In situ thermal parameter estimation for HIFU therapy planning and treatment monitoring

The paper presents a noninvasive method of estimating the bioheat transfer equation (BHTE) parameters (namely, thermal diffusivity, K, and the normalized local heat source, Q) in situ during HIFU therapy. The method analyses the raw acoustic backscatter data using novel signal processing techniques. First, a heat exposure at sub-ablative intensities is performed to determine K, followed by another at therapeutic intensities to obtain Q. In vitro experiments, performed in a tissue-mimicking alginate phantom, demonstrate that the noninvasive estimates of K and Q are in good agreement with those obtained independently using established methods. The results show potential for the applicability of these techniques in therapy planning and monitoring for therapeutic dose optimization using real-time temperature feedback.