In Vivo Transcranial Acoustoelectric Brain Imaging of Different Steady-State Visual Stimulation Paradigms

Abstract

Based on the acoustoelectric (AE) effect, transcranial acoustoelectric brain imaging (tABI) is of potential for brain functional imaging with high temporal and spatial resolution. With nonlinear and non-steady-state, brain electrical signal is microvolt level which makes the development of tABI more difficult. This study demonstrates for the first time in vivo tABI of different steady-state visual stimulation paradigms. Method: To obtain different brain activation maps, we designed three steady-state visual stimulation paradigms, including binocular, left eye and right eye stimulations. Then, tABI was implemented with one fixed recording electrode. And, based on decoded signal power spectrum (tABI-power) and correlation coefficient between steady-state visual evoked potential (SSVEP) and decoded signal (tABI-cc) respectively, two imaging methods were investigated. To quantitatively evaluate tABI spatial resolution performance, ECoG was implemented at the same time. Finally, we explored the performance of tABI transient imaging. Results: Decoded AE signal of activation region is consistent with SSVEP in both time and frequency domains, while that of the nonactivated region is noise. Besides, with transcranial measurement, tABI has a millimeter-level spatial resolution (<3mm). Meanwhile, it can achieve millisecond-level (125ms) transient brain activity imaging. Conclusion: Experiment results validate tABI can realize brain functional imaging under complex paradigms and is expected to develop into a brain functional imaging method with high spatiotemporal resolution.

In Vivo Transcranial Acoustoelectric Brain Imaging of Different Deep Brain Stimulation Currents

“…Besides, we have demonstrated that the pulse repetition frequency (PRF) of FUS is capable of encoding electroencephalography (EEG) signal and decoding AE signal and proved its feasibility through in vivo rat brain AEBI experiments [26][27][28][29][30][31]. Furtherly, based on PRF, living rat steady-state visual evoked potentials activation was mapped and the AE signal processing network of the rat brain was revealed [32][33][34][35]. The above studies made important contributions to optimize AEBI imaging method for further clinical application.…”

“…To evaluate AEBI image performance, the spatiotemporal resolution and imaging signal-to-noise ratio (SNR) were quantified. Spatial lateral (axial) resolution was defined as the width at 3 dB attenuation of AE signal peak which was measured along the x or y direction [24,28,34,45]. The SNR was calculated in decibels according to (7).…”