Hi everyone I'm trying to co-registrate an MRI image with a Siemens CT-PET using the coregistrate option of SPM but I can't. The program returns this message: Undefined function or variable "ibig" Do this option need some overlap between the images to function? because my 3D images origins are very distants. MRI origin: 130 149 101 CT-PET origin: 167 -13.6 -163 I can't do the realign neither Any suggestion? Thanks Jorge ____________________________________________________________________________________ Sé un Mejor Amante del Cine ¿Quieres saber cómo? ¡Deja que otras personas te ayuden! http://advision.webevents.yahoo.com/reto/entretenimiento.html