High frequency ultrasound imaging of changes in cell structure including apoptosis

It has been previously shown that high frequency ultrasound (20-100 MHz) can be used to detect cellular structure changes in tissues and cell ensembles. Using spectral analysis methods to analyze radio-frequency data collected from in vitro and in vivo models, the changes seen during apoptotic cell death are very striking. Imaging changes in cell structure has implications in a broad range of fields, from cancer treatment monitoring to organ transplantation. However, the changes seen in the backscattered ultrasound intensity and frequency spectrum are not fully understood. In this paper we propose and explore a model for studying how the changes in the sizes, spatial distribution, and acoustic impedance of the scattering sources within the cells are related to the resulting backscattered ultrasound signal.