A retrograde pyelogram is a urologic procedure where the physician injects a radiocontrast agent into the ureter in order to visualize the ureter and kidney with fluoroscopy or radiography. The flow of contrast (up from the bladder to the kidney) is opposite the usual outbound flow of urine, hence the retrograde ("moving backwards") name.
Reasons for performing a retrograde pyelogram include identification of filling defects (e.g. stones or tumors), as an adjunct during the placement of ureteral stents or ureteroscopy, or to delineate renal anatomy in preparation for surgery. Retrograde pyelography is generally done when an intravenous excretory study (intravenous pyelogram or contrast CT scan) cannot be done because of renal disease or allergy to intravenous contrast.
Relative contraindications include the presence of infected urine, pregnancy and contrast allergy.
The procedure requires cystoscopy and the placement of a small tube into the lower part of the ureter to inject contrast and opacify the ureter and renal pelvis. Fluoroscopy, or dynamic X-Rays, is typically used for visualization. The procedure is usually done under general or regional anesthesia.
- Campbell's Textbook of Urology, Chapter 3, Urinary Tract Imaging, Basic Principles