Full Body CT Scans: Info to Know Before You Go (Part 2)
Based on the article “Full-Body
CT Scans: What You Need to Know”
by Carol Lewis, on
fda.gov
Edited (with Introduction)
by Dr. Don Rose, Writer, Life
Alert
--
This is the second half of our two-part
article discussing full body CT (Computed Tomography)
scans. Providers of these (and similar) body scans point
out that serious problems often have no symptoms, especially in their early stages.
On the other hand, some sources (see below) say that healthy folks without symptoms
should not be advised to undergo such scans. Hence, it is not a simple choice; doing
due diligence and gathering data from multiple sources is recommended before making
a final decision. –Don Rose
--
Dozens of clinics nationwide are touting a new service
for health-conscious people: full-body CT scans -- high-tech computerized X-rays
that promise early warnings for cancer, cardiac disease, and other abnormalities.
But the practice is controversial because the long-term benefits and risks have
not been researched.
The Food and Drug Administration (FDA) has approved the CT X-ray system only as
a diagnostic tool to be used when symptoms exist, or when there is reason for further
testing. But no studies have been done to support
using CT scans for screening people without symptoms, or when there is no suspicion
or indication of a problem or disease.
Thomas B. Shope, Ph.D., a radiation physicist in the FDA's
Center for Devices and Radiological Health, says the agency's concern is that "some
of the kinds of things screening CT may find are not necessarily of any health significance."
In addition, because no screening test is 100 percent accurate,
the FDA is concerned that many people will get false-positive
results, leading them to seek additional, possibly risky tests or surgical procedures. While there is a small danger of this when symptoms exist,
its occurrence is far more probable when they do not.
Furthermore, the use of any X-ray imaging procedure is
always accompanied by a concern about the possible effects of
radiation exposure.
"The effective dose from a CT procedure can be
hundreds of times larger
than the effective dose from a conventional radiographic procedure," says Shope.
During a CT scan, an X-ray tube housed inside a doughnut-shaped machine rotates
around and transmits radiation through a person's body at various angles. Detectors
inside the machine measure the radiation transmitted through the body and these
data are converted into electrical signals. A computer gathers these signals and
produces three-dimensional images that are displayed on a monitor. A technologist
or radiologist can change the contrast or brightness of the displayed image, or
use other image processing or display techniques to emphasize areas or tissues of
interest.
Using CT systems for diagnosis in medicine has been accepted
as a valuable medical practice based on a wealth of experience. Physicians may use
it for any condition or disease, as long as they deem the use legitimate within
the doctor-patient relationship. Therefore, although the device was approved as
a diagnostic tool for specific purposes, the FDA has limited authority to control
how it is actually used. The agency continues to approve CT systems and their enhancements
on the basis that
they are to be used in the diagnoses of symptomatic people.
The
American College
of Radiology "does not believe there is sufficient scientific evidence
to justify recommending total body computed tomographic (CT) screening for patients
with no symptoms or a family history suggesting disease."
The organization says there is no evidence that the procedure is either cost-effective,
or effective in prolonging life. Robert Smith, director of cancer screening at the
American Cancer Society, says his organization
also "discourages full-body scanning" for the same reasons.
The information provided here is, to the best of our
knowledge, reliable and accurate. However, while
Life Alert
strives to provide true, precise and consistent information, we cannot guarantee
100 percent accuracy. Readers are encouraged to review the original article and
gather more information before drawing conclusions and making decisions.
Dr. Don Rose writes books, papers and articles
on many topics, including computers, the Internet, artificial intelligence, science
and technology, and issues related to seniors.
For more information about
Life Alert,
its emergency response services and other benefits for seniors -- available in
New York
,
California,
Florida
, and other states nationwide -- please visit the following
websites:
http://www.lifealert.com
http://www.seniorprotection.com
http://www.911seniors.com