Abstract：
Shear wave elastography (SWE) is a promising technique used to assess cardiac function through the evaluation of cardiac stiffness non-invasively. However, in the literature, SWE varies in terms of tissue motion data (displacement, velocity or acceleration); method used to characterize mechanical wave propagation (time domain [TD] vs. frequency domain [FD]); and the metric reported (wave speed [WS], shear or Young\'s modulus). This variety of reported methodologies complicates comparison of reported findings and sheds doubt on which methodology better approximates the true myocardial properties. We therefore conducted a simulation study to investigate the accuracy of various SWE data analysis approaches while varying cardiac geometry and stiffness. Lower WS values were obtained by the TD method compared with the FD method. Acceleration-based WS estimates in the TD were systematically larger than those based on velocity (∼10% difference). These observations were confirmed by TD analysis of 32 in vivo SWE mechanical wave measurements. In vivo data quality is typically too low for accurate FD analysis. Therefore, our study suggests using acceleration-based TD analysis for in vivo SWE to minimize underestimation of the true WS and, thus, to maximize the sensitivity of SWE to detect stiffness changes resulting from pathology.
摘要：
剪切波弹性成像（SWE）是一种有前途的技术，用于通过非侵入性评估心脏硬度来评估心脏功能。然而,在文学中,SWE在组织运动数据(位移，速度或加速度)；用于表征机械波传播的方法(时域[TD]与频域[FD])；以及报告的度量(波速[WS]，剪切模量或杨氏模量)。报道的各种方法使报道的发现的比较变得复杂，并对哪种方法更接近真实的心肌特性表示怀疑。因此，我们进行了一项模拟研究，以研究各种SWE数据分析方法的准确性，同时改变心脏几何形状和刚度。与FD方法相比,通过TD方法获得更低的WS值。TD中基于加速度的WS估计系统地大于基于速度的估计(差异10%)。这些观察结果通过32个体内SWE机械波测量的TD分析得到证实。体内数据质量通常对于准确的FD分析而言太低。因此,我们的研究建议对体内SWE使用基于加速度的TD分析，以最大程度地减少对真实WS的低估，因此，最大限度地提高SWE的灵敏度，以检测由病理引起的硬度变化。
