Ultrasonic synthetic aperture angular scatter imaging

Conventional coherent imaging systems map the energy which is reflected directly back towards the transducer. While extremely useful, these systems fail to utilize information in the energy field which has been scattered at other angles. Angular scatter imaging attempts to form images from the scattered energy field at angles other than the 180° backscattered path. We propose a synthetic aperture based imaging scheme for acquiring angular scatter data in medical ultrasound. We describe this technique in k-space and provide an intuitive explanation of the imaging system´s behavior. This method, which we term Synthetic Aperture Angular Scatter (SAAS) imaging effectively uses single element geometries to acquire data at a range of scattering angles. In this paper, we present experimental results implementing SAAS on a GE Logiq 700MR system. We applied the SAAS method to form angular scatter images of a 5-wire depth of field (DOF) phantom and a tissue mimicking 3-wire phantom (steel, nylon and cotton). We present results from this data and discuss the degree of uniformity necessary in element response for successful SAAS imaging. Results from these experiments show new image information previously unavailable in conventional B-mode images and suggest that angular scatter imaging may have applications in the breast, thyroid and peripheral vasculature.