Before you do anything else with the images, make sure the headers are correct. Run Check reg, including one of the MNI space images released with SPM, and some of your PET images. If they are not within a few cm and a few degrees of each other before you begin, then you'll need to patch up the headers.

Best regards,

-John

On 4 April 2017 at 10:24, Philip Lin <[log in to unmask]> wrote:

Dear SPM experts,

I've collected about 700 preprocessed FDG-PET images from ADNI (http://adni.loni.usc.edu/). All downloaded images were well preprocessed and be compressed as I001.nii to I700.nii files. The preprocessed procedure were listed in (http://adni.loni.usc.edu/methods/pet-analysis/pre-processing/).

In each image with dimension 160x160x96 and 1.5mm voxel size, we'd like to map voxels to the standard atlas (e.g., Automated Anatomical Labeling) to understand the name of regions. As we known, we need to do a non-linear warping on each image once and it belongs to the "Normalization" step in SPM12. However, in our manipulation with SPM12, how do we specify "image to aling" and how to set "writing options" ?

If we choose "Image to aling" as the I001.nii and "Image to write" as I001.nii to I700.nii, and leave the rest as default, It leads to a prefixed "w" images with NaN intensities.

Philip Lin