What @gasman and @krrazypassions says is technically correct. However, like any good engineer, when somebody says “that’s impossible” I immediately try to think of ways to bend the laws of nature to accomplish the goal.
I would think that different tissue densities are more reflective of certain frequency bands than others, thus giving them a spectral signature. That being the case, I see no reason why one wouldn’t be able to produce a multi-frequency sonic imaging device that would be able to recognize the spectral signatures of various tissue types (and depths) and render them in differentiated colors. Sure it would be “false” color, but then again, so is any color image you see on a computer screen regardless of the source. Even images from cameras are digitized and then re-constructed for your viewing pleasure.
So… should I apply for a patent?