<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <style type="text/css" style="display:none;"></style> </head> <body dir="ltr"> <div id="divtagdefaultwrapper" style="font-size:12pt;color:#000000;background-color:#FFFFFF;font-family:Calibri,Arial,Helvetica,sans-serif;"> <p>Hi,</p> <p><br> </p> <p>I've found that the when defining the maximum radius of the CylindricalPET world geometry using the /gate/cylindricalPET/geometry/setRmax command, the value of Rmax can be smaller than what you would expect analytically from the actual scanner geometry, and yet no 'overlapping volumes' error is generated. This is not just machine precision error, since I've seen the radius be up to 0.3 mm less than expected without any error.</p> <p><br> </p> <p>Does anyone know why this occurs? Perhaps I'm missing something in how Rmax is defined wrt the scanner geometry. I would have thought that once you've defined the rsector of your PET geometry which you want to repeat around a ring, you can simply calculate the maximum distance from the center of the world coord system to the extremity of this sector, and use this as the Rmax setting. So why can Rmax be less than this?</p> <p><br> </p> <p>Thanks,</p> <p><br> </p> <p>Andre Kyme<br> </p> <div id="Signature"> <div name="divtagdefaultwrapper" style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:; margin:0"> <br> </div> </div> </div> </body> </html>