I am an anatomical pathologist doing some research using scanning acoustic microscopy (SAM). SAM uses the same slides as light microscopy(LM), except their thickness is about 10 micrometers. Speed and attenuation of sound through tissues are obtained to plot on the screen to make histological images with almost the same resolution as LM. Speed of sound and attenuation of sound correlate with tissue stiffness and viscosity, respectively. So, SAM tells us not only structure but also functions.