UGI Radiology
Radiograph from double-contrast upper
GI showing a normal duodenum |
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. 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?
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 proximal small intestine. 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 bleeding).
How should I prepare for the procedure?
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 morning of the examination.
Nor should you chew gum or smoke after this time as these activities
can cause stomach secretions, which 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 equipment
look like?
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?
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?
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. Then, you will be given a cup of
liquid barium, which resembles a light-colored milkshake. After
drinking about 20 ounces of barium, you may be asked to swallow
baking-soda crystals (sometimes called fizzies), which will create
gas in your stomach.
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 30 minutes.
What will I experience during the procedure?
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 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 and stomach. 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 esophagus and stomach. As the procedure continues, the
technologist or the radiologist may want 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?
Most patients undergo an upper GI because their primary care
physician (also called the 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?
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 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 GI Tract Radiography?
- 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 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 discs, rather
than as film in large hospital libraries.