Pyelography (or "pyelogram") refers to imaging of the urinary collecting system.
The term is most often encountered in 'intravenous pyelography' (or "IVP"). For some, this is a misnomer and a test that images intravenous contrast as it travels through the kidney parenchyma into the urinary collecting system should only be called 'intravenous urography'. In practice, both terms are used interchangeably.
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).
History and etymology
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').