基于超快超声多普勒的三维脑损伤成像方法研究

三维超声微血管成像可直观呈现血流信息,对于脑血管疾病诊断和治疗具有重要意义。本文旨在将超快超声成像技术、超快超声功率多普勒技术和机械扫描相结合,实现脑血管三维成像和脑缺血区域评价。通过工程实现,完成了可同步控制微型线性位移平台移动和超声阵列超快发射、高速采集与压缩存储的三维扫描数据采集序列与系统。利用GPU并行运算,高效实现了超声图像波束合成方法,对原始射频超声数据完成重建。进而,基于SVD杂波滤除技术,从重建三维超声数据中提取了脑部的动态小血管信号,并获得了各切面的功率多普勒成像和冠状面彩色多普勒超声小血管成像。最后,采用体素方法对三维脑血管进行重建。大鼠在体实验结果表明,该成像系统可用于三维脑血管网络在体成像,以及脑血管损伤区域定位与量化评价。本工作对脑病检测技术发展与诊断方法研究具有一定的借鉴意义。此外,相关检测系统和成像算法具有一定普适性,对其他富含微血流血管的组织检测也有一定的参考价值。

Ultrafast ultrasound Doppler imaging for three-dimensional cerebral injury evaluation

Three-dimensional ultrasound microvascular imaging is helpful for the diagnosis of cerebrovascular diseases. In this paper, ultrafast ultrasound imaging, ultrafast ultrasound power Doppler and mechanical scanning were combined to perform three-dimensional imaging of cerebrovascular and evaluation of cerebral ischemic status. The ultrafast data acquisition sequence and 3D scanning system with the capability of high-speed acquisition and compression storage, were developed. GPU based algorithm was carried out for efficient beamforming. Furthermore, based on SVD clutter filtering, dynamic signals of small vessel were extracted from 3D ultrasound data, and power Doppler images of each slice and color Doppler imaging of small vessels in coronal plane were obtained. Finally, the 3D image was obtained using a voxel-based reconstruction method. Results of a rat brain showed that such an imaging system can be used for in vivo imaging of three-dimensional cerebral vascular networks, as well as quantitative evaluation of cerebral vascular injury. This work can benefit for the development of new methods for encephalopathy detection and diagnosis. In addition, the method and systems in present study can be helpful for microvascular imaging of other tissues.