Wijesinghe Philip, Johansen Niloufer J, Curatolo Andrea, Sampson David D, Ganss Ruth, Kennedy Brendan F
BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands and Centre for Medical Research, The University of Western Australia, Perth, Western Australia, Australia; Optical+Biomedical Engineering Laboratory, School of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth, Western Australia, Australia.
Centre for Medical Research, The University of Western Australia, Perth, Western Australia, Australia; Research Department, St John of God Subiaco Hospital, Subiaco, Western Australia, Australia.
Biophys J. 2017 Dec 5;113(11):2540-2551. doi: 10.1016/j.bpj.2017.09.022.
Cellular-scale imaging of the mechanical properties of tissue has helped to reveal the origins of disease; however, cellular-scale resolution is not readily achievable in intact tissue volumes. Here, we demonstrate volumetric imaging of Young's modulus using ultrahigh-resolution optical coherence elastography, and apply it to characterizing the stiffness of mouse aortas. We achieve isotropic resolution of better than 15 μm over a 1-mm lateral field of view through the entire depth of an intact aortic wall. We employ a method of quasi-static compression elastography that measures volumetric axial strain and uses a compliant, transparent layer to measure surface axial stress. This combination is used to estimate Young's modulus throughout the volume. We demonstrate differentiation by stiffness of individual elastic lamellae and vascular smooth muscle. We observe stiffening of the aorta in regulator of G protein signaling 5-deficient mice, a model that is linked to vascular remodeling and fibrosis. We observe increased stiffness with proximity to the heart, as well as regions with micro-structural and micro-mechanical signatures characteristic of fibrous and lipid-rich tissue. High-resolution imaging of Young's modulus with optical coherence elastography may become an important tool in vascular biology and in other fields concerned with understanding the role of mechanics within the complex three-dimensional architecture of tissue.
组织力学特性的细胞尺度成像有助于揭示疾病的起源；然而，在完整的组织体积中不容易实现细胞尺度的分辨率。在这里，我们展示了使用超高分辨率光学相干弹性成像对杨氏模量进行体积成像，并将其应用于表征小鼠主动脉的硬度。我们在完整主动脉壁的整个深度上，在1毫米的横向视野内实现了优于15微米的各向同性分辨率。我们采用一种准静态压缩弹性成像方法，该方法测量体积轴向应变，并使用一个柔顺的透明层来测量表面轴向应力。这种组合用于估计整个体积内的杨氏模量。我们展示了通过单个弹性层和血管平滑肌的硬度进行区分。我们在G蛋白信号调节因子5缺陷小鼠（一种与血管重塑和纤维化相关的模型）中观察到主动脉变硬。我们观察到靠近心脏处硬度增加，以及具有纤维和富含脂质组织特征的微观结构和微观力学特征的区域。利用光学相干弹性成像对杨氏模量进行高分辨率成像可能会成为血管生物学以及其他关注理解力学在组织复杂三维结构中作用的领域的重要工具。
