Analysis of coronary artery calcification using dual energy CT and transparency technique

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K19850
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Radiation science
• Research Institution: Keio University
• Principal Investigator: Matsumoto Shunsuke 慶應義塾大学, 医学部(信濃町), 助教 (20573281)
• Research Collaborator: JINZAKI Masahiro ; IMANISHI Nobuaki ; YAMADA Minoru ; YAMADA Yoshitake ; MIYAWAKI Atsushi
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 冠動脈 / 石灰化 / ハイドロキシアパタイト / CT / ２重エネルギー

Outline of Final Research Achievements

Although dual energy CT enables material decomposition and component analysis, in practice there are many cases where it is difficult to separate iodine contrast agent and calcified plaque. Analysis of of real calcified plaque may lead to better material decomposition images in dual energy CT. The calcified plaques of the coronary artery excised from cadaver donars were analyzed by dual energy CT and X-ray diffractometer. The component of calcified plaque had a significantly lower effective atomic number than hydroxyapatite in the dual energy CT, on the other hand, the result of the X-ray diffractometer was that hydroxyapatite was the main component of calcified plaque. In dual energy CT, it was possible that the average effective atomic number might be reduced due to the effects of other calcium phosphate crystals, proteins and fibrosis contained in the plaque.

Free Research Field

画層診断学

Academic Significance and Societal Importance of the Research Achievements

石灰化プラークをハイドロキシアパタイトと仮定して2重エネルギーCTで撮影してもヨード造影剤と石灰化プラークの分離が困難であることが多い。冠動脈の石灰化プラークの主成分はハイドロキシアパタイトであることがわかったが、その他のリン酸カルシウム結晶、たんぱく質や線維化が含まれており、実効原子番号がハイドロキシアパタイトよりかなり低い値となっていることが2重エネルギーCTでうまく石灰化プラークとヨード造影剤を分離できない原因と考えられる。
今後は複数の物質やある程度の幅をもった値の実効原子番号の物質を分離できるような技術革新が望まれる。