don't look at this yet!

http://www.chestnet.org/accp/pccsu/new-classification-pleural-effusions-after-cabg-surgery?page=0%2C3

what's wrong here?

This x-ray has been everywhere to get here so sorry for the poor image. I gave you this view because it shows the problem and the cross sections would require multiple views.

This patient had a chest surgery about two months prior to this CT. He was sob but not severe. He complained of abdomen fullness which I ignored.

What surgery did he have?
What part of that surgery caused the finding on CT?
What was done to relieve his symptoms?

A question: what caused the "artifact"?