Early relaxation time assessment for characterization of breast tissue and diagnosis of breast tumors
Early relaxation time assessment for characterization of breast tissue and diagnosis of breast tumors
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DOI：
10.1016/j.jmbbm.2018.07.037
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发表时间：
2018-11-01
影响因子：
3.9
通讯作者：
Mojra, A.
中科院分区：
文献类型：
--
作者：
Baghban, M.;Mojra, A.
近年来，人们做出了许多努力，通过根据相关组织的规范调整治疗来提高治疗方法的效率。非穿透性压痕测试是一种表征组织机械行为的非侵入性方法。在这项研究中，通过松弛时间来研究乳腺组织粘弹性行为的表征。为此，我们对 18 名女性的乳腺组织进行了体内研究，通过控制变形率进行压缩压痕试验。测试分两个后续阶段进行；在第一阶段，组织被指定的应变率压缩，称为加载过程。在第二阶段，即卸载过程，以相同的速率去除负载，并研究组织在返回到卸载位置时的行为。具有两个麦克斯韦臂的广义麦克斯韦模型用于模拟组织粘弹性响应。获得卸载过程中的力与压缩数据，并通过粘弹性模型的传递函数进行插值，并获得两个松弛时间。数值较小的称为早期弛豫时间，结果表明它随组织机械结构的变化而变化，这使得它适合作为特性。这种特性在每个人的乳腺组织中的变化并不显着，同时在不同病例之间以及在存在肿瘤的情况下观察到重大变化。结果表明，乳腺组织中肿瘤的存在可使早期弛豫时间比健康组织的相应值增加最多6倍。根据早期弛豫时间的病例依赖性特征，应针对每个病例单独执行基于特征性早期弛豫时间升高的肿瘤检测程序。
During recent years, many efforts have been made to increase the efficiency of the treatment methods by adjusting the treatment with the specification of related tissue. Non-penetrating indentation test is a non-invasive method for characterizing mechanical behavior of the tissue. In this study, characterization of the viscoelastic behavior of breast tissue is investigated by means of the relaxation time. To this end, an in-vivo study is conducted on the breast tissue of 18 female cases by performing a compressive indentation test with controlled rate of deformation. The test is performed in two subsequent stages; at first stage, the tissue is compressed by a specified strain rate and is called the loading procedure. At the second stage, which is the unloading procedure, the load is removed by the same rate and the tissue behavior is studied while it returns to the unloaded position. A generalized Maxwell model with two Maxwell-arms is used to model the tissues viscoelastic response. Force vs. compression data during the unloading course, are obtained and interpolated by the transfer function of the viscoelastic model and two relaxation times are obtained. The smaller in value is referred to as the early relaxation time and results show that it has variation with the tissues mechanical structure, which makes it suitable as a characteristic property. This property has insignificant variation over each individual's breast tissue, meanwhile major variation is observed between different cases and also in the presence of a tumor. Results show that existence of tumor in the breast tissue can increase the early relaxation time up to 6 times more than the corresponding value at the healthy tissue. Based on case-dependent character of the early relaxation time, tumor detection procedure based on the elevation of characteristic early relaxation time should be performed individually for each case.