Systematic Review of Phase Aberration Correction Algorithms for Transcranial Focused Ultrasound

Abstract

Transcranial focused ultrasound (tFUS) is an emerging modality with strong potential for non-invasively treating brain disorders. However, the inhomogeneity and complex structure of the skull induce substantial phase aberrations and pressure attenuation; these can distort and shift the acoustic focus, thus hindering the efficiency of tFUS therapy. To achieve effective treatments, phased array transducers combined with aberration correction algorithms are commonly implemented. The present report aims to provide a comprehensive review of the current methods used for tFUS phase aberration correction. We first searched the PubMed and Web of Science databases for studies on phase aberration correction algorithms, identifying 54 articles for review. Relevant information, including the principles of algorithms and refocusing performances, were then extracted from the selected articles. The phase correction algorithms involved two main steps: acoustic field estimation and transmitted pulse adjustment. Our review identified key benchmarks for evaluating the effectiveness of these algorithms, each of which was used in at least three studies. These benchmarks included pressure and intensity, positioning error, focal region size, peak sidelobe ratio, and computational efficiency. Algorithm performances varied under different benchmarks, thus highlighting the importance of application-specific algorithm selection for achieving optimal tFUS therapy outcomes. The present review provides a thorough overview and comparison of various phase correction algorithms, and may offer valuable guidance to tFUS researchers when selecting appropriate phase correction algorithms for specific applications.