Soft tissue elasticity measurement : techniques,instrument and applications

Abstract

在临床上,可以通过用手触诊去感知某 些组织的硬块来作出一些初步的诊断,例如乳腺癌的早期诊断。但是这种手触诊技术只能给出定性的结果,该结果依赖于操作者的经验,所以带有很大的主观性,于 是能让诊断结果更加客观化的弹性成像和测量技术应运而生。弹性成像和弹性测量技术各有不同特点:弹性成像往往给出成像区域里面的弹性对比度而不必给出组织 的本征参数;不同于弹性成像,弹性测量技术能给出组织弹性的本征参数例如杨氏模量等,有利于诊断某些弥漫性的组织疾病,例如肝硬化,并且跟踪组织的弹性随 时间的变化情况,而且结果的比较不会受制于所使用的测量仪器。因此,伴随着各种医学成像技术,例如超声、核磁共振成像(MRI)和光学成像的广泛普及,针 对活体组织的弹性测量学在最近的二三十年里得到了长足的发展,诞生了很多新的测量技术和仪器,并且部分已经开始用于临床测试。可以预见,随着这些测量技术 的发展和进步还将有源源不断的新的测量技术诞生,将会有越来越多的临床领域开始尝试或者大力普及通过弹性测量的方法来补充现有的一些不太完善的诊断方法, 或者用来评估治疗方法的有效性。本文尝试给读者介绍一些传统和近来出现的弹性测量的技术和系统,然后简要介绍它们在诊断特定组织病变和评估治疗方法疗效方 面的应用,最后我们对此领域的未来研究方向和前景作一些展望。对于其中比较成熟的几种方法,我们会在这一期刊的随后几期作详细的介绍。 还原 Clinically it is generally known that palpation can be used to detect the existence of hard lesion in soft tissues for a first-step diagnosis,such as the detection of breast cancer.However,palpation can only give qualitative results,which quite depend on the experience of the operator and suffer from diagnosis subjectivity.To address this problem,more quantitative and objective tools,i.e.elasticity imaging and elasticity measurement techniques have been developed.These two techniques have their own characteristics: elasticity imaging normally gives information related to the contrast of elasticity while no intrinsic properties are provided for the detected tissue;in contrast,elasticity measurement gives an absolute value for the intrinsic elastic properties of the tissue,such as Young’s modulus,which will be helpful for the diagnosis of diffused diseases such as liver fibrosis and their longitudinal follow-up.Furthermore,the obtained results do not or less depend on the instrument used.Consequently,with the broad applications of various medical imaging modalities,such as ultrasound,magnetic resonance imaging(MRI) and optical imaging techniques,the field of elasticity measurement is developing fast in the last two to three decades,generating a large number of new techniques and instrument,among which some clinical trials are ongoing.It is expected that with the further development of the currently existing techniques and the emergence of new methods,the elasticity measurement will be more widely tested and applied to clinical fields.The elasticity measurement can be used to complement the currently imperfect diagnosis of some diseases or to evaluate the effectiveness of the treatment strategies.In this review,we will firstly introduce the traditional and recently developed tissue elasticity measurement techniques and then their applications for the diagnosis of diseases and evaluation of therapy are overviewed.Finally some future research directions and perspective of this field are presented.For some relatively matured techniques,we will introduce them in more details in coming issues of this journal.