pyelogram /pī″əlōgram′/ [Gk, pyelos, pelvis, gramma, record] , a radiographic picture of the kidneys and ureters taken after the IV or intraureteral injection of a radiopaque contrast medium. It shows the size and location of the kidneys, the outline of the ureters and bladder, the filling of the renal pelves, the patency of the urinary tract, and any cysts or tumors within the kidneys. Preparation for an IV pyelogram includes withholding of fluids for 8 hours and testing for sensitivity to the iodine in the contrast medium; people with known sensitivity are not tested lest anaphylaxis occur. Patients able to tolerate the contrast medium may feel warm and experience a salty taste when it is injected. Retrograde pyelograms, which demonstrate filling of the renal collecting structures, are taken after the contrast medium is injected into the ureters by means of catheters in a cystoscope introduced through the urethra into the bladder. Also called urogram.
