Real-Time Heterogeneous Helical Wave Spectrum Method for Transabdominal Passive Acoustic Mapping

Area of Science:

• Medical Imaging
• Acoustic Physics
• Ultrasound Therapy

Background:

• Passive acoustic mapping (PAM) with convex arrays monitors cavitation in focused ultrasound (FUS) therapy.
• Speed-of-sound (SoS) heterogeneity in the abdominal wall causes phase aberration, degrading PAM image quality and FUS therapy safety.

Purpose of the Study:

• To develop a method for correcting SoS heterogeneity in transabdominal PAM.
• To improve the accuracy of cavitation source localization in FUS therapy.

Main Methods:

• Derived a general solution to the wave equation in SoS heterogeneous media.
• Proposed the real-time heterogeneous helical wave spectrum (HHWS) method for transabdominal PAM.
• Validated the HHWS method using in silico and in vitro experiments.

Main Results:

• The HHWS method demonstrated significant phase aberration correction.
• Improved image quality and cavitation source localization accuracy compared to the HWS method.
• Achieved real-time image reconstruction (tens of milliseconds) and dual-mode monitoring.

Conclusions:

• The HHWS method effectively accounts for SoS heterogeneity in transabdominal PAM.
• HHWS enhances the safety, efficacy, and control of cavitation-based FUS therapies.
• Real-time dual-mode monitoring is feasible for abdominal FUS applications.