From: sbharris@ix.netcom.com(Steven B. Harris)
Newsgroups: sci.med
Subject: Re: PET
Date: 1 Sep 2000 06:27:33 GMT

In <39AF141C.EE29BD56@ripco.com> ronald <ronald@ripco.com> writes:
>
>Judith wrote:
>>
>> Can anyone give me information on a new bodyscan called the PET.  It is
>> suppose to detect diseases such as cancer, tumors, heart defects etc.
>>
>
>if you mean positron emission tomography, that's been around for some
>time.  since this falls under the field of nuclear medicine i would
>suggest that you could find general information by going to any
>medical school web site and looking for a link to "nuclear medicine".
>
>as i recall, in a nutshell, pet is different from stuff like cat or
>mri scans in that pet is based upon monitoring of metabolic function.
>in particular i believe that the idea is to inject radioactive glucose
>into a patient, then the pet scan detects the consumption of that
>glucose in the body.


  That describes only the particular PET isotope (18F) and scan (FDG)
that medicare pays for: it's approved to look for mets in a few kinds
of cancer, and to work up primary lung nodules. Many other PET isotopes
and compounds have been used for various purposes, but all are
considered experimental just now.

   The big problem with PET logistically is that the longest lived
positron emitting isotope has a half life of only about 2 hours, so you
have to be not much further than 2 hours by road from a medical
cyclotron to do PET at all. The UCLA cyclotron, for instance, supplies
18-F throughout lower California. Mobile PET scanners from San Diego go
out even to places like Pomona Valley Hospital, but they get their
isotope from UCLA.  And if traffic is bad, they don't work at all.