100% agree with the other posters–your horse is sound. Ride him. They can’t read the rads and navicular radiographs really seem to be a fairly poor indicator of soundness, anyway.
But also…I’ve personally had enough really shitty experiences at CSU that I would never, ever take their word on something like this. Send the radiographs and the MRI off to someone else–someone who specializes in this stuff–for a second (or third, whatever you’re up to :lol:) opinion. That’s the beauty of imaging…it’s portable. You can have it read by the best, most experienced, person in the WORLD, if you want, generally for nothing or next to nothing. Take advantage of that