Figure 3: 9.8 mCi Tc-99m MAG3 Radionuclide differential renal scan with furosemide. Blood flow phase of the study shows relatively symmetric perfusion; blood flow to the left kidney is minimally decreased with respect to the right kidney. Differential perfusion is 44% to the left kidney and 56% to the right kidney. Renogram phase of the study shows symmetric uptake bilaterally, with only minimally delayed excretion to 17 minutes in the left kidney, suggesting a mildly patulous collecting system. Following Lasix administration, there is normal clearance of activity bilaterally.