Re: x-rays, IRB, rad-safty, consents, r

[JMUCKERHEIDE@delphi.com]

Good point.
 
> By the way, your comment about the CT doses implied that the dose from several
> slices were additive.  If the collimation is less than the table increment (or
> pitch for spiral CT), the primary beam doses do not add, but the scatter does. 
> You should use the multiple scan average dose (MSAD) to describe the absorbed
> dose.
> 
> David Scherer
> scherer@mirlink.wustl.edu 

Of course this begs the question of whether 1 rad to 1 gram, and 1 rad to the
whole brain, are equivalent when dealing with dose risks, and the matter of
the need to look at  radiation differently than other toxins.  Dr. Victor Bond 
has made a substantial case for the need  to quantify total imparted energy
rather than the radiation form of "energy/unit mass" for the whole biological
unit (cell, organ, organism) of interest, demonstrable both in the mathematics 
of assessing dose/risk, and in the data (eg, the Japanese survivor
population). It's a more interesting problem in considering trying to
accurately describe risk (with significant exposure) to a patient. Do you "add 
it up", or not (implying that 1 slice has as much risk as 20 slices)? 

Thanks.

Regards, Jim