Dose-Response in BBB Opening via MRgFUS using subharmonic measurements of cavitation dose (SCD) and Contrast Enhanced (CE) MRI-derived metrics.

Motivation: The relationship between blood-brain barrier opening (BBBO) observed in contrast-enhanced MRI and the real-time cavitation dose measured during low-intensity focused ultrasound treatment (LIFU) is not fully understood. Goal(s): The aim was to identify the relationship between MRI-derived metrics and real-time cavitation dose measured by hydrophones. Approach: Cavitation dose and semi-quantitative MRI derived metrics from 28 putamen openings in patients with Parkinson's disease (PDD) were analyzed. Results: The cavitation dose correlated strongly with semi-quantitative metrics, indicating a reliable relationship between cavitation parameters and BBBO. Additionally, a positive but weaker correlation was observed between cavitation dose and hypointensities (damage) in SWI images. Impact: This study highlights a promising relationship between MRI-derived metrics and real-time cavitation dose measured by hydrophones during LIFU. This insight could enable dynamic adjustments during treatment, improving BBBO monitoring and potentially enhancing treatment efficacy and safety.