Abstract
For the application of the ultrasound inverse scattering imaging method to medical diagnosis, measurement under a limited viewing range is strongly desired. To achieve this, we present an inverse scattering image reconstruction method based on the reflection and transmission data obtained by placing a reflector plate behind an object. The reflection and transmission data are measured while rotating the transmitter/receiver pair around a half-circumference of the object. We can simultaneously obtain two different directional data from one observation of the object through this method, therefore enabling us to reduce the range of the views to half compared with the conventional transmission method. In this paper, the reflection and transmission inverse scattering image reconstruction method using multifrequency illumination is proposed in order to improve the robustness of the method against the restriction of the viewing range. The validity of the method is examined using simulation data assuming an irregularly shaped triangular specimen. As a result, it was established that the precision of the sound speed values and reproducibility of the object shape in the reconstructed image were satisfactory although the aperture viewing range was limited to around 100 deg.