Elucidating the acoustic scattering centres in cells at high frequencies
Baddour RE
At high frequencies (20 - 80 MHz), ultrasound wavelength begins to approach the size of cells and cellular components. Because of its high density, the nucleus has been theorised to be the dominant scattering source within a cell. To further investigate this hypothesis we have studied the backscatter from suspensions of differing sized cells at various cell volume fractions (CVF, the proportion of the suspension volume occupied by cells). Although the nonlinear relationship between backscatter intensity and volume fraction has been well documented for non-biological scatterers and red blood cells, only recently has the case of nucleated cells been examined (Baddour et al., The effect of volume fraction on the backscatter from nucleated cells at high frequencies. Proc. IEEE Ultrason. Symp., 2005: pp. 1672-1674). By using both time-domain and frequency-domain techniques to analyse the backscatter from different CVFs for each cell line, it is possible to better understand the varying importance of the cell nucleus.