Synchronous Mapping of Neural Current Source and Sulcus With Acoustoelectric Brain Imaging

Acoustoelectric brain imaging (AEBI) is an emerging functional neuroimaging method that directly maps current density distributions. It is proved that AEBI is closely related to the resistivity distribution. With nonuniform resistivity of brain, it is potential for AEBI to synchronously map of neural current density and brain structural distributions. This article first investigates the feasibility of AEBI to synchronously map simulated neural current source and sulcus distribution. The AEBI experiments are performed on isolated fresh pig brain tissues with different current sources and sulcus distributions. The AEBI performance is analyzed in terms of both structure and function. The current sources and sulcus both can be accurately located in AEBI images. The sulcus regions recognized in the binarized AEBI images closely match the co-registered pulse-echo (PE) images (
${r} =0.776$
) and tissue photos (
${r} =0.753$
). Besides, it is still able to locate the sulcus distribution and synchronously map current source activating state variation within a quite short source oscillation period of 76.9 ms. Focused on the current source and sulcus region, the acoustoelectric (AE) responses are analyzed in the frequency, time, and space domain to evaluate AEBI functional performance. The SNR of decoded AE signal spectrum at current source reaches 13.8 dB which is much higher than that of sulcus. The decoded AE signals in current source regions are significantly consistent with the source signals (
${r} \gt 0.5$
) in time domain which is not feasible for the decoded AE signals in sulcus region. For spatial response, there are significant differences between AE intensity variation of current source and sulcus regions. Experimental results demonstrate that AEBI enables synchronous mapping of neural current source and sulcus which can reflect the structural and functional features. This study confirms the potential of functional AEBI method combined with sulcus location, which provides a new possibility for AEBI as a synchronous functional-structural brain imaging method.