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1.
Nat Commun ; 14(1): 7047, 2023 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-37923713

RESUMO

Fetal biometry and amniotic fluid volume assessments are two essential yet repetitive tasks in fetal ultrasound screening scans, aiding in the detection of potentially life-threatening conditions. However, these assessment methods can occasionally yield unreliable results. Advances in deep learning have opened up new avenues for automated measurements in fetal ultrasound, demonstrating human-level performance in various fetal ultrasound tasks. Nevertheless, the majority of these studies are retrospective in silico studies, with a limited number including African patients in their datasets. In this study we developed and prospectively assessed the performance of deep learning models for end-to-end automation of fetal biometry and amniotic fluid volume measurements. These models were trained using a newly constructed database of 172,293 de-identified Moroccan fetal ultrasound images, supplemented with publicly available datasets. the models were then tested on prospectively acquired video clips from 172 pregnant people forming a consecutive series gathered at four healthcare centers in Morocco. Our results demonstrate that the 95% limits of agreement between the models and practitioners for the studied measurements were narrower than the reported intra- and inter-observer variability among expert human sonographers for all the parameters under study. This means that these models could be deployed in clinical conditions, to alleviate time-consuming, repetitive tasks, and make fetal ultrasound more accessible in limited-resource environments.


Assuntos
Líquido Amniótico , Aprendizado Profundo , Gravidez , Feminino , Humanos , Líquido Amniótico/diagnóstico por imagem , Estudos Retrospectivos , Automação , Biometria/métodos
2.
Comput Math Methods Med ; 2012: 961257, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23401720

RESUMO

Functional magnetic resonance imaging (fMRI) exploits blood-oxygen-level-dependent (BOLD) contrasts to map neural activity associated with a variety of brain functions including sensory processing, motor control, and cognitive and emotional functions. The general linear model (GLM) approach is used to reveal task-related brain areas by searching for linear correlations between the fMRI time course and a reference model. One of the limitations of the GLM approach is the assumption that the covariance across neighbouring voxels is not informative about the cognitive function under examination. Multivoxel pattern analysis (MVPA) represents a promising technique that is currently exploited to investigate the information contained in distributed patterns of neural activity to infer the functional role of brain areas and networks. MVPA is considered as a supervised classification problem where a classifier attempts to capture the relationships between spatial pattern of fMRI activity and experimental conditions. In this paper , we review MVPA and describe the mathematical basis of the classification algorithms used for decoding fMRI signals, such as support vector machines (SVMs). In addition, we describe the workflow of processing steps required for MVPA such as feature selection, dimensionality reduction, cross-validation, and classifier performance estimation based on receiver operating characteristic (ROC) curves.


Assuntos
Biologia Computacional/métodos , Imageamento por Ressonância Magnética/métodos , Área Sob a Curva , Encéfalo/patologia , Mapeamento Encefálico/métodos , Humanos , Cinética , Análise dos Mínimos Quadrados , Modelos Lineares , Modelos Biológicos , Neurônios/metabolismo , Distribuição Normal , Oxigênio/metabolismo , Curva ROC , Máquina de Vetores de Suporte , Fatores de Tempo
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