Elastic Full-Waveform Inversion for Transcranial Ultrasound Computed Tomography using Optimal Transport

This work explores the use of an optimal transport misfit function combined with the coupled acoustic-elastic wave equation for transcranial ultrasound computed tomography. This approach utilizes full-waveform inversion together with a starting model derived from reverse time migration. Source encoding is additionally used to reduce the overall computational cost of the full-waveform inversion reconstruction process. The cycle skipping effects which are accentuated due to the inexact knowledge of the skull geometry can be effectively mitigated using this optimal transport approach. This strategy is validated using an in silico inversion of a numerical brain phantom.