{HEAD ~ System} for marking {TAIL ~ the locations} of imaged tissue with respect to the surface of the tissue 
for marking
{ HEAD ~ System } for marking { TAIL ~ the locations } of imaged tissue with respect to the surface of the tissue
HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH