Hiroshi Kanai

Hiroshi Kanai

Tohoku University

H-index: 42

Asia-Japan

About Hiroshi Kanai

Hiroshi Kanai, With an exceptional h-index of 42 and a recent h-index of 23 (since 2020), a distinguished researcher at Tohoku University, specializes in the field of Medical Ultrasound, Ultrasonics, Cardiac Diagnosis.

His recent articles reflect a diverse array of research interests and contributions to the field:

Device for treating dementia, method for operating said device, and program

Automated mode chart generation for finite element analysis of piezoelectric resonators using principal component analysis based on clustering

Appropriate indicator of modeling error for threshold-based model selection in statistics-based ultrasound tissue characterization

Optimizing irradiation conditions for low-intensity pulsed ultrasound to upregulate endothelial nitric oxide synthase

Publisher’s Note:“A novel ultrasonic method for measuring minute sinusoidal displacement by network analyzer”[Rev. Sci. Instrum. 95, 025105 (2024)]

Estimation error in speed of sound caused by rotation of measured cross-section from short-axis plane of blood vessels: a preliminary study

Optimal treatment conditions for low-intensity pulsed ultrasound therapy for Alzheimer’s disease: applications from mice to humans

Influence of Power-Weighted Center of Echo Signal Within Window Function on Local Strain Rate Distribution in Left Ventricular Wall

Hiroshi Kanai Information

University

Tohoku University

Position

Professor of Electronic Engineering

Citations(all)

8783

Citations(since 2020)

2244

Cited By

8463

hIndex(all)

42

hIndex(since 2020)

23

i10Index(all)

218

i10Index(since 2020)

56

Email

University Profile Page

Tohoku University

Hiroshi Kanai Skills & Research Interests

Medical Ultrasound

Ultrasonics

Cardiac Diagnosis

Top articles of Hiroshi Kanai

Device for treating dementia, method for operating said device, and program

Published Date

2024/2/6

The present invention provides a device for treating dementia, including: a plurality of ultrasound probes; an ultrasound transducer arranged in each of the ultrasound probes and configured to propagate unfocused ultrasound energy to a brain; and an ultrasound generator connected to each of the ultrasound probes.

Automated mode chart generation for finite element analysis of piezoelectric resonators using principal component analysis based on clustering

Authors

Kenji Inoue,Yuji Ohashi,Mototaka Arakawa,Hiroshi Kanai

Journal

Japanese Journal of Applied Physics

Published Date

2024/1/9

This paper presents a new clustering method for identifying the vibration mode shapes of piezoelectric resonators using image processing and principal component analysis (PCA). The finite element method (FEM) is an indispensable tool for analyzing the vibration-displacement distribution of resonators and suppressing spurious vibration modes. Although the FEM exports eigenfrequencies as a list, including spurious vibration modes, recognizing the vibration shape of each eigenfrequency requires manual operation by operators to view the displacement distribution and identify the vibration shapes. The proposed method consists of a preprocessing step based on a threshold selection before the PCA step. Preprocessing significantly simplifies the vibration displacement distribution and reduces the amount of data required for post-processing PCA. The mode chart of the AT-cut quartz crystal resonator obtained …

Appropriate indicator of modeling error for threshold-based model selection in statistics-based ultrasound tissue characterization

Authors

Shohei Mori,Mototaka Arakawa,Tadashi YAMAGUCHI,Hiroshi KANAI,Hiroyuki Hachiya

Journal

Japanese Journal of Applied Physics

Published Date

2024/3/21

Analysis of the envelope statistics of ultrasound echo signals contributes to quantitative tissue characterization in medical ultrasound. Many probability distribution model functions have been studied, and the model function that should be used for tissue characterization depends on the type of disease, even in the same organ. Thus, an appropriate model selection is important for an accurate diagnosis. In this study, we aimed to select a model using threshold processing for modeling errors instead of a simple selection by minimizing the modeling error. For this purpose, we compared several indicators of modeling errors using random number simulations, ultrasonic simulation, and phantom experiment. The results validated that the Mahalanobis distance of moments is an appropriate indicator because it enables the use of a constant threshold value, regardless of the type of model function and data length.

Optimizing irradiation conditions for low-intensity pulsed ultrasound to upregulate endothelial nitric oxide synthase

Authors

Daiki Ouchi,Shohei Mori,Mototaka Arakawa,Tomohiko Shindo,Hiroaki Shimokawa,Satoshi Yasuda,Hiroshi Kanai

Journal

Journal of Medical Ultrasonics

Published Date

2024/1

PurposeHere we aimed to develop a minimally invasive treatment for ischemic heart disease and demonstrate that low-intensity pulsed ultrasound (LIPUS) therapy improves myocardial ischemia by promoting myocardial angiogenesis in a porcine model of chronic myocardial ischemia. Studies to date determined the optimal treatment conditions within the range of settings available with existing ultrasound equipment and did not investigate a wider range of conditions.MethodsWe investigated a broad range of five parameters associated with ultrasound irradiation conditions that promote expression of endothelial nitric oxide synthase (eNOS), a key molecule that promotes angiogenesis in human coronary artery endothelial cells (HCAEC).ResultsSuboptimal irradiation conditions included 1-MHz ultrasound frequency, 500-kPa sound pressure, 20-min total irradiation time, 32–48- pulse duration, and 320- pulse …

Publisher’s Note:“A novel ultrasonic method for measuring minute sinusoidal displacement by network analyzer”[Rev. Sci. Instrum. 95, 025105 (2024)]

Authors

Yuya Komatsu,Shohei Mori,Mototaka Arakawa,Hiroshi Kanai

Journal

Review of Scientific Instruments

Published Date

2024/3/1

This article was originally published online on 12 February 2024 with typesetting errors. In the fourth line of the abstract,“on” was changed to “to.” In the eighth line on page 7, μm was made roman rather than italic. On page 8, in the tenth line under “V. Discussion,” a thin space was added between “50” and “μm.” In the “Appendix” heading, a dot was changed to a multiplication sign. On page 9, a thin space was added between “10” and “μm.” AIP Publishing apologizes for the error. All online versions of the article were corrected on 16 February 2024; the article is correct as it appears in the printed version of the journal.

Estimation error in speed of sound caused by rotation of measured cross-section from short-axis plane of blood vessels: a preliminary study

Authors

Shohei Mori,Keiji Onoda,Mototaka Arakawa,Hiroshi Kanai

Journal

Journal of Medical Ultrasonics

Published Date

2024/1

PurposeEstimating the speed of sound (SoS) in ultrasound propagation media is important for improving the quality of B-mode images and for quantitative tissue characterization. We have been studying a method for estimating the SoS by measuring the reception time distribution of waves scattered from a scatterer at the elements in a probe. Previously, the measurement cross section was assumed to be perpendicular to the long axis of the blood vessel. In this study, we experimentally investigated the relationship between rotation angle of the probe relative to the short-axis plane of the blood vessel and the estimated SoS, .MethodsWater tank and phantom experiments were conducted to investigate the characteristics of and element signals when the probe was rotated.ResultsThe received signal powers at the elements around both edges greatly decreased as increased. We introduced a parameter representing the decrease in power,  …

Optimal treatment conditions for low-intensity pulsed ultrasound therapy for Alzheimer’s disease: applications from mice to humans

Authors

Tomohiko Shindo,Kumiko Eguchi,Yuto Monma,Hiroshi Kanai,Satoshi Yasuda,Hiroaki Shimokawa

Journal

Journal of Medical Ultrasonics

Published Date

2024/5/2

PurposeWe previously developed a novel therapy with low-intensity pulsed ultrasound (LIPUS) that ameliorates cognitive decline through upregulation of endothelial nitric oxide synthase (eNOS) in mouse models of Alzheimer’s disease (AD). In a randomized, double-blind, placebo-controlled pilot trial, we demonstrated that whole-brain LIPUS therapy is safe and tends to suppress the cognitive decline in early AD patients. We herein report the findings of our basic experiments that we performed for the pilot trial in order to apply whole-brain LIPUS therapy to humans, as well.MethodsFirst, we examined the relationship between bone density/thickness and ultrasound transmittance using human temporal bone. Next, based on the results of ultrasound transmittance, we further examined mRNA expression of VEGF, FGF2, and eNOS in response to variable ultrasound frequencies, duty cycles, and sound pressures …

Influence of Power-Weighted Center of Echo Signal Within Window Function on Local Strain Rate Distribution in Left Ventricular Wall

Authors

Yu Obara,Shohei Mori,Masumi Iwai-Takano,Mototaka Arakawa,Hiroshi Kanai

Journal

Ultrasound in Medicine & Biology

Published Date

2024/2/26

ObjectiveThe deviation of the power-weighted center of the echo signal from the geometric center within the velocity estimation window for calculating strain rate (SR) causes an estimation error. This study aimed to confirm whether an erroneous multilayer pattern in the SR distribution of the left ventricular wall could be corrected by considering the power-weighted center of the echo signal.MethodsThe SR distributions were measured locally in the transmural direction around the pre-ejection and early diastolic phases in healthy volunteers. The estimation error related to the power-weighted center of the echo signal was corrected using a previously proposed method, and the effectiveness of the correction was confirmed based on the accuracy of the estimated myocardial displacement.ResultsThe SR distribution in early diastole was observed as multilayers of low- and high-amplitude negative SRs. However, this …

Method for measuring time waveforms of minute sinusoidal displacements using continuous waves with a network analyzer

Authors

Yuya Komatsu,Shohei Mori,Mototaka Arakawa,Hiroshi Kanai

Journal

Japanese Journal of Applied Physics

Published Date

2024/4/11

This study proposes a method for precise measurement of time waveforms of minute sinusoidal displacements using continuous waves. The technique involves measuring the S-parameter of ultrasonic waves reflected from an object undergoing sinusoidal vibration with a network analyzer. When the sinusoidal displacement is not sufficiently small, second-order side peaks emerge in its inverse Fourier transform, alongside the main and first-order side peaks. This method, which incorporates second-order side peaks previously overlooked, enhances the accuracy of measurements. It facilitates precise measurement of sinusoidal displacements ranging from 0.3 to 50 μm at frequencies between 10 and 300 Hz.

A novel ultrasonic method for measuring minute sinusoidal displacement by network analyzer

Authors

Yuya Komatsu,Shohei Mori,Mototaka Arakawa,Hiroshi Kanai

Journal

Review of Scientific Instruments

Published Date

2024/2/1

We developed a method for generating continuous sinusoidal displacements of an object to estimate viscoelastic parameters. However, the amplitude of the displacement caused by the ultrasonic excitation force under safe guidelines was small (a few micrometers), and it was difficult to stably measure the displacement. Therefore, to stably measure the amplitude of sinusoidal displacement as small as the order of micrometers, we proposed a novel method using a network analyzer. Ultrasonic waves were irradiated using an ultrasonic transducer on an object vibrating sinusoidally. The S parameter of the first reflected wave received from the surface of the object was measured using a network analyzer. The S parameter and the inverse Fourier transform were formulated theoretically, and the amplitude of the sinusoidal displacement of the object was estimated from the amplitude characteristics of the inverse Fourier …

Lateral M-Mode: Ultrasound Visualization of Displacement Along Longitudinal Direction at Intima–Media Complex

Authors

Shohei Mori,Mototaka Arakawa,Hiroshi Kanai

Journal

Ultrasound in Medicine & Biology

Published Date

2023/3/1

Quantification of the dynamics of the carotid artery wall is useful in evaluating arteriosclerosis and atherosclerosis. As the carotid artery wall moves not only in the radial direction but also in the longitudinal direction, longitudinal movement should be considered in the analysis of the dynamic properties of the carotid artery wall. In this study, we propose a “lateral M-mode” method for visualizing the longitudinal movement of the intima–media complex (IMC). For the lateral M-mode, we set the target line in the longitudinal direction along the IMC and visualize the signals on the target line frame-by-frame by correcting the position of the target line along the radial displacement estimated by the phased tracking method. Differentiating the envelope signals between consecutive ultrasound beams was effective in visualizing the lateral movement of the IMC. The precision of the longitudinal displacement of the IMC estimated …

Ultrasonic measurement of carotid luminal surface roughness with removal of axial displacement caused by blood pulsation

Authors

Ryota Yamane,Shohei Mori,Mototaka Arakawa,Jens E Wilhjelm,Hiroshi Kanai

Journal

Japanese Journal of Applied Physics

Published Date

2023/4/3

For early diagnosis of atherosclerosis, we have developed a method to measure the initial minute surface roughness utilizing the natural longitudinal displacement of the intima-media-complex (IMC) on the carotid artery caused by pulsation. However, the IMC displaces not only in the longitudinal direction but also in the axial direction due to the pulsation. In the present paper, we proposed a novel method to remove the pulsation component by spatially convolving a high-pass filter with the measured depths of IMC in the longitudinal direction. The proposed method was validated by a phantom experiment, and the surface roughness with ten saw teeth was correctly measured. Next, the surface roughness of the carotid artery wall was measured for two healthy volunteers. The proposed method reduced the variation of measured surface roughness among beams compared to the previous method.

2P5-17 A Method of Automatically Detecting of Intima-Media Complex for Ultrasonic Measurement of Carotid Luminal Surface Roughness

Authors

Ryota Yamane,Shohei Mori,Mototaka Arakawa,Jens E Wilhjelm,Hiroshi Kanai

Journal

Proceedings of Symposium on Ultrasonic Electronics

Published Date

2023/11/13

For early detection of atherosclerosis, we have been developing a method to measure the minute surface roughness of intima-media complex (IMC) using the longitudinal displacement of IMC naturally caused by pulsation. 1) In our previous study, it was necessary to manually set the threshold for detecting IMC. However, automatic detection is desirable for clinical applications. In the present study, we investigated an automatic IMC detecting method for surface roughness measurement.

Spatial Frequency Analysis of Luminal Surface Roughness of the Carotid Artery Measured by Ultrasound

Authors

Ryota Yamane,Shohei Mori,Mototaka Arakawa,Jens E Wilhjelm,Hiroshi Kanai

Published Date

2023/9/3

For early detection of atherosclerosis, we have developed a method to measure minute surface roughness by utilizing the natural longitudinal displacement of the intima-media complex on the carotid artery caused by pulsation. In this study, the surface roughness of three healthy subjects in their 20s were measured using this method to investigate the spatial frequency characteristics of surface roughness. As a result, the spatial frequency spectrum showed a similar tendency in all subjects.

Beneficial effects of low-intensity pulsed ultrasound therapy on right ventricular dysfunction in animal models

Authors

Takashi Nakata,Tomohiko Shindo,Kenta Ito,Kumiko Eguchi,Yuto Monma,Sadamitsu Ichijo,Rie Ryoke,Wakako Satoh,Kazunori Kumasaka,Haruka Sato,Ryo Kurosawa,Kimio Satoh,Ryuta Kawashima,Masahito Miura,Hiroshi Kanai,Satoshi Yasuda,Hiroaki Shimokawa

Journal

Basic to Translational Science

Published Date

2023/3/1

Right ventricular failure (RVF) is a leading cause of death in patients with pulmonary hypertension; however, effective treatment remains to be developed. We have developed low-intensity pulsed ultrasound therapy for cardiovascular diseases. In this study, we demonstrated that the expression of endothelial nitric oxide synthase (eNOS) in RVF patients was downregulated and that eNOS expression and its downstream pathway were ameliorated through eNOS activation in 2 animal models of RVF. These results indicate that eNOS is an important therapeutic target of RVF, for which low-intensity pulsed ultrasound therapy is a promising therapy for patients with RVF.

Speed-of-sound estimation in ultrasound propagation medium by considering size of target scatterer

Authors

Shohei Mori,Hiroshi Kanai,Mototaka Arakawa

Journal

Journal of Medical Ultrasonics

Published Date

2023/4

PurposeAccurate speed-of-sound (SoS) estimation in an ultrasound propagation medium improves imaging quality and contributes to better diagnosis of diseases. In conventional time-delay-based SoS estimation approaches studied by several groups, a received wave is assumed to be scattered from an ideal point scatterer. In these approaches, the SoS is overestimated when the target scatterer has a non-negligible size. In this paper, we propose the SoS estimation method that considers target size.MethodsIn the proposed method, the error ratio of the estimated SoS using the conventional time-delay-based approach is determined from measurable parameters using the geometric relationship between the received elements and target. Subsequently, the SoS erroneously estimated using conventional estimation, assuming the ideal point scatterer as a target, is corrected by the determined estimation error ratio …

3J2-4 Preliminary study on ultrasonic visualization of myocardial contractile response based on local strain rate measurement

Authors

Yu Obara,Shohei Mori,Nobuo Masauzi,Masumi Iwai-Takano,Mototaka Arakawa,Hiroshi Kanai

Journal

Proceedings of Symposium on Ultrasonic Electronics

Published Date

2023/11/13

Myocardial ischemia leads to an abnormality in the propagation of the contractile response to the electrical excitation of the myocardium. 1) This contractile response can be captured by ultrasound measurements. 1-3) The local visualization of the contractile response may contribute to the detection of myocardial ischemia.In our previous study for healthy volunteers, the propagation of the contractile response in the left ventricular (LV) wall was locally captured by the local strain rate (SR) measurement. 4) In the local measurement, the contractile response was observed to propagate along the longitudinal direction of the LV wall and different for depth within the LV wall. In the present paper, the propagation of the contractile response was visualized based on the waveforms of the SR locally measured. The difference in the propagations between the right ventricular (RV) and LV sides was discussed.

Optimal Treatment Conditions of the Low-intensity Pulsed Ultrasound Therapy for the Treatment of Alzheimer’s Disease-Applications from Mice to Humans

Authors

Tomohiko Shindo,Kumiko Eguchi,Yuto Monma,Hiroshi Kanai,Satoshi Yasuda,Hiroaki Shimokawa

Published Date

2023/7/18

Background and PurposeWe have previously developed a novel therapy with low-intensity pulsed ultrasound (LIPUS) that ameliorates cognitive decline through upregulation of endothelial nitric oxide synthase in mouse models of Alzheimer's disease (AD) and vascular dementia. We then conducted a randomized, double-blind, placebo-controlled (RCT) pilot trial for efficacy and safety of the whole-brain LIPUS therapy in patients with early AD. We demonstrated that the LIPUS therapy is safe and tends to suppress the cognitive decline in AD patients. We here report the findings of our basic experiments that we performed for the pilot trial in order to apply the whole-brain LIPUS therapy from mice to humans.MethodsWe performed basic experiments of the LIPUS therapy to identify the optimal treatment condition. First, by using human temporal bone, we examined the relationship between bone density/thickness and ultrasound transmittance. Next, based on the results of ultrasound transmittance, we further examined mRNA expression of vascular endothelial growth factor (VEGF), fibroblast growth factor 2 (FGF2), and endothelial nitric oxide synthase (eNOS) in response to variable frequencies, duty cycles, and sound pressures.ResultsThere was a significant correlation between bone thickness and transmittance (1.0 MHz, P< 0.001), while there was no significant correlation between bone density and transmittance (1.0 MHz, P= 0.421). At a frequency of 0.5 MHz, the optimum duty cycle was considered to be~ 20%. When the tissue amplitude was in the range of 0.05–0.5 MPa, VEGF, FGF2 and eNOS were significantly upregulated by LIPUS. Thus …

In vivo measurement of attenuation coefficient of blood in a dorsal hand vein in a frequency range of 10–45 MHz: A preliminary study

Authors

Mototaka Arakawa,Kyohei Higashiyama,Shohei Mori,Satoshi Yashiro,Yasushi Ishigaki,Hiroshi Kanai

Journal

Frontiers in Physics

Published Date

2023/2/7

In this study, the attenuation coefficient of blood was measured in vivo in the frequency range of 10–45 MHz. A procedure to correct the distribution of sound pressure in the measurements was discussed. Further, in vivo measurements were applied on the dorsal hand vein of four healthy subjects at rest and during avascularization. As a preliminary result, less variation of the measured attenuation coefficients was achieved by the proposed method. The comparable results of the inclination of the attenuation coefficients were obtained at rest and during avascularization. Furthermore, the attenuation coefficients during avascularization were markedly higher than those at rest, reflecting the degree of red blood cell aggregation promoted by avascularization. This method may aid in the noninvasive evaluation of blood properties reflecting the degree of red blood cell aggregation.

High-speed measurement of two-dimensional displacement of myocardium using element RF data of ultrasonic probe

Authors

Kaisei Hara,Shohei Mori,Mototaka Arakawa,Hiroshi Kanai

Journal

Japanese Journal of Applied Physics

Published Date

2023/3/27

Improving the accuracy of heart wall motion measurement is essential to realise better cardiac function evaluation. This paper proposed a two-dimensional (2D) displacement estimation method with a high temporal resolution using the 2D complex cross-correlation of element RF signals of an ultrasonic probe between frames returned from the target scatterers. The application of the proposed method to the phantom displacement confirmed its principle. The estimated 2D displacement of the phantom was consistent with the set displacement. Subsequently, the method was applied to two healthy subjects to measure the 2D displacement of the interventricular septum during one cardiac cycle. Consequently, during systole and diastole, the movement of the myocardium was measured, and the results were validated.

See List of Professors in Hiroshi Kanai University(Tohoku University)

Hiroshi Kanai FAQs

What is Hiroshi Kanai's h-index at Tohoku University?

The h-index of Hiroshi Kanai has been 23 since 2020 and 42 in total.

What are Hiroshi Kanai's top articles?

The articles with the titles of

Device for treating dementia, method for operating said device, and program

Automated mode chart generation for finite element analysis of piezoelectric resonators using principal component analysis based on clustering

Appropriate indicator of modeling error for threshold-based model selection in statistics-based ultrasound tissue characterization

Optimizing irradiation conditions for low-intensity pulsed ultrasound to upregulate endothelial nitric oxide synthase

Publisher’s Note:“A novel ultrasonic method for measuring minute sinusoidal displacement by network analyzer”[Rev. Sci. Instrum. 95, 025105 (2024)]

Estimation error in speed of sound caused by rotation of measured cross-section from short-axis plane of blood vessels: a preliminary study

Optimal treatment conditions for low-intensity pulsed ultrasound therapy for Alzheimer’s disease: applications from mice to humans

Influence of Power-Weighted Center of Echo Signal Within Window Function on Local Strain Rate Distribution in Left Ventricular Wall

...

are the top articles of Hiroshi Kanai at Tohoku University.

What are Hiroshi Kanai's research interests?

The research interests of Hiroshi Kanai are: Medical Ultrasound, Ultrasonics, Cardiac Diagnosis

What is Hiroshi Kanai's total number of citations?

Hiroshi Kanai has 8,783 citations in total.

What are the co-authors of Hiroshi Kanai?

The co-authors of Hiroshi Kanai are James P. Butler, Noriko Osumi, Kenta Ito, Yoshifumi Saijo, Mami Matsukawa, Hiroyuki Hachiya.

    Co-Authors

    H-index: 86
    James P. Butler

    James P. Butler

    Harvard University

    H-index: 64
    Noriko Osumi

    Noriko Osumi

    Tohoku University

    H-index: 55
    Kenta Ito

    Kenta Ito

    Tohoku University

    H-index: 35
    Yoshifumi Saijo

    Yoshifumi Saijo

    Tohoku University

    H-index: 31
    Mami Matsukawa

    Mami Matsukawa

    Doshisha University

    H-index: 27
    Hiroyuki Hachiya

    Hiroyuki Hachiya

    Tokyo Institute of Technology

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