超快超声编码矢量多普勒流速与血流阻抗成像方法  

Ultrafast ultrasound coded vector Doppler imaging of blood flow velocity and resistivity

作　　者：闫少渊 丁逸鸣 马国奡 付亚鹏 许凯亮 他得安[1,2] YAN Shaoyuan;DING Yiming;MA Guoao;FU Yapeng;XU Kailiang;TA Dean(Department of Biomedical Engineering,School of Information Science and Technology,Fudan University,Shanghai 200438,China;State Key Laboratory of Integrated Chips and Systems,Fudan University,Shanghai 201203,China;Poda Medical Technology Co.,Ltd.,Shanghai 200438,China)

机构地区：[1]复旦大学信息科学与工程学院,生物医学工程系,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 [3]上海波达医疗科技有限责任公司,上海200438

出　　处：《物理学报》2025年第1期194-206,共13页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12274093);上海市国际科技合作项目(批准号:23490713500)资助的课题.

摘　　要：血流速度的动态精确测量对血管疾病诊疗至关重要.传统超声彩色多普勒技术只能获取血流速度在声波传播方向的分量,无法获取准确的血流速度大小和方向.近期发展的超快矢量多普勒技术可用于小血流速度矢量测量,然而其测量精度对噪声较为敏感.本文提出了一种基于哈达玛矩阵的超快超声脉冲编码矢量多普勒流速测量方法.螺旋血流仿真实验和大鼠脑血流在体实验表明,与现有方法相比,所提出方法显著地提升了低信噪比情况下的血流速度测量准确度.此外,本文实现了脑血流在单个心动周期内的速度矢量动态测量,并实现了脑血流网络阻抗特征分析,具有较高的成像信噪比和高时空分辨率.本文提出的超快脉冲编码矢量多普勒成像方法,可应用于复杂血流网络可视化和血流动力学参数动态评估,对发展基于超快超声的血流矢量化成像方法具有重要借鉴意义.Dynamic and precise measurement of cerebral blood flow velocity plays a critical role in neuroscience and the diagnosis of cerebrovascular diseases.Traditional color Doppler ultrasound can only measure the velocity component along the ultrasound beam,thus limiting its ability to accurately capture the full blood flow vector in complex environments.To break through these limitations,we propose an ultrafast pulse-coded vector Doppler(PC-UVD)imaging method,by using Hadamard matrix pulse encoding to enhance velocity estimation accuracy in low signal-to-noise ratio(SNR)conditions.Our study includes spiral flow simulations and in vivo rat brain experiments,which demonstrate significantly improved measurement precision compared with traditional ultrafast vector Doppler(UVD).This novel approach can measure dynamic cerebral blood flow velocity within a single cardiac cycle,presenting insights into cerebrovascular resistivity characteristics.The proposed PC-UVD method encodes plane waves with Hadamard matrices and can increase SNR without sacrificing temporal or spatial resolution.Velocity vectors are then estimated using a weighted least squares(WLS)approach,where iterative residual-based weight optimization enhances robustness to noise and reduces contributions of outliers.The effectiveness of this technique is validated through simulations using a spiral blood flow phantom,indicating a substantial improvement in velocity estimation accuracy,especially in deep imaging regions with significant signal attenuation.In vivo experiments on rat brains further corroborate that the proposed method has higher accuracy than existing UVD approaches,especially for small vessels.Notably,our method can accurately distinguish between arterial flow and venous flow by analyzing pulsatility and resistivity within the cerebral vascular network.This work demonstrates the potential of PC-UVD in complex vascular imaging,providing high SNR,high temporal and spatial resolution,and accurate vectorized flow measurements.Our results highlight its a

关 键 词：矢量多普勒成像 血流速度 血管阻抗 超快超声 脉冲编码 

分 类 号：R445.1[医药卫生—影像医学与核医学] TP391.41[医药卫生—诊断学]