Re: patient doses in CT scanning

[Douglas Simpkin <dsimpkin@execpc.com>]

At 10:57 AM 2/25/00 -0600, Pedro de Almeida wrote:
>I am trying to find a description (a table for example) of typical radiation
>doses delivered to patients during conventional or helical CT scanning.

The radiation dose to patients from CT scanners is contained in a stylized
format called the "computed tomography dose index" (CTDI). This is the dose
to a pencil-shaped ion chamber placed either in or out of a standard
phantom, for a given scanning technique. See
<http://www.drs.dk/guidelines/ct/quality/htmlindex.htm>
and 
<http://www.sghphy.demon.co.uk/index.htm>
for very thorough descriptions of CTDI and dose to patients.

If pushed, a diagnostic medical physicist would say that patient doses from
CT range between a "few rad" in the part of patient that was scanned, to a
"few mrad" >10 cm inferior/superior to the scanned region.

Doug
Douglas J. Simpkin, Ph.D., DABR
St. Luke's Medical Center
2900 West Oklahoma Avenue
Milwaukee, WI 53215
phone: (414)649-6457
fax: (414)649-5118
email: dsimpkin@execpc.com
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