Department of Reproductive Biology, Imperial College at Queen Charlotte's and Chelsea Hospital, London, UK.
Ultrasound Obstet Gynecol. 2011 Feb;37(2):150-7. doi: 10.1002/uog.8815.
To assess the spatial and temporal performance of fetal myocardial speckle tracking, using high-frame-rate (HFR) storing and Lagrangian strain analysis.
Dummy electrocardiographic signaling permitted DICOM HFR in 124 normal fetuses and paired low-frame-rate (LFR) video storing at 25 Hz in 93 of them. Vector velocity imaging (VVI) tracking co-ordinates were used to compare time and spatial domain measures. We compared tracking success, Lagrangian strain, peak diastolic velocity and positive strain rate values in HFR vs. LFR video storing. Further comparisons within an HFR subset included Lagrangian vs. natural strain, VVI vs. M-mode annular displacement, and VVI vs. pulsed-wave tissue Doppler imaging (TDI) peak velocities.
HFR (average 79.4 Hz) tracking was more successful than LFR (86 vs. 76%, P = 0.024). Lagrangian and natural HFR strain correlated highly (left ventricle (LV): r = 0.883, P < 0.001; right ventricle (RV): r = 0.792, P < 0.001) but natural strain gave 20% lower values, suggesting reduced reliability of measurement. Lagrangian HFR strain was similar in LV and RV and decreased with gestation (P = 0.015 and P < 0.001, respectively). LV Lagrangian LFR strain was significantly lower than the values for the RV (P < 0.001) and those using paired LV-HFR recordings (P = 0.007). Annular displacement methods correlated highly (LV = 1.046, r = 0.90, P < 0.001; RV = 1.170, r = 0.88, P < 0.001). Early diastolic waves were visible in 95% of TDI, but in only 26% of HFR and 0% of LFR recordings, and HFR-VVI velocities were significantly lower than those for TDI (P < 0.001).
Doppler estimation of velocities remains superior to VVI but image gating and use of original co-ordinates should improve offline VVI assessment of fetal myocardial function.
使用高帧率（HFR）存储和拉格朗日应变分析来评估胎儿心肌斑点追踪的时空性能。
在 124 例正常胎儿中，通过虚拟心电图信号允许 DICOM HFR，在其中的 93 例中配对 25 Hz 的低帧率（LFR）视频存储。使用向量速度成像（VVI）跟踪坐标来比较时域和空域测量值。我们比较了 HFR 与 LFR 视频存储中的跟踪成功率、拉格朗日应变、舒张末期速度和正向应变率值。在 HFR 子集中的进一步比较包括拉格朗日应变与自然应变、VVI 与 M 模式环形位移以及 VVI 与脉冲波组织多普勒成像（TDI）峰值速度的比较。
HFR（平均 79.4 Hz）跟踪比 LFR（86%对 76%，P = 0.024）更成功。HFR 的拉格朗日应变与自然应变高度相关（左心室（LV）：r = 0.883，P < 0.001；右心室（RV）：r = 0.792，P < 0.001），但自然应变值低 20%，表明测量可靠性降低。HFR 中的 LV 和 RV 的拉格朗日应变相似，且随胎龄降低（P = 0.015 和 P < 0.001，分别）。LV 拉格朗日 LFR 应变明显低于 RV（P < 0.001）和配对 LV-HFR 记录的应变值（P = 0.007）。环形位移方法高度相关（LV = 1.046，r = 0.90，P < 0.001；RV = 1.170，r = 0.88，P < 0.001）。TDI 中可见 95%的早期舒张波，但在 HFR 中仅为 26%，在 LFR 记录中为 0%，HFR-VVI 速度明显低于 TDI（P < 0.001）。
尽管多普勒法对速度的估计仍然优于 VVI，但图像门控和原始坐标的使用应能改善胎儿心肌功能的离线 VVI 评估。
