Division of Cardiology, Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada.
Hypertrophic Cardiomyopathy Center, Division of Cardiology, Tufts Medical Center, Boston, Massachusetts.
J Am Soc Echocardiogr. 2013 Oct;26(10):1153-1162. doi: 10.1016/j.echo.2013.06.008. Epub 2013 Jul 19.
Regional and global function can be measured by echocardiography using speckle-tracking, a technique that has previously been validated against crystal sonomicrometry. However, the application of Velocity Vector Imaging (VVI) to images obtained from cardiac magnetic resonance (CMR) imaging has never been validated against those values derived from VVI applied to two-dimensional echocardiographic images in the same patient group. The aim of this study was to validate for the first time the application of VVI to retrospectively acquired CMR data sets for the assessment of left ventricular strain and rotation, using echocardiographic strain assessment by VVI as the reference technique.
Cine steady-state free precession CMR data sets and two-dimensional echocardiographic images obtained on the same day in 36 adult patients with hypertrophic cardiomyopathy were analyzed retrospectively using VVI to quantify global longitudinal and circumferential strain and rotation parameters.
The absolute differences in longitudinal strain between the two imaging modalities were -1.1 ± 3.3% (endocardial) and -2.2 ± 3.6% (full thickness). The absolute differences in circumferential strain were -4.7 ± 5.3% (endocardial) and -3.4 ± 3.8% (full thickness). CMR consistently resulted in higher strain values than echocardiography. The absolute differences in twist were -0.2 ± 5.6% (endocardial) and 0.1 ± 5.8% (full thickness).
The application of VVI to CMR data sets allows a feasible and reproducible method for strain analysis in HCM, demonstrating excellent agreement with two-dimensional echocardiography-derived values. Given the superior image quality obtained with CMR in a significant proportion of patients, this technique provides a method for strain assessment without the need for dedicated CMR acquisition and analytic techniques.
超声心动图中的斑点追踪技术可用于测量区域性和全球性功能，该技术先前已经过晶核声反射仪测量的验证。然而，Velocity Vector Imaging（VVI）在心脏磁共振成像（CMR）图像中的应用从未经过与同一患者群体的二维超声心动图图像的 VVI 应用得出的结果进行验证。本研究的目的是首次验证 VVI 在回顾性获取 CMR 数据集以评估左心室应变和旋转方面的应用，使用 VVI 进行的超声心动图应变评估作为参考技术。
对 36 例肥厚型心肌病成年患者的心脏电影稳态自由进动 CMR 数据集和二维超声心动图图像进行回顾性分析，使用 VVI 对整体纵向和圆周应变以及旋转参数进行量化。
两种成像方式之间纵向应变的绝对差值为 -1.1 ± 3.3%（心内膜）和 -2.2 ± 3.6%（全层）。圆周应变的绝对差值为 -4.7 ± 5.3%（心内膜）和 -3.4 ± 3.8%（全层）。CMR 总是产生比超声心动图更高的应变值。扭转的绝对差值为 -0.2 ± 5.6%（心内膜）和 0.1 ± 5.8%（全层）。
VVI 应用于 CMR 数据集为 HCM 中的应变分析提供了一种可行且可重复的方法，与二维超声心动图衍生值具有极好的一致性。鉴于在很大一部分患者中 CMR 获得的图像质量优越，该技术提供了一种应变评估方法，而无需专门的 CMR 采集和分析技术。
