[Accuracy of correlation function method for evaluating pulsed high intensity focused ultrasound].

Area of Science:

• Medical Imaging
• Acoustic Physics
• Biomedical Engineering

Background:

• Pulsed high-intensity focused ultrasound (PHIFU) is an emerging therapeutic modality.
• Accurate monitoring of tissue necrosis during PHIFU treatment is crucial for efficacy and safety.
• Current ultrasound monitoring methods, relying on grayscale changes, may lack sensitivity.

Purpose of the Study:

• To evaluate the accuracy of ultrasound monitoring during PHIFU treatment.
• To enhance the sensitivity of ultrasound in detecting PHIFU-induced tissue necrosis.

Main Methods:

• Ex vivo bovine liver was treated with PHIFU at varying energy levels and exposure parameters.
• Ultrasound imaging was used to observe grayscale changes post-treatment.
• Image correlation functions were calculated before and after PHIFU exposure.
• The accuracy of grayscale and correlation function-based evaluations for tissue necrosis was compared.

Main Results:

• Grayscale change evaluation correctly identified tissue necrosis in only 51% of cases.
• Correlation function-based evaluation achieved an 85% correct rate for detecting tissue necrosis.
• The correlation function demonstrated superior accuracy and sensitivity.

Conclusions:

• Relying solely on grayscale changes in ultrasound images is insufficient for monitoring PHIFU-induced tissue necrosis.
• Image correlation function analysis offers a more accurate and sensitive method for ultrasound monitoring of PHIFU treatments.
• This improved monitoring can enhance the clinical application of PHIFU therapy.