Instantaneous frequency-based ultrasonic temperature estimation during focused ultrasound thermal therapy

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Acoustics

Background:

• Focused ultrasound thermal therapy requires precise temperature monitoring for effective treatment delivery.
• Current methods using ultrasound echo time-shifts have limitations in efficiency and processing speed.

Purpose of the Study:

• To develop and validate a novel, computationally efficient ultrasound-based temperature measurement technique.
• To compare the performance of the new method against conventional cross-correlation techniques.

Main Methods:

• A new algorithm detecting instantaneous frequency changes along the ultrasound beam direction was proposed.
• Focused ultrasound was used for heating tissue-mimicking phantoms and ex vivo porcine muscles.
• Radiofrequency (RF) data from an ultrasound imager were analyzed using both the proposed and cross-correlation methods.

Main Results:

• The proposed algorithm accurately estimated temperature in a linear sound speed-temperature range.
• It demonstrated a six-fold increase in computational efficiency compared to the cross-correlation method.
• Comparable contrast-detection ability and precision were achieved.

Conclusions:

• The novel instantaneous frequency-based ultrasound method offers an efficient alternative for temperature estimation.
• This technique can potentially be integrated into clinical ultrasound imagers for real-time thermal therapy guidance.