We haven't proven it cannot work. But we don't know if we're doing it right. We don't know if just the head is enough, or if including the whole body slows the

We haven't proven it cannot work. But we don't know if we're doing it right. We don't know if just the head is enough, or if including the whole body slows the process so much the brain is damaged. We don't know if we're using chemicals that best accommodate thawing or scanning, whichever turns out to work better. We don't know if waiting until death causes some kind of irreversible damage or psychological problems.