CT Scan of the Chest
What is a CT scan of the chest?
CT scan is a type of imaging test. It uses X-ray and computer technology to make detailed
pictures of the organs and structures inside your chest. These images are more detailed
than regular X-rays. They can give more information about injuries or diseases of
the chest organs.
In a CT scan, an X-ray beam moves in a circle around your body. It takes many images,
called slices, of the lungs and inside the chest. A computer processes these images
and displays it on a monitor.
During the test, you may receive a contrast dye. This will make parts of your body
show up better in the image.
Why might I need a CT scan of the chest?
A CT scan of the chest may be done to check the chest and its organs for:
- Intrathoracic bleeding
- Other health problems
- Tumors and other lesions
- Unexplained chest pain
A CT scan may be done when another type of exam, such as an X-ray or physical exam,
is not conclusive.
This test may also be used to guide needles during biopsies of thoracic organs or
tumors. A biopsy is when a small piece of tissue is removed so it can be examined
in the lab. CT scans can also be done to help remove a sample of fluid from the chest.
They are useful in keeping an eye on tumors and other conditions of the chest before
and after treatment.
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 chest?
You may want to ask your healthcare provider about the amount of radiation used during
the CT scan. You should discuss the risks related to your particular situation. It
is a good idea to keep a record of your past history of radiation exposure. Tell your
healthcare provider about previous CT scans and other types of X-rays. Your risks
of radiation exposure may be related to the total number of X-ray exams or treatments
over a long period of time.
If you are pregnant or think you may be pregnant, tell your healthcare provider. Radiation
exposure during pregnancy may lead to birth defects. If you are breastfeeding, let
your healthcare provider know. Ask if you should pump and save breastmilk to use after
If contrast dye is used, there is a risk you may have an allergic reaction to the
dye. Tell your healthcare provider if you have ever had a reaction to any contrast
dye, or if you’ve had any kidney problems.
If you have kidney failure or other kidney problems, tell your healthcare provider.
In some cases, the contrast dye can cause kidney failure. This is especially true
if the patient has underlying kidney problems or is dehydrated.
If you take the diabetes medicine called metformin with the contrast, you are at risk
for developing metabolic acidosis. This is a condition where you have an unsafe change
in blood pH. People with kidney disease are more prone to kidney damage after contrast
There may be other risks depending on your specific medical problems. Make sure your
healthcare provider knows about all your medical problems before the procedure.
Certain things may make a CT scan of the chest less accurate. These include:
- Barium in the esophagus from a recent barium study
- Body piercing on the chest
- Metallic objects within the chest, such as surgical clips or a pacemaker
How do I get ready for a CT scan of the chest?
- Make a list of questions you have about the chest CT scan. Discuss these questions and
any concerns with your healthcare provider before to the procedure. Consider bringing
a family member or trusted friend to the medical appointment to help you remember
your questions and concerns.
- If your procedure involves the use of contrast dye, you may be asked to sign a consent
form that gives permission to do the procedure. Read the form carefully and ask questions
if something is not clear.
- Tell the technologist if you have ever had a reaction to any contrast dye, or if you
are allergic to iodine. If you take metformin, you will be asked to stop taking the
medicine for at least 48 hours after your injection.
- Usually, there is no fasting requirement prior to a CT scan, unless a contrast dye
is going to be used. You will be given special instructions ahead of time if contrast
is to be used and if you won’t be able to eat or drink.
- 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 and/or abdomen.
- Dress in clothes that give access to the area or that can easily be taken off.
- Follow all other instructions your healthcare provider gives you to get ready.
What happens during a CT scan of the chest?
You may have a chest CT scan as an outpatient or as part of your stay in a hospital.
Procedures may vary depending on your condition and your hospital’s practices.
Generally the chest CT scan follows this process:
- You will be asked to remove any clothing, jewelry, or other objects that may get in
the way of the procedure.
- If you are asked to remove clothing, you will be given a gown to wear.
- If you need to have a procedure done with contrast, an IV line will be started in
the hand or arm for injection of the contrast dye. For oral contrast, you will be
given a liquid contrast preparation to drink.
- You will lie on your back with your arms above your head on a scan table. The table
slides into a large, circular opening of the scanning machine. Pillows and straps
may be used to prevent movement during the procedure.
- The technologist will be in another room where the scanner controls are located. However,
you will be to see the technologist through a window. Speakers inside the scanner
will let the technologist 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 procedure.
The technologist will be watching you at all times and will be in constant communication.
- As the scanner begins to rotate around you, X-rays will pass through the body for
short amounts of time. You will hear clicking sounds, which are normal.
- The X-rays absorbed by the body’s tissues will be picked up by the scanner and sent
to the computer. The computer processes these images and displays it as an image to
be interpreted by the radiologist.
- It will be important that you stay very still during the procedure. You may be asked
to hold your breath at various times during the procedure.
- If contrast dye is used for your procedure, 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 for your procedure, you may feel some effects when the dye
is injected into the IV line. These effects include a flushing sensation, a salty
or metallic taste in the mouth, a brief headache, or nausea and/or vomiting. These
effects usually last for a few moments.
- You should tell the technologist if you feel any breathing difficulties, sweating,
numbness, or heart palpitations.
- When the procedure has been completed, you will be removed from the scanner.
- If an IV line was inserted for contrast administration, 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.
The CT scan itself causes no pain. However, having to lie still for the length of
the procedure might cause some discomfort or pain, particularly in the case of a recent
injury or invasive procedure such as 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 chest?
If contrast dye was used during your procedure, 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 your healthcare provider if you notice any pain, redness, or swelling at the
IV site after you return home. These could be signs of an infection or other type
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 chest. You may go
back to your usual diet and activities unless your healthcare provider tells you differently.
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 will you get the results
- Who to call after the test or procedure if you have questions or problems
- How much will you have to pay for the test or procedure