No, Medusa was unaltered. It's the statues in the trick manor that had poorly-drawn clothes placed on them.
The dungeon stage has blood pools and blood dripping from the ceiling instead of green slime or whatever.
There's some religion imagery that was erased in the US version.
The name on Dracula's tombstone was omitted in the US, 'cos it said "Dracura." (Why they didn't just alter the second R to an L, I don't know. Instead they just scrambled the pixels.)
The chain whip sounds different and more chain-like.
The logo is waaaaay cooler. Plus it has blood dripping off it on the title screen complete with "blood drop landing in blood pool" sound effect.
The status text was altered in the US for whatever reason. The font and coloring melds with the game's graphics much better in the Japanese version.
Aaaand I think that's just about everything (that I can think of right now).