Computed Tomography (CT) Scan of the Spine
What is a CT scan of the spine?
Computed tomography 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, and organs.
CT scans are more detailed than standard X-rays.
In standard X-rays, a beam of energy is aimed at the body part being studied. A plate
behind the body part captures the variations of the energy beam after it passes through
skin, bone, muscle, and other tissue. While healthcare providers can get much information
from a standard X-ray, it doesn't give a lot of detail about internal organs and other
In a CT scan, an X-ray beam moves in a circle around the body. This allows many different
views of the same organ or structure. The X-ray information is sent to a computer
that interprets the X-ray data and displays it in a 2-D form on a monitor.
CT scans may be done with or without contrast. Contrast refers to a substance taken
by mouth or injected into an IV (intravenous) line that causes the particular organ
or tissue under study to show up more clearly on the scan.
CT scans of the spine can provide more detailed information about the bones of the
spine (vertebrae), the disks between the vertebrae, and other spinal structures and
tissues than standard X-rays of the spine. CT scans can give healthcare providers
more information related to injuries or diseases of the spine.
Why might I need a CT scan of the spine?
A CT scan of the spine may be used to check the spine for:
A CT scan may be done when another type of exam, such as an X-ray, MRI, or physical
exam, doesn't give enough information.
A CT of the spine may also be used to assess the effects of treatment of the spine,
such as surgery or other therapy.
There may be other reasons for your healthcare provider to recommend a CT scan of
What are the risks of a CT scan of the spine?
You may want to ask your healthcare provider about the amount of radiation used during
the CT scan and the risks related to your particular situation. Radiation from CT
scans varies, but it may be up to 100 times greater than a normal chest X-ray. It's
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 tell your provider. Risks linked to radiation
exposure may be related to the number of X-ray exams or treatments over a long period.
Tell your provider if you're pregnant or think you may be. Radiation exposure during
pregnancy may lead to birth defects. If you need to have a CT of the spine, special
precautions will be taken to reduce the radiation exposure to the fetus.
If you're breastfeeding, talk with your provider about delaying breastfeeding after
getting contrast. There are conflicting recommendations on this topic.
If contrast dye is used, there is a risk for allergic reaction to the dye. Tell your
provider if you're allergic to or sensitive to medicines, contrast, or iodine. Most
people won't have any problems from contrast dye. But tell your provider if you've
ever had a reaction to any contrast dye. Having a seafood allergy won't stop you from
Tell your provider if you have any kidney problems. In some cases, the contrast dye
can cause kidney failure. People with kidney disease are more likely to have kidney
damage after contrast exposure.
There may be other risks depending on your specific health condition. Talk about any
concerns with your provider before the test.
How do I get ready for a CT scan of the spine?
The CT technologist will explain the test and you can ask questions.
If your CT scan involves the use of contrast dye, you'll be asked to sign a consent
form that gives permission to do the scan . Read the form carefully and ask questions
if anything is unclear.
Tell the technologist if you've ever had a reaction to any contrast dye or if you're
allergic to iodine.
You don't usually need to fast before 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 need to fast.
Tell your provider about all prescription and over-the-counter medicines, vitamins,
herbs, and supplements you're taking.
Tell your provider about any recent illnesses or other health conditions you have,
such as heart disease, kidney disease, asthma, diabetes, or thyroid problems. These
can increase the risk for problems.
Tell the technologist if you're pregnant or think you may be.
Tell the technologist if you have any body piercings on your chest or stomach.
If you're claustrophobic, talk about taking medicine before the test with your provider.
Your provider may have other instructions on how to get ready.
What happens during a CT scan of the spine?
CT scans can be done on an outpatient basis or as part of your hospital stay. Steps
may vary depending on your condition and your healthcare provider’s practices.
Generally, a CT scan of the spine follows this process:
You'll be asked to remove any clothing, jewelry, or other objects that may interfere
with the test, such as eyeglasses, hairpins, dentures, and possibly hearing aids.
If you're asked to remove clothing, you'll be given a gown to wear.
If you're to have a scan done with contrast, a healthcare professional will start
an IV (intravenous) line in your hand or arm for injection of the contrast dye.
You'll lie on a narrow table that slides into a large, circular opening of the ring-shaped
scanning machine. Pillows and straps may be used to help keep you still during the
The technologist will be in another room where the scanner controls are located. But
you'll be in constant sight of the technologist through a window. Speakers inside
the scanner will allow the technologist to talk with you and hear you. You'll 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
The scanner will start to rotate around you and X-rays will pass through your body
for short amounts of time. You'll hear clicking and whirring sounds, which are normal.
The X-rays absorbed by the body's tissues will be detected by the scanner and transmitted
to the computer. The computer will transform the information into an image to be interpreted
by the radiologist.
It will be important for you to 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'll 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 only last for a few
Tell the technologist if you feel any breathing difficulties, sweating, numbness,
or heart palpitations.
When the test has been completed, you'll be removed from the scanner.
If an IV line was inserted, it will be removed.
You may be asked to wait for a short time while the radiologist examines the scans
to make sure they are clear.
While the CT test itself causes no pain, having to lie still for the length of the
test might be uncomfortable, particularly if you’ve recently been injured or had surgery.
The technologist will use all possible comfort measures and complete the test as quickly
as possible to minimize any discomfort or pain.
What happens after a CT scan of the spine?
If contrast dye was used, you may be watched for a period for any side effects or
reactions to the contrast dye, such as itching, swelling, rash, or trouble breathing.
Tell the radiologist or your healthcare provider right away if you notice any of these
If you notice any pain, redness, or swelling at the IV site after you go home, tell
your provider as this could be a sign of infection or other type of reaction.
Otherwise, there is no special type of care needed after a CT scan of the spine. You
may go back to your usual diet and activities unless your provider tells you differently.
Your provider may give you other instructions after the test, 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