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Computed Tomography Scan (CAT Scan or CT)

What is a CAT Scan or CT?
When is CT used?
How do I prepare?
What can I expect?
When can I expect results?
How do I schedule a test?

What is a Computed Tomography Scan?

A Computed Tomography Scan (also called a CAT scan or CT) is a non-invasive procedure that uses advanced x-ray technology to provide detailed images of the inside of the human body. Cross sectional views produced by the CT enable physicians to see and evaluate multiple structures in all areas of the body, such as:

  • colon
  • kidneys
  • liver
  • lungs
  • bones
  • veins and arteries

When is CT used?

CT provides a detailed view inside the body's organs and tissues, so it can be used to identify sources of internal pain, diagnose internal growths and tumors and detect blood clots. CT also can examine bone density to screen for osteoporosis, detect spinal injuries and problems with disks in the spinal column. CT may be used to help localize radiation treatment for cancer and help surgeons prepare for surgery by providing a look inside the area where the procedure will be performed.

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How do I prepare?

Preparation may vary slightly depending on the area of the body being examined. However, all individuals undergoing a CT examination must complete a four-hour fast prior to the test, to maximize your safety and comfort. Iodine contrast dye is often used during the exam, and it can briefly cause nausea, a bad taste, slight dizziness or light-headedness. Recent intake of food may increase your chance of a reaction to the iodine. The four-hour fast also ensures the best quality test results by preventing false interpretations. You should, however, continue taking all medications as prescribed by your physician.

Wear comfortable clothing with no metal. Bring your referral, insurance card and picture I.D. with you. For your convenience, free parking is available across from the hospital's main entrance. Upon entering the hospital, report to the Admitting department, which is located to the right of the front lobby area. After registering for your test, you will be directed to the CT area. Small children are not permitted in the examination area.

Please note: If you are allergic to iodine or seafood, or have had a previous reaction to any contrast dye, you should inform your physician before your exam. You should also inform the CT staff if you are:

  • allergic to other medications
  • diabetic
  • pregnant
  • have kidney problems 

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What can I expect?

You will remove clothing worn over the area being examined and put on a dressing gown. A technician will review your medical history and explain the examination. You will be asked to lie down on a cushioned table connected to the CT. If you have difficulty lying down or remaining still because of pain, you may wish to speak with your physician before the CT scan about the possible benefits of pain medication for the exam.

An IV line will be started so that an intravenous contrast solution can be used if necessary. A contrast material containing iodine may be injected into the bloodstream to enhance the view of blood vessels and blood flow in your body.

While you will be alone in the exam room, the technician will be able to communicate with you throughout the exam. The table will begin moving through the CT's donut shaped ring. You will hear mechanical noises as pictures are taken and data is collected by the scanner. It is important to remain as motionless as possible during the CT exam, as any movement will affect the quality of the image produced.

The exam usually takes about 20 minutes to complete. Because sedation is not needed for this exam, you will be able to leave, eat or drive as soon as the exam is over. Following the CT, it is important to increase your water intake to help flush the IV or oral contrast from your body. Both contrast materials will leave your body within 24 hours of the CT scan.

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When can I expect results?

The results of your exam will be faxed to your physician within three working days. Please contact your physician for your test results.

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How do I schedule a CT?

For more information or to schedule a CT, call 773.967.1000.

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