Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK.
Department of Physics, University of Oxford, Oxford OX1 3RH, UK.
Europace. 2014 Nov;16 Suppl 4(Suppl 4):iv86-iv95. doi: 10.1093/europace/euu234.
Cardiac histo-anatomical organization is a major determinant of function. Changes in tissue structure are a relevant factor in normal and disease development, and form targets of therapeutic interventions. The purpose of this study was to test tools aimed to allow quantitative assessment of cell-type distribution from large histology and magnetic resonance imaging- (MRI) based datasets.
Rabbit heart fixation during cardioplegic arrest and MRI were followed by serial sectioning of the whole heart and light-microscopic imaging of trichrome-stained tissue. Segmentation techniques developed specifically for this project were applied to segment myocardial tissue in the MRI and histology datasets. In addition, histology slices were segmented into myocytes, connective tissue, and undefined. A bounding surface, containing the whole heart, was established for both MRI and histology. Volumes contained in the bounding surface (called 'anatomical volume'), as well as that identified as containing any of the above tissue categories (called 'morphological volume'), were calculated. The anatomical volume was 7.8 cm(3) in MRI, and this reduced to 4.9 cm(3) after histological processing, representing an 'anatomical' shrinkage by 37.2%. The morphological volume decreased by 48% between MRI and histology, highlighting the presence of additional tissue-level shrinkage (e.g. an increase in interstitial cleft space). The ratio of pixels classified as containing myocytes to pixels identified as non-myocytes was roughly 6:1 (61.6 vs. 9.8%; the remaining fraction of 28.6% was 'undefined').
Qualitative and quantitative differentiation between myocytes and connective tissue, using state-of-the-art high-resolution serial histology techniques, allows identification of cell-type distribution in whole-heart datasets. Comparison with MRI illustrates a pronounced reduction in anatomical and morphological volumes during histology processing.
心脏组织解剖结构是功能的主要决定因素。组织结构的变化是正常和疾病发展的一个相关因素，并形成治疗干预的靶点。本研究的目的是测试旨在允许从大型组织学和磁共振成像（MRI）数据集定量评估细胞类型分布的工具。
在心脏停搏期间对兔心进行固定，并进行 MRI 检查，然后对整个心脏进行连续切片，并对三染色组织进行光学显微镜成像。专门为此项目开发的分割技术应用于分割 MRI 和组织学数据集中心肌组织。此外，将组织学切片分割为心肌细胞、结缔组织和未定义组织。为 MRI 和组织学建立了包含整个心脏的边界表面。边界表面内包含的体积（称为“解剖体积”）以及被识别为包含上述任何组织类别的体积（称为“形态体积”）被计算出来。MRI 中的解剖体积为 7.8cm3，组织学处理后减少到 4.9cm3，代表 37.2%的“解剖”收缩。MRI 和组织学之间形态体积减少了 48%，突出了组织水平收缩的存在（例如，间质裂隙空间增加）。分类为包含心肌细胞的像素与被识别为非心肌细胞的像素的比例大致为 6:1（61.6%对 9.8%；其余 28.6%为“未定义”）。
使用最先进的高分辨率连续组织学技术对心肌细胞和结缔组织进行定性和定量区分，允许在整个心脏数据集上识别细胞类型分布。与 MRI 的比较表明，在组织学处理过程中解剖学和形态学体积明显减少。
