interstitial cystitis See CYSTITIS.
intravenous pyelogram (IVP) A diagnostic imag-
ing procedure to evaluate the flow of BLOODand
URINEthrough the KIDNEYS, ureters, BLADDER, and
URETHRA. IVP requires moderate preparation that
typically includes taking a laxative the night
before the scheduled procedure to empty the
intestines so the IVP provides clear visualization of
the renal structures and then consuming nothing
by mouth until after the IVP. An IVP takes about
an hour to complete though does not require any
recovery time after the procedure.
A radiologist performs IVP by injecting an
iodine-based contrast medium into a VEINin the
arm. Some people experience a mild burning sen-
sation with the contrast medium’s injection. The
person lies on the X-RAYtable, and the radiologist
takes X-rays at timed intervals as the contrast
medium travels through the bloodstream and into
the kidneys.
Sometimes the radiologist uses an inflatable
compression belt, applied around the abdomen and
back, to slow progress of the contrast medium
through the kidneys. Near the end of the procedure
the person urinates to empty the bladder, after
which the radiologist takes a final series of X-rays.
It is important to drink plenty of water after an
IVP to help flush the residual contrast medium
from the body. Complications and side effects are
rare, the most common being an allergic reaction
to the contrast medium. People who have allergies
to iodine or shellfish should discuss the possibility
of sensitivity to the contrast medium with the
radiologist or urologist before undergoing the IVP.
The IVP provides an abundance of information
about the structure and functions of the urinary
system that is useful for the urologist in reaching
or confirming diagnosis of numerous conditions
affecting the kidneys.
See also COMPUTED TOMOGRAPHY(CT) SCAN; CYS-
TOURETHROGRAM.198 The Urinary System