Measurement of angular dependence of ultrasonic scattering from wire phantom mimicking myocardial fiber

The difference between a normal and a hypertrophic heart is whether the direction of regional myocardial fibers are homogeneously aligned along one direction. In order to investigate the angle dependence of ultrasonic scattering in relation to the fiber direction, we measured the ultrasonic echoes from a metal wire phantom, which mimics a bundle of myocardium fibers, as a function of the insonification angle. In this study, we focused on ultrasonic scattering properties in relation to the azimuth and elevation angles of insonification and reception. Experimental results showed that the amplitude of the reflected echo from the metal wire became maximum when the ultrasonic beam was insonified parallel to the fiber direction. In the case of such parallel insonification, echoes from the wire showed directivity like those from an interface. Such directivity was considered to contribute to the dependence of echoes on the azimuth angle.