Novel evaluation and calibration method with traceable point-like sources for PET

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K07688
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 52040:Radiological sciences-related
• Research Institution: Kitasato University
• Principal Investigator: Hasegawa Tomoyuki 北里大学, 医療衛生学部, 教授 (10276181)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: PET / トレーサブル点状線源 / 校正 / 性能評価 / 医学物理

Outline of Final Research Achievements

We developed practical phantom tools using novel traceable point-like Ge-68/Ga-68 sources with acrylic positron absorber. These tools are useful for determining calibration constants and for evaluating the quantitative imaging accuracy of various types of PET scanners including Positron Emission Mammography (PEM) and dedicated-breast PET (dbPET) scanners as fundamental responses to point-like inputs in a medium. Without the handling of an unsealed solution of radioisotope, they are convenient and safe, minimizing human error, workload, and radiation exposure for staffs. In addition, the traceability path is simpler because the point-like sources can be calibrated at accredited calibration centers directly by professionals prior to delivery. Therefore, the inherent uncertainty in the calibration should be smaller than that of conventional methods. This study has been performed in collaboration with many collaborators and PET facilities.

Free Research Field

医学物理学

Academic Significance and Societal Importance of the Research Achievements

従来の点状線源はPET装置の校正や定量性評価に適する物理特性を有していなかった。これに対して、本研究で開発しているトレーサブル点状線源はこの目的のために研究代表者らが世界に先駆けて独自に考案したものであり、国家標準とPET装置を直接的に結びつける信頼性と利便性に優れたかつてない独創的な校正ツールとなる。そして、トレーサブル点状線源を用いる校正・定量性評価法は、水ファントムや樹脂ファントムに基づく従来法に比べて、不確かさや利便性において優れた特徴を有している。それゆえ、これまでにない校正・定量性評価法の可能性が拓けるなど、PET装置の物理的品質管理に関わる分野における１つのブレークスルーとなる。