Computed Tomography (CT) scans are performed on a sophisticated machine that focuses a narrow x-ray beam to make images of anatomical structures within the body. CT images are in thin slices, showing multiple sections of the region being examined. CT scans are commonly used to picture the brain, chest, heart, lungs, abdomen, pelvis, bones, blood vessels, and sinuses

Some types of CT scans can be done with little or no preparation on the part of the patient. In other instances, for example during a CT scan of the abdomen or pelvis, the patient is often required to drink a liquid containing a contrast dye to better outline the stomach or intestines during the scan. In other types of CT scans, a patient may receive an injection of iodine into the blood vessels. Iodine causes a contrast that helps put the body tissues that are being examined into sharper relief. The kind of preparation necessary varies with each type of CT scan. See our Preparation for Exams page for more information.

How much radiation do I get from a CT scan?
New CT scanning machines are designed to expose to radiation only the small part of your body that is being examined. The amount of radiation you receive is comparable to the same amount you get for plain x-rays of the abdomen or spine. One of our goals for our CT scan is to expose you to as little radiation as possible and still get the images needed to make a diagnosis.

The Imaging Center utilizes Diagnostic CT Shielding to reduce exposure to scattered radiation to our patients.

How do I prepare for my CT scan of the abdomen or pelvis?
You need to drink a liquid containing a contrast dye before the study. You may pick up this drink at the Harmony campus. Drink one 8-ounce glass the night before your study. The next day, usually starting about three to five hours before the exam, slowly drink the rest of the drink—usually 6 to 8 ounces every 30 minutes until the study starts. It is better to drink small amounts frequently rather than large amounts at once.

I am allergic to x-ray dye. What do I do?
If your CT study requires intravenous (IV) contrast, you should speak with a radiology nurse the day before the study. Usually the study can be safely done with contrast even if you have an allergy history. Commonly we treat you the night before and the morning of your study with medicines designed to decrease your chance of allergic reaction. These medicines include Benadryl (which is a medicine commonly used for itching or colds that you can buy at the grocery store), Tagamet (which is usually used for stomach pain and ulcers but also has a side effect of decreasing allergic reactions), and steroids. If you have asthma, please bring your inhaler with you to the exam. You may be asked to use it before the study.

How do I know if I am allergic to the x-ray contrast (x-ray dye)?
True allergic reactions to the x-ray contrast are very rare, in the range of 1 in 50,000. If your CT exam requires IV contrast, we will ask you to fill out a questionnaire about other allergies you may have. People with a history of allergy to the x-ray dye, who have asthma, or who have a history of multiple food or drug allergies may be at a mildly increased risk of being allergic to the x-ray contrast. We commonly treat those people with the medicines described above.

Some of my relatives are allergic to x-ray dye. Does that mean that I am more likely to be allergic?
In general, no. We do not "pre-treat" patients for possible contrast reaction in the instance of those who have relatives who have such an allergy.

Am I going to feel bad after I get this contrast injection, or can I do all of my regular activities after I have this injection?
You should not feel anything from the contrast injection except a possible warm or flushed feeling as it is being injected. This sensation passes very quickly and you will be feeling normal again when the examination is finished. After the examination, you should drink plenty of fluids to help your body eliminate the contrast. Contrast administration will not result in any limitations of regular activities.

How do I prepare for a CT scan?
If you have allergies as described above, please call (970) 297-6202 and ask to speak with one of the radiology nurses at least one day before your CT scan. For CT studies in which you will get IV or oral contrast, please do not eat or drink anything except for the contrast liquid for three hours prior to the study.

How long will my CT exam take?
The CT scan itself usually takes 10 to 15 minutes. If you receive IV contrast, it may take another 15 to 30 minutes.

When will my doctor get the test results?
Our radiologists look at all of your CT images and compare the study with any previous exams you may have had. Our typed report is available to your doctor usually within three days.

I have more questions. Who can I ask about them?
Please call the Imaging Center at (970) 282-2900. The receptionist will direct you to someone who can answer your questions.