Tc-99m DTPA renal scan provides information on renal function and urinary tract drainage based on split renal function and renal washout curves and can be useful for the evaluation of severe grade 3 and 4 hydronephrosis in concert with VCUG [20,29,53,62,63]. Given the lower glomerular filtration rate in newborns, these examinations are frequently delayed until at least 2 months of age [29,63-65]. However, because of its rapid renal clearance and primary excretion by the tubules on which furosemide acts, Tc-99m MAG3 is preferred over Tc-99m DTPA in patients with suspected obstruction or impaired renal function [61]. MAG3 Renal Scan Tc-99m MAG3 is primarily excreted through active renal tubular transport, and its extraction fraction is 40% to 50% [61]. This greater extraction fraction, versus DTPA, accounts for less background, versus renal, activity compared to DTPA. Because of its rapid renal clearance and primary excretion by the tubules on which furosemide acts, Tc-99m MAG3 is preferred over Tc-99m DTPA in patients with suspected obstruction or impaired renal function [61]. Tc-99m MAG3 renal scan is useful for the evaluation of severe grade 3 and 4 hydronephrosis and may be performed in concert with a VCUG study [20,29,53,62,63]. Tc-99m MAG3 renal scan provides information on renal function and urinary tract drainage based on split renal function [61]. Diuretic renal scan is used for diagnosis of multiple causes of obstruction, including primary obstructing megaureter [52,66-68]. Approximately 5% to 10% of antenatal hydronephrosis is attributable to primary megaureter [4,69] diagnosed by persistent ureteral dilation (>7 mm). Primary megaureter is classified according to the presence or absence of reflux and obstruction. Most will resolve spontaneously [20,70-72].
Antenatal Hydronephrosis Infant. Tc-99m DTPA renal scan provides information on renal function and urinary tract drainage based on split renal function and renal washout curves and can be useful for the evaluation of severe grade 3 and 4 hydronephrosis in concert with VCUG [20,29,53,62,63]. Given the lower glomerular filtration rate in newborns, these examinations are frequently delayed until at least 2 months of age [29,63-65]. However, because of its rapid renal clearance and primary excretion by the tubules on which furosemide acts, Tc-99m MAG3 is preferred over Tc-99m DTPA in patients with suspected obstruction or impaired renal function [61]. MAG3 Renal Scan Tc-99m MAG3 is primarily excreted through active renal tubular transport, and its extraction fraction is 40% to 50% [61]. This greater extraction fraction, versus DTPA, accounts for less background, versus renal, activity compared to DTPA. Because of its rapid renal clearance and primary excretion by the tubules on which furosemide acts, Tc-99m MAG3 is preferred over Tc-99m DTPA in patients with suspected obstruction or impaired renal function [61]. Tc-99m MAG3 renal scan is useful for the evaluation of severe grade 3 and 4 hydronephrosis and may be performed in concert with a VCUG study [20,29,53,62,63]. Tc-99m MAG3 renal scan provides information on renal function and urinary tract drainage based on split renal function [61]. Diuretic renal scan is used for diagnosis of multiple causes of obstruction, including primary obstructing megaureter [52,66-68]. Approximately 5% to 10% of antenatal hydronephrosis is attributable to primary megaureter [4,69] diagnosed by persistent ureteral dilation (>7 mm). Primary megaureter is classified according to the presence or absence of reflux and obstruction. Most will resolve spontaneously [20,70-72].