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1.
Appl Opt ; 57(10): 2545-2552, 2018 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-29714238

RESUMO

Wide-field interferometric microscopy is a highly sensitive, label-free, and low-cost biosensing imaging technique capable of visualizing individual biological nanoparticles such as viral pathogens and exosomes. However, further resolution enhancement is necessary to increase detection and classification accuracy of subdiffraction-limited nanoparticles. In this study, we propose a deep-learning approach, based on coupled deep autoencoders, to improve resolution of images of L-shaped nanostructures. During training, our method utilizes microscope image patches and their corresponding manual truth image patches in order to learn the transformation between them. Following training, the designed network reconstructs denoised and resolution-enhanced image patches for unseen input.

2.
Hum Brain Mapp ; 38(6): 2913-2922, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28294464

RESUMO

Many of the clinical and behavioral manifestations of traumatic brain injury (TBI) are thought to arise from disruption to the structural network of the brain due to diffuse axonal injury (DAI). However, a principled way of summarizing diffuse connectivity alterations to quantify injury burden is lacking. In this study, we developed a connectome injury score, Disruption Index of the Structural Connectome (DISC), which summarizes the cumulative effects of TBI-induced connectivity abnormalities across the entire brain. Forty patients with moderate-to-severe TBI examined at 3 months postinjury and 35 uninjured healthy controls underwent magnetic resonance imaging with diffusion tensor imaging, and completed behavioral assessment including global clinical outcome measures and neuropsychological tests. TBI patients were selected to maximize the likelihood of DAI in the absence of large focal brain lesions. We found that hub-like regions, with high betweenness centrality, were most likely to be impaired as a result of diffuse TBI. Clustering of participants revealed a subgroup of TBI patients with similar connectivity abnormality profiles who exhibited relatively poor cognitive performance. Among TBI patients, DISC was significantly correlated with post-traumatic amnesia, verbal learning, executive function, and processing speed. Our experiments jointly demonstrated that assessing structural connectivity alterations may be useful in development of patient-oriented diagnostic and prognostic tools. Hum Brain Mapp 38:2913-2922, 2017. © 2017 Wiley Periodicals, Inc.


Assuntos
Lesões Encefálicas Traumáticas/patologia , Vias Neurais/patologia , Lesões Encefálicas Traumáticas/diagnóstico por imagem , Conectoma , Imagem de Tensor de Difusão , Função Executiva/fisiologia , Análise Fatorial , Feminino , Escala de Coma de Glasgow , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Vias Neurais/diagnóstico por imagem , Testes Neuropsicológicos , Estatística como Assunto , Aprendizagem Verbal/fisiologia
3.
Abdom Radiol (NY) ; 45(8): 2469-2475, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32372206

RESUMO

PURPOSE: The purpose of this study is to evaluate diagnostic performance of a commercially available radiomics research prototype vs. an in-house radiomics software in the binary classification of CT images from patients with pancreatic ductal adenocarcinoma (PDAC) vs. healthy controls. MATERIALS AND METHODS: In this retrospective case-control study, 190 patients with PDAC (97 men, 93 women; 66 ± 9 years) from 2012 to 2017 and 190 healthy potential renal donors (96 men, 94 women; 52 ± 8 years) without known pancreatic disease from 2005 to 2009 were identified from radiology and pathology databases. 3D volume of the pancreas was manually segmented from preoperative CT scans. Four hundred and seventy-eight radiomics features were extracted using in-house radiomics software. Eight hundred and fifty-four radiomics features were extracted using a commercially available research prototype. Random forest classifier was used for binary classification of PDAC vs. normal pancreas. Accuracy, sensitivity, and specificity of commercially available radiomics software were compared to in-house software. RESULTS: When 40 radiomics features were used in the random forest classification, in-house software achieved superior sensitivity (1.00) and accuracy (0.992) compared to the commercially available research prototype (sensitivity = 0.950, accuracy = 0.968). When the number of features was reduced to five features, diagnostic performance of the in-house software decreased to sensitivity (0.950), specificity (0.923), and accuracy (0.936). Diagnostic performance of the commercially available research prototype was unchanged. CONCLUSION: Commercially available and in-house radiomics software achieve similar diagnostic performance, which may lower the barrier of entry for radiomics research and allow more clinician-scientists to perform radiomics research.


Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Carcinoma Ductal Pancreático/diagnóstico por imagem , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Neoplasias Pancreáticas/diagnóstico por imagem , Estudos Retrospectivos , Sensibilidade e Especificidade , Software , Tomografia Computadorizada por Raios X
4.
Philos Trans R Soc Lond B Biol Sci ; 371(1688): 20150111, 2016 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-26833832

RESUMO

Recent years have witnessed an increased attention to studies of sex differences, partly because such differences offer important considerations for personalized medicine. While the presence of sex differences in human behaviour is well documented, our knowledge of their anatomical foundations in the brain is still relatively limited. As a natural gateway to fathom the human mind and behaviour, studies concentrating on the human brain network constitute an important segment of the research effort to investigate sex differences. Using a large sample of healthy young individuals, each assessed with diffusion MRI and a computerized neurocognitive battery, we conducted a comprehensive set of experiments examining sex-related differences in the meso-scale structures of the human connectome and elucidated how these differences may relate to sex differences at the level of behaviour. Our results suggest that behavioural sex differences, which indicate complementarity of males and females, are accompanied by related differences in brain structure across development. When using subnetworks that are defined over functional and behavioural domains, we observed increased structural connectivity related to the motor, sensory and executive function subnetworks in males. In females, subnetworks associated with social motivation, attention and memory tasks had higher connectivity. Males showed higher modularity compared to females, with females having higher inter-modular connectivity. Applying multivariate analysis, we showed an increasing separation between males and females in the course of development, not only in behavioural patterns but also in brain structure. We also showed that these behavioural and structural patterns correlate with each other, establishing a reliable link between brain and behaviour.


Assuntos
Encéfalo/fisiologia , Conectoma/métodos , Rede Nervosa/fisiologia , Adolescente , Animais , Criança , Feminino , Humanos , Masculino , Análise Multivariada , Fatores Sexuais , Adulto Jovem
5.
IEEE Trans Pattern Anal Mach Intell ; 34(10): 2064-70, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22641705

RESUMO

method is proposed for identifying five crowd behaviors (bottlenecks, fountainheads, lanes, arches, and blocking) in visual scenes. In the algorithm, a scene is overlaid by a grid of particles initializing a dynamical system defined by the optical flow. Time integration of the dynamical system provides particle trajectories that represent the motion in the scene; these trajectories are used to locate regions of interest in the scene. Linear approximation of the dynamical system provides behavior classification through the Jacobian matrix; the eigenvalues determine the dynamic stability of points in the flow and each type of stability corresponds to one of the five crowd behaviors. The eigenvalues are only considered in the regions of interest, consistent with the linear approximation and the implicated behaviors. The algorithm is repeated over sequential clips of a video in order to record changes in eigenvalues, which may imply changes in behavior. The method was tested on over 60 crowd and traffic videos.


Assuntos
Algoritmos , Processamento de Imagem Assistida por Computador/métodos , Reconhecimento Automatizado de Padrão/métodos , Comportamento Espacial , Humanos , Veículos Automotores , Movimento , Gravação em Vídeo
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