What Is an Abdominal CT Scan?
A CT (computed tomography) scan is a type of specialized X-ray
that can show cross-sectional images of a specific area of the body. In a CT
scan, the machine circles the body and sends the images to a computer, where
they are viewed by a technician.
Each picture is viewed as a cross section (like a piece of
sliced bread) of the body to provide doctors with alternate views of your body.
An abdominal CT scan helps doctors see the organs, vessels, and bones in the
A CT scan is also referred to as a CAT scan. Keep reading to
learn why your doctor may order an abdominal CT scan, how to prepare for your
procedure, and any possible risks and complications.
Why an Abdominal CT Scan Is Performed
Abdominal CT scans are used when a doctor suspects that
something might be wrong in the abdominal area but can’t find the specifics
through a physical examination.
Some of the reasons your doctor may want you to undergo an
abdominal CT scan include:
- abdominal pain
- palpable abdominal mass
- kidney stones (to check for size and location of
- unexplained weight loss
- infections, such as appendicitis
- to check for intestinal obstruction
- inflammation of the intestines, such as Crohn’s
- injuries following trauma
- recent cancer diagnosis
- blood clots
How to Prepare for an Abdominal CT Scan
Your doctor will probably ask you to fast for two to four
hours before the scan. You may be asked to stop certain medications prior to your test. You may want to wear loose, comfortable clothing because
you will be required to lie down on the table. You may also be given a hospital
gown to wear. You’ll be instructed to remove any jewelry and other unnecessary
items from your body.
Depending on the reason you’re getting your CT scan, you may
need to drink a large glass of oral contrast, a liquid that contains barium and
has a chalky taste and texture. Barium is a chemical that helps doctors better
see the lining of your organs.
You’ll usually wait between 60 and 90 minutes after drinking
the contrast for it to distribute into the bowels.
Before going into your CT scan, tell your doctor if you have
any of the following conditions:
- allergy to oral contrast (barium)
- diabetes (fasting may lower blood sugar levels)
How an Abdominal CT Scan Is Performed
An abdominal CT scan is performed in a hospital’s radiology
department or a clinic that specializes in diagnostic procedures. Once you’re
dressed in your hospital gown, a CT technician will have you lie down on the
Depending on the reason for your scan, you may be hooked up
to an IV so contrast dye can be put through your veins (it is critically important to convey any dye allergies to your doctor,
and to the X-ray staff). This contrast helps the machine get better images of
your blood vessels and organs. You may also have to swallow a barium shake.
The technician may require you to lie in a specific position
during the test. They may use pillows or straps to make sure that you stay in
the right position long enough to get a good quality image. You may also have
to hold your breath briefly during parts of the scan.
Using a remote control from a separate room, the technician
will move the table into the CT machine, which looks like a giant doughnut made
of plastic and metal. You will most likely go through the machine several
After a round of scans, you may be required to wait while
the technician reviews the images to ensure they are clear enough for your
doctor to read correctly.
A typical abdominal CT scan takes between 10 and 30 minutes
The Risks of an Abdominal CT Scan
An abdominal CT is a relatively safe procedure, but there
are risks. You’ll be exposed to ionizing radiation during the test. This amount
of radiation is higher than the amount with an X-ray. As a result, an abdominal
CT scan slightly increases your risk for cancer. A 2009 study found that of
the 72 million CT scans done in 2007, it was suspected that 29,000 led to cancer. This is a
relatively small risk.
Since exposure to radiation during pregnancy may increase
the risk of birth defects, it’s important to tell your doctor if you are or may
be pregnant. As a precaution, your doctor may recommend another imaging test instead,
such as an MRI or an ultrasound.
You may develop a skin rash or itchiness if you're allergic
to the oral contrast. A life-threatening allergic reaction can also happen, but
this is rare. Tell your doctor about any sensitivities to medications, or any
kidney problems you have. IV contrast can increase the risk of kidney failure
if you're dehydrated or have a pre-existing kidney problem.
Since children are more sensitive to radiation exposure,
your child's doctor may order a CT scan as a last resort, and only if other
tests cannot confirm a diagnosis.
After an Abdominal CT Scan
After the test, you can typically go about your day. Side effects of barium contrast can include abdominal cramping, diarrhea, nausea, vomiting, or constipation. If these symptoms become severe you should contract your doctor right away. Fewer than 3 out of 100 people will experience other symptoms such as immediate rash, itching, retching, coughing and dizziness. People with a history of asthma or allergies are at higher risk for these reactions.
Results for an abdominal CT scan typically take a day to
process. Your doctor will schedule a follow-up appointment to discuss your
results and how to proceed, depending on what was found.