{HEAD ~ Each} of {TAIL ~ the different methods} in use is sensitive to some particular aspect of the structures to be imaged 
{ HEAD ~ Each } of { TAIL ~ the different methods } in use is sensitive to some particular aspect of the structures to be imaged
HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH