Simplified phantom for electron density calibration by dual-energy CT

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K09011
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Medical Physics and Radiological Technology
• Research Institution: Niigata University
• Principal Investigator: Saito Masatoshi 新潟大学, 医歯学系, 教授 (40241583)
• Research Collaborator: HAYAKAWA Takahide
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: electron density / dual-energy CT

Outline of Final Research Achievements

The purpose of this research is to develop a simple phantom for electron density calibration necessary to calculating dose distribution in a radiation treatment plan of cancer using dual-energy CT. The basic performance of this simple phantom built in the study was checked through electron density calibration of a known standard substance. It was found that an excellent linear relationship is formed between the energy-subtracted CT values and the electron densities. The obtained electron density values could be determined within 1-2% errors.

Free Research Field

医学物理学・放射線技術学

Academic Significance and Societal Importance of the Research Achievements

これまでの電子密度ファントムは、人体組織に極めて近いロッド素材の選択・合成とその正確な電子密度の見積りが要求され、必要な組織等価ロッドの本数も多くなるため、結果的に高価なものになっていた。Dual-energy CTを活用することにより、従来の高価な材料を用いずとも、より安価で入手が容易な材料で構成されるファントムを使用しても、放射線治療計画に不可欠な高精度の電子密度校正が十分可能となることが期待できる。