CT/CAT Scan
You are scheduled to have a CT on: __________________ at: ________ am/pm.
UW Hospital
600 Highland Ave
Take the Atrium elevators to 3rd floor
Check in at the G3/3 reception desk
Research Park Clinic
621 Science Drive
Madison, WI 53711
Check in at 2nd Floor Radiology
East Clinic
5249 E. Terrace Dr
Madison, WI 53718
Check in at the main reception desk
UW Health Digestive Center
750 University Row
Madison, WI 53705
Phone Numbers
To Cancel or change your appointment
Call 608-263-XRAY (9729) ext. #1 for CT
Fax Number 608-266-6120Attention: CT Department
What is a CT scan?
Your doctor has ordered a computerized tomography (also referred to as a CT or CAT scan). A
CAT scan is a special computer that makes detailed pictures of your internal organs and bones
through the use of x-rays. The CT is very useful tool that helps the doctors look closely at the
specific areas.
Will I have any discomfort?
CAT scans are painless but may involve other tests.
Blood test to check your kidney function.
The doctor will decide if blood tests are needed before the scan and will call to let you know.
If you are scheduled to have your blood drawn on the day of your CT scan please have your
doctor order the IV to be left in for the CT procedure. This will help you to avoid having a
second needle stick. If you are having blood drawn any time before the day of your test it is
best to bring those results with you or have them faxed to the UW Hospital Fax number
608-266-6120.
Placement of an IV for contrast injection
A small plastic catheter is placed in a vein in your arm to give IV contrast, a clear dye liquid.
The doctor will decide if you will need IV contrast because it depends on what he or she is
looking for.
A central line (GROSHONG®, HICKMAN®, Infusaport, PAS or PICC) cannot be used for
IV contrast. If we are not able to access your arm or hand veins and your central line is
working, this may be an option. It will need to be cleared with the Radiology doctor. Purple
Power PICC Lines or Power Infusa Ports are okay to use.
Drinking contrast dye
Some scans require patients to drink 2-3 large glasses of cold contrast or water to help
highlight the area being scanned. The technologist will decide the amount based on the scan
being ordered. You will be given a drinking schedule to follow. It is common for patients to
get chilled while drinking. You may want to bring extra clothing like a jacket or sweater to
wear during this time.
What are the risks of a CT scan?
CT scan risks are similar to those of x-rays.
If you are pregnant or suspect you might be pregnant tell your doctor. Your doctor will
order a pregnancy test to be done within 24 hours of the exam at a hospital or clinic. This is
to reduce the risk to your fetus of being exposed to radiation. Your doctor may suggest that
you postpone the CT or choose a different exam that doesn't involve radiation, such as an
ultrasound.
If you are breast-feeding: In the past, a woman who was breast feeding and had a CT scan
with IV contrast was told to "pump and dump" for 24 hours after she was given the contrast.
This was to make sure no contrast was transferred to an infant while breast feeding.
Iodinated contrast may lead to direct toxicity and allergic sensitization or reaction. There
have been no reports on this happening. A few studies have shown the amount of iodinated
contrast in breast milk is small. The infant absorbs even less than that of the mother.
However, if the mother decides not to breast feed, she should throw away any milk for the
next 24 hours after being given contrast.
If you have diabetes and are taking any of the pills listed below you will need to hold these
medicines for 48 hours (2 days) after your scan is done. Please talk with your doctor about
other ways to control your blood sugar during this time. You may take these medicines
before your scan but not after.
Avandamet®
Glumetza®
ActoPlus Met®
Glucophage®
Janumet®
Fortamet®
glyburide
Metaglip®
metformin
Glucovance®
Riomet®
If you have allergies to contrast dye, let your doctor who orders the scan know you are
allergic to contrast or iodine. You can be given medicine to prevent a reaction. Therefore,
your scan will not need to be rescheduled.
The Day of Your Scan
Do not eat or drink for 4 hours before you arrive for your scan. You may take any prescribed
pills ordered by your doctor with a few sips of water.
If you have diabetes, we prefer to do your CT scan in the morning. If your scan is early, do not
eat breakfast and take one-half of your morning insulin dose. If your scan is after 12 noon, you
can eat up to 4 hours before your scan and take your normal insulin dose. When you arrive, tell
the nurse or tech that you have diabetes and if you are take any of the medicines listed above.
Please wear loose clothing so your arm is easy to access for your IV.
For the scan you will lie on a table fully dressed. For chest scans, your bra must be taken off if
it has metal in it. Sports bras are okay. If you are wearing jeans or any other metal on the area to
be scanned, you will be covered with a sheet and the metal will be slipped out of the scan range.
Once you have checked in at the reception area, a nurse or technologist from the CT area will
come to get you.
If you need an IV, you will be brought back to a private room where a nurse will ask you a few
questions, answer any questions you might have, and start your IV.
If you are having an abdomen or pelvis scan, the technologist will have you drink 2-3 large cups
of contrast dye in the waiting area over 45-90 minutes. This dye is mixed with a sugar-free
(Nutra Sweet®) flavored drink. This will fill your stomach and your small and large bowel, to
highlight them for the scan. You may use the restrooms as needed.
During the Scan
The CT scan and IV contrast
You will be placed on a table that can move
in and out of the scanner. During the scan
you will hear the machine make a humming
noise. You may be asked to hold your
breath for short amounts of time. If you
need dye during the scan, the contrast
injection will be placed in your IV line
during the scan. When the contrast is given,
you will have a brief feeling of heat
throughout your body. You may also have a
metallic taste in your mouth. While you
receive the IV contrast, it is very common to
feel as if you have urinated when this has
not really occurred. This feeling is very
brief and often lasts about one minute.
If you receive IV contrast during your CAT scan, you must drink six 8 oz glasses of
nonalcoholic and non-caffeinated beverages within the next 12-24 hours to make sure the
contrast is flushed out of your body.
The machine and room are very large, with a large open space. People who are claustrophobic
often do not have problems during the scan. There will be no pain during the scan. If you do
have problems during or after the scans, please tell the staff. Most scans take about 15-20
minutes to complete. Some may take an hour.
When the scan is done
Scan results will be sent to the doctor who ordered the scan for you. If you have not received a
report within a couple of weeks, please call your doctor’s office.
When to Call the Doctor
If you have questions or concerns before or after your CT scan, please call your referring doctor
or clinic.
For more information see our website at www.uwhealth.org. Search: health information, CT
scan.
The Spanish version of this Health Facts for You is #6886.
HICKMAN® and GROSHONG® are registered trademarks of C.R. Bard, Inc. and its related company, BCR, Inc.
Your health care team may have given you this information as part of your care. If so, please use it and
call if you have any questions. If this information was not given to you as part of your care, please check
with your doctor. This is not medical advice. This is not to be used for diagnosis or treatment of any
medical condition. Because each person’s health needs are different, you should talk with your doctor or
others on your health care team when using this information. If you have an emergency, please call 911.
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