Phase Aberration Correction in Transcranial Ultrasound Imaging using Averaged Sound Velocity Map in Delay-and-Sum Beamformer

Deep brain stimulation (DBS) is used to modify the brain function. Localization of the electrode(s) used in DBS is an important mater since the success of the treatment highly depends on it. Transcranial ultrasound imaging (TUI) can be a proper candidate to monitor the electrode(s), but it is affected by the phase aberration caused by the skull bone. To address this issue, in this paper, we propose a novel beamforming method based on the sound velocity map of the imaging medium. For each combination of the imaging grid and element of the array, an averaged sound speed (ASD) is calculated. Then, the ASD is used inside a delay-and-sum beamforming method. The numerical results show that the proposed method compensates the phase aberration caused by the skull having a thickness of 5 mm with a sound speed twice of the imaging medium (i.e., water). The proposed method can be implemented in a real-time manner, which makes it a great candidate to be used in operation rooms for surgeries.