Time Domain Wavefield Correlation for Distributed Aberration Correction through High Contrast Aberrators with Application to Transcranial Doppler

The distorting effects of the skull and the inability to account for the resulting aberration by conventional beamforming (DAS) and near-field aberration correction methods limit the widespread application of transcranial Doppler. However, distributed aberration correction methods such as the shot-gather migration method (wavefield correlation) implemented in the frequency domain have shown potential in imaging through aberration. As such, in this study, we aim to implement and investigate a time domain wavefield correlator (td-wfc) in the context of Doppler imaging, specifically through a high-contrast aberrator mimicking the skull. We collected low-frequency plane-wave transmit data through two in-silico skull models and compared B-mode and Power Doppler images for pixel-based delay-and-sum with td-wfc. We also studied the sensitivity of the td-wfc to the accuracy of the sound speed map used while beamforming. We found an improvement in the contrast, spatial sensitivity, and visibility of the B-mode images as well as an improvement in the normalized power Doppler signal when beamforming with td-wfc as opposed to DAS.