SPM5 segmentation/normalization/bias correction

SPM5 includes a unified (read combined) segmentation, normalization and bias correction algorithm.

Bias correction If the images show extreme bias distortions, then bias correct first (use "Save bias corrected" option), and run a second pass to obtain the segmentation and normalization.

Coregistration The images must be roughly aligned with the template; the simplest way to do this is to run a Coregistration to the template with the "Estimate only" option (reslice will reslice into the same space as the template).

Example of T2 normalization with and without coregistration

Raw image (in template space)

Template

Normalized T2 with coregistration

Normalized T2 no coregistration