[Methodological observations on double radionuclide technics in joint scintigraphy]

Double-radionuclide scintigraphy for the differentiation between inflammatory and degenerative diseases of the joint ought to be performed with a radiopharmaceutical that remains within the intravascular space as an indicator of blood flow, and an osteotropic radiopharmaceutical. The former ought not to leave the intravascular space even in inflammatory disease. This condition is, however, not met by 113mIn-labelled transferrin as shown by measurements of plasma volumes as well as of its local kinetics. On the other hand, the biological behavior of 99mTc-labelled red cells does not, up to 30 min p.i., differ from that of 51Cr-labelled red cells so that they may be used as an intravascular tracer even in inflammatory disease. In that case, the osteotropic radiopharmaceutical to be employed should be 113mIn-EDTMP.