OPTIMAL HANDLING OF DIMERCAPTOSUCCINIC ACID FOR QUANTITATIVE RENAL SCANNING

Abstract

Methods of optimizing quantitative renal imaging with 99mTc dimercaptosuccinic acid (DMSA) were investigated. Rats were injected with DMSA (1 kit/rat) and sacrificed at 0.5, 2.0 and 24 h after injection. Of the injected dose, 50% localized in the kidneys at 0.5, 2 and 24 h after injection while background activity peaked at 0.5 h and then declined to give substantially higher kidney-to-background ratios at 24 h. Delayed scanning should increase the accuracy of clinical studies in patients with low kidney-to-background ratios at 1-2 h. After injection of DMSA, 1 ml of air was introduced into the reaction vials and incubated 20 min. Kidney uptake decreased from 50-40% and liver uptake increased from 7.5-17%. If multiple doses must be drawn from a single vial, air should not be introduced and the doses should be drawn together and administered immediately to minimize radiopharmaceutical deterioration.