Thyroid Shields

[mikeg@SLAC.Stanford.EDU (Michael P. Grissom)]

1.  I feel somewhat compelled to respond to this particularly
after the recent message indicating this might be an "optional"
item whose funding is contingent on available resources.  At
least for our old training program (at soon to close Oak Knoll),
we taught radiologic technology candidates the proper and
appropriate use of shadow shields and other techniques to
provide patient/organ protection during a wide variety of
radiographic procedures (this message was also delivered to
the dental technology candidates at other facilities).

2.  Unfortunately, even when a fairly complete inventory of
shadow shields, aprons, blankets, etc., were available, I
would often find their use nearly nil in many clinics during
radiation protection surveys (take a look at some KVP films,
and almost any abdominal study on female patients, for 
example and see if you see shadow shields in use).  The
new graduates of our program would use some of them.  The
old hands often gave up under the pressure of numerous
patients and either didn't rig up the devices (some are 
attached to adapters on collimators or tables) or laid the
shield over the appropriate general area of the body.  Of
course, at a medical facility training radiologists, the
patient organ dose to sensitive organs not in the study
purview (but in the x-ray field) could prove very large due
to the widely observed phenomenon (reported many times on
radsafe) of longer beam on times for new residents that
gradually becomes relatively short (and closer to the
right place at initial beam on, maybe even with an already
partially collimated fluoroscopic field of view) for the
experienced house officer (board certified, many patients
studied, diagnostic radiologist).

3.  While shadow shields may not be of great importance
(depending on your point of few) for most plain film
radiographic procedures, I believe there is good evidence
that they can be of assistance in patient organ dose
reduction (but perhaps most difficult to use) in fluoroscopic
procedures.  Of course, there is no organ dose reduction if
you did buy 'em, but didn't use 'em!
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This is of course my personal opinion and not that of my current
employer (who doesn't do this sort of work!).
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Michael P. Grissom
mikeg@slac.stanford.edu
Phone:  (415) 926-2346
Fax:    (415) 926-3030