PET Facilities

["Case, Diane (OD)" <DCase@exchange.nih.gov>]

I agree with Dan Perrero--one should consider designing a facility that will
accomodate the largest reasonable amount of activity that may be potentially
used.  F-18 studies can use up to 10 mCi per injection.  I'm not sure from the
discussions if other PET isotopes will be used, and how they will be transferred
to the suite (O-15, for example) - but transfer tubing exposures and type of
tube material, and exposures from pneumatic transport systems must also be
considered. 

See the paper "Radiation Protoection Design for a Clinical Positron Emission
Tomography Imaging Suite", HP Journal, Nov. 1992, Volume 63, p 581.

Some quick measurements we've taken:

4 mCi F-18:  15 mR/hr at patient bedside, 2 mrem/hr at 1 meter.
11 mCi O-15: 9 mrem/hr at bedside, 1.5 mR/hr at 1 meter.
Next to the receiving O-15 port, in scanning room, 8 mrem/hr for 42 mCi.
18 mCi C-11:  5 mR/hr at shoulder level in scanning room during C-11 transit
through overhead lines.

The exposure rate constant for F-18, 0-15, N-13, and C-11 ) 0.511 kev gammas) is
~ 0.71 mR/hr per mCi at 1 meter.

Diane Case
dcase@exchange.nih.gov
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