intravenous pyelography (IVP), a radiographic technique for examining the structure and function of the urinary system. A contrast medium is injected intravenously, and serial x-ray films are taken as the medium is cleared from the blood by the kidneys. The renal calyces, renal pelvis, ureters, and urinary bladder are all visible on the radiographs. Tumors, cysts, stones, and many structural and functional abnormalities may be diagnosed with this technique. Fasting and bowel cleansing with a cathartic or an enema before the procedure improve visualization of the urinary tract. The patient may also be asked to void immediately before injection of the contrast medium to prevent dilution of the medium in the bladder and immediately afterward to check residual urine in the bladder. Also called descending urography, excretory urography, intravenous urography, pyelography.
