2023 Fiscal Year Final Research Report

Synchrotron radiation based phase X-ray tomography for mechanical analysis of structural heart disease

Research Project

PDF

Project/Area Number	21K08843
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Review Section	Basic Section 55030:Cardiovascular surgery-related
Research Institution	Kobe University
Principal Investigator	Tsukube Takuro 神戸大学, 医学研究科, 非常勤講師 (50304100)
Co-Investigator(Kenkyū-buntansha)	星野真人公益財団法人高輝度光科学研究センター, 分光推進室, 主幹研究員 (30508461)
Project Period (FY)	2021-04-01 – 2024-03-31
Keywords	僧帽弁腱索 / 位相差X線CT法 / 膠原繊維 / Tenomoduline / 僧帽弁閉鎖不全症
Outline of Final Research Achievements	The link between the structural property and the rupturing of chordae tendineae in the mitral valve complex is still unclear. Synchrotron radiation-based X-ray phase computed tomography (SR-XPCT) imaging has been employed, we measured the density of 6 ruptured mitral chordae tendineae, obtained during surgical repairs for mitral regurgitation, and 12 healthy chordae tendineae, obtained from autopsies. The specimens were subsequently analyzed pathologically. The mean densities were 1.0288±0.0043 in the rupture group and 1.0848±0.0147 g/cm3 in the control group (p<0.0001). Histological examination revealed a change in the components of the connective tissues in ruptured chordae tendineae, in accordance with the low density measured by SR-XPCT. SR-XPCT made it possible to measure tissue density in mitral chordae tendineae. Low density in mitral chordae tendineae is associated with a greater fragility in ruptured mitral chordae tendineae.
Free Research Field	心臓血管外科
Academic Significance and Societal Importance of the Research Achievements	位相差X 線CT法を利用し僧帽弁閉鎖不全症の異常構造を三次元・非破壊で解析し、僧帽弁腱索の異常構造をＣＴ像として可視化しえた。その主な学術的意義として2022年にアメリカ胸部心臓外科学会の僧帽弁ワークショップで成果を講演、2023年に誌上発表した。位相差X線CT像と病理学的所見と一致した。腱索内の組織密度測定は、高周波心臓超音波検査法などで再現が可能であり、腱索断裂前の腱索異常を早期にとらえられる可能性を示唆している。さらに形成術術中に温存する腱索の異常をとらえられる可能性があり再発予防に寄与しえる。社会的意義として僧帽弁弁下組織異常の早期検出は、多数の患者の治療・予防に直結すると期待される。