Monitoring thermally-induced lesions with supersonic shear imaging

Area of Science:

• Medical Imaging
• Biophysics
• Acoustic Physics

Background:

• Thermally-induced lesions exhibit increased stiffness compared to surrounding tissues.
• Monitoring tissue changes during thermal ablation is crucial for effective therapy.
• High-intensity focused ultrasound (HIFU) is a therapeutic modality inducing localized heating.

Purpose of the Study:

• To evaluate the feasibility of using supersonic shear imaging (SSI) for real-time monitoring of high-intensity focused ultrasound (HIFU) therapy.
• To demonstrate the capability of SSI in detecting and quantifying the stiffness of HIFU-induced thermal lesions.

Main Methods:

• Utilized an HIFU probe to create thermal lesions in fresh tissue samples.
• Employed a diagnostic transducer with an ultrafast scanner to generate and image shear wave propagation at 5,000 images/s.
• Interleaved therapeutic and imaging sequences to capture shear wave propagation during the heating process.
• Applied an inversion algorithm to elasticity estimations derived from shear wave propagation movies.

Main Results:

• Successfully generated shear waves remotely using acoustic radiation force.
• Captured real-time movies of shear wave propagation during HIFU treatment.
• Demonstrated the ability to detect and quantify the increased stiffness of HIFU-induced lesions.
• Elasticity estimations correlated with lesion formation and hardening.

Conclusions:

• Supersonic shear imaging (SSI) is a feasible technique for monitoring HIFU therapy.
• SSI can effectively detect and quantify the mechanical property changes (stiffness) associated with thermal lesions.
• This non-invasive elasticity imaging approach holds promise for guiding and optimizing thermal ablation treatments.