[gate-users] RE: STIR reconstruction software (GATE simualtions)

[Kris Thielemans]

Dear Vandana

> Thanks. I would be using STIR with GATE output (ecat7 
> format). I am looking up the manual and trying to figure out 
> if STIR would work with raw output format from GATE. Any 
> suggestions would be very helpful. Thanks Vandana
> 

I suggest in the future you ask these questions to the GATE users list.

My understanding is that as long as you are simulating a CTI/Siemens PET
scanner that actually exists and is supported by STIR (which essentially
means one that outputs ECAT7 data, so no PET/CT), then you don't have to do
anything specific. 

One of the problems with ECAT7 output is that it doesn't contain all scanner
dimensions. Instead, it contains a system_type field. If GATE fills this in
correctly, then STIR can figure out the dimensions and off you go.

However, if you are simulating your own fancy scanner, there is no way that
GATE can put those dimensions in the ECAT7 file (and hence STIR can figure
them out). STIR contains a work-around (in IO/stir_ecat7.cxx) that if the
system_type is not recognised and #if defined(B_JOINT_STIRGATE) then call
Scanner::ask_parameters() [KT and Long Zhang]. This will mean that you will
be asked for a lot of data interactively. That's obviously a pain but
there's no way around it.

An alternative way would be to let GATE write Interfile headers that STIR
can understand. This shouldn't be incredibly difficult, but I don't know of
anybody who has plans in that direction.

Kris