Development of low noise current sensitive preamplifier for low dose exposure computed tomography

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K21161
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 31:Nuclear engineering, earth resources engineering, energy engineering, and related fields
• Research Institution: Kyoto University
• Principal Investigator: Kanno Ikuo 京都大学, 工学研究科, 教授 (50234167)
• Project Period (FY): 2020-07-30 – 2022-03-31
• Keywords: X線 / 電流測定 / 低被ばく / コンピュータ断層撮影 / 電流敏感型前置増幅器 / 電荷敏感型前置増幅器

Outline of Final Research Achievements

X-ray computed tomography (CT) is an effective modality to find cancers inside a human body. In the CT measurement at hospitals, X-rays are measured as electric current, without using the energy information of X-rays. For the current measurement, a current sensitive preamplifier is used, which is sensitive to the dark current of a detector and is a noisy electric circuit. With a low noise current sensitive preamplifier, CT measurement will be carried out with lower dose exposure. For the purpose of developing low dose exposure CT, we invented a low noise current sensitive preamplifier made of a charge sensitive preamplifier, and named it VIEC. With comparing to a conventional current sensitive preamplifier IPA-6, we demonstrated that the VIEC could give a CT image with 1/300 dose exposure than that by the IPA-6 with the same signal-to-noise ratio.

Free Research Field

放射線物理学，放射線計測学

Academic Significance and Societal Importance of the Research Achievements

X線コンピュータ断層撮影(CT)が従来の被ばく量の1/300で実施できる．日本の医療診断被ばく量は世界平均の6倍あり，その1/2がCTによってもたらされるが，本研究の成果により，被ばく量が一挙に低減できる．これは日本のみならず，世界的な医療被曝の低減につながる．また健康診断にCTを用いることも可能となり，がんの早期発見が一層，進展する．さらに，X線管出力の低減，X線管の小型化が可能となる．これにより発展途上国においてもCTが実施できるようになる．また医療のみならず，X線，ガンマ線，赤外線などを電流測定する応用において，けた違いに敏感な測定が可能となる．