Anwar Shafkat, Negishi Kazuaki, Borowszki Allen, Gladding Patrick, Popović Zoran B, Erenberg Francine, Thomas James D
Division of Pediatric Cardiology, Heart and Vascular Institute. Cleveland Clinic, Cleveland, OH, USA.
Division of Cardiovascular Medicine, Heart and Vascular Institute. Cleveland Clinic, Cleveland, OH, USA.
JRSM Cardiovasc Dis. 2017 Jun 6;6:2048004017712862. doi: 10.1177/2048004017712862. eCollection 2017 Jan-Dec.
Two-dimensional strain analysis is a powerful analysis modality, however, clinical utilization has been limited by variability between different analysis systems and operators. We compared strain in adults and children using vendor-specific and vendor-independent software to evaluate variability.
One hundred and ten subjects (50/110 pediatric, 80/110 normal left ventricular function) had echocardiograms with a General Electric ultrasound scanner between September 2010 and January 2012. Left ventricular longitudinal strain was derived with EchoPAC (General Electric, v10.8.1), a vendor-specific software, and Velocity Vector Imaging (Siemens, v3.5), which is vendor-independent. Three independent readers analyzed all the echocardiograms yielding 330 datasets.
Mean left ventricular global longitudinal Lagrangian strain was -18.1 ± SD 4.4% for EchoPAC and -15.3 ± SD 4.1% for Velocity Vector Imaging. Velocity Vector Imaging yielded lower absolute global longitudinal Lagrangian strain by mean 2.9 (±SD 2.7, p < 0.0001), and lower regional longitudinal strain. These differences persisted in normal subjects versus those with cardiomyopathy. Longitudinal strain differences were slightly higher in the pediatric cohort. There was no significant difference in inter-observer longitudinal strain and a small difference in intra-observer strain between analysis systems. On repeat measurements, a significant change in global longitudinal Lagrangian strain occurred after the difference exceeded 3-5 strain points for EchoPAC and Velocity Vector Imaging, respectively.
Velocity Vector Imaging produces lower left ventricular longitudinal strain values versus EchoPAC for the same echo images. Both systems have similar inter-observer variability, Velocity Vector Imaging slightly higher intra-observer variability. A statistically significant change in global longitudinal Lagrangian strain occurs with changes >3-5 strain points on repeat measurements. Strain values between the systems are not interchangeable.
二维应变分析是一种强大的分析方式，然而，临床应用一直受到不同分析系统和操作人员之间差异的限制。我们使用特定厂商和独立于厂商的软件比较了成人和儿童的应变，以评估差异。
2010年9月至2012年1月期间，110名受试者（50名儿科患者/110名，80名左心室功能正常/110名）使用通用电气超声扫描仪进行了超声心动图检查。左心室纵向应变通过特定厂商的软件EchoPAC（通用电气，v10.8.1）和独立于厂商的速度向量成像（西门子，v3.5）得出。三名独立的阅片者分析了所有超声心动图，产生了330个数据集。
EchoPAC测得的左心室整体纵向拉格朗日应变平均值为-18.1±标准差4.4%，速度向量成像测得的为-15.3±标准差4.1%。速度向量成像得出的绝对整体纵向拉格朗日应变平均值低2.9（±标准差2.7，p<0.0001），区域纵向应变也较低。这些差异在正常受试者和心肌病患者中均持续存在。儿科队列中的纵向应变差异略高。分析系统之间观察者间纵向应变无显著差异，观察者内应变有小差异。重复测量时，EchoPAC和速度向量成像的整体纵向拉格朗日应变在差异分别超过3-5个应变点后发生了显著变化。
对于相同的超声图像，速度向量成像产生的左心室纵向应变值低于EchoPAC。两个系统的观察者间变异性相似，速度向量成像的观察者内变异性略高。重复测量时，整体纵向拉格朗日应变在变化>3-5个应变点时有统计学显著变化。两个系统的应变值不可互换。
