A backend processing system for high-frequency, high-frame rate ultrasound B-mode imaging

This paper presents a recently developed backend processing system for high-frequency high-frame rate ultrasound B-mode imaging, which is responsible for extracting clinically useful information from acquired echo signals and displaying the information on a monitor in real time. The system is capable of producing up to 400 images per second with minimal signal processing error for real-time display. With this capability, the system can be used for cardiac imaging of the mouse where the heart rate is 5-10 beats per second. The backend processing system was implemented by using a single FPGA (Stratix EP1S60F1020C6, Altera Corporation, San Jose, CA) and software programs written by C++. Its performances were evaluated by wire phantom, in vitro pig eye, and in vivo mouse heart imaging tests. Experimental results demonstrate that the implemented system is capable of acquiring up to 400 images per second of which an image size is 256 by 256 pixels and providing the -6dB axial and lateral resolutions of 48 μm and 103 μm, respectively. In addition, it is shown that the image display rate of the system is currently 95 images per second due to the limitation of a monitor's capability although one thousand consecutive images can be stored in a hard disk of a personal computer.