Odd looking x ray

[Smithj82]

Can anyone explain what's happened to this x ray or what it is? (highlighted in red) I thought initially it had been scratched but there are no indentations on the radiograph.I've taken a photo of both the front and back of the xray

 

[MattKW]

A poor quality X-ray that is hard to see. Looks like a lower premolar that has a cast post-and-core, followed by an amalgam apicocectomy.