X-RAY
With the advent of being able to produce a very narrow beam of RF that is not isotropic and small width with reference to the wavelength used only low powers will be required to scan a human body and collect in a standard type receiver and gate out the wanted time portions. Thus a real picture would emerge of the complete body or sections as required without using X-RAYS that are more dangerous than low power RF (1m/w or less).
With the aid of a PC and its memory and Visual aspects could sort out the different densities and/or reflections.