When the photographic elements are intended to be exposed by x rays, they can include {HEAD ~ features} found in {TAIL ~ conventional radiographic elements} 
When the photographic elements are intended to be exposed by x rays , they can include { HEAD ~ features } found in { TAIL ~ conventional radiographic elements }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL