Cyclic variation of integrated backscatter: Dependence of time delay on the echocardiographic view used and the myocardial segment analyzed

To determine the influence of myocardial anisotropy in ultrasonic tissue ch aracterization, we measured the time delay land magnitude) of the cyclic va riation of myocardial integrated backscatter from specific segments visuali zed in the 4 standard transthoracic echocardiographic views. The cyclic var iation data in 10 myocardial regions were obtained from analyses of 2-dimen sional integrated backscatter images from 23 healthy subjects. Resultant va lues (mean +/- SD) for the time delay were as follows: parasternal long-axi s view: 1.08 +/- 0.17 (septum) and 1.00 +/- 0.14 (posterior wall); paraster nal short-axis view: 1.03 +/- 0.16 (anterior septum), 1.03 +/- 0.14 (poster ior wall), 2.22 +/- 0.71 (lateral wall), and 1.65 +/- 0.66 (posterior septu m); apical 4-chamber view: 1.08 +/- 0.51 (septum) and 2.20 +/- 0.79 (latera l wall); and apical 2-chamber view: 1.68 +/- 0.62 (inferior wall) and 2.04 +/- 0.72 (anterior wall). Hence, results of this study indicate that myocar dial ultrasonic characterization that uses the cyclic variation is influenc ed by the echocardiographic view and the specific segment of the left ventr icle.