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Hi Daniel, if you "only" want to do realign & unwarp (without having acquired a fieldmap), then this will realign the images and additionally correct for motion*B0 interaction effects. It will not undo the distortions induced by using EPI in the first place. If you want to do that, you need an additional set of images coming from a dedicated fieldmap sequence. If you have those images, you can/must enter the TE of the early and late echo of the fieldmap, not the EPI (click Toolbox, Fieldmap), which will then allow you to properly unwarp the EPI images (a kind of "realign & unwarp & unwarp"). I don't think field strength is explicitly used anywhere as the fieldmap must of course be from the same subject, session, and thus, scanner. Hope this helps, Marko Daniel ROQUET wrote: > Hello SPM'ers > I have two EPI data-sets (with distinct TE) which I want to realign and > unwarp. I wonder whether FieldMap-Toolbox takes (1) the TE of the EPI > images which have to be corrected, and (2) the strength of the magnetic > field, into account . If it doesn't, why ? if it does, where can we > change these parameters ? > Best wishes > -- > Daniel ROQUET > PhD student > Clinique Psychiatrique > Unité INSERM 666 > 1 Place de l'Hôpital > 67091 Strasbourg -- ____________________________________________________ PD Dr. med. Marko Wilke Facharzt für Kinder- und Jugendmedizin Leiter, Experimentelle Pädiatrische Neurobildgebung Universitäts-Kinderklinik Abt. III (Neuropädiatrie) Marko Wilke, MD, PhD Pediatrician Head, Experimental Pediatric Neuroimaging University Children's Hospital Dept. III (Pediatric Neurology) Hoppe-Seyler-Str. 1 D - 72076 Tübingen, Germany Tel. +49 7071 29-83416 Fax +49 7071 29-5473 [log in to unmask] http://www.medizin.uni-tuebingen.de/kinder/epn ____________________________________________________