Dual Energy CT Imaging of Atherosclerotic Plaque using Novel Ultrasmall Superparamagnetic Iron Oxide in Hyperlipidemic Rabbits

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K17614
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 53020:Cardiology-related
• Research Institution: Juntendo University
• Principal Investigator: Okano Yuko 順天堂大学, 医学部, 非常勤助教 (90835620)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: USPIO / CMEADM-U / Dual Energy CT / 動脈硬化 / マクロファージ集積

Outline of Final Research Achievements

Ultrasmall Superparamagnetic Iron Oxide (USPIO) has been reported to be phagocytosed by macrophages of arteriosclerotic lesions. Carboxymethyl-diethylaminoethyl dextran magnetite ultra-small superparamagnetic iron oxide (CMEADM-U), which has a longer blood retention time than USPIO, was administered to Watanabe hereditary atherosclerotic rabbits and New Zealand white rabbits, and dual energy CT (DECT) was performed to prepare virtual monochromatic images and iron-based map for visualization of CMEADM-U in atherosclerotic lesions.
CMEADM-U accumulation consistent with an arteriosclerotic lesion was observed at 35 keV and the iron-based map. Further, there were significant differences in the iron-based map value at the site of accumulation among the grades of expression on berlin blue staining and RAM11 immunostaining. In addition, there was a good correlation at 35kev and iron-based map value.

Free Research Field

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Academic Significance and Societal Importance of the Research Achievements

急性冠症候群の前駆病変である不安定プラークを同定することは重要な課題の一つであるが現在確立した方法はない。動脈硬化病変のマクロファージに貪食されるCarboxymethyl-diethylaminoethyl Dextran Magnetite USPIO (CMEADM-U) を動脈硬化モデルウサギに投与しDual Energy CT (DECT)で撮像することにより、動脈硬化病変におけるCMEADM-Uの集積の画像化および炎症を表すマクロファージ集積の定量評価が可能であることが示された。
臨床応用が可能になれば非侵襲的に、より精度の高い急性冠症候群のリスク層別化が可能になると考えられる。