Photoacoustic assisted device guidance and thermal lesion imaging for radiofrequency ablation

Abstract

Radiofrequency ablation (RFA) is a widely used treatment method for unresectable malignant tumors. In percutaneous RFA, the tumor recurrence rate is high due to incomplete ablation. Feedback from the imaging system during the RFA procedure is vital in reducing the tumor recurrence. We propose the use of photoacoustic (PA) imaging, integrated with an ultrasound (US) system to monitor the RFA procedure. The imaging system consists of a US system with a linear array and a pulsed laser illumination. We study the PA assisted RFA device guidance to an anomalous target embedded inside a chicken breast tissue. We compare both US and PA images to highlight the advantage of using the proposed method. Further, we image an ablated ex vivo bovine liver sample using the system. The result shows a drop in PA intensity from the ablated region compared to normal tissue. Our preliminary study shows that PA imaging is a potential modality for RFA procedures.