Idle thought:

[cdave]

Colour is (badly) defined as the relative amount of one three frequencies of light waves reflected off a visible point.

Could you make a false colour ultrasound image by using three different frequencies of ultrasound? If so would they be of any use?

Comments

[the-magician.livejournal.com]

Red/Green 3D glasses would appear to be the obvious first answer to that.

And that doesn't necessarily need different frequencies if you can use two transmitters and time slice between then and combine the two to build a three d virtual image ...

Now it may be that different frequencies penetrate differently so you might be able to do the "looking under the skin" bit ... but I have no knowledge of that.

[andrewducker]

I don't believe your definition of colour is correct. Colour is a combination of different wavelengths of light. Because we have three receivers in our eyes we tend to define things in combinations of the colours that each of those produces, but one could as simply use different base colours - there's nothing magical about those particular three.

[sharikkamur.livejournal.com]

You can define 'false colour' using any combination of colours; all you're doing is colour-coding particular areas using a defined code set.

The ultrasound approach is more like the astronomical approach of viewing something through multiple filters and then shifting the wavelengths to the visible. Astronomical images are often false-coloured because they are made up of a set of particular wavelengths - Hα comes immediately to mind.

Of course, ultrasound is a longitudinal wave form, not a transverse waveform. How about thinking of a multi-frequency ultrasound as a polyphonic piece of music instead of a single tone?

Hmm... there's an art idea - transforming your ultrasound baby scans into orchestral pieces.