The X-ray is signed by Ali, saying: "To Carol & Russ From Muhammad Ali, 1973".
Muhammad Ali
The piece shows where Ken Norton cracked Ali's face during their big fight in 1973. Ali did end up losing that fight.
The X-ray was just auctioned as part of Simpsons creator Sam Simon's collection, in order to raise money for his charity organisation. The X-ray brought in $1,500 (£980) of the total $250,000 (£162,840) made at the auction. All of the proceeds will go to animal welfare programs as well as poverty alleviation and disaster relief organisations.