About us

Group Leader

Takayuki Obata, MD, PhD

Takayuki Obata
  • Deputy Director of Molecular Imaging and Theranostics
  • Group Leader of Applied MRI Research, National Institute of Radiological Sciences
  • National-boarded diagnostic radiologist
  • Visiting Professor, Chiba University
  • Visiting Professor, Tokyo Metropolitan University
  • Visiting Professor, Yokohama City University

My group investigates novel MRI techniques for measuring human biological processes in the clinic. My early research was centered on non-proton MR imaging, and later branched out into functional and diffusion-weighted MRI. More recently, my major interest is in developing diffusion MR techniques to probe tissue microstructures and measure the permeability of cell membranes.

MRI is an interesting and useful method for both fundamental and clinical scientific studies. The development of MRI for medical, chemical, engineering and pharmacological applications continues to be an active field of research worldwide. I am very happy that I met MRI at an early stage of my research life. Over the years many researchers, all of whom are fascinated by MRI, have been drawn to our group. If you are interested in any aspect of MRI research you will always be welcomed by our group.

Personal history

2011-present
Group Leader of Applied MR Research, NIRS
2006-2011
Team Leader of Biosignal Physiology, Molecular Imaging Center, NIRS
2002-2006
Senior Researcher, Department of Medical Imaging, Research Center for Charged Particle Therapy, NIRS
2000-2002
Physician, Hospital of Research Center for Charged Particle Therapy, NIRS
1999-2000
Visiting Scholar, Department of Radiology, University of California at San Diego
1996-1999
Post-doc Researcher, Research Center for Charged Particle Therapy, NIRS
1992-1996
Graduate student, Department of Physiology, Yokohama City University
1991-1992
Junior Resident, Yokohama City University Hospital
1991
Graduated from Yokohama City University, School of Medicine
1965
born in Tokyo

Key publications

  1. Tachibana Y, Obata T, Yoshida M, Hori M, Kamagata K, Suzuki M, Fukunaga I, Kamiya K, Yokoyama K, Hattori N, Inoue T, Aoki S.

    Analysis of normal-appearing white matter of multiple sclerosis by tensor-based two-compartment model of water diffusion.

    Eur Radiol 2015.
  2. Sutoh C, Matsuzawa D, Hirano Y, Yamada M, Nagaoka S, Chakraborty S, Ishii D, Matsuda S, Tomizawa H, Ito H, Tsuji H, Obata T, Shimizu E.

    Transient contribution of left posterior parietal cortex to cognitive restructuring.

    Scientific Reports 2015;5:9199.
  3. Omatsu M, Obata T, Minowa K, Yokosawa K, Inagaki E, Ishizaka K, Shibayama K, Yamamoto T.

    Magnetic displacement force and torque on dental keepers in the static magnetic field of an MR scanner.

    J Magn Reson Imaging 2014;40(6):1481-1486.
  4. Kuroiwa D, Obata T, Kawaguchi H, Autio J, Hirano M, Aoki I, Kanno I, Kershaw J.

    Signal contributions to heavily diffusion-weighted functional magnetic resonance imaging investigated with multi-SE-EPI acquisitions.

    Neuroimage 2014;98C:258-265.
  5. Kawaguchi H, Obata T, Takano H, Nogami T, Suhara T, Ito H.

    Relation between Dopamine Synthesis Capacity and Cell-Level Structure in Human Striatum: A Multi-Modal Study with Positron Emission Tomography and Diffusion Tensor Imaging.

    PLoS ONE 2014;9(1):e87886.
  6. Obata T, Liu TT, Miller KL, Luh WM, Wong EC, Frank LR, Buxton RB.

    Discrepancies between BOLD and flow dynamics in primary and supplementary motor areas: application of the balloon model to the interpretation of BOLD transients.

    Neuroimage 2004;21(1):144-153.
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Director, Department of Diagnostic Radiology and Radiation Oncology

Riwa Kishimoto

Riwa Kishimoto, MD, PhD

I am a national-boarded diagnostic radiologist. I specialize in body computed tomography (CT), ultrasound (US), and magnetic resonance imaging (MRI). My research focuses on diffusion-weighted imaging (DWI) of body MRI and US/MR elastography. I graduated from medical school in 1988, and received my PhD degree in 1995, both at Hokkaido University. I worked as a research doctor at Tulane Medical Center, USA, from 1996, and then from 1999 worked as a research associate at Hokkaido Univ. Since 2001, I have been working as a chief physician ate the Central Hospital for Charged Particle Therapy at NIRS.

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Head of Diagnostic Radiology

Tokuhiko Omatsu

Tokuhiko Omatsu, MD, PhD

I specialize in clinical diagnostic radiology. I also have special interests in oncology imaging, as well as gynecologic and breast cancer imaging. Now I mainly focus on malignant tumors in respect to the change in images between pre- and post-radiotherapy. Detection of radiotherapy efficacy at the lesion in the early stage and also of adverse affects to normal tissue are important for managing the therapy.

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Senior Researchers

Yasuhiko Tachibana

Yasuhiko Tachibana, MD, PhD

I am a board certified diagnostic radiologist in Japan. Developing analytical methods and tools to connect basic science and clinical diagnostic radiology is what I wish to realize in my research. Now I am mainly focusing on in vivo water diffusion based on MR imaging. Image processing and analysis are my major approaches to these fields; in addition, I am performing computer simulations and developing software to support my studies.

Yoko Ikoma

Yoko Ikoma, PhD

I have been involved in data analysis of positron emission tomography (PET) for about 10 years. Recently, I have been working on image processing for MRI in addition to PET, particularly, quantitative analysis of dynamic contrast-enhanced MRI. I also have an interest in the multi-modal analysis with PET and MRI.

Moyoko Tomiyasu

Moyoko Tomiyasu, PhD

My main research field is magnetic resonance spectroscopy (MRS) in medicine. By collaborating with some clinical sites, I am currently studying in vivo human brain/body metabolites such as N-acetylaspartate, choline, and creatine. I also aim to apply the knowledge and techniques obtained from my studies to clinical application.

Jeff Kershaw

Jeff Kershaw, PhD

My favourite pastime is to play football. If anybody wants to start up a game in Chiba, let me know and I will try to be there. Other than that, most of my life is spent watching either football, road cycling or youtube. To earn the money I need to pay for these activities I occasionally have to make myself do a bit of research. I currently have a stack of about a hundred papers on my desk. They are organised in layers according to the subjects they address. One layer has something to do with diffusion-weighted MRI using oscillating gradients.

Mari Miyata

Mari Miyata, MD

I am a neuroradiologist interested in advanced neuroimaging techniques for neurodegenerative diseases and dementia. I am currently involved in MRI research to diagnose chronic traumatic encephalopathy, known as punch-drunk syndrome, in former professional boxers. In this project, I am concerned about the relationship between MRI, tau-PET images, and various clinical biomarkers.

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Technical Staff

Akino Ishii

Akino Ishii

I work as an office staff. I would like to challenge new things so that I can grow every day without forgetting my sense of gratitude.

Hiroko Kamada

Hiroko Kamada

I am able to contribute to the group by managing their clinical research projects, constructing and managing network systems, and providing various other supports in research operating procedures. I previously worked as a systems engineer. My favorite words in Japanese are "Jinkan banji saioh ga uma" which means that joy and sorrow are today and tomorrow.

Yasuka Sahara

Yasuka Sahara

My research goal is to investigate how “context”, as typified by the placebo effect, may impact the human body. Although it has been reported that internal context (e.g., patient expectation) and external context (e.g., verbal suggestion from a therapist), may positively or negatively affect a patient’s body, the mechanisms behind the effect have not been clarified. It is my desire to understand and utilize this mechanism in daily clinical practice to improve therapeutic efficiency and the quality of life for patients.

Hiromi Sano

Hiromi Sano

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Supporting Staff

Sayaka Hayashi

Sayaka Hayashi

Kaomi Higuchi

Kaomi Higuchi

Sayako Taguchi

Sayako Taguchi

I would like to support Lab's research as an office staff. Playing the piano makes me happy.

Naho Yoshioka

Naho Yoshioka

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Collaborating Researchers

Kei Majima, PhD

Junko Ota, PhD

Yuhei Takado, MD, PhD

Yoichi Takakusagi, PhD

Hiroyuki Takuwa, PhD

Kensuke Umehara, PhD

Noriaki Yahata, PhD

Zhang Hong, PhD

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