Sapin P M, Schröeder K M, Gopal A S, Smith M D, King D L
Division of Cardiology, University of Kentucky Medical Center, Lexington 40536, USA.
J Am Soc Echocardiogr. 1995 Sep-Oct;8(5 Pt 1):576-84. doi: 10.1016/s0894-7317(05)80370-0.
A new three-dimensional echocardiographic system creates a "line of intersection" display to allow precise and known positioning of echocardiographic images. Our purpose was to determine whether use of the line-of-intersection display will improve positioning of the apical four-chamber and apical two-chamber views and thereby improve the agreement between estimates of left ventricular volume by apical biplane echocardiography and cineventriculography. Unguided and line of intersection-guided apical biplane views were obtained in 31 patients immediately before cardiac catheterization and single-plane cineventriculography. In 15 patients the line-of-intersection display was used to measure the position of the image plane in studies of unguided and guided methods. Linear regression and limits of agreement analysis were used to assess the agreement between cineventriculographic volumes and echocardiographic volumes determined from each set of images. The Wilcoxon test was used to compare guided and unguided image positioning. The line-of-intersection display improved four-chamber and two-chamber view positioning closer to the center of the ventricle and rotation closer to orthogonal positioning. Guided-image positioning was not able to correct displacement of the ultrasound beam anterior to the ventricular apex without deterioration of image quality in most patients. Despite improvements in image plane positioning, the agreement between echocardiographic and cineventriculographic volumes was unchanged. For end-diastole views, the unguided images had an r value = 0.84, standard error of the estimate of +/- 23.0 cc, and limits of agreement of +/- 62.4 cc. Corresponding values for the guided images at end diastole were r = 0.85, standard error of the estimate of +/- 22.9 cc, and limits of agreement of +/- 60.8 cc. At end systole the unguided results were r = 0.91, standard error of the estimate of 16.8 cc, and limits of agreement of +/- 52.2 cc. The line-of-intersection guiding of image plane positioning can improve apical image positioning but does not improve the agreement between apical biplane echocardiographic and cineventriculographic left ventricular volumes. The optimal apical imaging window is frequently occluded by the rib cage, resulting in a decrease in image quality. This reduction of image quality, combined with assumptions of left ventricular geometry, limit the accuracy of estimates of left ventricular volume from apical biplane echocardiography.
一种新型三维超声心动图系统创建了一种“相交线”显示，以实现超声心动图图像的精确且已知的定位。我们的目的是确定使用相交线显示是否会改善心尖四腔心和心尖两腔心切面的定位，从而提高通过心尖双平面超声心动图和电影心室造影术对左心室容积估计值之间的一致性。在31例患者进行心脏导管插入术和单平面电影心室造影术之前，立即获取了非引导和相交线引导的心尖双平面切面图像。在15例患者中，在非引导和引导方法的研究中使用相交线显示来测量图像平面的位置。采用线性回归和一致性界限分析来评估电影心室造影术容积与从每组图像确定的超声心动图容积之间的一致性。采用Wilcoxon检验来比较引导和非引导图像定位。相交线显示改善了四腔心和两腔心切面的定位，使其更靠近心室中心，并且旋转更接近正交定位。在大多数患者中，引导图像定位无法纠正超声束在心尖前方的移位而不降低图像质量。尽管图像平面定位有所改善，但超声心动图和电影心室造影术容积之间的一致性并未改变。对于舒张末期切面，非引导图像的r值 = 0.84，估计标准误差为±23.0 cc，一致性界限为±62.4 cc。舒张末期引导图像的相应值为r = 0.85，估计标准误差为±22.9 cc，一致性界限为±60.8 cc。在收缩末期，非引导结果为r = 0.91，估计标准误差为16.8 cc，一致性界限为±52.2 cc。图像平面定位的相交线引导可改善心尖图像定位，但不能改善心尖双平面超声心动图和电影心室造影术左心室容积之间的一致性。最佳的心尖成像窗口经常被肋骨遮挡，导致图像质量下降。这种图像质量的降低，再加上对左心室几何形状的假设限制了通过心尖双平面超声心动图估计左心室容积的准确性。
