CAT Scan

Computerized Tomography (CT) is a diagnostic tool doctors use to see inside the body. 

CT is sometimes referred to as a CAT scan. Physicians use the information obtained from a CT scan to rule out or confirm the presence of certain abnormalities or diseases. If doctors do see anything on your scan, the information can be extremely vital to determining the proper treatment options.

A CT scanner combines X-rays with advanced computer processing technology to create accurate, detailed images of your internal structures and organs. You will be asked to lie still on a table as it gently moves you through the scanner.

Patient Preparation Instructions

IV Contrast

The Intravenous (IV) contrast used in CT is iodine based, and is a useful tool to help radiologists identify some types of pathology in CT. If your exam is ordered with IV Contrast, please do not eat or drink for 4 hours prior to your exam.

We routinely draw lab work to test kidney function in CT patients who:

  • Are older than 65 or younger than 5

  • Are diabetic
  • Have a personal history of renal disease or failure
  • Have a personal history of cancer
  • Are taking glucophage / metformin

If your CT exam is ordered with IV contrast and you meet any of these criteria, please arrive 45 minutes before the scheduled appointment time to complete this lab work. This will help to expedite the completion of your exam. If you have none of these indicators, please arrive 30 minutes before the scheduled appointment time for registration.

Power PICCs and Power ports can be used for the injection of IV Contrast. These patients must bring verification that the port is a Power PICC or Power Port.

Oral Contrast

Oral contrast is used in some CT abdomen and pelvis exams. The oral contrast is usually diluted iodine-based contrast that we flavor with sugar free flavoring. We also have the option to use barium contrast if you are allergic to iodine. Also, some exams require patients to drink water as oral contrast. You will need to drink 1 glass of this contrast every 15 minutes for an hour before completing your exam. This contrast will be given to you by the CT technologist when you arrive in Diagnostic Imaging.

If your exam is ordered with oral contrast, please arrive 1 hour and 15 minutes before your scheduled exam time to register and drink the contrast.


These are preparation guidelines for imaging exams performed at Knox Community Hospital (KCH). If you have any questions regarding prep for your exam, please contact us at 740.393.9038. For invasive procedure prep (CT Biopsy, drainage, drain insertion, arthrogram etc.), visit here.