<div dir="ltr">Hi Hyejoo, It depends on what you want to do but of course it could... You will have a part of your source out of your phantom so there will be a lot of non-attenuated photons, that risks to overload your detector if you have dead-time for example. But again it depends on what you want to do. Hope you've not lost to much time ! Good luck, Simon <div class="gmail_quote">On Fri, Oct 3, 2008 at 3:45 PM, <<a href="mailto:kangh@mskcc.org">kangh@mskcc.org</a>> wrote: <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Hi Sebastien, Thanks for the reply.  Yes, I shifted the center and I made a mistake move to far for a couple of centimeters when I did that.  I wonder whether misalignment (~ 2 cm) could cause serious problem. Thanks again, Hyejoo <div><div></div><div class="Wj3C7c"> -----Original Message----- From: <a href="mailto:gate-users-bounces@lists.healthgrid.org">gate-users-bounces@lists.healthgrid.org</a> [mailto:<a href="mailto:gate-users-bounces@lists.healthgrid.org">gate-users-bounces@lists.healthgrid.org</a>] On Behalf Of Sebastien JAN Sent: Friday, October 03, 2008 7:57 AM To: gate users Subject: Re: [Gate-users] misalignment between a phantom and source Hi, If I understand correctly your problem, don't forget that the default position of the voxelized source is in the 1st quarter of the voxelized phantom. This is why you must shift the voxelized source over half its dimensions in the negative direction on each axis (as it is note in the users guide p. 107 - last version) Hope this help Cheers Sebastien > Hi, > > I have simulated voxelized phantom/source.  I found that the source > and phantom were misaligned about a couple of centimeters in x-y > directions. The voxelized source was off from the center about 1.5 cm > in each x and y direction. > > Would it cause any dramatic changes in simulation results?  The > dimension in x & y directions is  42 X 30 cm.   I think the phantom > and source were properly aligned in z-direction. > > Thanks, > > Hyejoo > > > ===================================================================== > >     Please note that this e-mail and any files transmitted with it may be >     privileged, confidential, and protected from disclosure under >     applicable law. If the reader of this message is not the intended >     recipient, or an employee or agent responsible for delivering this >     message to the intended recipient, you are hereby notified that any >     reading, dissemination, distribution, copying, or other use of this >     communication or any of its attachments is strictly prohibited. If >     you have received this communication in error, please notify the >     sender immediately by replying to this message and deleting this >     message, any attachments, and all copies and backups from your >     computer. > > >----------------------------------------------------------------------- - > >_______________________________________________ >Gate-users mailing list ><a href="mailto:Gate-users@lists.healthgrid.org">Gate-users@lists.healthgrid.org</a> ><a href="http://lists.healthgrid.org/mailman/listinfo/gate-users" target="_blank">http://lists.healthgrid.org/mailman/listinfo/gate-users</a> > > _______________________________________________ Gate-users mailing list <a href="mailto:Gate-users@lists.healthgrid.org">Gate-users@lists.healthgrid.org</a> <a href="http://lists.healthgrid.org/mailman/listinfo/gate-users" target="_blank">http://lists.healthgrid.org/mailman/listinfo/gate-users</a> _______________________________________________ Gate-users mailing list <a href="mailto:Gate-users@lists.healthgrid.org">Gate-users@lists.healthgrid.org</a> <a href="http://lists.healthgrid.org/mailman/listinfo/gate-users" target="_blank">http://lists.healthgrid.org/mailman/listinfo/gate-users</a> </div></div></blockquote></div> </div>