Transcranial image quality improvement with a multi-step approach

Transcranial ultrasound image quality suffers from the presence of the skull bone in the acoustic path, leading to beam defocusing that reduces spatial resolution and image contrast. Besides the requirement of an adequate transtemporal acoustic window, phase aberration correction and adaptive application of spatially-dependent weights have been proposed to refocus wavefronts and mitigate the effects of sidelobes. In this study, the effectiveness of a combination of techniques: adaptive window selection, aberration correction, and Wiener post-filtering, was tested to enhance transcranial grayscale image quality in vivo. Optimal window selection had a significant positive effect on signal-to-noise ratio; aberration correction provided marginal resolution improvement in a small sector of the image; and Wiener post-filtering further increased image contrast.