Radionuclide Diuresis Pyelography

Abstract

Radionuclide diuresis renography continues to be relied upon as a major diagnostic tool to differentiate obstructive and nonobstructive hydronephrosis. Controversy continues to exist with respect to methodology and interpretation of intermediate obstructive patterns. In this study radionuclide diuresis pyelography was performed in 11 renal units with hydronephrosis and a preexisting percutaneous nephrostomy tube in place. The procedure consisted of the introduction per kidney of 20 μc./kg. 99mtechnetium-diethylenetriaxninepentaacetic acid and sterile saline as a bolus into the renal pelvis via a percutaneous nephrostomy tube to produce a volume equal to the capacity of the hydronephrotic system. The kidney was monitored with a gamma camera and computer system. Furosemide (0.3mg./kg.) was injected intravenously halfway into a 40-minute study. The time/activity curves thus generated were relatively independent of the cortical transport phase. The 2 types of curves were accelerated and constant. Analysis of these pyelogram curves revealed a strong correlation between the presence of an accelerated clearance rate response to furosemide and hydronephrosis without obstruction in 5 of 6 renal units. A constant clearance rate response to furosemide correlated with the presence of obstruction in 4 of 5 units. These observations may indicate that diuretic pyelogram curve dynamics may reflect not only the presence or absence of obstruction but also the ability of the hydronephrotic kidney to respond to the diuretic. More experience must be accumulated to determine the conditions under which diuresis pyelography may become useful clinically.