whole-body retention ( wbr ) was measured together with regional uptakes in the following four areas : head , chest , bladder , and legs using two structurally related tc-99m-diphosphonate skeletal imaging agents : 1-hydroxyethylidene diphosphonate ( hedp ) and methylene diphosphonate ( mdp ) .
C0012544
diphosphonate
C0066351
methylene diphosphonate