About us

Takayuki Obata, MD, PhD

I have been engaged in research for the past 20 years as the leader of the AMR group. During that time, I was fortunate enough to receive generous support and cooperation from many people, which allowed the group to maintain a high level of activity. I would like to express my sincere gratitude to all of you. Although I stepped down from the position of group leader in April 2026, I will continue to perform research in the MR field. I hope to continue the many relationships and collaborations I have formed over the years.

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.

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.

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, 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.

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, MD, PhD

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.

Kaomi Higuchi

Akino Ishii

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

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, PhD

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

Sayako Taguchi

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

Naho Yoshioka

Kei Majima, PhD