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Computerized Tomography (CT)

1. What is a CT scan?

A CT scan, also known as Computerized Tomography or just CT, is an X-ray technique that creates images of your internal structures that can be viewed in cross sections, like slices, rather than the overlapping images produced by most conventional X-rays that produce flat or two-dimensional images.

2. Why is it done?

A CT scan is a valuable diagnostic tool and is used for a variety of reasons such as locating a tumor or blood clot, detecting internal injuries or bleeding, detection and monitoring of diseases and much more.

3. What are the risks?

The risks associated with CT are similar to those of conventional X-ray. During the exam you will be briefly exposed to radiation but the diagnostic benefits of a CT scan far outweigh the risks.

Patients who have pacemakers or other such devices can still have a CT scan done unlike with an MRI exam. If you are pregnant or think you could be pregnant be sure to tell your doctor or the technologist performing the exam. Your doctor may want to recommend another procedure.

Also, inform your doctor or technologist if you have ever had an allergic reaction to a contrast medium or have a medical condition such as diabetes, asthma, heart disease, kidney problems or a thyroid condition as this may increase your risk of an allergic reaction. On rare occasions the contrast used in a CT scan can cause an allergic reaction. Most reactions are mild but in some cases can be severe. Please inform your technologist if you experience adverse symptoms such as itching or swelling during or following your exam. 

4. How should I prepare?

How you prepare for your CT scan will depend on which part of your body is being scanned. You may be asked to remove your clothing and wear a hospital gown, so wearing loose-fitting clothing with no metal can make this transition easier. Also, any metal objects such as jewelry can interfere with your image results so it suggested that you not wear these to your exam.

Some exams may require you to fast a few hours prior to your scan because you will be asked to drink a contrast liquid or, in some instances, have a contrast injected into your arm or delivered through an enema.

You will receive specific instructions for your particular exam prior to your exam date.

5. What should I expect?

During your CT scan, you will be asked to lie still on a table inside a large doughnut-shaped machine called a gantry. Depending on the part of your body being X-rayed you may be asked to lie on your back, stomach or side. An X-ray tube inside the machine will rotate around your body, gathering information. The information is then converted and transmitted into images that can be viewed on a monitor.

Your technologist will be nearby in a shielded room monitoring your scan and images, but they will be still be able hear you and communicate with you through an intercom.  As the X-ray tube rotates around your body, the table slowly moves through the gantry. You may be asked to hold your breath to avoid blurring the images and you may hear noises as the machines works. CT scans are painless. However, if you receive contrast through an injection you might feel a slight burning sensation or have a metallic taste in your mouth.  If you receive contrast through an enema you may experience some slight cramping or fullness. Depending on your particular exam the scan could last anywhere from five to twenty minutes.

Following your exam you can return to your routine as normal. However, if you have received contrast you may receive special instructions and it is suggested that you drink a lot of water to clear your system.

6. Who interprets the results and how do I get them?

One of our radiologists will analyze the images from your scan and then report any findings to your doctor. Your doctor will discuss the results with you and recommend any further actions.