Dr. Keiji Umetani Profile

Dr. Keiji Umetani

at Japan Synchrotron Radiation Research Institute

SPIE Involvement:

Author

Publications (29)

Proceedings Article | 7 April 2023 Poster + Paper

Extraction of alveolar walls in 3D lung micro-images from large-field synchrotron radiation micro-CT using U-Net

Haruki Kurita, Yoshiki Kawata, Hidenobu Suzuki, Keiji Umetani, Yasutaka Nakano, Hiroaki Sakai, Toshihiro Okamoto, Noboru Niki

Proceedings Volume 12463, 1246326 (2023) https://doi.org/10.1117/12.2652484

KEYWORDS: 3D modeling, 3D image processing, Synchrotron radiation, Lung, Computed tomography

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Proceedings Article | 4 April 2022 Presentation + Paper

Counting of alveoli in synchrotron radiation 3D CT images using U-Net

Keisuke Fukuda, Kurumi Saito, Yoshiki Kawata, Keiji Umetani, Yasutaka Nakano, Hiroaki Sakai, Toshihiro Okamoto, Noboru Niki

Proceedings Volume 12036, 120360H (2022) https://doi.org/10.1117/12.2612810

KEYWORDS: Lung, 3D image processing, Synchrotron radiation, 3D microstructuring, Computed tomography, Image processing

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Proceedings Article | 4 April 2022 Presentation + Paper

Pulmonary alveoli cluster analysis of 3D human lung microstructure using synchrotron radiation micro-CT

Kurumi Saito, Keisuke Fukuda, Yoshiki Kawata, Keiji Umetani, Yasutaka Nakano, Hiroaki Sakai, Toshihiro Okamoto, Noboru Niki

Proceedings Volume 12036, 120360G (2022) https://doi.org/10.1117/12.2612692

KEYWORDS: Lung, 3D microstructuring, 3D image processing, Synchrotron radiation, Principal component analysis, Arteries, 3D image reconstruction, Stereoscopy, Image processing algorithms and systems, Image filtering

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Proceedings Article | 15 February 2021 Poster + Presentation + Paper

Alveolar sac analysis of 3D human lung microstructure using synchrotron radiation micro-CT

Kurumi Saito, Keisuke Fukuda, Yoshiki Kawata, Noboru Niki, Keiji Umetani, Yasutaka Nakano, Hiroaki Sakai, Toshihiro Okamoto

Proceedings Volume 11600, 116001U (2021) https://doi.org/10.1117/12.2582050

KEYWORDS: Lung, Synchrotron radiation, 3D microstructuring, 3D image processing, Statistical analysis, Quantitative analysis, Optical filters, Emphysema, Computed tomography

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Proceedings Article | 28 February 2020 Paper

3D microstructure analysis of human pulmonary emphysema using a synchrotron radiation CT

Kurumi Saito, Shota Fuketa, Ryouhei Shimatani, Yoshiki Kawata, Noboru Niki, Keiji Umetani, Yasutaka Nakano, Hiroaki Sakai, Toshihiro Okamoto, Harumi Itoh

Proceedings Volume 11317, 113170H (2020) https://doi.org/10.1117/12.2549441

KEYWORDS: Emphysema, Lung, 3D microstructuring, Synchrotron radiation, Capillaries, Blood vessels, 3D image reconstruction, Analytical research, 3D image processing, Visualization

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Proceedings Article | 15 March 2019 Paper

Pulmonary blood vessels extraction from dual-energy CT images using a synchrotron radiation micro-CT

K. Saito, S. Ohnishi , S. Fuketa, Y. Kawata, N. Niki, K. Umetani, H. Sakai, Y. Nakano, T. Okamoto, H. Itoh

Proceedings Volume 10953, 109530G (2019) https://doi.org/10.1117/12.2512369

KEYWORDS: Blood vessels, Lung, Capillaries, Synchrotron radiation, 3D image processing, Image segmentation, X-ray computed tomography, Visualization, Veins, Computed tomography

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Proceedings Article | 5 November 2018 Paper

High-resolution wide-field synchrotron radiation micro-CT for large human lung specimen imaging

Keiji Umetani, Harumi Itoh, Yoshiki Kawata, Noboru Niki

Proceedings Volume 10816, 108160A (2018) https://doi.org/10.1117/12.2501282

KEYWORDS: Cameras, Lung, Imaging systems, X-rays, Image processing, X-ray imaging, Sensors, Spatial resolution, Image sensors, Optical filters

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Proceedings Article | 12 March 2018 Paper

Bronchial based pulmonary acinus analysis in human lungs using a synchrotron radiation micro-CT

K. Saito, Y. Kobayashi, Y. Kawata, N. Niki, K. Umetani, T. Okamoto, H. Sakai, Y. Nakano, H. Itoh

Proceedings Volume 10578, 105781W (2018) https://doi.org/10.1117/12.2293428

KEYWORDS: Lung, Image segmentation, 3D microstructuring, 3D image processing, Synchrotron radiation, Analytical research, Computed tomography, Synchrotrons, Medical research, Heart

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Proceedings Article | 31 October 2016 Paper

Development of 36M-pixel x-ray detector for large field of view and high-resolution micro-CT

Keiji Umetani, Yoshiki Kawata, Noboru Niki

Proceedings Volume 10020, 1002005 (2016) https://doi.org/10.1117/12.2246186

KEYWORDS: X-rays, Cameras, Digital cameras, Lung, X-ray detectors, Sensors, CMOS sensors, Imaging systems, Spatial resolution, Visualization

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Proceedings Article | 1 April 2016 Paper

Microstructure analysis of the pulmonary acinus by a synchrotron radiation CT

K. Minami, K. Maeda, Y. Kawata, N. Niki, K. Umetani, Y. Nakano, H. Sakai, H. Ohmatsu, H. Itoh

Proceedings Volume 9783, 978355 (2016) https://doi.org/10.1117/12.2216642

KEYWORDS: Synchrotron radiation, Lung, Computed tomography, Synchrotrons, Quantitative analysis, Diagnostics, Arteries, Veins, Analytical research, Image segmentation, Image analysis, Medical imaging

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Proceedings Article | 17 March 2015 Paper

Microstructure analysis of the pulmonary acinus using a synchrotron radiation CT

Y. Tokumoto, K. Minami, Y. Kawata, N. Niki, K. Umetani, Y. Nakano, H. Sakai, H. Ohmatsu, H. Itoh

Proceedings Volume 9417, 94172P (2015) https://doi.org/10.1117/12.2081357

KEYWORDS: Lung, Synchrotron radiation, Arteries, Veins, Computed tomography, 3D image processing, Image segmentation, Quantitative analysis, Image resolution, X-rays

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Proceedings Article | 19 March 2014 Paper

Phase contrast portal imaging for image-guided microbeam radiation therapy

Keiji Umetani, Takeshi Kondoh

Proceedings Volume 9033, 90335P (2014) https://doi.org/10.1117/12.2043216

KEYWORDS: Phase contrast, Bone, Radiotherapy, X-rays, Synchrotron radiation, X-ray imaging, Tumors, Head, Camera shutters, Cerebrum

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Proceedings Article | 18 March 2014 Paper

Microstructure analysis of the secondary pulmonary lobules by 3D synchrotron radiation CT

Y. Fukuoka, Y. Kawata, N. Niki, K. Umetani, Y. Nakano, H. Ohmatsu, N. Moriyama, H. Itoh

Proceedings Volume 9035, 90352F (2014) https://doi.org/10.1117/12.2043454

KEYWORDS: Image segmentation, Lung, Synchrotron radiation, 3D image processing, Arteries, Veins, Computed tomography, 3D microstructuring, Spatial resolution, Tissues

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Proceedings Article | 29 March 2013 Paper

Stochastic tracking of small pulmonary vessels in human lung alveolar walls using synchrotron radiation micro CT images

Y. Kawata, N. Niki, K. Umetani, Y. Nakano, H. Ohamatsu, N. Moriyama, H. Itoh

Proceedings Volume 8672, 867211 (2013) https://doi.org/10.1117/12.2006895

KEYWORDS: Lung, Synchrotron radiation, Particle filters, Image segmentation, Stochastic processes, 3D image processing, Computed tomography, Cancer, Optical spheres, X-ray computed tomography

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Proceedings Article | 19 March 2013 Paper

Rat coronary microangiography system for preclinical imaging using synchrotron radiation

Keiji Umetani, James Pearson, Daryl Schwenke, Mikiyasu Shirai

Proceedings Volume 8668, 866864 (2013) https://doi.org/10.1117/12.2006570

KEYWORDS: X-rays, Camera shutters, Synchrotron radiation, Arteries, Imaging systems, X-ray imaging, Visualization, Heart, X-ray detectors, Angiography

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Proceedings Article | 9 March 2011 Paper

Human pulmonary acinar airspace segmentation from three-dimensional synchrotron radiation micro CT images of secondary pulmonary lobule

Y. Kawata, T. Hosokawa, N. Niki, K. Umetani, Y. Nakano, H. Ohmatsu, N. Moriyama, H. Itoh

Proceedings Volume 7965, 79651P (2011) https://doi.org/10.1117/12.877938

KEYWORDS: Image segmentation, Lung, 3D image processing, Synchrotron radiation, Tissues, Computed tomography, X-ray computed tomography, Natural surfaces, Cancer, Spatial resolution

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Proceedings Article | 9 March 2010 Paper

Microstructural analysis of secondary pulmonary lobule imaged by synchrotron radiation micro CT using offset scan mode

Y. Kawata, K. Kageyama, N. Niki, K. Umetani, K. Yada, H. Ohamatsu, N. Moriyama, H. Itoh

Proceedings Volume 7626, 762610 (2010) https://doi.org/10.1117/12.845583

KEYWORDS: Image segmentation, Lung, Arteries, Veins, 3D displays, Synchrotron radiation, 3D image processing, Computed tomography, Image resolution, Signal attenuation

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Proceedings Article | 11 March 2009 Paper

Measurement of spatial and density resolutions in x-ray nanocomputed tomography

Y. Kawata, K. Kageyama, Y. Nakaya, N. Niki, K. Umetani, K. Yada, H. Ohmatsu, K. Eguchi, M. Kaneko, N. Moriyama

Proceedings Volume 7258, 725809 (2009) https://doi.org/10.1117/12.811323

KEYWORDS: Modulation transfer functions, Point spread functions, Spatial resolution, Computed tomography, Synchrotron radiation, Cancer, Fourier transforms, Imaging systems, X-ray sources, Nanowires

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Proceedings Article | 29 February 2008 Paper

In vivo microscopic x-ray imaging in rat and mouse using synchrotron radiation

Keiji Umetani, Takashi Sakurai, Takeshi Kondoh

Proceedings Volume 6816, 68160U (2008) https://doi.org/10.1117/12.765828

KEYWORDS: X-rays, Arteries, X-ray imaging, Synchrotron radiation, Cameras, Imaging systems, Sensors, X-ray detectors, Spatial resolution, Solid state electronics

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Proceedings Article | 21 February 2007 Paper

Microscopic x-ray imaging system for biomedical applications using synchrotron radiation

Keiji Umetani, Makito Kobatake, Akira Yamamoto, Takenori Yamashita, Shigeki Imai

Proceedings Volume 6501, 650112 (2007) https://doi.org/10.1117/12.702426

KEYWORDS: X-rays, Tumors, X-ray imaging, Sensors, Blood vessels, Imaging systems, Synchrotron radiation, Cameras, Arteries, Iodine

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Proceedings Article | 30 April 2004 Paper

Three-dimensional visualization of morphology and ventilation procedure (air flow and diffusion) of a subdivision of the acinus using synchrotron radiation microtomography of the human lung specimens

Kenji Shimizu, Hirohiko Ikura, Junpei Ikezoe, Tomofumi Nagareda, Naoto Yagi, Keiji Umetani, Yutaka Imai

Proceedings Volume 5369, (2004) https://doi.org/10.1117/12.536034

KEYWORDS: Lung, Visualization, Diffusion, Synchrotron radiation, Image segmentation, 3D microstructuring, X-rays, Synchrotron radiation microtomography, Emphysema, Volume rendering

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Proceedings Article | 25 April 2000 Paper

Observation and analysis of microcirculation using high-spatial-resolution image detectors and synchrotron radiation

Keiji Umetani, Naoto Yagi, Yoshio Suzuki, Yasuo Ogasawara, Fumihiko Kajiya, Takeshi Matsumoto, Hiroyuki Tachibana, Masami Goto, Takenori Yamashita, Shigeki Imai, Yasumasa Kajihara

Proceedings Volume 3977, (2000) https://doi.org/10.1117/12.384528

KEYWORDS: Sensors, X-rays, X-ray imaging, Cameras, Synchrotron radiation, Tumors, X-ray detectors, Blood vessels, CCD cameras, Imaging systems

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A microangiography system using monochromatized synchrotron radiation has been investigated as a diagnostic tool for circulatory disorders and early stage malignant tumors. The monochromatized X-rays with energies just above the contrast agent K-absorption edge energy can produce the highest contrast image of the contrast agent in small blood vessels. At SPring-8, digital microradiography with 6 - 24 micrometer pixel sizes has been carried out using two types of detectors designed for X-ray indirect and direct detection. The indirect-sensing detectors are fluorescent-screen optical-lens coupling systems using a high-sensitivity pickup-tube camera and a CCD camera. An X-ray image on the fluorescent screen is focused on the photoconductive layer of the pickup tube and the photosensitive area of the CCD by a small F number lens. The direct-sensing detector consists of an X-ray direct- sensing pickup tube with a beryllium faceplate for X-ray incidence to the photoconductive layer. Absorbed X-rays in the photoconductive layer are directly converted to photoelectrons and then signal charges are readout by electron beam scanning. The direct-sensing detector was expected to have higher spatial resolution in comparison with the indict-sensing detectors. Performance of the X-ray image detectors was examined at the bending magnet beamline BL20B2 using monochromatized X-ray at SPring-8. Image signals from the camera are converted into digital format by an analog-to- digital converter and stored in a frame memory with image format of 1024 X 1024 pixels. In preliminary experiments, tumor vessel specimens using barium contrast agent were prepared for taking static images. The growth pattern of tumor-induced vessels was clearly visualized. Heart muscle specimens were prepared for imaging of 3-dimensional microtomography using the fluorescent-screen CCD camera system. The complex structure of small blood vessels with diameters of 30 - 40 micrometer was visualized as a 3- dimensional CT image.

Proceedings Article | 25 April 2000 Paper

Synchrotron radiation microtomography of lung specimens

Kenji Shimizu, Junpei Ikezoe, Hirohiko Ikura, Hidemi Ebara, Tomofumi Nagareda, Naoto Yagi, Keiji Umetani, Kentaro Uesugi, Kyoko Okada, Atsuro Sugita, Minoru Tanaka

Proceedings Volume 3977, (2000) https://doi.org/10.1117/12.384493

KEYWORDS: Lung, Radiography, Synchrotron radiation, Charge-coupled devices, X-rays, Signal detection, Monochromators, Sensors, Computed tomography, Image processing

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Proceedings Article | 6 October 1999 Paper

Refraction-contrast imaging using undulator radiation at SPring-8

Yoshio Suzuki, Naoto Yagi, Keiji Umetani, Yoshiki Kohmura, Katsuhito Yamasaki

Proceedings Volume 3770, (1999) https://doi.org/10.1117/12.368183

KEYWORDS: X-rays, Refraction, X-ray imaging, Spatial resolution, Absorption, Sensors, Geometrical optics, Light sources, X-ray detectors, Image sensors

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Proceedings Article | 6 October 1999 Paper

Two-dimensional aortographic coronary angiography with synchrotron radiation at aortic regurgitation state

Tohoru Takeda, Keiji Umetani, Toshiki Doi, Yuji Itai, Quanwen Yu, Takao Akatsuka

Proceedings Volume 3770, (1999) https://doi.org/10.1117/12.368182

KEYWORDS: Arteries, X-rays, X-ray imaging, Angiography, Synchrotron radiation, Imaging systems, X-ray detectors, Diagnostics, Silicon, Iodine

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Proceedings Article | 22 September 1999 Paper

Development of microtomography imaging system for rock and mineral samples

Kentaro Uesugi, Akira Tsuchiyama, Tsukasa Nakano, Yoshio Suzuki, Naoto Yagi, Keiji Umetani, Yoshiki Kohmura

Proceedings Volume 3772, (1999) https://doi.org/10.1117/12.363724

KEYWORDS: X-rays, Tomography, Spatial resolution, Minerals, Sensors, X-ray computed tomography, Crystals, Imaging systems, Signal attenuation, 3D image processing

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Proceedings Article | 28 May 1999 Paper

X-ray refraction-contrast imaging using synchrotron radiation at SPring-8

Keiji Umetani, Naoto Yagi, Yoshio Suzuki, Yoshiki Kohmura, Katsuhito Yamasaki

Proceedings Volume 3659, (1999) https://doi.org/10.1117/12.349534

KEYWORDS: X-rays, X-ray imaging, Synchrotron radiation, Sensors, X-ray detectors, Refraction, Lung, Lung cancer, Image sensors, Angiography

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Proceedings Article | 2 May 1997 Paper

Ellipsoid scan: chest cone-beam CT with a large ellipsoidal view field using a 16-in. x-ray image intensifier

Rika Baba, Ken Ueda, Hironori Ueki, Keiji Umetani

Proceedings Volume 3032, (1997) https://doi.org/10.1117/12.274002

KEYWORDS: X-ray computed tomography, X-rays, X-ray imaging, Sensors, Cameras, Chest, Image resolution, Imaging systems, Televisions, Lung

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Proceedings Article | 1 May 1994 Paper

High-sensitivity digital radiography using an avalanche-type image pickup tube camera

Keiji Umetani, Tomoharu Kajiyama, Ken Ueda, Yukio Takasaki, Hisatake Yokouchi

Proceedings Volume 2163, (1994) https://doi.org/10.1117/12.174273

KEYWORDS: Cameras, Signal to noise ratio, X-rays, X-ray imaging, Radiography, Image quality, Aluminum, Digital imaging, Medical imaging, Spatial resolution

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Showing 5 of 29 publications

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