A 3-D Reconstruction Solution to Current Density Imaging Based on Acoustoelectric Effect by Deconvolution: A Simulation Study

Abstract

Hybrid imaging modality combining ultrasound scanning and electrical current density imaging through the acoustoelectric (AE) effect may potentially provide solutions to imaging electrical activities and properties of biological tissues with high spatial resolution. In this study, a 3-D reconstruction solution to ultrasound current source density imaging (UCSDI) by means of Wiener deconvolution is proposed and evaluated through computer simulations. As compared to previous 2-D UCSDI problem, in a 3-D volume conductor with broadly distributed current density field, the AE signal becomes a 3-D convolution between the electric field and the acoustic field, and effective 3-D reconstruction algorithm has not been developed so far. In the proposed method, a 3-D ultrasound scanning is performed while the corresponding AE signals are collected from multiple electrode pairs attached on the surface of the imaging object. From the collected AE signals, the acoustic field and electric field were first decoupled by Wiener deconvolution. Then, the current density distribution was reconstructed by inverse projection. Our simulations using artificial current fields in homogeneous phantoms suggest that the proposed method is feasible and robust against noise. It is also shown that using the proposed method, it is feasible to reconstruct 3-D current density distribution in an inhomogeneous conductive medium.

A Reconstruction Algorithm of Magnetoacoustic Tomography With Magnetic Induction for an Acoustically Inhomogeneous Tissue

“…It is of importance to image electrical properties of biological tissues and various electrical impedance imaging approaches have been pursued [1–26, 34–40]. MAT-MI is a non-invasive impedance imaging approach with high spatial resolution and does not suffer from the “shielding effect”.…”

High resolution transcranial acoustoelectric imaging of current densities from a directional deep brain stimulator

“…Whereas standard computational models of DBS are difficult to validate in vivo, tAEI may provide in vivo and patient-specific feedback for improving models of current spread and volume of neuronal activation produced by DBS. As described by equation ( 6), V AE directly relates to the underlying J matrix and conductivity distribution, such that multichannel tAEI should be able solve an overdetermined inverse problem for estimating J, as demonstrated previously using numerical simulations and bench-top experiments for simple dipole patterns [25,[58][59][60]. The union of existing computational models of DBS with tAEI for feedback could further improve the accuracy for generating patient-specific maps of neuronal tracts activated during stimulation.…”

Biological current source imaging method based on acoustoelectric effect: A systematic review

“…There are two possible approaches to solve this problem, and the first solution is to improve the bipolar pulsed ultrasonic current imaging method. The Werner deconvolution-based ultrasound current imaging scheme helps to reconstruct high-quality current distributions (Renhuan et al, 2013 ). The second approach is to use unipolar ultrasound pulses.…”

“…Despite the importance of current source imaging for brain and heart treatment, current imaging methods are difficult to have both non-invasive and high spatiotemporal resolution. In recent years, hybrid current source imaging techniques, represented by AE effect-based current source imaging, have been widely pursued (Witte et al, 2007 ; Olafsson et al, 2008b , 2009 ; Wang et al, 2011 ; Li et al, 2012 ; Qin et al, 2012b , 2015 ; Renhuan et al, 2013 ; Wang and Witte, 2014 ). These techniques not only allow imaging of currents injected from outside and have the promise of imaging real currents in tissue (see Table 1 for details).…”