The lead provides for {HEAD ~ efficient attenuation} of x rays, and the high percentage of {TAIL ~ open area} provides for unrestricted passage of the desired imaging x rays 
The lead provides for { HEAD ~ efficient attenuation } of x rays , and the high percentage of { TAIL ~ open area } provides for unrestricted passage of the desired imaging x rays
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH