What is a CT scan?
The CT, or computed tomography, scanner operated by rotating an x-ray tube around your body while measuring the constantly changing absorption of the x-ray beam by different tissues in your body. The information is then fed into a computer which produces a reconstructed image of a thin cross section or "slice" of the body. Because the scanner is very sensitive, small differences in absorption of the beam by various body tissues are recorded sharper and clearer than even the best x-ray.
You may be startled by the size and shape of the scanner. Remember nothing touches you, so it will not hurt. You will be asked to lie on the table, usually on your back, and usually with your arms over your head. The moveable table will raise, lower and move in and out of the scanner.
It is extremely important that you do not move during the entire procedure, which lasts from 15 minutes to an hour depending on the examination. The radiologist will study the final images and report the findings to your physician, who will in turn discuss the results with you.
Head CT:
Your head will be placed in a holder with a strap across your forehead. Images will be taken. The examination will take from 15 - 30 minutes. No prior preparation is required. Sometimes intravenous contrast is required, which will be given in a vein in the arm or hand.
Chest CT:
Most chest CT scans are performed with an IV contrast and prior preparation is not necessary. You will be lying on your back with your arms above your head. The technologist will instruct you to hold your breath for each exposure. The examination should take from 20 - 30 minutes.
Abdomen and/or Pelvis CT:
Most CT scans of the abdomen and/or pelvis require preparation prior to the study. Usually you will be asked to skip the meal immediately prior to your exam.
For an abdomen CT, you will be given a bottle of contrast material that outlines the intestines on the image and another bottle just prior to getting on the table for your exam. For an abdomen and pelvis or just a pelvis CT, you will be asked to arrive one hour prior to exam time. You will be given a bottle of contrast material to drink while you are registering and then you will be given a bottle to drink when you arrive at the scanner and asked to wait approximately 45 minutes. For an abdomen and pelvis CT, you will be asked to drink one more bottle of contrast material just prior to getting on the exam table. Most CT scans of the abdomen require an IV contrast injection in the hand or arm. You will be positioned on your back on the scan table with your arms over our head. You will be instructed by the technologist to hold your breath for each image taken. A scan of the abdomen and pelvis should take approximately 34 - 45 minutes.
