You are scheduled to have a CT on: __________________ at: ________ am/pm.
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
5249 E. Terrace Dr
Madison, WI 53718
Check in at the main reception desk
UW Health Digestive Center
750 University Row
Madison, WI 53705
To cancel or change your appointment
Call 608-263-XRAY (9729) ext. #1 for CT
Fax Number 608-266-6120 Attention: 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
Will I have any discomfort?
CAT scans are painless but may involve
Blood test to check your kidney
The doctor will decide if blood tests are
needed before the scan and will call to
let you know.
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
Placement of an IV for contrast
A small plastic catheter is placed in a
vein in your arm to give IV contrast, a
clear dye liquid. The doctor and
Radiologist 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
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 may be
asked to withhold 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.
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.
What can I expect the day of the scan?
Depending on the exam ordered, 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
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.
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
large cups of contrast dye in the waiting area
over 30-60 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.
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.
What can I expect 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 warmth
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
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.
What can I expect after 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 would I need to contact my doctor
after the scan?
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 #4351s
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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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