Together We Can -- Newsletter of the Joan Karnell Cancer Center

Fall 2005

Putting Patients Back in the Center of their Care
Message From the Administrator
Understanding Computer Assisted Tomography
Cancer Risk Evaluation
Shiatsu Bodywork
Honors, Awards & Publications
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Understanding Computer Assisted Tomography (CT/CAT Scan)

Computer Assisted Tomography (CT or CAT) is a scan that provides anatomical information, which is used to differentiate abnormal from normal structures. It is often referred to as the “roadmap” of the body and is an important part of diagnosing, monitoring and treating patients with cancer.

A CT scanner is a special x-ray machine combined with a computer that produces cross-sectional images, or “slices” of any part of your head and/or body. Unlike the standard “flat” x-ray, where some organs can block out other structures, a CT scan sends shows structures within each slice on a three-dimensional surface. The scans are also used in surgical procedures to help accurately guide the placement of instruments or treatments.

Preparing for a CT Scan
Each type of CT scan has its own special preparations. The most frequently performed scans are head, chest, abdomen, and pelvis. Some scans require patients to drink a liquid prior to the study called a “contrast.” This makes it easier to see the organs, blood vessels, etc. on the pictures. If taking the liquid, patients are asked to refrain from eating and/or drinking for at least 2 hours prior to their scan. Some scans also require the contrast be administered intravenously prior to the scan. Your doctor or nurse will review the specific instructions for your CT scan.

The scan takes approximately 10 to 30 minutes to complete. The length of times depends on the number of pictures and the different angles being taken. During this time, you will be asked to lie still on a table that moves through a round opening called a “gantry.” The CT scanner is open around you, does not come in contact with you, and is not confining. It should not be confused with the MRI scanner that is shaped more like a tunnel. Because X-rays are unable to pass through metal, you may be asked to remove jewelry, glasses, or clothing, which have zippers, snaps, etc.

Do people experience any reactions because of a CT scan?
Some individuals may need special blood tests when receiving the contrast intravenously. You should notify the technologist about previous allergies (especially to iodine), and previous reaction to X-ray dye, any renal problems, or diabetes. Most patients have no issues related to having a CT.

For more information, visit the Radiology at Pennsylvania Hospital web site or call 1-800-789-PENN (7366). You can also request an appointment online.


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Need an appointment? Request one online 24 hours/day, 7 days/week or call 800-789-PENN (7366) to speak to a referral counselor.

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