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<DIV><SPAN class=376453819-08022005><FONT face=Arial color=#0000ff size=2>Hi
Martin,</FONT></SPAN></DIV>
<DIV><SPAN class=376453819-08022005><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=376453819-08022005><FONT face=Arial color=#0000ff size=2>I
don't think you can define two independent detector systems.
I</FONT></SPAN><SPAN class=376453819-08022005><FONT face=Arial color=#0000ff
size=2><SPAN class=376453819-08022005><FONT face=Arial color=#0000ff size=2>t is
my understanding that layer level of the Cylindrical_PET system might do what
you want, but the fact that you are using smaller crystals in the inner
layer than in the outer one might make this feature useless to
you. I</FONT></SPAN></FONT></SPAN><SPAN
class=376453819-08022005><FONT face=Arial color=#0000ff size=2> think you have
hit on a difficult limitation. I can give you a couple of quick ideas
about what to do.</FONT></SPAN></DIV>
<DIV><SPAN class=376453819-08022005><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=376453819-08022005><FONT face=Arial color=#0000ff
size=2>1) The cleanest would be to add a new detector system to the GATE
code, but this would be quite difficult and time consuming.</FONT></SPAN></DIV>
<DIV><SPAN class=376453819-08022005><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=376453819-08022005><FONT face=Arial color=#0000ff
size=2>2) As an alternative you could build two simulation models and
combined them. The first would make the outer detector ring the active
detector with the inner ring defined as a part of the phantom. The second
would make the inner ring the active detector ring and ignore the outer
one. Singles files could then be built for each simulation and an external
coincidence sorter could be used to generated the coincidences. However,
binning the LOR's and sorting the coincidences, especially if you are interested
in count rate performance, could be difficult. </FONT></SPAN></DIV>
<DIV><SPAN class=376453819-08022005><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=376453819-08022005><FONT face=Arial color=#0000ff size=2>Hope
this helps,</FONT></SPAN></DIV>
<DIV><SPAN class=376453819-08022005><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=376453819-08022005><FONT face=Arial color=#0000ff
size=2>ross</FONT></SPAN></DIV>
<DIV><SPAN class=376453819-08022005><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=376453819-08022005><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV></DIV>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B>
gate-users-bounces@lphe1pet1.epfl.ch
[mailto:gate-users-bounces@lphe1pet1.epfl.ch] <B>On Behalf Of
</B>janecekm@mir.wustl.edu<BR><B>Sent:</B> Tuesday, February 08, 2005 2:35
PM<BR><B>To:</B> gate-users@lphe1pet1.epfl.ch<BR><B>Subject:</B> [gate-users]
Attaching system<BR><BR></FONT></DIV><FONT
face="Default Sans Serif, Verdana, Arial, Helvetica, sans-serif" size=2><FONT
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<DIV>
<DIV><FONT face="Courier New">Hello everybody,</FONT></DIV><FONT
face="Courier New">
<DIV><FONT face=Arial color=#0000ff></FONT><FONT face=Arial
color=#0000ff></FONT><BR></FONT><FONT face="Courier New">My name is Martin
Janecek and I am part of a the Imaging Physics Group at Washington
University in St Louis. We are developing an unconventional PET
system consisting of a small detector ring - an insert -
placed inside of a large clinical scanner ring. The insert has smaller
(high-resolution) LSO detectors compared to the scanner detectors. We want
to simulate the system in GATE. A problem arises however when we want
to attach the detectors to a system. Does the GATE code allow to attach two
different resolution detectors in coincidence? (We get an error message,
telling us a volume is already attached when trying to attach a second
layer). The "attachment tree" seems to be of a single branch, without the
possibility to attach two different detector blocks to one layer (Table 4.2
in the manual). </FONT></DIV>
<DIV><FONT face="Courier New"></FONT> </DIV>
<DIV><FONT face="Courier New"></FONT></DIV>
<DIV><FONT face="Courier New"></FONT></DIV><FONT
face="Courier New"></FONT></DIV>
<DIV></DIV>
<DIV><FONT face="Courier New">Sincerely,</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face="Courier New"></FONT></DIV>
<DIV></DIV>
<DIV><FONT face="Courier New"></FONT></DIV>
<DIV><FONT face="Courier New">WashU Imaging Physics Group through Martin
Janecek</FONT></DIV></FONT></FONT></FONT></FONT></FONT></FONT></FONT></FONT></FONT></FONT></BODY></HTML>