King D L, Harrison M R, King D L, Gopal A S, Martin R P, DeMaria A N
Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, New York 10032.
J Am Coll Cardiol. 1992 Nov 1;20(5):1238-45. doi: 10.1016/0735-1097(92)90383-x.
The objective of this study was to determine whether guided three-dimensional echocardiography could improve the reproducibility of left atrial and left ventricular anteroposterior measurements over that of standard unguided two-dimensional echocardiography.
Although these measurements are standard indexes for evaluating chamber size, their use is limited by significant interobserver variability largely due to variable image plane positioning. To improve measurement accuracy and reproducibility, we have developed a three-dimensional echocardiograph that displays the line of intersection of the real-time image with a previously saved orthogonal reference image. This display shows the relation of the real-time image to anatomic landmarks in its third, nonvisualized dimension and may be used to guide image positioning.
Three pairs of operators independently performed unguided two-dimensional and guided three-dimensional examinations on three groups of 10 patients each. The left atrium was measured in a plane through the inferior surface of the aortic cusps and the left ventricle in a plane perpendicular to its long axis 1 cm below the mitral leaflet tips. Interobserver variability of these measurements on unguided parasternal long-axis images and on guided short-axis images was assessed.
The standard unguided two-dimensional examination was associated with an interobserver variability of 14.6% and 9.1% for atrial and ventricular measurements, respectively. Guided three-dimensional echocardiography significantly reduced interobserver variability to 5.0% and 3.1%, respectively, for the same measurements (p < 0.005 by McNemar's test).
Significant interobserver variability occurs with standard unguided two-dimensional echocardiographic measurement of left atrial and left ventricular dimensions. Guided three-dimensional echocardiography achieves a nearly threefold improvement of reproducibility of these measurements and provides the basis for improved serial evaluation and comparison of atrial and ventricular size by different operators.
本研究的目的是确定三维超声心动图引导是否能比标准的非引导二维超声心动图提高左心房和左心室前后径测量的可重复性。
尽管这些测量是评估腔室大小的标准指标，但由于很大程度上因图像平面定位可变导致观察者间存在显著差异，其应用受到限制。为提高测量准确性和可重复性，我们开发了一种三维超声心动图仪，它能显示实时图像与先前保存的正交参考图像的交线。这种显示展示了实时图像在其第三个不可见维度上与解剖标志的关系，并可用于引导图像定位。
三对操作者分别对三组患者（每组10例）独立进行非引导二维和引导三维检查。在通过主动脉瓣尖下表面的平面测量左心房，在二尖瓣叶尖下方1 cm处垂直于左心室长轴的平面测量左心室。评估在非引导胸骨旁长轴图像和引导短轴图像上这些测量的观察者间差异。
标准的非引导二维检查中，心房和心室测量的观察者间差异分别为14.6%和9.1%。对于相同测量，引导三维超声心动图显著将观察者间差异分别降低至5.0%和3.1%（McNemar检验，p < 0.005）。
标准的非引导二维超声心动图测量左心房和左心室尺寸时存在显著的观察者间差异。引导三维超声心动图使这些测量的可重复性提高了近三倍，并为不同操作者改进心房和心室大小的系列评估及比较提供了基础。
