摘要
合成孔径超声成像,因其可以利用少量超声传感器得到高分辨率及高对比度超声图像而成为现代数字医学超声成像常采用的方法.传统合成孔径方法的复杂性限制了实时成像系统的成像速度.对比传统的定制目标区域及非均匀采样的成像方法,利用高速数字电路设计出了应用于多阵元合成孔径超声成像系统的均匀采样波束合成算法,并利用现场可编程门阵列(FPGA)技术进行硬件实现.使用Altera公司的CycloneⅡ系列EP2C8Q208C8芯片,利用同步动态随机存储器(SDRAM)存储回波数据,数据经延时叠加及加权处理后通过USB送入PC端成像.系统测试结果表明:采用流水线结构及并行数字电路,FPGA可以在高速时钟下完成合成孔径超声成像的波束合成算法,结果精确高效,可以运用于实时成像系统.
Synthetic aperture ultrasound imaging is often used in modern digital medical ultrasound imaging for its high-resolution and high-contrast images with a small number of transducers. But the traditional synthetic aperture method is very complex and limited in real-time imaging. Contrast to the non-uniformly sampling data imaging from customized target area, a beam-forming algorithm of the uniformly sampling system applied to a multi-element synthetic aperture ultrasound imaging system using a high speed digital eircuit was designed and implemented in a hardware circuit based on field programmable gate array （FPGA）. The system was composed of one FPGA EP2C8Q208C8 of Cyclone II series from Ahera corporation and one synchronous dynamic random access memory （SDRAM） chip to store echo data, which were delay superimDosed and oparallel nature of FPGA, the beam-forming algorithm was implemented. The test results demonstrate that the system is accurate and effective and can be applied to real-time ultrasound imaging.
基金
国家自然科学基金(60871087
61172037)
国家重大科学仪器设备开发专项(2012YQ200224
2013YQ20060708)资助
关键词
超声成像
波束形成
延时叠加
FPGA
ultrasound imaging
beam-former
delay superimpose
field programmable gate array （FPGA）
