基于互信息与二次方变换的超声宽景成像

Wide-field-of-view ultrasound imaging based on mutual-information and quadratic transformation

超声宽景成像技术能获取超过正常超声图像显示范围的图像信息。由于超声图像的噪声和图像采集时组织的复杂运动,使用互信息和二次方变换实现宽景成像。对高斯预处理后的图像使用基于互信息的图像配准技术得到运动向量。利用基于角度的校正提高向量精度,通过二次方变换估计图像间的非刚体运动。最后,使用基于非线性方程组的多边形填充融合方法获取宽景图像。实验表明,获得的高质量宽景图信噪比和对比度有明显提高。

Wide-field-of-view （WFOV） imaging method obtains an ultrasound image over an area much larger than normal ul- trasound images. Because of the noise in ultrasound images and complicated tissue motions during images acquisition, utilized mutual-information and quadratic transformation to make the WFOV. Firstly, applied the mutual information based motion esti- mation method to the preprocessed Gaussian images to generate a filed of motion vectors. Secondly, improved these vectors by the angle based motion correction, and then used the quadratic transformation to estimate the nonrigid motion between images. Finally, applied nonlinear equations based polygon filling compounding method to gain the WFOV image. From experiments, the proposed method can generate a high quality WFOV image with improved signal-to-noise ratio （SNR） and contrast-to-noise ratio （CNR）.