Does a thread = a Pick process?

Hi,

Is there a 1-1 relationship between a thread and a Pick process on D3/NT?

I am using a trigger to log changes to items, however I want to ignore
changes by a particular process. At present I am doing this by checking the
thread ID of whichever process is calling the trigger, however this will not
work if it is possible for the same process to switch between threads.
Hopefully one of the Pick insiders can give me a definitive answer, and
possibly suggest an alternative method if the one I am using is not
suitable.

Thanks,

Peter