Hi Steve, "Alternatively, you could work out how to reduce the field-of-view to just include the brain of each time point before feeding the output of that into SIENA. You would use FSLView on each image to work out the field-of-view and then use fslroi to reduce the FOV of the image." I created a whole brain mask for the animal brain using FSLView. But, it is not easy to understand how to use fslroi. fslroi <input> <ouput> <xmin> <xsize> <ymin> ... I just don't know how to determine these parameters and when I am supposed to use the mask file in fslroi. Would you kindly let me know how to reduce the field-of-view to include the brain? Thank you, Buyean ---------------------------------------------------------------------------? ________________________________________________________________________ Check Out the new free AIM(R) Mail -- Unlimited storage and industry-leading spam and email virus protection.