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Published on: January 31, 2025
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Passive Acoustic Mapping for Convex Arrays With the Helical Wave Spectrum Method
IEEE Transactions on Medical Imaging
|January 10, 2024
Summary
A new helical wave spectrum (HWS) method significantly speeds up passive acoustic mapping (PAM) for focused ultrasound therapies using convex arrays. This efficient technique achieves millisecond-level image reconstruction for real-time cavitation monitoring.
Area of Science:
- Medical Imaging
- Acoustics
- Biomedical Engineering
Background:
- Passive acoustic mapping (PAM) is crucial for monitoring cavitation in focused ultrasound therapies.
- Convex arrays are preferred for abdominal imaging but current PAM methods (e.g., delay-and-sum) are computationally intensive, limiting real-time applications.
- Existing methods struggle with large fields-of-view (FOV) and fast image reconstruction.
Purpose of the Study:
- To develop an efficient and frequency-selective passive acoustic mapping (PAM) method for convex arrays.
- To improve image reconstruction speed for real-time cavitation monitoring in focused ultrasound therapies.
- To enable accurate mapping of microbubble (MB) cavitation activity and its anatomical location.
Main Methods:
- Proposed a helical wave spectrum (HWS) method for PAM, projecting wave spectra between cylindrical surfaces.
- Implemented a parallel version of the HWS method for accelerated image reconstruction.
- Combined HWS-based PAM with B-mode imaging for dual-mode real-time visualization.
Main Results:
- The HWS method demonstrated comparable image quality and cavitation source localization accuracy to delay-and-sum (DAS) methods.
- Achieved significant reductions in time-complexity compared to frequency-domain (1 order) and time-domain (2 orders) DAS.
- Realized millisecond-level image reconstruction speeds with parallel implementation.
- Successfully mapped different microbubble (MB) cavitation states (none, stable, inertial).
- Demonstrated real-time dual-mode imaging of MB cavitation in a liver phantom.
Conclusions:
- The HWS method offers an efficient and fast alternative for PAM with convex arrays, overcoming limitations of traditional DAS methods.
- This technique facilitates real-time monitoring of cavitation activity, crucial for advancing focused ultrasound therapies.
- The dual-mode imaging approach provides anatomical context for cavitation events, enhancing clinical applicability.
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