Correlation Between Brain Tissue Damage and Inertial Cavitation Dose Quantified Using Passive Cavitation Imaging

Area of Science:

• Neurology
• Biomedical Engineering
• Ultrasound Technology

Background:

• Focused ultrasound (FUS) therapies utilizing microbubble cavitation show promise for neurologic diseases.
• Monitoring cavitation is crucial for FUS safety, as inertial cavitation can cause tissue damage.

Purpose of the Study:

• To investigate the correlation between inertial cavitation dose and histologic brain tissue damage induced by FUS.
• To assess the utility of passive cavitation imaging (PCI) in quantifying cavitation dose and predicting FUS-induced damage.

Main Methods:

• An ultrasound image-guided FUS system with a single-element transducer and linear imaging array was used.
• Mice underwent FUS treatment with microbubbles at varying peak negative pressures (0.5-6.5 MPa).
• Acoustic emissions were detected, and inertial cavitation maps were generated using offline processing.

Main Results:

• PCI successfully mapped dynamic microbubble behaviors during FUS treatment.
• A linear correlation was observed between the inertial cavitation dose quantified by PCI and the extent of histologic tissue damage.
• Different pressure levels resulted in varying degrees of cavitation and associated tissue damage.

Conclusions:

• Passive cavitation imaging (PCI) effectively quantifies inertial cavitation dose during FUS treatments.
• PCI can serve as a predictive tool for assessing FUS-induced histologic brain tissue damage.
• This finding supports the use of PCI for ensuring the safety of FUS-mediated therapies.