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What is a CT Scan?
"CT" stands for Computerized Tomography, a system which
produces xray pictures as sectional slices of your body. This technology
shows the details of your brain, spine, liver or other internal
organs not visible on regular x-ray films.
CT works with very narrow x-ray beams that pass through the body
at
different levels. Instead of registering the image directly on film
(like in
a regular x-ray), the images are created digitally by a computer
and then
printed on film or stored on other types of media such as digital
tape or
optical disks. Once the images have been acquired, a computer reconstructs
the raw data into a two-dimensional image, which represents a "slice"
of the
body part being examined.
Benefits of CT Scan
As a general rule, CT is the modality of choice for examining bony
detail,
calcification, sinus disease, and chest and abdomen imaging with
contrast,
while musculoskeletal, spine, and soft tissue imaging are preferred
for MRI.
However, evolving technology makes CT and MRI exams equally appropriate
in
many cases.
CT is especially useful at pinpointing lesions or tumors, revealing
information about their location, size, and extent. Because of its
short
scan times, CT exams are also good for imaging areas that are prone
to
movement, such as the chest and liver.
Some people may be concerned about the amount of radiation they
receive
during a CT scan. It is true that the radiation exposure from a
CT scan can
be slightly higher than from a regular x-ray. However, not having
the
procedure can be more risky than having it, especially if cancer
is
suspected. People considering CT must weigh the risks and benefits.
Any special precautions?
Generally, any ionizing radiation exam is contraindicated for pregnant
women. Under circumstances where the benefits outweigh the risks,
CT scans
of certain body parts may be allowed.
If the patient is breast feeding and has had contrast as part of
her exam,
she should suspend nursing for 24 hours after the scan.
In very rare cases, contrast agents can cause allergic reactions.
Some
people experience mild itching or hives (small bumps on the skin).
Symptoms
of a more serious allergic reaction include shortness of breath
and swelling
of the throat or other parts of the body. People should tell the
technician
immediately if they experience any of these symptoms, so they can
be
promptly treated.
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