摘要
根据傅里叶衍射投影定理,不同频率的超声波得到的投影数据的傅里叶变换对应着复平面上不同半径的圆弧。文中对多频率衍射层析成像原理进行深入探讨,提出了多频率超声CT模型,并对多频率超声CT进行实验研究。重建步骤如下:首先,根据标准的体模算出重建数据点的值;然后运用网格插值法将非笛卡分布的重建数据点插值到笛卡网格内;最后用二维的傅里叶逆变换完成图像的重建。多频率超声衍射CT的成像速度要快于单频率CT的成像速度。
According to the Fourier diffraction projection theorem,the Fourier transformation of projection data from multi-band frequency ultrasonic is distributed to different radius arcs on the complex plane.In this paper,the theory of multi-band frequency diffractive computer tomography and the quality of reconstructive images are profoundly studied,and then the multi-band ultrasonic CT model is proposed and experimentally simulated.The reconstruction is as follows： firstly,the reconstruction data is calculated by Shepp and Loganl,then the non-Cartesian distributed reconstruction data is interpolated to Cartesian grid with gridding method,and finally image reconstruction is fulfilled by 2-dimensional IFFT.Results of simulation demonstrate that its imaging speed is faster than that of single frequency ultrasonic CT.
出处
《计算机技术与发展》
2010年第5期227-229,233,共4页
Computer Technology and Development
基金
安徽省优秀人才基金重点项目(2010SQRL184)
安徽省自然科学基金项目(KJ2010A325
090412261X
kj2009a54)
