This essentially defines the field of view of the brain/head that you want in
the spatially normalised images. By default, spatially normalised images
come out with a smaller field of view than the template images supplied with
SPM. Bits of non-brain are essentially chopped out of the data to save a bit
of disk space.
On Thursday 26 June 2008 11:35, Zhang Zhiqiang wrote:
> Dear SPMers,
> We often resample fMRI data to 3*3*3, so I must adjust the option each
> time, in the inferior panel of "SPM for function MRI" , to select :
> /Defaults/ Spatial Nornalization/ Default for writting normalized/
> Preserved concentrations/, then an option of "Bounding Box" appears with 4
> matrix. The first is labeled with "default", and the third is "Template".
> when the first is used, the resampled data will be 300k, whereas when the
> third is used, the resampled data will become 700k !!!,
> we usually used the first option of "default", but a problem arises as
> the brain shape differring from the MNI coordinate (Template image provided
> by SPM), which will cause many inconvenience in the subsequent process.
> I just want to know which coordinate the "default" belong to? Talairach?
> as well why the sizes of resampled outputs with two option ("default" and
> "Template") are so different?
> Thank you very much.
> Zhiqiang Zhang