ガンマ線医用イメージング: 陽電子断層撮影法（PET)機器開発研究の最新動向

摘要

Positron emission tomography (PET) plays important roles in cancer diagnosis and molecular imaging research; but potential points remain for which big improvements could be made, including resolution, sensitivity and costs. Therefore, research on next generation PET technologies remains a hot topic worldwide. In this paper, we introduce some research trends by describing PET physics research in the National Institute of Radiological Sciences (NIRS). A depth-of-interaction (DOI) detector, for which various methods have been studied, will be a key device to get any significant improvement in sensitivity while maintaining high spatial resolution. DOI measurement also has a potential to expand PET application fields because it allows for more flexible detector arrangement. As an example, we are developing the world's first, open-type PET geometry "OpenPET", which is expected to lead to PET imaging during treatment. The DOI detector itself continues to evolve with the help of recently developed semiconductor photodetectors, often referred to as silicon photomultipliers (SiPMs).%本稿では，放医研を中心とした最先端のPET装置の研究開発について概説した.DOI検出器は，PETの課題とされてきた装置感度と空間分解能の両立を実現するキーデバイスである.OpenPETは，開放化という新しい特徴によって，PETのフィールドを大きく広げるポテンシャルを持つ.