Depth-resolved mapping of tissue mechanical properties using a novel optical approach.
Depth-resolved mapping of tissue mechanical properties using a novel optical approach.
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DOI：
10.1109/iembs.2011.6091421
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Nadkarni SK
中科院分区：
文献类型：
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作者：
Hajjarian Z;Nadkarni SK
大多数疾病的进展，如动脉粥样硬化、癌症、神经退行性疾病和骨关节炎，都伴随着组织生物力学的剧烈变化。因此，用于组织生物力学三维制图的非接触和非侵入性技术对于诊断目的是无价的。激光散斑微流变学（LSM）是我们实验室开发的一种高分辨率组织力学评价方法。为此，用相干聚焦激光束照射组织样本，并对后散射激光散斑图进行时空处理，提取图像平面上每个像素上强度去相关的衰减时间常数τ的颜色图。时间常数τ被证明与组织力学性能密切相关。在本文中，我们验证了LSM技术的理论基础，并研究了从光散射角度获取深度分辨信息的潜力。引入了贴片分析方法，并探讨了每个贴片τ、若干散射事件和穿透深度之间的相互关系。表征了两个样品动脉区域τ的轴向变化，并表征了机械性能的深度变化。最后，对需要采取的纠正措施进行了讨论。
Progression of most diseases, such as atherosclerosis, cancer, neurodegenerative disease and osteoarthritis is accompanied with drastic changes in biomechanics of tissue. Hence, non-contact and non-invasive technologies for 3-dimensional mapping of tissue biomechanics are invaluable for diagnostic purposes. Laser speckle Microrheology (LSM) is developed in our lab to enable high resolution mechanical evaluation of tissue. To this end, the tissue sample is illuminated by a coherent and focused laser beam and the back-scattered laser speckle pattern is spatio-temporally processed to extract a color-map of τ, which is the decay time constant of intensity decorrelation at each pixel in the image plane. Time constant, τ, is proven to be closely correlated with tissue mechanical properties. In this paper we validate the theoretical basis for LSM technology and investigate the potential for acquiring depth-resolved information from a light-scattering point of view. The patch analysis approach is introduced and the inter-relation between τ, a number of scaterring events, and penetration depth is explored for each patch. Axial variation of τ is characterized for two sample arterial regions and in-depth changes of mechanical properties are characterized. Finally, the required corrective measures are discussed.