Evaluation of CT scan protocols appropriate for patient size based on the evaluation of radiation doses and image quality

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K07709
• 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: Nagoya University
• Principal Investigator: Fujii Keisuke 名古屋大学, 医学系研究科(保健), 講師 (40469937)
• Co-Investigator(Kenkyū-buntansha): 野村 恵一 国立研究開発法人国立がん研究センター, 東病院, 放射線技師 (50767738)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 医療被ばく / CT / 線量評価 / 画質評価

Outline of Final Research Achievements

The aim of this study is to evaluate CT scan protocol appropriate for patient size based on the evaluation of radiation doses and image quality. We performed Monte Carlo simulation using the simulation models created from CT images of each patient, and evaluated how much organ doses in adult and pediatric chest-abdomen-pelvis CT examinations differ depending on patient size. In addition, we developed image qualuty evaluation phantoms representing adult and child abdominal shapes, and evaluated image noise reflecting visual impression (apparent noise) on the phantom CT images obtained with different radiation doses and non-linear reconstruction algorithms. Furthermore, we examined radiation doses appropriate for each patient size based on the apparent noise evaluation.

Free Research Field

放射線防護学

Academic Significance and Societal Importance of the Research Achievements

X線CT検査は、他の放射線診断検査に比べ高い被ばく線量を伴い、受診者がCT検査によって受ける放射線リスク(発がんリスク等)を可能な限り低減するために、CT検査時の撮影線量の最適化が課題となっている。本研究で作成した、小児および成人腹部径を模擬した画質評価ファントム、および、このファントムを様々な条件で撮影、再構成して得られたCT画像の画質評価結果は、各被検者体型に適した撮影条件を検討する際に有益であると考えられる。