FPGA based ultrasound backend system with image enhancement technique

Ultrasound imaging uses high-frequency sound waves in medical imaging like obstetric diagnosis, stones in kidney etc. As ultrasound images are captured in real-time, they can show movement of the body's internal organs as well as blood flowing through blood vessels. In this paper medical B-mode architecture of the backend system is implemented in Kintex-7 FPGA platform. The backend processing consists of envelope detection which uses fixed filter coefficients for Hilbert transformation, log compression technique to achieve the desired dynamic range for display and image enhancement technique to increase the contrast. In-phase and quadrature phase components are computed using envelope detection block, whose absolute value is compressed to fit the dynamic range of display and interpolated to avoid artifacts while displaying. Further full scale contrast stretch enhancement technique is used to improve the image clarity. The implementation of the backend algorithms along with image enhancement technique on FPGA, show that the resolution of display is improved and also the hardware resource utilization is minimized leading to compact design for portable ultrasound systems.