The X-ray shows a forearm pierced by a bullet from a Kalashnikov.
It belongs to a woman who survived the attack.
The doctor, who is said to have operated on several of the victims of the terrorist attack on Bataclán, tried to sell the X-ray plate as a digital work of art, a so-called NFT.
The X-ray image was for sale on the auction site Open sea, which specializes in NFTs.
The doctor has said that the auction was a mistake and that he regrets that he had not asked the patient for permission to use the image.
The head of Paris Hospital, Martin Hirsch, calls the doctor's actions scandalous and disrespectful.
The hospital has taken disciplinary action against the doctor, who was also reported to the police.