Fig. 6. Spontaneous resolution of primary megaureter.

A, B. Marked dilation of the right pelvocalyces and ureter in a 20-day-old neonate. The right ureter is indicated by cross marks (B). C. Intravenous pyelogram obtained 90 minutes after contrast administration revealed significant dilation of the entire excretory system on the right side. Dynamic renal scintigraphy showed excretion of the isotope after a diuretic challenge (data not shown). D. The patient was followed clinically without any intervention, and ultrasonography at 12 years of age shows near-complete spontaneous resolution of the hydroureteronephrosis.