PREPARING FOR THE EXAMINATION
Preparation for the examination varies, depending on the
part of your body being examined. Your doctor will provide instructions to
fit your particular situation. In some cases, a medication or special
diet, or both, may be prescribed for a period of time prior to the
examination. This information can be obtained from the Department of
Radiology.
Whether or not you are hospitalized, the procedure and instructions in
preparing for it are basically the same. Be sure to follow your doctor’s
instructions carefully. If you don’t the examination may have to be
repeated at a later date.
SPECIAL COMMENTS
- Any woman who is pregnant, or who thinks she
might be, should advise her doctor BEFORE proceeding with the
examination.
- If you have ever had any problems involving a
contrast medium before, tell the Radiologist or technologist of this
fact BEFORE proceeding with the examination.
WHAT HAPPENS DURING A CT Scan
For the examination, you may be asked to remove part of all of your
clothing and put on a gown.
After you enter the CT room, the technologist will position you on a
special table. Once you are securely in place, you will be moved
into the ring of the scanner. The technologist will control the
scanner and watch the progress of the test from an adjacent room. As you
are moved through the scanner, relax and remain as quiet as you can. Each
scan will require you to hold your breath for a few seconds, so listen for
instructions from the technologist.
After each image, or scan, made the table will move you into position for
the next scan. You will hear the sounds of gears and motors in the ring as
the X-ray equipment scans your body.
Frequently, it may be necessary to use a contrast medium to image certain
internal structures. The contrast medium is given orally or injected into
a vein, or both. The Radiologist can give you specific information about
the contrast medium before the examination begins.
COMPLETION OF THE EXAM
The examination itself usually takes less than an hour. Your
doctor’s office can advise you on just how long you should plan to spend.
The Radiologist will study your examination and give an evaluation to your
physician. Your doctor will then discuss the results with you and explain
what they mean in relation to your health. If you have not heard from your
physician within one week of your CT, you should contact her/him directly
to discuss the findings of your CT.
The contrast medium will be eliminated through your urine and should not
discolor the urine or stool. You can resume your regular diet immediately
after the examination.
HOW THE BODY CT WORKS
The ring encircling your body contains an X-ray tube and a receptor which
are mounted opposite each other. These rotate around your body, which is
positioned in the exact center of the ring. With each scan, a portion of
the complete information is accumulated by the receptor. The receptor
measures this amount and feeds the information into a computer. The
computer calculates the density of each area within the body based on the
energy absorbed as the
scanner rotates. This density is a number that is assigned a shade of
gray, which is then displayed on a viewing screen. The information
obtained from the total number of scans can be used to recreate on the
screen an accurate picture of the structures inside your body. The
computer takes only seconds to make the calculations, compared to years
with a human being! |
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