"Pyelography may also be performed retrograde through a catheter inserted into the distal ureter, or it may be performed antegrade after percutaneous access to the renal upper collecting system (e.g. through a percutaneous nephrostomy)."
"The term is derived from a combination of the Greek words puelos (‘trough' or 'basin’) as a metaphor for the urinary collecting system, and graphia ('writing')."
"Pyelography may also be performed retrograde through a catheter inserted into the distal ureter, or it may be performed antegrade after percutaneous access to the renal upper collecting system (e.g. through a percutaneous nephrostomy)."