Back in the 90s, there was this guy who donated his body to science.
The scientists froze him, and then shaved off something like a millimeter at a time before polishing the ice and taking a high quality picture.
They started at the head, and slowly worked down the body. Keeping everything frozen the entire time.
Anyway what?
https://www.latimes.com/archives/la-xpm-1996-01-07-mn-21878-story.html