Apatient with hydronephrosis has a left nephrostomy and he has agreed to a pyelography (ivp) to rule out a right renal obstruction. the patient was placed prone on the x-ray table one hour after iv infusion of contrast. contrast flowed from the left and right renal pelvis, down the ureters into the bladder where a foley catheter was positioned. the ivp showed no obstruction or abnormalities in the urinary tract aside from the left hydronephrosis of the pelvis. the right kidney and ureter showed no obstruction. bladder appeared within normal limits. what cpt® code is reported for the radiological services?