Okay, some comments on this (after long last—my apologies on the delay!):
Can we invert the colours, to look more like the standard ultrasound visualisation? (Light reflections on a black background—and I prefer dark backgrounds anyway.)
Can the original design be in SVG format? Much more lightweight and git-trackable than XCF.
The crosshairs should be on the border between the dark and light areas—i.e., the light and dark areas reflect two different materials, and the border between them (such as the surface of the tongue) is what you usually want to trace.
Okay, some comments on this (after long last—my apologies on the delay!):