It's also possible to freeze the person, cut the brain in small slices while it's frozen, and scan the slices.

This is what I referred to as "destructive imaging" above. Unless the brain is vitrified (which essentially kills any chemical data, which we may or may not need) the ice damage is going to play havoc with the scanning results. Every time you refreeze/rethaw the brain to try another scan, more of the brain gets damaged from the ice. It's a lot riskier.

Again, I'm not saying it's impossible, but there's a difference between a technology possible in 2025 and a technology possible in 2060. After all, I may not live to see the latter.