Almeida Thiago W J, Sampaio Diego R Thomaz, Bruno Alexandre Colello, Pavan Theo Z, Carneiro Antonio A O
IEEE Trans Ultrason Ferroelectr Freq Control. 2015 Dec;62(12):2138-45. doi: 10.1109/TUFFC.2015.007353.
Several methods have been developed over the last several years to analyze the mechanical properties of soft tissue. Elastography, for example, was proposed to evaluate soft tissue stiffness in an attempt to reduce the need for invasive procedures, such as breast biopsies; however, its qualitative nature and the fact that it is operator-dependent have proven to be limitations of the technique. Quantitative shearwave- based techniques have been proposed to obtain information about tissue stiffness independent of the operator. This paper describes shear wave dispersion magnetomotive ultrasound (SDMMUS), a new shear-wave-based method in which a viscoelastic medium labeled with iron oxide nanoparticles is displaced by an external tone burst magnetic field. As in magnetomotive ultrasound (MMUS), SDMMUS uses ultrasound to detect internal mechanical vibrations induced by the interaction between a magnetic field and magnetic nanoparticles. These vibrations generated shear waves that were evaluated to estimate the viscoelastic properties of tissue-mimicking phantoms. These phantoms were manufactured with different concentrations of gelatin and labeled with iron oxide nanoparticles. The elasticity and viscosity obtained with SDMMUS agreed well with the results obtained by traditional ultrasound-based transient elastography.
在过去几年中，已经开发出了几种分析软组织力学性能的方法。例如，弹性成像技术被提出来评估软组织硬度，以减少诸如乳房活检等侵入性检查的需求；然而，其定性性质以及依赖操作者这一事实已被证明是该技术的局限性。基于定量剪切波的技术已被提出，以获取与操作者无关的组织硬度信息。本文介绍了剪切波频散磁动力超声（SDMMUS），这是一种基于剪切波的新方法，其中用氧化铁纳米颗粒标记的粘弹性介质被外部短纯音磁场位移。与磁动力超声（MMUS）一样，SDMMUS使用超声来检测由磁场和磁性纳米颗粒之间的相互作用引起的内部机械振动。这些振动产生剪切波，通过对其进行评估来估计仿组织体模的粘弹性特性。这些体模用不同浓度的明胶制成，并用氧化铁纳米颗粒标记。SDMMUS获得的弹性和粘度与传统基于超声的瞬态弹性成像获得的结果非常吻合。
