99mTc-methyl-CCNU for the static imaging of kidneys.

A new radiopharmaceutical, 99mTc-Methyl-CCNU, was prepared for the static imaging of kidneys and the radiochemical purity was tested by paper and thin-layer chromatography. The biological distribution was studied in 15 mice sacrificed at 10 min. 30 min, 1 h, 3 h, and 6 h after IV injection. Blood clearance and excretion of the agent in urine were followed in three volunteers for a period of 24 h. Renal uptake was high (25% in 6 h), plasma clearance very fast (90% in 1 h), and urinary excretion reached a platueau after 6 h with 25% excretion. A longitudinal slice of a rabbit kidney showed the cortical accumulation on autoradiography and scintigraphy. Clinical studies indicated the usefulness of this radiopharmaceutical as a kidney imaging agent.