A convenient method for the preparation of 99mTc(V)dimercaptosuccinic acid (99mTc(V)-DMSA).

Tc(IV)-DMSA for kidney scintigraphy has been prepared in acidic solution. Once the labeling is done in basic solution, upon addition of a small amount of NaHCO3, a mixture of 3-4 other DMSA-complexes is formed, presumably containing Tc(V). Kidney uptake in male adult rats of the 99mTc(V)-DMSA is 1.6% injected dose/g (4.9%/total organ) compared to 16.4% injected dose/g (resp. 50.3%/total organ) for 99mTc(IV)-DMSA.