The 54th Annual Meeting of Japanese Society of Pediatric Cardiology and Cardiac Surgery

Presentation information



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Thu. Jul 5, 2018 5:30 PM - 6:40 PM 第2会場 (301)

座長:石川 友一(福岡市立こども病院 循環器センター 循環器科)
座長:脇 研自(倉敷中央病院 小児科)

[I-OR01-07] ヒト剖検心における位相差CTイメージングによる刺激伝導組織密度の評価

篠原 玄1, 森田 紀代造1, 宇野 吉雅1, 金子 幸裕2, 吉竹 修一2, 松久 弘典3, 岩城 隆馬3, 高橋 昌4, 橋本 和弘1 (1.東京慈恵会医科大学 心臓外科, 2.国立成育医療研究センター 心臓血管外科, 3.兵庫県立こども病院 心臓血管外科, 4.新潟大学 心臓外科)

Keywords:Cardiac conduction system, phase-contrast imaging, 刺激伝導系

【Objective】 Phase-contrast computed tomography (PCCT) enables imaging the atrioventricular (AV) conduction axis. In the present study, densities of AV conduction axis and its adjacent heart tissue were evaluated, with the aim to establish the benchmark to more objective analysis of the cardiac conduction system (CCS).
【Methods】 Formalin-fixed human whole heart specimens obtained by autopsy from four neonates were used. A PCCT imaging system based on an X-ray Talbot grating interferometer at beamline BL20B2 in a SPring-8 synchrotron radiation facility was used (voxel size, 12.5 μm; target density range, 0.9 - 1.2 g/cm3; density resolution, 1 mg/cm3). Linear contiguous areas containing conduction tissue in three major subdivisions of AV conduction axis, compact node; penetrating bundle; branching bundle, and these surrounding tissues: working myocardium in interatrial septum, inter ventricular septum, central fibrous body, and other surrounding fibrous tissue were sampled with adequately thinness (3 pixels of width). Tissue density per voxel of 12.5 to 25 μm cubic was measured from averaged value of each 3 pixels along the line.
【Results】 The CCS composed of specialized cardiomyocytes is low-density tissue, compared to IVS myocardium with statistical significance in all four specimens (p<0.05). The insulating fibrous tissue around the AV conduction axis is remarkably high-density tissue (p<0.01).
【Conclusion】 Mathematical analysis based on the tissue density would allow to evolve semi-automatic segmentation as an objective identification method.