C7547 HCPCS - CONVERT NEPHROSTOMY CATHETER TO NEPHROURETERAL CATHETER, PERCUTANEOUS VIA PRE-EXISTING NEPHROSTOMY TRACT, WITH URETERAL STRICTURE BALLOON DIALATION, INCLUDING DIAGNOSTIC NEPHROSTOGRAM AND/OR URETEROGRAM WHEN PERFORMED, IMAGING GUIDANCE (EG, ULTRASOUND AND/OR FLUOROSCOPY) AND ALL ASSOCIATED RADIOLOGICAL SUPERVISION AND INTERPRETATION