I'm just guessing here but similar to a CAT scan, having actuators/probes at all angles could mean you can get an image around such obstacles. skull is probably an exception and it's the reason why we don't see any head scans in any one of the videos.
Also I imagine it pretty difficult to get good data from that because of all the muscles that do stuff if put in water and you would hold your breath.
There is no way people will put up with that.