Fast ultrasonic ablation monitoring: An innovative approach using ultrasound RF signals and singular value decomposition

Microwave ablation (MWA) can rapidly lead to tumor cell necrosis by heating local tissues using electromagnetic field energy, making it a highly efficient modality widely utilized in clinical ablation surgeries. However, the lack of timely and accurate intraoperative monitoring methods is a critical issue that urgently needs to be addressed in MWA. This article introduces an innovative approach for real-time monitoring of ablation therapies by the combination of ultrasound radio frequency (RF) signal acquisition and singular value decomposition (SVD), which breaks through the limitations of current monitoring techniques during MWA procedures. Due to the difference in acoustic scattering properties between the gas generated in high-temperature ablated region and the non-ablated tissues, the current new method aimed to apply SVD analyses to ultrasound RF signals scattered from the tissues, through which the range of gas generation could be determined and then the ablation area could be estimated. Eventually, high-precision differentiation between ablated and non-ablated tissues could be achieved, enabling real-time adjustment and improvement of MWA strategies. Validated through ex vivo experiments on pig liver, this technique demonstrated a relative error in monitoring the size of ablation region of approximately 7%, indicating a strong correlation with actual ablation outcomes. The study indicated the proposed method should have great potential to improve the precision and safety of MWA therapy.