Konofagou E E
Department of Biomedical Engineering, Columbia University, 1210 Amsterdam Avenue, 351 Engineering Terrace, Mail Code 8, New York, NY 10027, USA.
Ultrasonics. 2004 Apr;42(1-9):331-6. doi: 10.1016/j.ultras.2003.11.010.
In the past decade, an important field that has emerged as complementary to ultrasonic imaging is that of elasticity imaging. The term encompasses a variety of techniques that can depict a mechanical response or property of tissues. In ultrasound, its premise is built on two important facts: (a) that significant differences between mechanical properties of several tissue components exist and (b) that the information contained in the coherent scattering, or speckle, is sufficient to depict these differences following an external or internal mechanical stimulus. Parameters, such as velocity of vibration, displacement, strain, strain rate, velocity of wave propagation and elastic modulus, have all been demonstrated feasible in their estimation and have resulted in the accurate depiction of stiffer tissue masses, such as tumors, high-intensity focused ultrasound (HIFU) lesions and atherosclerotic plaques. More recently, through the development of ultrafast algorithms tailored to suitable hardware as well as the familiarity of the physician with the sensitivity of the methods used, one elasticity imaging technique in particular, elastography, has been shown applicable in a typical clinical ultrasound setting. In other words, elastograms can currently be obtained at quasi real-time (approximately at a frame rate of 8 frames/s) and with the use of a hand-held transducer (as opposed to the previously used frame-suspended setup) during and simultaneously with an ultrasound exam of, e.g., the breast or the prostate. The higher frame rate available with certain clinical ultrasound scanners has also resulted in the successful application of elasticity imaging techniques on the myocardium and monitoring its deformation over several cardiac cycles for the detection of ischemic regions. As a result, elasticity imaging with its ever increasing number of applications and demonstrated applicability in a typical, clinical ultrasound setting promises to make an important contribution to the ultrasound practice as we know it.
在过去十年中，作为超声成像补充的一个重要领域是弹性成像。该术语涵盖了多种能够描绘组织机械响应或特性的技术。在超声领域，其前提基于两个重要事实：（a）几种组织成分的机械特性存在显著差异；（b）相干散射或散斑中包含的信息足以在外部或内部机械刺激后描绘这些差异。诸如振动速度、位移、应变、应变率、波传播速度和弹性模量等参数，在其估计中均已证明可行，并已准确描绘出较硬的组织块，如肿瘤、高强度聚焦超声（HIFU）病灶和动脉粥样硬化斑块。最近，通过针对合适硬件开发超快算法以及医生对所用方法灵敏度的熟悉，特别是一种弹性成像技术——弹性成像，已被证明适用于典型的临床超声检查。换句话说，目前在超声检查（例如乳腺或前列腺）期间并同时使用手持换能器（与先前使用的帧悬浮设置相反），可以以准实时（大约8帧/秒的帧率）获得弹性图。某些临床超声扫描仪可用的更高帧率也导致弹性成像技术成功应用于心肌，并在多个心动周期内监测其变形以检测缺血区域。因此，弹性成像在典型临床超声检查中的应用越来越多且已得到证实，有望为我们所知的超声实践做出重要贡献。
