Acoustic microscopy of red blood cells.

We used a scanning acoustic microscope to image normal and outdated red blood cells, cells with different hemoglobin content, red cell ghosts, and cells treated with various drugs that induce echinocyte-stomatocyte transformation. Images were obtained at different planes of focus within the cells, corresponding to maxima and minima of signal intensity. Digitization and gray scale amplitude mapping were used to create axonometric plots that display signal amplitude variations within the cells. The images of red cells contain features produced by differences in topology, density, elasticity, and absorption. Both hemoglobin content and the cell cytoskeleton contribute to image features, and various deformations, characterized by the formation of blebs and vacuoles, are displayed in cells undergoing echinocyte-stomatocyte transformation. These preliminary findings, although mainly descriptive, indicate that acoustic microscopy may be a useful new method for evaluating red cell deformation and associated changes in mechanical properties.