Search Results - "HASEGAWA, HIDEYUKI"

Advances in ultrasonography: image formation and quality assessment by Hasegawa, Hideyuki

“…Delay-and-sum (DAS) beamforming is widely used for generation of B-mode images from echo signals obtained with an array probe composed of transducer elements…”
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Analysis of arterial wall motion for measurement of regional pulse wave velocity by Hasegawa, Hideyuki

“…The regional elastic property of the arterial wall is a useful marker for the diagnosis of atherosclerosis because an atherosclerotic lesion is formed locally…”
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Complex-Valued Neural Networks: A Comprehensive Survey by Lee, ChiYan, Hasegawa, Hideyuki, Gao, Shangce

“…Complex-valued neural networks (CVNNs) have shown their excellent efficiency compared to their real counter-parts in speech enhancement, image and signal…”
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High-frame-rate echocardiography using diverging transmit beams and parallel receive beamforming by Hasegawa, Hideyuki, Kanai, Hiroshi

“…Purpose Echocardiography is a widely used modality for diagnosis of the heart. It enables observation of the shape of the heart and estimation of global heart…”
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Apodized adaptive beamformer by Hasegawa, Hideyuki

“…Purpose A number of studies aimed at improvement of ultrasound image quality, such as spatial resolution and contrast, have been conducted. Apodization is…”
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Phase-Sensitive 2D Motion Estimators Using Frequency Spectra of Ultrasonic Echoes by Hasegawa, Hideyuki

“…Recently, high-frame-rate ultrasound has been extensively studied for measurement of tissue dynamics, such as pulsations of the carotid artery and heart…”
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Fully Complex-Valued Gated Recurrent Neural Network for Ultrasound Imaging by Lei, Zhenyu, Gao, Shangce, Hasegawa, Hideyuki, Zhang, Zhiming, Zhou, Mengchu, Sedraoui, Khaled

“…Ultrasound imaging is widely used in medical diagnosis. It has the advantages of being performed in real time, cost-efficient, noninvasive, and nonionizing…”
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Initial phantom study on estimation of speed of sound in medium using coherence among received echo signals by Hasegawa, Hideyuki, Nagaoka, Ryo

“…Purpose Ultrasound beamforming is required to obtain clinical ultrasound images. In the beamforming procedure, the distance between the receiving focal point…”
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Two-Dimensional Wavenumber Analysis Implemented in Ultrasonic Vector Doppler Method with Focused Transmit Beams by Hasegawa, Hideyuki, Omura, Masaaki, Nagaoka, Ryo, Saito, Kozue

“…The multi-angle Doppler method was introduced for the estimation of velocity vectors by measuring axial velocities from multiple directions. We have recently…”
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Effect of subaperture beamforming on phase coherence imaging by Hasegawa, Hideyuki, Kanai, Hiroshi

“…High-frame-rate echocardiography using unfocused transmit beams and parallel receive beamforming is a promising method for evaluation of cardiac function, such…”
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A study on understanding the physical mechanism of change in ultrasonic envelope statistical property during temperature elevation by Omura, Masaaki, Takeuchi, Michio, Nagaoka, Ryo, Hasegawa, Hideyuki

“…Purpose Our previous studies demonstrate that the variation in ultrasonic envelope statistics is correlated with the temperature change inside scattering…”
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Enhancing effect of phase coherence factor for improvement of spatial resolution in ultrasonic imaging by Hasegawa, Hideyuki

“…Purpose Spatial resolution is one of the important factors that determines ultrasound image quality. In the present study, methods using the phase variance of…”
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Converting Coherence to Signal-to-noise Ratio for Enhancement of Adaptive Ultrasound Imaging by Hasegawa, Hideyuki, Nagaoka, Ryo

“…High-frame-rate ultrasound is an emerging technique for functional ultrasound imaging. However, the lateral spatial resolution and contrast in high-frame-rate…”
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Singular value decomposition filter for speckle reduction in adaptive ultrasound imaging by Hasegawa, Hideyuki, Nagaoka, Ryo

“…Various adaptive beamforming methods have been developed recently for improvement of image quality in medical ultrasonic imaging. Such adaptive beamformers…”
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Improvement of penetration of modified amplitude and phase estimation beamformer by Hasegawa, Hideyuki

“…Purpose High-frame-rate ultrasound is the predominant technique for the measurement of tissue dynamics. It enables an imaging frame rate of over 1 kHz using…”
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Contrast analysis in ultrafast ultrasound blood flow imaging of jugular vein by Omura, Masaaki, Yagi, Kunimasa, Nagaoka, Ryo, Hasegawa, Hideyuki

“…Purpose The contrasts of flowing blood in in vitro experiments using porcine blood and in vivo measurements of human jugular veins were analyzed to demonstrate…”
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Utilization of singular value decomposition in high-frame-rate cardiac blood flow imaging by Mozumi, Michiya, Nagaoka, Ryo, Hasegawa, Hideyuki

“…Visualization of blood flow is important to evaluate the cardiac function. In this study, we propose two signal processing techniques based on singular value…”
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Temporal averaging introduced in linear regression beamforming for improvement of contrast-to-noise ratio by Hasegawa, Hideyuki, Nagaoka, Ryo

“…Coherence-based adaptive imaging has been investigated for the improvement of image quality in medical ultrasound imaging. The coherence factor (CF) was…”
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Improving image contrast and accuracy in velocity estimation by convolution filters for intracardiac blood flow imaging by Mozumi, Michiya, Nagaoka, Ryo, Hasegawa, Hideyuki

“…•Velocity estimation has been used in echocardiography as a diagnostic tool.•Ultrasound images were filtered using characteristics of an imaging system to…”
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Estimation of speed of sound using coherence factor and signal-to-noise ratio for improvement of performance of ultrasonic beamformer by Sannou, Fumitada, Nagaoka, Ryo, Hasegawa, Hideyuki

“…Ultrasound beamforming is an indispensable process to obtain an ultrasound image. In the conventional ultrasonography, the speed of sound (SoS) in tissue is…”
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