Optimized Echo Decorrelation Imaging Feedback for Bulk Ultrasound Ablation Control.

Area of Science:

• Medical Imaging
• Ultrasound Technology
• Thermal Ablation

Background:

• Bulk ultrasound (US) thermal ablation is a promising therapeutic technique.
• Precise control over ablation extent is crucial for efficacy and safety.
• Echo decorrelation imaging offers a potential method for real-time monitoring of thermal ablation.

Purpose of the Study:

• To investigate the feasibility of controlling bulk US thermal ablation using echo decorrelation imaging.
• To compare the effectiveness of minimum decorrelation versus average decorrelation criteria for ablation control.
• To evaluate the impact of constant-intensity versus variable-intensity sonication sequences on ablation outcomes.

Main Methods:

• Ex vivo bovine liver model used for ablation experiments.
• A linear image-ablate array performed US exposures and echo decorrelation imaging.
• Two control strategies were employed: minimum decorrelation in a ROI and spatially averaged decorrelation.
• Controlled trials were compared against uncontrolled trials with fixed sonication cycles (9 or 18).

Main Results:

• Both minimum and average decorrelation criteria significantly reduced treatment times compared to 18-cycle uncontrolled treatments.
• Controlled trials demonstrated superior ablation prediction performance over uncontrolled 9-cycle and 18-cycle treatments.
• Both control approaches yielded higher ablation rates than uncontrolled methods.
• Variable-intensity sonication resulted in larger ablated regions compared to constant-intensity sonication.

Conclusions:

• Echo decorrelation imaging, using either minimum or average decorrelation criteria, is a feasible method for controlling bulk US thermal ablation.
• Variable-intensity sonication sequences can enhance the extent of thermal ablation.
• These findings support the development of image-guided US ablation systems for improved therapeutic outcomes.