Relative renal accumulation of Tc-99m penicillamine as an index of differential renal function: concise communication.

The relative renal accumulation of technetium-99m penicillamine (TPEN) was evaluated as an index of differential renal function. Using a scintillation camera interfaced to a computer, renal uptake of TPEN was determined for each kidney by subtracting the renal activity at 10 min from that at 25 min. This percentage of TPEN activity in the left kidney was compared with the percentage of total creatinine clearance contributed by the left kidney in six patients with ureteral obstruction and nephrostomy drainage. The two measurements agreed extremely well, with a correlation coefficient of 0.98. The relative renal uptake of TPEN and similar cortex imaging agents such as Tc-99m dimercaptosuccinic acid can probably be used to assess differential renal function.