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Q: CT - radiation ( Answered 5 out of 5 stars,   1 Comment )
Question  
Subject: CT - radiation
Category: Health > Children
Asked by: inon-ga
List Price: $10.00
Posted: 17 Apr 2004 11:58 PDT
Expires: 17 May 2004 11:58 PDT
Question ID: 331785
What are the risks in doing CT scans and more specifically head scan
for a 9 month old baby.
How much radiation is there comapge to normal x-ray scan you do at the
dentist for example.
Is the radiation more dangerous for a child then for adult?
Answer  
Subject: Re: CT - radiation
Answered By: pinkfreud-ga on 17 Apr 2004 12:43 PDT
Rated:5 out of 5 stars
 
You're right to be concerned. A CT (computerized or computed
tomography) scan exposes a patient to approximately 100 times as much
radiation as a standard x-ray. Recent studies indicate that CT scans
on infants and children should be "dialed down" from the adult
settings. An advisory panel to the FDA has recommended that the agency
should require CT machines to automatically adjust the dose by
measuring, during the scanning procedure, how much of the x-ray beam
is attenuated by the patient's body. The FDA has not yet acted upon
this recommendation, so it's important to ask your radiologist or your
primary physician whether the child's body size has been taken into
account when calculating the scanning dose.

I've gathered some online resources related to pediatric CT scans.
Please keep in mind that Google Answers is not a source of
authoritative medical advice; this material is intended for
informational purposes. For reasons of copyright, I am posting
excerpts here, with links to the sources; you may want to read these
articles in their entirety.

"While the benefits of computed tomography are well known in
diagnosing diseases and trauma and in the guidance of interventional
and therapeutic procedures, those benefits are not without risks. 
This Notification is to emphasize the importance of keeping radiation
doses during CT procedures as low as reasonably achievable, especially
for pediatric and small adult patients, who may sometimes receive more
radiation than needed to obtain diagnostic images.  To prevent this,
we want to stress the importance of adjusting CT scanner parameters
appropriately for each individual?s weight and size, and for the
anatomic region being scanned."

U.S. Food & Drug Administration: Reducing Radiation Risk from Computed
Tomography for Pediatric and Small Adult Patients
http://www.fda.gov/cdrh/safety/110201-ct.html

"CT scans account for approximately 4% of medical imaging exams;
however, research shows that CT scans contribute to 40% of the total
amount of radiation received from diagnostic tests. While Dr. Donnelly
and his colleagues emphasize that the risk from CT radiation exposure
is minimal, higher radiation doses can increase the lifetime risk of
cancer in children. 'Of the approximately 600,000 abdominal and head
CT examinations annually performed in children under the age of 15
years, a rough estimate is that 500 (approximately 1/10th of a
percent) of these individuals might ultimately die from cancer
attributable to the CT radiation,' wrote David Brenner of the Center
for Radiological Research at Columbia University and his colleagues,
who performed a study which examined the risks of radiation-induced
fatal cancer from pediatric CT...

In most cases, the benefits of finding disease with a CT scan outweigh
the risks of x-ray radiation exposure and/or injections of imaging
contrast and use of sedatives during the scan.

To ensure that their child is receiving a safe and necessary CT scan,
parents may wish to:

1. Ask whether the scanning protocol has been optimized for the
child?s weight and body type (this is especially important if the CT
scan is not performed at a children?s center).

2. Make sure the CT scan is absolutely necessary, especially if
multiple CT scans are performed."

Imaginis: Studies Find Radiation Doses From CT Scans Often Too High For Children 
http://www.imaginis.com/ct-scan/news/news1.26.01.asp

"Children getting computed tomography (CT) scans may be exposed to
excess radiation that can increase their cancer risk later in life,
according to a study published in the February issue of the American
Journal of Roentgenology (AJR). But experts agree that the benefits of
CT scans outweigh any risk from using them.

Lead researcher David J. Brenner, PhD, a Professor of Radiation
Oncology at Columbia University in New York, says about 1.6 million
children under the age of 15 are given CT scans to the head and
abdomen every year in the United States, and an estimated 1,500 of
them may eventually die from cancer caused by excess radiation."

American Cancer Society: CT Scans May Increase Cancer Risk for Young Children
http://www.cancer.org/docroot/NWS/content/NWS_1_1x_CT_Scans_May_Increase_Cancer_Risk_for_Young_Children.asp

"The latest data... suggests that of every 2,500 newborns who receive
a head scan at adult settings, one can be expected to die prematurely
from cancer because of the scan. But the older and larger a child is
when scanned, the lower the danger. So a 15-year-old getting the same
scan would incur only half that risk. And some experts believe that
even these numbers exaggerate the risk...

Many physicians don't realize that a single CT scan gives roughly as
much radiation as 100 x-rays, according to many radiologists. Dialing
down CT scans for kids is especially important because radiation
impacts them much more than it affects adults...

- Children who are scanned will usually live much longer than adults
who are scanned, giving them longer to develop any cancer a scan might
cause.

- A newborn is 10 times as radiosensitive as a 50-year-old adult, and
girls are twice as sensitive as boys.

- Even when children and adults are exposed to exactly the same
strength CT beams, kids get substantially larger doses because their
thinner bodies allow the beam to penetrate them with higher average
intensity."

American Medical News: National Cancer Institute issues warning on pediatric CTs
http://www.ama-assn.org/amednews/2002/10/07/gvsd1007.htm 

Google search strategy:

Google Web Search: "risk" + "ct scan" + "children"
://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=risk+%22ct+scan%22+children

Google Web Search: "ct scan" + "pediatric" + " safety"
://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=%22ct+scan%22+pediatric+safety

I hope this information is helpful. If anything is unclear or
incomplete, please request clarification; I'll gladly offer further
assistance before you rate my answer.

Best regards,
pinkfreud

Clarification of Answer by pinkfreud-ga on 17 Apr 2004 13:40 PDT
My friend and colleage hummer-ga has suggested that I mention
something that may help to set your mind at ease. During a CT scan of
the head, the patient's abdomen and pelvis are generally draped with a
lead apron, to shield the area from radiation. This ensures that the
patient's reproductive organs won't be exposed to x-rays.

"Special care is taken during x-ray examinations to ensure maximum
safety for the patient by shielding the abdomen and pelvis with a lead
apron, with the exception of those examinations in which the abdomen
and pelvis are being imaged."

Radiology Info: Computed Tomography (CT) - Head
http://www.radiologyinfo.org/content/ct_of_the_head.htm
inon-ga rated this answer:5 out of 5 stars
Thank you pinkfreud, the material was fast and to the point.

Comments  
Subject: Re: CT - radiation
From: pinkfreud-ga on 17 Apr 2004 13:52 PDT
 
Please excuse my typo in the answer clarification above. For
'colleage', I meant to type 'colleague'. Sometimes the fingers are
faster than the brain.

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