CT Scans and CAT Scans

What is Computed Tomography?

CT (computed tomography), also called a CAT scan, uses x-ray and computer equipment to produce cross-sectional images of body tissues and organs. CT imaging is useful because it can show several types of tissue, such as lung, bone, soft tissue and blood vessels.

What are some common uses of CT?

    • Studying the chest and abdomen for pain or shortness of breath
    • Diagnosing cancer – CT examinations are often used to:
      • Plan and properly administer radiation treatments for tumors
      • Guide biopsies and other minimally invasive procedures
      • Plan surgery
      • Determine surgical resectability
    • Diagnosing and treating spinal problems and injuries to the hands, feet and other skeletal structures
    • Identifying injuries to the liver, spleen, kidneys, or other internal organs
    • Detecting, diagnosing and treating vascular diseases that can lead to stroke, kidney failure, or even death
    • Diagnosing generalized pain in the abdomen/ pelvis/ chest after clinical exam from physician

How should I prepare for a CT scan?

  • On the day of your exam, wear comfortable, loose-fitting clothing with no metal
  • Avoid clothing with zippers and snaps, as metal objects can affect the image
  • Depending on the part of the body that is being scanned, you may also be asked to change into a gown or remove hairpins, jewelry, eyeglasses, hearing aids and any dentures
  • You may be asked not to eat or drink anything for 3 and 1/2 hours before the exam:
    • Please inform staff if a medical condition requires you to eat or drink
    • You can take medication if it can be taken without eating
  • Women should inform their doctor or x-ray tech if there is any possibility that they are pregnant

What should I expect during this exam?

A CT examination usually takes 10 minutes to half an hour.

  • The technologist positions you on the CT table and pillows are used to help keep you still and in the proper position during the scan. The table will move slowly into the CT scanner opening. Depending on the area of the body being examined, the increments of movement may be very small and almost undetectable, or large enough to feel the motion.
  • To enhance the visibility of certain tissues or blood vessels, the use of different contrast materials may be required. Depending on the type of examination, contrast material may be injected through an IV or swallowed. Before administering the contrast material, you should inform the radiologist or technologist of the following:
    • Any allergies, especially to medications or iodine
    • Whether you have a history of diabetes, asthma, kidney problems, heart or thyroid conditions. These conditions may indicate a higher risk of reaction to the contrast material or potential problems eliminating the material from the patient’s system after the exam.
  • You will be alone in the room during your scan however your technologist can see, hear and speak with you at all times. If necessary, we will allow a friend or family member to stay in the room with you during the exam. To prevent radiation exposure, the friend or family member will be required to wear a lead apron.
  • To determine if more images are needed, you may be asked to wait until the images are reviewed.

What will I experience during the procedure?

CT scanning is painless. Depending on the type of scan you are having, your preparation may differ. To enhance the visibility of body tissue or blood vessels, the use of different contrast materials may be administered by:

  • Mouth: You may be asked to swallow water or contrast material, a liquid that allows the radiologist to better see the stomach, small bowel, and colon. Some patients find the taste of the contrast material slightly unpleasant, but tolerable.
  • IV injection: To accentuate the appearance between normal and abnormal tissue in organs like the liver and spleen and to better define the blood vessels and kidneys, a contrast material is commonly injected into a vein. You might feel:
    • Flushed or have a metallic taste in your mouth. These are common reactions which disappear in a minute or two.
    • In very rare cases, you may experience shortness of breath or swelling in the throat or other parts of the body. These can be indications of a more serious reaction to the contrast material. Your technologist should be notified immediately. If you experience itching after the injection, medication and monitoring will be performed.

Learn More About CT Scans / CAT Scans

RadiologyInfo.org: About CT Scans of Your Sinuses