Performance of magnetic resonance elastography measuring the minimal displacements of the tissue generated by external oscillation and its clinical application.

本研究的目的是利用磁共振弹性成像(MRE)评估组织弹性，并尝试其临床应用。我们制备了两种不同硬度的组织状体模。外加振动产生的体模位移最小，捕获的不同剪切波传播的相衬图像和体模的剪切模数与体模的刚度有很好的相关性。动物实验采用体外猪肝和激光消融后的病理组织学。在MRE上，横波在动物肝脏中传播，消融组织比未消融组织僵硬。人肝硬变与非肝硬变体外肝的剪切模数不同。由于肝硬化性肝纤维化，肝硬化性肝较非肝硬化性肝僵硬。我们还测量了切除的人肝肿瘤的弹性。触诊和外按压显示胆管细胞癌伴大量纤维化时较周围肝僵硬，而肝细胞癌较周围肝柔软。MRE技术估计的肿瘤弹性模数与触诊和测量的弹性值相关。磁共振血管成像有可能无创性地评估人体的弹性特性，并成为一种新的诊断工具。

The purpose of this study was to estimate tissue elasticity using magnetic resonance elastography (MRE) and to try its clinical application. We prepared a tissue-like phantom with two different stiffness. External oscillation generated minimum displacements of the phantom and phase contrast image captured different shear waves propagation and shear modulus of phantom were well correlated with stiffness of phantom. Ex vivo pig liver and pathology generated by laser ablation were used for animal study. Shear wave propagation through animal liver were shown and ablated tissue was stiffer than non-ablated tissue on MRE. Shear modulus of ex vivo human cirrhotic liver was different from non-cirrhotic liver. Cirrhotic liver was stiffer than non-cirrhotic liver because cirrhotic liver had fibrosis. We also measured elasticity of resected human liver tumor. Cholangiocellular carcinoma with massive fibrosis was stiffer than surrounding liver and hepatocellular carcinoma was softer than surrounding liver using palpation and external compression apparatus. Elastic modull of tumors estimated by MRE technique were correlated with palpation and measured elastic value. MRE had a potential to noninvasively estimate human's elastic properties and to be a new diagnostic tool.