CT Scan of the Abdomen
What is a computed tomography (CT) scan of the abdomen?
A computed tomography (CT) scan is an imaging test that uses X-rays and a computer
to make detailed images of the body. A CT scan shows details of the bones, muscles,
fat, soft tissues, organs, and blood vessels. They are more detailed than regular
In a CT scan, an X-ray beam moves in a circle around your body. This allows many different
views of the same part of the body. The X-ray information is sent to a computer that
interprets the X-ray data and displays it on a monitor.
During some tests, you receive a contrast dye. This can be given orally, though a
vein, or both ways. It makes parts of your body show up better in the image.
CT scans of the abdomen can give more detailed information than regular X-rays. CT
scans can give healthcare providers more information about injuries or diseases of
the abdominal organs.
Why might I need a CT scan of the abdomen?
The abdomen contains many organs. These include the gastrointestinal, urinary, endocrine,
and reproductive systems. A CT scan of the abdomen may be used to check the abdomen
and its organs for:
Tumors or other lesions
Blood vessel problems
Unexplained belly pain
Other health problems
A CT scan may be done when another type of exam, such as an X-ray or physical exam,
is not conclusive.
It may also be used to check tumors and other conditions of the abdomen before and
after treatment. Or it can be done to guide the needle during biopsies and other procedures.
A biopsy is when a small piece of tissue is removed so it can be examined in the lab.
There may be other reasons that you may need a CT scan of the abdomen. Check with
your healthcare provider for more information.
What are the risks of a CT scan of the abdomen?
You may want to ask your healthcare provider about the amount of radiation used during
the CT scan. They can also explain your personal risks. CT scan radiation varies,
but it may be up to 100 times greater than a regular chest X-ray. It is a good idea
to keep a record of your radiation exposure, such as previous CT scans and other types
of X-rays, so that you can inform your healthcare provider. Risks linked to radiation
exposure may be related to the cumulative number of X-ray exams or treatments over
a long period.
If you are pregnant or think you may be pregnant, tell your healthcare provider. Radiation
exposure during pregnancy may lead to birth defects.
If contrast dye is used, there is a risk for allergic reaction to the dye. If you
are allergic to or sensitive to medicines, contrast, or iodine, tell your healthcare
If you are breastfeeding, ask if the contrast dye may pass to your breastmilk. Nursing
mothers should discuss with their provider whether to delay breastfeeding or to pump
enough breastmilk for a few days after receiving contrast. There are currently conflicting
recommendations on this topic.
People taking the medicine metformin for diabetes should alert their healthcare provider
before having IV (intravenous) contrast. It can cause a rare condition called metabolic
acidosis. If you take metformin, you will be asked to stop taking it 48 hours before
your CT scan. A blood test may be needed before you can start taking metformin again.
People with kidney failure or other kidney problems should talk with their healthcare
provider. In some cases, the contrast dye can cause kidney failure. People with kidney
disease are more prone to kidney damage after contrast exposure.
There may be other risks depending on your specific medical problems. Be sure to discuss
any concerns with your healthcare provider before the scan.
Certain things may make a CT scan of the abdomen less accurate. These include:
Metallic objects within the abdomen, such as surgical clips
Barium in the intestines from a recent barium study
Stool or gas in the bowel
Total hip replacement
How do I get ready for a CT scan of the abdomen?
Your healthcare provider will explain the scan to you and give you a chance to ask
If your CT scan involves the use of contrast dye, you will be asked to sign a consent
form that gives permission to do the scan. Read the form carefully and ask questions
if anything is not clear.
Tell the technologist if you have ever had a reaction to contrast dyes or if you are
allergic to iodine.
Generally, there is no fasting (not eating) requirement prior to a CT scan, unless
a contrast dye is to be used. Your healthcare provider will give you special instructions
ahead of time if contrast is to be used and you won’t be able to eat or drink.
Tell your healthcare provider about all the medicines, vitamins, herbs, and supplements
you are taking.
Tell the technologist if you are pregnant or think you may be pregnant.
Tell the technologist if you have any body piercings on your chest or abdomen.
Based on your medical condition, your healthcare provider may request other preparations.
If you are claustrophobic, discuss medicine to take beforehand with your healthcare
provider to help with the test.
What happens during a CT scan of the abdomen?
You may have a CT scan as an outpatient or as part of your stay in a hospital. Procedures
may vary depending on your condition.
Generally, a CT scan of the abdomen follows this process:
You will be asked to remove any clothing, jewelry, or other objects that may interfere
with the scan.
If you are asked to remove clothing, you will be given a gown to wear.
If you are to have a scan done with contrast, an IV line will be started in your hand
or arm for injection of the contrast dye. For oral contrast, you will be given a liquid
contrast to drink. In some situations, the contrast may be given rectally.
You will lie on a narrow scan table that slides into a large, circular opening of
the ring-shaped scanning machine. Pillows and straps may be used to help prevent movement
during the scan.
The technologist will be in another room where the scanner controls are located. However,
you will be able to see the technologist through a window at all times. Speakers inside
the scanner will allow the technologist to talk to you and hear you. You will have
a call button so that you can let the technologist know if you have any problems during
the scan. The technologist will be watching you at all times and will be in constant
As the scanner begins to rotate around you, X-rays will pass through your body for
short amounts of time. You will hear clicking and whirring sounds, which are normal.
The X-rays absorbed by the body’s tissues will be found by the scanner and sent to
the computer. The computer will send the information into an image to be interpreted
by the radiologist.
It will be important that you stay very still during the scan. You may be asked to
hold your breath for a short time at various times during the scan.
If contrast dye is used, you will be removed from the scanner after the first set
of scans has been completed. A second set of scans will be taken after the contrast
dye has been given.
If contrast dye is used, you may feel some effects when the dye is injected into the
IV line. These effects include a warm, flushing sensation, a salty or metallic taste
in the mouth, a brief headache, or nausea. These effects usually last only for a few
You should tell the technologist if you have any trouble breathing, sweating, numbness,
or heart palpitations.
When the scan has been completed, you will be removed from the scanner.
If an IV line was inserted, it will be removed.
You may be asked to wait for a short period of time while the radiologist examines
the scans to make sure they are clear.
While a CT scan itself causes no pain, having to lie still for the length of the procedure
might cause some discomfort or pain, particularly if you’ve recently been injured
or had surgery. The technologist will use all possible comfort measures and complete
the procedure as quickly as possible to minimize any discomfort or pain.
What happens after a CT scan of the abdomen?
If contrast dye was used, you may be watched for a period of time for any side effects
or reactions to the contrast dye. These include itching, swelling, rash, or trouble
breathing. Tell the radiologist or your healthcare provider right away if you notice
any of these symptoms.
Tell your healthcare provider if you notice any pain, redness, or swelling at the
IV site after you go home. These could be signs of infection or other type of reaction.
If you are given contrast by mouth, you may have diarrhea or constipation after the
Otherwise, you don't need any special care after a CT scan of the abdomen. You may
go back to your usual diet and activities unless your healthcare provider tells you
Your healthcare provider may give you other instructions depending on your situation.
Before you agree to the test or the procedure, make sure you know:
The name of the test or procedure
The reason you are having the test or procedure
What results to expect and what they mean
The risks and benefits of the test or procedure
What the possible side effects or complications are
When and where you are to have the test or procedure
Who will do the test or procedure and what that person’s qualifications are
What would happen if you did not have the test or procedure
Any alternative tests or procedures to think about
When and how you will get the results
Who to call after the test or procedure if you have questions or problems
How much you will have to pay for the test or procedure