What does the medical abbreviation IVP mean?

IVP stands for intravenous pyelogram. An alternative name for IVP is "intravenous urogram" (IVU).

IVP is a type of radiography: An x-ray image of the urinary tract obtained after an iodine contrast medium has been injected into the bloodstream. The contrast passes through the kidney and may reveal an obstruction, evidence of trauma, etc. It's a test to evaluate the kidneys.
Renal pelvis