True, I can't verify the source. Though a lot of the pictures featured in this forum come from leaked photos versus Life, CNN, etc. I found these while trolling for bizarre xrays.
I does seems plausible. Many homemade pipe bombs tend to include shrapnel to increase soft target damage beyond the initial blast. In this case, nuts only, seem to be the ingredient which is very visible on the xray.
If it were nuts and BOLTS, I'd expect at least ONE of the punctures to be a long gash from a bolt going in sideways... These are all relatively uniform circles.