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1.
Contrast Media Mol Imaging ; 2022: 8733632, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35833074

RESUMO

Myocarditis is heart muscle inflammation that is becoming more prevalent these days, especially with the prevalence of COVID-19. Noninvasive imaging cardiac magnetic resonance (CMR) can be used to diagnose myocarditis, but the interpretation is time-consuming and requires expert physicians. Computer-aided diagnostic systems can facilitate the automatic screening of CMR images for triage. This paper presents an automatic model for myocarditis classification based on a deep reinforcement learning approach called as reinforcement learning-based myocarditis diagnosis combined with population-based algorithm (RLMD-PA) that we evaluated using the Z-Alizadeh Sani myocarditis dataset of CMR images prospectively acquired at Omid Hospital, Tehran. This model addresses the imbalanced classification problem inherent to the CMR dataset and formulates the classification problem as a sequential decision-making process. The policy of architecture is based on convolutional neural network (CNN). To implement this model, we first apply the artificial bee colony (ABC) algorithm to obtain initial values for RLMD-PA weights. Next, the agent receives a sample at each step and classifies it. For each classification act, the agent gets a reward from the environment in which the reward of the minority class is greater than the reward of the majority class. Eventually, the agent finds an optimal policy under the guidance of a particular reward function and a helpful learning environment. Experimental results based on standard performance metrics show that RLMD-PA has achieved high accuracy for myocarditis classification, indicating that the proposed model is suitable for myocarditis diagnosis.


Assuntos
COVID-19 , Miocardite , Algoritmos , COVID-19/diagnóstico por imagem , Humanos , Irã (Geográfico) , Miocardite/diagnóstico por imagem , Miocardite/patologia , Redes Neurais de Computação
2.
Annu Int Conf IEEE Eng Med Biol Soc ; 2019: 6545-6548, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31947341

RESUMO

Ultrasound imaging is a standard examination during pregnancy that can be used for measuring specific biometric parameters towards prenatal diagnosis and estimating gestational age. Fetal head circumference (HC) is one of the significant factors to determine the fetus growth and health. In this paper, a multi-task deep convolutional neural network is proposed for automatic segmentation and estimation of HC ellipse by minimizing a compound cost function composed of segmentation dice score and MSE of ellipse parameters. Experimental results on fetus ultrasound dataset in different trimesters of pregnancy show that the segmentation results and the extracted HC match well with the radiologist annotations. The obtained dice scores of the fetal head segmentation and the accuracy of HC evaluations are comparable to the state-of-the-art.


Assuntos
Aprendizado Profundo , Ultrassonografia Pré-Natal , Biometria , Feminino , Cabeça , Humanos , Redes Neurais de Computação , Gravidez
3.
Mol Divers ; 14(3): 569-74, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19680770

RESUMO

The addition of acetylenic esters to aromatic amines such as 2-amino benzophenone derivatives in the presence of triphenylphosphine leads to highly functionalized phosphoranes, which undergo an intramolecular Wittig reaction following oxidation to produce quinoline derivatives.


Assuntos
Química Orgânica/métodos , Hidrocarbonetos Aromáticos/química , Cetonas/química , Quinolinas/síntese química , Sais/química , Compostos de Vinila/química , Aminas/síntese química , Aminas/química , Quinolinas/química
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