多倾角发射分组互相关降噪的超快超声脑功能成像方法研究  

Multi-Angle Tilting Emission Cross-Correlation-Based Noise Suppression for Ultrafast Ultrasound Functional Brain Imaging

作　　者：闫少渊 许凯亮 他得安[1,2] YAN Shaoyuan;XU Kailiang;TA De an(Center for Biomedical Engineering,School of Information Science and Technology,Fudan University,Shanghai 200433,China;State Key Laboratory of Integrated Chips and Systems,Fudan University,Shanghai 201203,China)

机构地区：[1]复旦大学信息科学与工程学院生物医学工程中心,上海200438 [2]复旦大学集成芯片与系统全国重点实验室,上海201203

出　　处：《复旦学报（自然科学版）》2023年第4期409-418,共10页Journal of Fudan University：Natural Science

基　　金：国家自然科学基金(11974081,12274093);上海市启明星项目(20QC1400200)。

摘　　要：小血流信号的检出是长期困扰超声多普勒成像的重要问题,提升该成像技术的检测灵敏度,开发鲁棒的降噪和伪影抑制方法具有重要的研究价值。近年来,基于多角度平面波相干复合发展而来的超快超声多普勒血流成像突破了传统聚焦超声成像的帧率瓶颈,可实现高灵敏度的微血流成像。而且平面波成像模式的发展也对超声降噪算法提出了新的需求。利用平面波发射条件下不同角度回波的血流信号的强相干性,有望实现降噪和伪影抑制。本研究探讨了角度分组互相关方法及其降噪在功能超声成像中的应用:首先将多角度平面波回波信号分为两个子组,信号经杂波滤除后对两子组数据进行时域互相关运算,从而获得降噪后的血流功率多普勒图像(PD)。大鼠脑血流成像和功能成像实验结果表明:本文提出的角度分组互相关降噪方法可提升血流图像信噪比约17~22 dB,有效抑制了图像中的非相干伪影,显著提升了超快超声脑功能成像的灵敏度。Small blood flow signal detection has long plagued ultrasound Doppler imaging,and thus it is of great research value to improve the imaging sensitivity and develop robust noise reduction and artifacts suppression methods.Recently,ultrafast ultrasound Doppler flow imaging,based on multi-angle planewave coherent compounding,has broken the framerate limitation of traditional focused ultrasound imaging and can achieve high-sensitivity small blood flow imaging.Planewave imaging has also enabled novel methods for ultrasound noise reduction.Taking advantage of the strong coherence of blood flow signals from different tilting planewave emissions,a multi-angle tilting emission cross-correlation based noise suppression method has been proposed.The method divides planewave signals into two subgroups based on the sign of tilting angles,and cross-correlation operation is performed on the two subgroups after clutter filtering to obtain noise-reduced blood flow power Doppler(PD)images.Experimental results of cerebral blood flow and functional imaging in rats demonstrate that this method can improve the signal-to-noise ratio of blood flow images by approximately 17—22 dB,effectively suppress the incoherent artifacts,and significantly enhance the sensitivity of ultrafast ultrasound functional brain imaging.

关 键 词：超快超声成像 超声功能成像 互相关 噪声抑制 伪影抑制 

分 类 号：R445.1[医药卫生—影像医学与核医学]