Department of Medicine, University of Chicago Medical Center, Chicago, Illinois.
Department of Medicine, University of Chicago Medical Center, Chicago, Illinois.
J Am Soc Echocardiogr. 2017 Dec;30(12):1193-1202. doi: 10.1016/j.echo.2017.08.003. Epub 2017 Oct 17.
Three-dimensional (3D) echocardiography directly assesses right ventricular (RV) volumes without geometric assumptions, despite the complex shape of the right ventricle, and accordingly is more accurate and reproducible than the two-dimensional methodology, which is able to measure only surrogate parameters of RV function. Volumetric analysis has been hampered by frequent inability to clearly visualize RV endocardium, especially the RV free wall, in 3D echocardiographic images. The aim of this study was to test the hypothesis that RV contrast enhancement during 3D echocardiographic imaging would improve the accuracy of RV volume and function analysis.
Thirty patients with a wide range of RV size and function and image quality underwent transthoracic 3D echocardiography with and without contrast enhancement and cardiovascular magnetic resonance imaging on the same day. RV end-diastolic and end-systolic volumes and ejection fraction were measured from contrast-enhanced and nonenhanced 3D echocardiographic images and compared with cardiovascular magnetic resonance reference values using linear regression and Bland-Altman analyses. Blinded repeated measurements were performed to assess measurement variability.
RV contrast enhancement was feasible in all patients. RV volumes obtained both with and without contrast enhancement correlated highly with cardiovascular magnetic resonance (end-diastolic volume, r = 0.90 and r = 0.92; end-systolic volume, r = 0.92 and r = 0.94, respectively), but the correlation for ejection fraction was better with contrast (r = 0.87 vs r = 0.70). Biases were smaller with contrast for all three parameters (end-diastolic volume, -16 ± 23 vs -36 ± 25 mL; end-systolic volume, -10 ± 16 vs -23 ± 18 mL; ejection fraction, -0.7 ± 5.5% vs -2.7 ± 8.1% of the mean measured values), reflecting improved accuracy. Also, measurement reproducibility was improved by contrast enhancement.
Contrast enhancement improves the visualization of RV endocardial borders, resulting in more accurate and reproducible 3D echocardiographic measurements of RV size and function. This approach may be particularly useful in patients with suboptimal image quality.
三维（3D）超声心动图可以直接评估右心室（RV）容积，而无需进行几何假设，尽管右心室的形状复杂，但与仅能测量 RV 功能替代参数的二维方法相比，它更准确且可重复性更高。由于在 3D 超声心动图图像中经常无法清晰地显示 RV 心内膜，尤其是 RV 游离壁，因此容积分析受到了阻碍。本研究旨在验证以下假设：在 3D 超声心动图成像过程中进行 RV 对比增强将提高 RV 容积和功能分析的准确性。
30 名 RV 大小和功能以及图像质量范围广泛的患者在同一天接受了经胸 3D 超声心动图检查，并进行了对比增强和非增强 3D 超声心动图检查，以及心血管磁共振成像检查。使用线性回归和 Bland-Altman 分析将 RV 舒张末期和收缩末期容积和射血分数从对比增强和非增强 3D 超声心动图图像中测量，并与心血管磁共振参考值进行比较。进行了盲法重复测量以评估测量变异性。
所有患者均可行 RV 对比增强。无论是否进行对比增强，RV 容积均与心血管磁共振高度相关（舒张末期容积，r=0.90 和 r=0.92；收缩末期容积，r=0.92 和 r=0.94），但射血分数的相关性更好（r=0.87 与 r=0.70）。对于所有三个参数，与无对比增强相比，有对比增强时的偏差更小（舒张末期容积，-16±23 与-36±25mL；收缩末期容积，-10±16 与-23±18mL；射血分数，-0.7±5.5% 与-2.7±8.1%），反映了准确性的提高。此外，对比增强还改善了测量的可重复性。
对比增强可改善 RV 心内膜边界的可视化，从而更准确且可重复地测量 RV 大小和功能。这种方法在图像质量欠佳的患者中可能特别有用。
