Equivalent-time-active-cavitation-imaging enables vascular-resolution blood-brain-barrier-opening-therapy planning

Area of Science:

• Neuroscience
• Biomedical Engineering
• Medical Imaging

Background:

• Focused-ultrasound blood-brain-barrier opening (FUS-BBBO) requires precise cavitation mapping for predictable outcomes.
• Current cavitation mapping techniques lack the resolution to fully resolve vascular anatomy or impose limitations on therapeutic pulse duration.
• High-resolution cavitation mapping is crucial for advancing FUS-BBBO therapies.

Purpose of the Study:

• To develop a high-resolution cavitation mapping technique capable of resolving vascular anatomy.
• To enable real-time monitoring and planning of FUS-BBBO procedures.

Main Methods:

• Developed BandPass-sampled-equivalent-time-active-cavitation-imaging (BP-ETACI) using bandpass sampling and dual-frequency contrast imaging at 12.5 MHz.
• Utilized a 1.5 MHz focused transducer for cavitation mapping in the brains of C57BL/6 mice.
• Acquired cavitation maps prior to and during FUS-BBBO with long therapeutic bursts.

Main Results:

• BP-ETACI generated high-resolution cavitation maps that correlated with vascular anatomy observed in ultrasound localization microscopy and histology.
• Cavitation maps from sub-disruptive doses identified the same vasculature as those from full FUS-BBBO procedures.
• The technique demonstrated utility for both monitoring FUS-BBBO and for therapy planning and target verification.

Conclusions:

• BP-ETACI provides high-resolution cavitation maps in the mouse brain, correlating with vascular structures.
• This technique is versatile and translatable to existing FUS-BBBO research.
• BP-ETACI offers a valuable tool for further investigation of cavitation phenomena in FUS-BBBO.