Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
Phys Med Biol. 2011 Jul 7;56(13):3825-42. doi: 10.1088/0031-9155/56/13/006. Epub 2011 May 31.
It is of importance to image electrical activity and properties of biological tissues. Recently hybrid imaging modality combing ultrasound scanning and source imaging through the acoustoelectric (AE) effect has generated considerable interest. Such modality has the potential to provide high spatial resolution current density imaging by utilizing the pressure-induced AE resistivity change confined at the ultrasound focus. In this study, we investigate a novel three-dimensional (3D) ultrasound current source density imaging approach using unipolar ultrasound pulses. Utilizing specially designed unipolar ultrasound pulses and by combining AE signals associated to the local resistivity changes at the focusing point, we are able to reconstruct the 3D current density distribution with the boundary voltage measurements obtained while performing a 3D ultrasound scan. We have shown in computer simulation that using the present method it is feasible to image with high spatial resolution an arbitrary 3D current density distribution in an inhomogeneous conductive media.
对生物组织的电活动和特性进行成像很重要。最近，结合超声扫描和通过电声（AE）效应进行源成像的混合成像方式引起了相当大的兴趣。这种方式有可能通过利用限制在超声焦点处的压力诱导的 AE 电阻率变化来提供高空间分辨率的电流密度成像。在这项研究中，我们使用单极超声脉冲研究了一种新颖的三维（3D）超声电流源密度成像方法。利用专门设计的单极超声脉冲，并结合与聚焦点处局部电阻率变化相关的 AE 信号，我们能够在进行 3D 超声扫描时通过边界电压测量重建 3D 电流密度分布。我们在计算机模拟中表明，使用本方法可以在非均匀导电介质中以高空间分辨率对任意 3D 电流密度分布进行成像。
