Visualization of HIFU acoustic intensity fields through photoacoustic tomography

We proposed a high-intensity focused ultrasound (HIFU) visualization approach based on photoacoustic tomography (PAT), exploiting the linear relationship between the Grneisen parameter and temperature to map the HIFU-induced temperature field.A differential photoacoustic (DPA) method was employed to effectively suppress background noise caused by changes in the optical absorption coefficient due to structural tissue damage, thereby successfully decoupling the temperaturedependent photoacoustic (PA) signal enhancement.Furthermore, a quantitative model was established to describe the relationship between the temperature rise (T) and the PA signal variation (PA), enabling reconstruction of the temperature distribution within the HIFU focal region.Under short-duration irradiation conditions, where thermal diffusion can be neglected, axial scanning was used to reconstruct the three-dimensional acoustic field distribution of HIFU.The proposed visualization strategy effectively resolves the challenge of characterizing high-energy focal zones, significantly enhancing the ability to assess HIFU acoustic fields and providing a reliable foundation for pre-treatment dose planning and intraoperative precision therapy.