yup, it shows just about every inperfection there is they go by shadows, like ip will be a  dark line down the center , a burn through  a dark circle , wagon tracks dark lines @ edges , also depending on the code ,but your allowed so much ,you can get away with about 1" of ip on 6" pipe,  if pipeline is 1104  (that's just an example i'm not sure if 1" is right) There's also internal-undercut , hollow bead . I'm no x-ray tech , but it's what i have seen through out the years. If those welds you were looking @ had any kind of marking's usually white marker,  then they were cut out's