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CT: Computed Tomography


Computed Tomography (CT or CAT Scan) is an x-ray technique that allows us to see organs that cannot be seen with conventional x-rays.

Computed Tomography (CT)
While a conventional x-ray will show your bones and subtle outlines of other organs, CT images will reveal the bones and organs with a high degree of precision. A conventional x-ray uses a stationary machine to focus beams of radiation on a specific part of your body, while a CT uses an x-ray generating device that rotates around your body and a powerful computer to create cross-sectional images (slices) of the inside of your body.

Unlike an MRI, CT Scans can be performed if you have a pacemaker. If you are pregnant, or suspect you are, tell your doctor. Your doctor may suggest an alternative exam that doesn't require radiation such as an MRI or ultrasound.

Preparation
Tell your doctor if you are pregnant or suspect you may be pregnant. Your doctor may postpone the exam or choose an alternative exam to reduce the possible risk of exposing your baby to radiation.

Preparation for your CT scan depends on which part of your body will be scanned.

Some scans, typically abdominal and pelvic, require a liquid contrast medium prior to your exam. Contrast medium can be taken by mouth or intravenously. If you are scheduled for a CT abdomen and/or pelvis, please arrive two hours before appointment time for contrast prep.

You may eat a normal diet and take daily medications, however, depending on the body area being scanned, your doctor may ask you to temporarily modify your diet, take laxatives, enemas or suppositories.

If you are receiving contrast during your exam please consider the following:
You may take your usual medications with water, but do not eat anything for at least 4 hours before your test. You may have clear liquids for 4 hours prior.
If you are on Glucophage (Metformin) you should take your morning dose and you should see your doctor for a blood test before taking Glucophage again.

Contrast medium can cause allergic reactions or may be difficult for some individuals to receive during the exam. We will ask you a series of questions at the time of scheduling and at the time of your exam to be sure all patients are properly screened before receiving contrast.

You may be asked to remove your clothing and put on a hospital gown.

You will be asked to remove all metal or electronic objects from your body before the exam as these objects interfere with the quality of the images.

Exam
CT scans are painless and can be expected to last no more than an hour depending on the required preparation and whether use of a contrast medium is included.

Our technologist will prepare and guide you by explaining the procedure, assisting in removal of jewelry and other metal objects, and positioning you to ensure the highest quality images are obtained from your exam.

You may feel a brief sensation of heat or experience a metallic taste in your mouth if an intravenous contrast medium is used.

You will lie on a narrow table that slides through the opening of a large device called the gantry. The table can be raised or lowered. During a CT scan, a special head cradle, pillows or straps may be used to help you remain in position.

The table will move slowly through the gantry as the X-ray tube rotates around your body. You may be asked to hold your breath while the table is moving to avoid blurring the images. You will hear noises similar to a small airplane or spinning clothes dryer as the X-ray rotates to create images of your body.

The technologist supervises the CT scan from a control room and can always see and hear you. An intercom is used to communicate.

Although it is rare, there is a slight risk of an allergic reaction to contrast material if your exam requires it. Most reactions result in itchiness or hives. For individuals with asthma who are allergic, the reaction can be an asthma attack. In very rare instances, an allergic reaction may cause swelling in your throat or other areas of your body. Immediately tell your technologist or doctor if you experience any of these symptoms during or after your exam.

Our staff and physicians are prepared should any type of emergency situation occur.

Results
When your exam is complete you may leave and resume regular activities based on your doctor's instructions. If you received a contrast medium you will be given instructions to help remove the medium from your body. This will likely include drinking lots of fluids.

A radiologist will review your exam images and report the findings to your doctor within 24 hours. Your doctor will then discuss the findings and next steps with you.
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