Ultrasonically guided antegrade pyelography.

Guided by ultrasound percutaneous antegrade pyelography can be accomplished with great ease in patients with obstructive hydronephrosis. The exact location and the depth of the dilated renal pelvis can be determined accurately with the use of ultrasound and the procedure is similar to that of a cyst puncture. Antegrade pyelography provides significant diagnostic information on the nature of the obstructive lesion and can be performed as an adjunct to a retrograde study or as an alternative to a retrograde pyelogram. Ultrasound is considered a most advantageous aid to the performance of antegrade pyelography.