<HTML> <HEAD> <TITLE>Re: [Gate-users] questions about 'system' types and an x-ray imaging system using GATE</TITLE> </HEAD> <BODY> Hi Weixing, The “system” is the hiearchy of elements that make up the PET (or SPECT) detector.  In the case of a CT scanner, the x-ray tube and other elements are not part of the system. The detector is a single element: a camera.  You can use “scanner” as a generic type.  Simply declare your imaging plate as a “sensitive detector” and you will be able to collect energy and/or counts.   Richard Taschereau On 8/7/08 9:53 AM, "Weixing Cai" <wxcai2005@hotmail.com> wrote: <BLOCKQUOTE>I am planning to model an x-ray imaging system that includes an x-ray tube, a detector and a phantom. I guess I should use the 'scanner' system type, right? But I am not sure how to divide my model into those five 'levels'. From the user guide, there is not strict definition of this 'levels'. The concept of system is quite confusing to me. And anybody can recommend more info about the concept of 'system'? And is there any existing model of x-ray tube with GATE? Thanks~ Weixing Cai <HR ALIGN=CENTER SIZE="3" WIDTH="100%">Your PC, mobile phone, and online services work together like never before. See how Windows® fits your life <a href="http://clk.atdmt.com/MRT/go/108587394/direct/01/"><http://clk.atdmt.com/MRT/go/108587394/direct/01/></a> <HR ALIGN=CENTER SIZE="3" WIDTH="95%"><TT>_______________________________________________ Gate-users mailing list Gate-users@lists.healthgrid.org <a href="http://lists.healthgrid.org/mailman/listinfo/gate-users">http://lists.healthgrid.org/mailman/listinfo/gate-users</a> </TT></BLOCKQUOTE><TT> </TT> -- Richard Taschereau, Ph.D. Crump Institute for Molecular Imaging University of California Los Angeles 700 Westwood Plaza, A222 Los Angeles, CA 90095-1770 Phone: (310) 825-0697 Fax:     (310) 206-8975 email: RTaschereau@mednet.ucla.edu ---------------------------------------------------------- IMPORTANT WARNING: This email (and any attachments) is only intended for the use of the person or entity to which it is addressed, and may contain information that is privileged and confidential. You, the recipient, are obligated to maintain it in a safe, secure and confidential manner. Unauthorized redisclosure or failure to maintain confidentiality may subject you to federal and state penalties. If you are not the intended recipient, please immediately notify us by return email, and delete this message from your computer. ---------------------------------------------------------- </BODY> </HTML>