Impact of focused ultrasound on the cellular network of liver tissue: a new perspective for thermal lesion detection

The noninvasive characterization of soft tissue microstructure remains challenging and has a significant clinical impact on diagnosis and therapy monitoring. During high-intensity focused ultrasound (HIFU) treatments, coagulation necrosis is accompanied by mechanical changes. We demonstrate that HIFU induces anisotropic alterations in the cellular architecture of liver tissue, which are detectable through the angular dependence of the backscattering coefficient (BSC). In vivo experiments reveal a distinct anisotropic histological pattern localized in the HIFU-treated region. Moreover, we show that the degree of anisotropy deduced from BSC measurements is correlated with the delivered energy, providing a quantitative link between treatment parameters and tissue response. These findings establish BSC anisotropy as a previously unexplored signature of thermal lesions, offering a promising approach for monitoring and feedback in thermal therapeutic ultrasound applications. This breakthrough could open the door to next-generation imaging tools, accelerating the widespread adoption of this highly effective therapeutic modality.