looks like this. All scans are of the same chip.
I studied many such chips. The purpose and conclusion being that unless a hole was filled with identical composition material as the chip, being reheated and recompressed etc., there is no way it could escape xray.
The lead weight scans are to show that only material of such a high density show as white on an xray. Any filler would be black, and that glue reservoirs show 'grey'
Of course most people dont believe any fixed chips exist so its all hypothetical