CT Scans

What is CT?

CT or Computerized Tomography is an advanced diagnostic imaging procedure that produces images of a cross-section of a part of the body. An X-ray tube focuses narrow beams across one layer or slice of the body; its energy is absorbed differently by different body structures. Receptors detect the number of X-rays remaining, and this information is relayed to a computer. The X-ray tube rotates around the body, scanning it. Thousands of readings are taken by the receptors and recorded by the computer. The information is then converted to high-quality images.

CT scans can render diagnostic images of all parts of the body. They are often used to monitor a patient’s progress during or after treatment.

In some cases, your doctor may order a CT scan to be done using a contrast medium to facilitate an enhanced image of the area being scanned. The contrast medium may be given by intravenous injection and/or orally.

Patient Experience

You should arrive at the center approximately 15 minutes before your appointment time for the usual screening procedures and paperwork. You may be asked to change into a patient gown as metal zippers or snaps can interfere with the scan. Before your exam, the CT technologist will obtain a brief medical history. Let the technologist or radiologist know if you have any questions.

The technologist will help you onto the examination table. Depending on the equipment used, the technologist may then secure you with a strap. This is painless and will help keep you from moving, since even slight movement blurs the results. The exam table will gently move into the opening of the scanner. You will feel nothing unusual during your exam. You will hear a whirring sound as the scanner operates. The exam table will move slightly after each scan. It is important that you remain relaxed and still during the exam so the images do not blur. The technologist will speak to you through a two-way intercom system. You will be able to talk to the technologist if you need assistance at any time during the exam.

If a contrast medium must be used, it will be given to you intravenously and/or orally. You may experience flushing, nausea, a headache, or a salty taste in the mouth. Let your technologist know immediately if you experience any of these or any other uncomfortable sensations.

Although CT exams are scheduled to minimize waiting time, unexpected delays may occur. Each examination is structured to the individual needs of the patient.

Exam Time

Each procedure lasts approximately 15-30 minutes.


A specially trained radiologist will review and interpret the images and prepare a report of findings to be sent to your referring physician who ordered the exam. Your physician can then explain to you what the findings mean.

Special Preparations

If your CT scan requires contrast, you may not eat or drink 4 hours prior to the exam. Otherwise, you may follow your normal diet and take any scheduled medications. Wear something comfortable with no metal (no zippers, etc.) Avoid make-up, as it may contain metal. Should your physician prescribe a mild sedative, someone will need to accompany you to escort you home. If you have had previous diagnostic studies (MRI scans, Ultrasound, X-ray, Bone scans, or other CT scans) of to the body part being evaluated, please bring those films and reports, or request they be sent to the center. These studies or reports are very helpful to the radiologist interpreting your CT scan.

Tell your doctor or the technologist:

  • If you are pregnant or breast feeding.
  • If you have had a Barium Enema or UGI within the last two weeks.
  • If you have had brain, heart, ear, eye or other surgeries especially prior to 1980).