Duke University, Durham, North Carolina, USA.
Siemens Medical Solutions, Issaquah, Washington, USA.
J Ultrasound Med. 2021 Mar;40(3):569-581. doi: 10.1002/jum.15609. Epub 2021 Jan 7.
To quantify the bias of shear wave speed (SWS) measurements between different commercial ultrasonic shear elasticity systems and a magnetic resonance elastography (MRE) system in elastic and viscoelastic phantoms.
Two elastic phantoms, representing healthy through fibrotic liver, were measured with 5 different ultrasound platforms, and 3 viscoelastic phantoms, representing healthy through fibrotic liver tissue, were measured with 12 different ultrasound platforms. Measurements were performed with different systems at different sites, at 3 focal depths, and with different appraisers. The SWS bias across the systems was quantified as a function of the system, site, focal depth, and appraiser. A single MRE research system was also used to characterize these phantoms using discrete frequencies from 60 to 500 Hz.
The SWS from different systems had mean difference 95% confidence intervals of ±0.145 m/s (±9.6%) across both elastic phantoms and ± 0.340 m/s (±15.3%) across the viscoelastic phantoms. The focal depth and appraiser were less significant sources of SWS variability than the system and site. Magnetic resonance elastography best matched the ultrasonic SWS in the viscoelastic phantoms using a 140 Hz source but had a - 0.27 ± 0.027-m/s (-12.2% ± 1.2%) bias when using the clinically implemented 60-Hz vibration source.
Shear wave speed reconstruction across different manufacturer systems is more consistent in elastic than viscoelastic phantoms, with a mean difference bias of < ±10% in all cases. Magnetic resonance elastographic measurements in the elastic and viscoelastic phantoms best match the ultrasound systems with a 140-Hz excitation but have a significant negative bias operating at 60 Hz. This study establishes a foundation for meaningful comparison of SWS measurements made with different platforms.
量化不同商用超声剪切弹性系统与磁共振弹性成像（MRE）系统在弹性和粘弹性体模中测量剪切波速度（SWS）的偏差。
使用 5 种不同的超声平台对 2 种代表健康至纤维化肝脏的弹性体模进行测量，使用 12 种不同的超声平台对 3 种代表健康至纤维化肝脏组织的粘弹性体模进行测量。在不同部位、不同焦点深度和不同评估者使用不同的系统进行测量。系统间的 SWS 偏差被量化为系统、部位、焦点深度和评估者的函数。还使用单一的 MRE 研究系统使用 60 至 500 Hz 的离散频率对这些体模进行了特征描述。
不同系统的 SWS 在两个弹性体模中具有 95%置信区间的平均差异±0.145 m/s（±9.6%），在粘弹性体模中具有±0.340 m/s（±15.3%）。焦点深度和评估者是 SWS 变异性的来源，其重要性低于系统和部位。MRE 使用 140 Hz 源在粘弹性体模中与超声 SWS 最佳匹配，但使用临床实施的 60 Hz 振动源时，其偏差为-0.27±0.027 m/s（-12.2%±1.2%）。
在弹性体模中，不同制造商系统之间的 SWS 重建更一致，在所有情况下平均差异偏差<±10%。在弹性和粘弹性体模中，MRE 测量与 140 Hz 激励的超声系统最佳匹配，但在 60 Hz 下工作时存在显著的负偏差。本研究为不同平台上进行的 SWS 测量的有意义比较奠定了基础。
