Radiography - Upper GI Tract
What is Upper Gastrointestinal (GI) Tract Radiography? Back to Top
Also
called an "upper gastrointestinal (GI) series" or simply an "upper GI,"
upper gastrointestinal tract radiography is an x-ray examination of the
esophagus, stomach and first part of the small intestine (also known as
the duodenum). However, in order for the anatomy to show up on
radiographic images the upper gastrointestinal tract must be coated or
filled with a contrast material called barium, an element that appears
bright white on radiographs. The barium is given to the patient to
drink. This procedure is called "upper gastrointestinal tract
radiography" when the esophagus, stomach and duodenum are evaluated or
a "barium swallow" when only the pharynx and esophagus are evaluated.
Additionally, some patients are asked to swallow baking-soda crystals
to create gas and further improve the images; this procedure has the
modified name of "air-contrast" or "double-contrast upper GI."
What are some common uses of the procedure? Back to Top
An
upper GI procedure is done to observe digestive function or to detect
abnormalities such as ulcers, tumors or inflammation of the esophagus,
stomach and duodenum. Patients who undergo this procedure are usually
those who have difficulty swallowing, are complaining of chest and
abdominal pain or reflux (a backward flow of partially digested food
and digestive juices), or have unexplained vomiting, severe indigestion
or blood in the stool (indicating internal GI bleeding).
How should I prepare for the procedure? Back to Top
Your
doctor will give you detailed instructions on how to prepare for your
upper GI imaging. The quality of the images obtained during this
procedure can be degraded if the stomach is not empty of food.
Therefore, you will likely be asked not to eat or drink anything
(including orally administered medications, especially antacids) after
midnight on the day before the examination. Nor should you chew gum or
smoke after this time as these activities can increase stomach
secretions that also may degrade the quality of the images.
Before
the procedure begins, you will be asked to remove all jewelry and also
may be asked to wear a special gown with no metal fasteners that could
show up on the images.
What does the x-ray equipment look like? Back to Top
You
will be positioned next to a box-like machine that contains the x-ray
tube and equipment that will send the radiographic images to the
radiologist via a screen monitor stationed either in the examining room
or in a separate room.
How does the procedure work? Back to Top
Initially,
the radiologist monitors the flow of barium into the upper
gastrointestinal tract. He or she does this by viewing your upper
gastrointestinal tract on a fluoroscope, a device that projects
radiographic images in a movie-like sequence onto the screen monitor.
Still images are then obtained. The x-rays are absorbed in varying
amounts by the barium-coated upper gastrointestinal tract, producing a
negative image—similar to that from a photographic camera—which is
stored on film or on a computer.
How is the procedure performed? Back to Top
Upper
GI imaging is simple enough to be done in a radiology office or a
medical center's radiology department as an outpatient procedure. It is
usually scheduled in the morning to reduce your time of fasting.
A
radiologic technologist or nurse will position you next to the
radiographic machinery. You may be asked to swallow baking-soda
crystals (sometimes called "fizzies") to create gas in your stomach.
Then you will be asked to drink a cup of liquid barium, which resembles
a light-colored milkshake.
The radiologist will note the
passage of barium into your esophagus and stomach on the fluoroscopic
monitor. Once the upper gastrointestinal tract is adequately coated
with the barium, still radiographs are obtained.
The examination is usually completed within 20 minutes.
What will I experience during the procedure? Back to Top
The
liquid barium has a chalky taste although the taste can be masked
somewhat by added flavors such as strawberry or chocolate. If you
receive gas producing crystals you may feel the need to belch. However,
the radiologist or technologist will tell you to hold the gas in (by
swallowing your saliva if necessary) as its presence in the stomach
enhances the detail in the radiographic images.
First you will
be standing up, then lying down as the radiologist obtains pictures of
your esophagus, stomach and duodenum. You will be asked to hold your
breath to prevent blurring of the still images. Also, periodically you
will be asked to move into different positions while standing and to
roll into different positions while lying on the examining table. In
some medical centers, the technologist can minimize patient movement by
automatically tilting the examining table. These actions assure that
the barium is coating all parts of the upper GI tract. As the procedure
continues, the technologist or the radiologist may ask you to drink
more barium.
During this procedure you may hear the mechanical
noises of the radiographic apparatus moving into place. Once the
examination is complete, you will be asked to wait. At this time the
radiologist will preliminarily examine the images to be sure they
contain the necessary information for a careful evaluation later. If
the radiographs are acceptable, you can dress and leave the examining
area. Occasionally repeat imaging may be necessary.
After the
examination you can resume a regular diet and take orally administered
medications unless told otherwise by your doctor. The barium may color
stools gray or white for 48 to 72 hours after the procedure. Sometimes
the barium can cause temporary constipation, which is usually treated
by an over-the-counter laxative.
Who interprets the results and how do I get them? Back to Top
Most
patients undergo an upper GI because their primary care physician
(referring physician) has recommended it. A radiologist—though not
necessarily the one who was present at your examination—will interpret
the images and forward a report to your primary care physician. You
will then most likely meet with your physician to learn of the results
of the procedure. Depending on the interpretation, you and your primary
care physician will determine the next course of action, such as
treatment for an abnormality if necessary.
What are the benefits vs. risks? Back to Top
Benefits
- Upper gastrointestinal tract radiography is safe and the
results usually lead to an accurate analysis of the esophagus, stomach
and duodenum.
- Exposure to radiation is kept to a minimum.
- This is an extremely safe, noninvasive procedure.
Risks
- Some patients may be allergic to the flavoring added to
some brands of barium. If you have experienced allergic reactions after
eating chocolate, certain berries or citrus fruit, be sure to tell your
doctor or the technologist before the procedure.
- There
is a slight chance that some barium could be retained, leading to a
blockage of the digestive system. Therefore, patients who have an
obstruction in the gastrointestinal tract should not undergo this
examination.
- The effective radiation dose from this
procedure is about 2 mSv, which is about the same as the average person
receives from background radiation in eight months. See the Safety page
for more information about radiation dose.
- Special
care is taken during x-ray examinations to ensure maximum safety for
the patient by shielding the lower abdomen and pelvis with a lead
apron, with the exception of those examinations in which the abdomen
and pelvis are being imaged. Women should always inform their doctor or
x-ray technologist if there is any possibility that they are pregnant.
What are the limitations of Upper Gastrointestinal (GI) Tract Radiography? Back to Top
The effectiveness of this procedure is limited only by the quality of the subsequent images.
Examinations
can be delayed due to scheduling conflicts or temporary problems with
equipment. However, as with many radiologic procedures, medical centers
have begun digitizing radiographs rather than developing them on film.
Digitizing the images shortens the time of the procedure, resulting in
fewer delays and more flexible examination schedules. In addition, many
medical centers can store images on electronic media, such as computer
disks, rather than as film in large hospital libraries. Back to Top
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