An intravenous pyelogram (also known as IVP, pyelography, intravenous urogram or IVU) is a radiological procedure used to visualize disturbances of the urinary system, including the kidneys, ureters, and bladder. Among other uses, IVP can detect kidney stones.
It is done as a series of X-rays before and after a contrast agent (dye) is injected into a vein. This contrast is removed from the blood by the kidneys at a predictable time, where they initially appear opaque on X-ray film early after injection, followed by the appearance of iodinated contrast in the urine which outlines the renal calyces, ureters and bladder in the later X-rays in the series. Finally the bladder is imaged while filled and then after emptying, allowing assessment of any unseen abnormalities and completeness of voiding. It has to be differentiated from KUB.
Role of X Ray Equipment
X-rays are a form of radiation like light or radio waves. X-rays pass through most objects, including the body. Once it is carefully aimed at the part of the body being examined, an x-ray machine produces a small burst of radiation that passes through the body, recording an image on photographic film or a special digital image recording plate.
The equipment typically used for this examination consists of a radiographic table, an x-ray tube and a television-like monitor that is located in the examining room or in a nearby room. When used for viewing images in real time (called fluoroscopy), the image intensifier (which converts x-rays into a video image) is suspended over a table on which the patient lies. When used for taking still pictures, the image is captured either electronically or on film.