Data from: Development of an intravascular ultrasound elastography based on a dual-element transducer

The ability to measure the elastic properties of plaques and vessels would be useful in clinical diagnoses, particularly for detecting a vulnerable plaque. This study demonstrates the feasibility of combination of intravascular ultrasound (IVUS) and acoustic radiation force (ARF) elasticity imaging for detecting the distribution of stiffness within atherosclerotic arteries ex vivo. A dual-frequency IVUS transducer with two elements was used to induce the propagation of shear wave (by the 8.5-MHz pushing element) which could be simultaneously monitored by the 31-MHz imaging element. The wave-amplitude image and the wave-velocity image was reconstructed by measuring the peak displacement and wave velocity of shear wave propagation, respectively. System performance was verified using gelatin phantoms. The phantom results demonstrate that the stiffness differences of shear modulus of 1.6 kPa can be distinguished through the wave-amplitude and wave-velocity images. Moreover, the stiffness distributions of the atherosclerotic aorta from a rabbit were obtained, for which the peak displacement and the shear-wave velocity were averaged to be 3.7 μm and 0.38 m/s, respectively, in the lipid-rich plaques, and 1.0 μm and 3.45 m/s in the arterial walls. These results indicate that IVUS elasticity imaging can be used to distinguish the elastic properties of plaques and vessels.对斑块与血管弹性特性的测量能力，在临床诊断中具备重要应用价值，尤其可辅助识别易损斑块。本研究验证了将血管内超声（intravascular ultrasound, IVUS）与声辐射力（acoustic radiation force, ARF）弹性成像相结合的可行性，用于体外检测动脉粥样硬化血管内的硬度分布。本研究采用双单元双频血管内超声换能器：其中8.5MHz的发射单元用于激发剪切波传播，同时由31MHz的成像单元对剪切波进行同步监测。研究人员通过分别测量剪切波传播的峰值位移与波速，重建出波幅图像与波速图像。本研究使用明胶体模对系统性能进行了验证。体模实验结果表明，通过波幅图像与波速图像，可以区分1.6kPa的剪切模量刚度差异。此外，本研究还获取了家兔动脉粥样硬化主动脉的硬度分布：脂质丰富斑块区域的峰值位移与剪切波波速平均值分别为3.7μm与0.38m/s，而动脉管壁区域的对应值分别为1.0μm与3.45m/s。上述结果证实，血管内超声弹性成像可有效区分斑块与血管的弹性特性。