Correction of LIFU Intensity Using MR Acoustic Radiation Force Imaging (ARFI): Improved Correlations with Treatment Outcomes

Motivation: The effectiveness of low-intensity focused ultrasound (LIFU) for neuromodulation may be compromised by inaccuracies in target localization and variable energy deposition caused by skull characteristics. Goal(s): We aimed to improve the estimation of LIFU pressure using MR-acoustic radiation force imaging (ARFI) and test whether the adjusted LIFU intensity correlates with treatment outcomes in a behavioral economic task using sucrose pellets. Approach: Eight female rats underwent LIFU targeting the nucleus accumbens (NAc) bilaterally with three different pressures. MR-ARFI confirmed the targeting and corrected the intensities during LIFU treatments. Results: Improved correlations between behavioral outcomes and ARFI-adjusted LIFU intensity were observed. Impact: Our preliminary findings demonstrate the beneficial effects for using MRI-ARFI not only to verify the FUS target location but also to refine LIFU intensities in neuromodulation procedures.