Computed Tomography (CT)
What is Computed Tomography (CT)?
CT scanning – sometimes called CAT scanning – is a noninvasive
medical test that helps physicians diagnose and treat medical conditions.
CT scanning combines special X-ray equipment with sophisticated computers
to produce multiple images or pictures of the inside of the body.
CT Radiation Dose Reduction
Hoag is working to improve patient safety by optimizing scan parameters
that reduce patient dose as much as possible without compromising diagnostic
quality. An efficient process has been developed to monitor, manage, and
optimize patient radiation dose. Hoag is on track to reduce CT radiation
dose for CT procedures by 20%.
What to Expect
CT exams are generally painless, fast and easy. With helical CT, the amount
of time that the patient needs to lie still is reduced.
Though the scanning itself causes no pain, there may be some discomfort
from having to remain still for several minutes. If you have a hard time
staying still, are claustrophobic or have chronic pain, you may find a
CT exam to be stressful. The technologist or nurse, under the direction
of a physician, may offer you some medication to help you tolerate the
CT scanning procedure.
If an intravenous contrast material is used, you will feel a pin prick
when the needle is inserted into your vein. You may have a warm, flushed
sensation during the injection of the contrast material and a metallic
taste in your mouth that lasts for a few minutes. Some patients may experience
a sensation like they have to urinate but this subsides quickly.
If the contrast material is swallowed, you may find the taste mildly unpleasant;
however, most patients can easily tolerate it. You can expect to experience
a sense of abdominal fullness and an increasing need to expel the liquid
if your contrast material is given by enema. In this case, be patient,
as the mild discomfort will not last long.
How to Prepare
When you schedule your appointment, we will inform you about any specific
preparations depending upon the specific procedure your doctor has ordered.
Please contact the Scheduling Department at 949/764-5573 if you have any
You should wear comfortable, loose-fitting clothing to your exam. You
may be given a gown to wear during the procedure.
If your physician has ordered your CT procedure with radiographic contrast:
- You should inform your physician if you have any allergies. If you have
been told you are allergic to contrast or have ever had a reaction to
Iodine or any form of contrast media, your doctor may prescribe medications
to reduce the risk of an allergic reaction. A Radiology nurse should contact
you. If you have not been contacted by a Radiology nurse at least 24 hours
prior to your appointment, please contact the Imaging Scheduler immediately.
- If you have diabetes, kidney problems, lupus, surgery on your kidneys or
multiple myeloma, you must have lab work that includes a BUN and Creatinine
performed within 30 days of your exam. If you are over the age of 65,
you must have lab work within 90 days of your exam. This provides us with
information regarding your current kidney function. Please call your physician
if you have not had this blood work.
- If you are currently receiving Dialysis, please schedule your dialysis
to follow your procedure with Contrast or the following day. It is imperative
you have dialysis no later than the following day after you have received
contrast for your procedure.
- If you have been diagnosed with diabetes and/or you are currently taking
any of the following medications: Metformin, Gluicophage, Glucophage XR,
Fortamet, Riomet, Metaglip, Glucovance, Actoplus Met, Avandament or Junamet,
stop taking your medication for a total of 48 hours after your exam. You
must contact your physician for alternative medications and instructions
prior to your exam
- We encourage you to hydrate with oral fluids at least 24 hours prior to
your study. You may have only clear liquids as well as your necessary
medications 2 hours before your exam.
You may receive additional specific instructions when you schedule your
appointment depending upon the type of procedure that will be performed.
Some types of scans require fasting beforehand. Please complete, print
out and bring the following forms to your appointment:
Outpatient Medication Reconciliation -
CT Outpatient Questionnaire -
Locations where Hoag provides CT scan services