It was like the first time I saw a cadaver.
You can X-ray a cadaver and then cut it open and find what the X-ray showed was there.
The time after death of the infected cadaver is also an important factor influencing the number infected.
The gaps in these images are where the frozen cadaver was initially divided with a saw to produce portions of a more manageable size.
Rather like the alleged alien cadaver itself, in fact.