About Molecular Imaging Center Research Group Facilities & Equipment Molecular Imaging Program Human Resource Development Researchers
Imaging Physics Team / Biophysics Group


Positron emission tomography (PET) is a promising method to promote molecular imaging research as well as cancer diagnosis. However there are still strong demands for higher resolution, higher sensitivity and lower cost. Therefore our research team carries out basic studies on instrumentation, image reconstruction and data corrections to improve image quality and quantity in nuclear medicine. In particular, based on our core technology for depth-of-interaction (DOI) measurement, we are developing a novel DOI detector X'tal Cube and a new equipment concept, OpenPET.

Team Leader
Taiga Yamaya

Major achievements in 2006-2010

Annual reports (in Japanese)

Research Introduction

1. X'tal cube detector

The recent development of small semiconductor photo-detectors such as Geiger-mode avalanche photodiodes, that can replace conventional photomultiplier tubes, is leading researchers to make available new PET detectors. Therefore we are developing a next generation PET detector X 'tal cube in collaboration with researchers at Chiba University, the University of Tokyo and Hamamatsu Photonics K.K. The challenging aspect of this work is implementing effective detection of scintillation photons by optically covering all 6 surfaces of a segmented crystal block with multi-pixel photon counters (MPPCs).

2. OpenPET

An open-type geometry for PET, OpenPET, is our new idea to visualize a physically opened space between two detector rings. Axial spatial resolution, which is degraded with the extended gap due to the parallax error, can be recovered by use of DOI detectors. OpenPET is expected to enable: 1) PET image-guided radiation therapy by letting the beams pass though the gap; 2) real-time multimodal imaging by inserting another imaging device in the gap; and 3) extension of an axial field-of-view (FOV) with a limited number of detectors. For charged particle therapy, in particular, OpenPET will enable on-line visualization of the distribution of primary particles stopped in a patient body.



Taiga Yamaya
Team Leader
Naoko Inadama, Eiji Yoshida
Senior Researcher
Fumihiko Nishikido, Hideaki Tashima, Mohammadi Akram
Fujino Obata
Technical Staff
Hidekatsu Wakizaka
Technical Assistant
Ahmed Abdella Mohammednur, Md Shahadat Hossain Akram, Yuma Iwao, Jiang Jianyong
Postdoctoral Fellow
Munetaka Nitta
Junior Research Associate
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