Professor Seiichi Yamamoto at the Nagoya University Graduate School of Medicine and his coworkers have developed a new high-resolution positron emission tomography (PET) system for small animals that provides the world's finest imaging as of October 2013. Their paper was published online in Physics in Medicine and Biology on October 21, 2013.
PET is an imaging device that captures molecules in vivo, and has attracted widespread attention as a key device in molecular imaging research. A radiological material is administered to an observation object as a landmark, and radiation is emitted when positrons discharged from the radiological material are integrated with electrons in vivo. By processing the radiation using a computer, PET can determine the intravital molecular distribution and concentration of molecules. Current PET systems offer up to 1.5 mm spatial resolution because of technological limitations; however, this resolution is not fine enough to capture molecules in small animals. Therefore, the development of an imaging device with a spatial resolution of less than 1 mm is required.
Detector ring of the ultrahigh-resolution PET system developed by Prof. Yamamoto
In 2012, Prof. Yamamoto developed a flexible optical-fiber-based high-resolution integrated PET/MRI system and led the development of molecular imaging devices globally. Presently, he has succeeded in building an ultrahigh-resolution Si-PM-based PET system for small animals. He first manufactured a new radiation detector in block form that enables higher spatial resolution using a 0.5 mm scintillator (a substance that shines when radiation is encountered), a light guide, which he previously developed, and a new photoconductor, Si-PM array. He then built the PET system by developing a detector ring with eight block detectors. The PET system allows a high resolution of 0.7 mm, which is the world's finest resolution realized as of October 2013. The system is widely expected to be applied to PET/MRI integrated systems and to play an important role in the research of drug development by molecular imaging.
Professor Seiichi Yamamoto
Professor Seiichi Yamamoto aims to create an impact on society by applying his devices to the research of practical machines. He has been researching manufacturing technology at Nagoya University and is engaged in the development of molecular imaging devices that can support medical care in the future. He is believed to be the only researcher who has succeeded in developing both an optical-fiber-based PET/MRI and a Si-PM-based PET/MRI, and promoting the further development of molecular imaging devices.
Outlook for the Future
"I aim to realize a molecular imaging device that has not existed previously. Currently I am developing devices for small animal, but I would like to make clinical equipment in the future. "
Message to Young Students
"I enjoy a sense of fulfillment when I design a new device and it works as I expected. Also I can broaden my views by making oversea friends through my research and learn foreign cultures."