Model-based ultrasound temperature visualization during and following HIFU exposure

Area of Science:

• Medical Imaging
• Biomedical Engineering
• Signal Processing

Background:

• High-intensity focused ultrasound (HIFU) requires accurate temperature monitoring for effective and safe treatment.
• Ultrasound feedback can be affected by low signal-to-noise ratios, particularly in abdominal applications.
• Existing methods for temperature estimation from ultrasound displacements may be sensitive to outliers and signal quality.

Purpose of the Study:

• To improve the robustness and accuracy of ultrasound-based temperature estimation during HIFU treatments.
• To develop an adaptive signal processing method for real-time temperature visualization.
• To address challenges posed by low signal-to-noise ratios and material heterogeneity in HIFU therapy.

Main Methods:

• Application of a Kalman filter, a statistical signal processing technique, for temperature estimation.
• Incorporation of a simple analytical temperature model of heat dispersion into the Kalman filter.
• Development of an adaptive Kalman filter to reduce sensitivity to signal-to-noise ratio and material assumptions.
• Validation using ex vivo bovine liver data from HIFU exposure.

Main Results:

• The Kalman filter significantly improves the robustness of temperature estimation from ultrasound displacements.
• The adaptive approach enhances reliability even with low signal-to-noise ratios and varying tissue properties.
• Stable temperature visualization was achieved during and between HIFU exposures.
• The method demonstrated improved accuracy in tracking temperature changes in ex vivo liver tissue.

Conclusions:

• The proposed Kalman filter-based signal processing technique enhances ultrasound feedback for HIFU temperature monitoring.
• The adaptive method offers a more robust and reliable approach for in vivo applications, especially in challenging abdominal environments.
• This advancement facilitates improved real-time temperature visualization, crucial for optimizing HIFU treatment efficacy and safety.