Unilateral decrease in renal vascularity on the “excretory” urogram

Unilateral decrease in renal vascularity is demonstrated by a new technique for studying the renal vascular parenchyma on the “excretory” urogram.Renal vascularity, decreased on the side of acute ureteral obstruction, returns to normal with the relief of the obstruction.The use of the vascular nephrogram as a screening test for renovascular hypertension is illustrated and discussed.