized as one of the most important confounding factors in brain imaging research. It is particularly important for studies of brain development, where age is systematically related to in-scanner motion and data quality. Prior work has demonstrated that in-scanner head motion biases estimates of structural neuroimaging measures. However, objective measures of data quality are not available for most structural brain images. Here we sought to identify quantitative measures of data quality for T1-weighted volumes, describe how these measures relate to cortical thickness, and delineate how this in turn may bias inference regarding associations with age in youth. Three highly-trained raters provided manual ratings of 1840 raw T1-weighted volumes. These images included a training set of 1065 images from Philadelphia Neurodevelopmental Cohort (PNC), a test set of 533 images from the PNC, as well as an external test set of 242 adults acquired on a different scanner. Manual ratings were compared to automated quality measures provided by the Preprocessed Connectomes Project's Quality Assurance Protocol (QAP), as well as FreeSurfer's Euler number, which summarizes the topological complexity of the reconstructed cortical surface. Results revealed that the Euler number was consistently correlated with manual ratings across samples. Furthermore, the Euler number could be used to identify images scored "unusable" by human raters with a high degree of accuracy (AUC: 0.98-0.99), and out-performed proxy measures from functional timeseries acquired in the same scanning session. The Euler number also was significantly related to cortical thickness in a regionally heterogeneous pattern that was consistent across datasets and replicated prior results. Finally, data quality both inflated and obscured associations with age during adolescence. Taken together, these results indicate that reliable measures of data quality can be automatically derived from T1-weighted volumes, and that failing to control for data quality can systematically bias the results of studies of brain maturation.


Asunto(s)
Corteza Cerebral/diagnóstico por imagen , Exactitud de los Datos , Imagen por Resonancia Magnética/normas , Neuroimagen/normas , Control de Calidad , Adolescente , Adulto , Estudios de Cohortes , Conjuntos de Datos como Asunto , Humanos
19.
Stat Anal Data Min ; 11(5): 203-226, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34386148

RESUMEN

In this paper, we propose a procedure to find differential edges between two graphs from high-dimensional data. We estimate two matrices of partial correlations and their differences by solving a penalized regression problem. We assume sparsity only on differences between two graphs, not graphs themselves. Thus, we impose an ℓ 2 penalty on partial correlations and an ℓ 1 penalty on their differences in the penalized regression problem. We apply the proposed procedure to finding differential functional connectivity between healthy individuals and Alzheimer's disease patients.

20.
Neuroimage ; 170: 68-82, 2018 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-28739120

RESUMEN

Moving from group level to individual level functional parcellation maps is a critical step for developing a rich understanding of the links between individual variation in functional network architecture and cognitive and clinical phenotypes. Still, the identification of functional units in the brain based on intrinsic functional connectivity and its dynamic variations between and within subjects remains challenging. Recently, the bootstrap analysis of stable clusters (BASC) framework was developed to quantify the stability of functional brain networks both across and within subjects. This multi-level approach utilizes bootstrap resampling for both individual and group-level clustering to delineate functional units based on their consistency across and within subjects, while providing a measure of their stability. Here, we optimized the BASC framework for functional parcellation of the basal ganglia by investigating a variety of clustering algorithms and similarity measures. Reproducibility and test-retest reliability were computed to validate this analytic framework as a tool to describe inter-individual differences in the stability of functional networks. The functional parcellation revealed by stable clusters replicated previous divisions found in the basal ganglia based on intrinsic functional connectivity. While we found moderate to high reproducibility, test-retest reliability was high at the boundaries of the functional units as well as within their cores. This is interesting because the boundaries between functional networks have been shown to explain most individual phenotypic variability. The current study provides evidence for the consistency of the parcellation of the basal ganglia, and provides the first group level parcellation built from individual-level cluster solutions. These novel results demonstrate the utility of BASC for quantifying inter-individual differences in the functional organization of brain regions, and encourage usage in future studies.


Asunto(s)
Ganglios Basales/diagnóstico por imagen , Ganglios Basales/fisiología , Mapeo Encefálico/métodos , Individualidad , Imagen por Resonancia Magnética/métodos , Adulto , Mapeo Encefálico/normas , Femenino , Humanos , Imagen por Resonancia Magnética/normas , Masculino , Persona de Mediana Edad , Adulto Joven
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