What is that white circle thingy on my X-Ray

1+ years ago, i had (what I thought) was RNY. Today I had an X-ray done at the Chiro's office and was surprised to see a white circle aroud the area where my stomach is. I have e-mailed my dr's office, so I hope to hear from them, but I'm not expecting it. Is it possible that I had a FOBI? I have done remarkably well with this surgery.. Im a size 4 now!! My docs website (www .gastric band. com) says he only does lapband and RNY. I know I didnt have a lap band since Ihave no port.

UPDATE:
My surgeon called to let me know it was a silisatic band placed to prevent stretching of the pouch long term.