<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=Content-Type content="text/html; charset=iso-8859-1"> <META content="MSHTML 6.00.2900.2963" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#ffffff> <DIV><FONT face=Arial size=2>Dear all,</FONT></DIV> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV><FONT face=Arial size=2>I know that they exist, but I cannot remember the few GATE command lines dealing with the block difference of a photon that interacted in two different blocks of a block-based cylindrical PET system (block diff=block1-block2). There is in particular a way to limit the block difference, i.e. to only allow interaction of a single photon in two consecutive blocks, or 3 consecutive blocks etc... Could anyone refresh my memory?</FONT></DIV> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV><FONT face=Arial size=2>Many thanks!</FONT></DIV> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV><FONT face=Arial size=2>Bastien G.<BR>-------------------------------<BR>Bastien P Guerin<BR>PhD candidate, University of Paris VI<BR>Visiting Fellow, Harvard University<BR>t: 617 817 2762<BR>f: 617 732 6695</FONT></DIV></BODY></HTML>