View source for Projects:SlicerFAQ:RegistrationContrast

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= I want to register images with different contrast = 
*The two most critical image features that determine automated registration accuracy and robustness are image contrast and resolution. Differences in image contrast are best addressed with the appropriate cost function. The cost function that has proven most reliable for registering images with different contrast (e.g. a T1 MRI to a T2 or an MRI to CT or PET) is '''mutual information'''. All intensity-based registration modules use mutual information as the default cost function. Only the ''Expert Automated Registration'' module lets you choose alternative cost function.

No extra adjustment is therefore needed in terms of adjusting parameters to register images of different contrast. Depending on  the amount of differences you may consider masking to exclude distracting image content or adjusting the ''Histogram Bins'' setting to increase/decrease the level of intensity detail the algorithm is aware of.