"Tc-99m-MAG3: Agent of choice due to a high extraction rate, which may be necessary for an obstructed system. Diuretic (furosemide) renogram is performed to evaluate between obstructive vs nonobstructive hydronephrosis. The non-obstructive hydronephrosis will demonstrate excretion (downward slope on renogram) after administration of diuretic from the collecting system. Whereas mechanical obstructive hydronephrosis will show no downward slope on renogram, with retained tracer in the collecting system."
"Tc-99m-DTPA: Not the agent of choice because of predominantly glomerular filtration of Tc-99m-DTPA. Glomerular function declines earlier and more rapidly than does tubular function in obstructive uropathy. Tc-99m-DTPA may be used if the kidney is known to have good function."
"Doppler sonography: the obstructed kidneys may show higher resistive indices"
"when multiple can be indistinguishable on US or unenhanced CT"
Expected headings
"Associations"
"Fluoroscopy/IVU"
"Renal scintigraphy"
"Pelviureteric junction obstruction is most commonly unilateral but is reported to be bilateral in ~30% (range 10-49%) of cases 10. There is a recognised predilection towards the left side (~67% of cases)."
"idiopathic and often unknown; proposed causes include"