When performing image registrations with Brainsfit the output log file always records the mutual information metric value as -123.457, regardless of the image data used.
I think it is related to the BRAINSFitHelper::RunRegistration() function BRAINSTools/BRAINSCommonLib/BRAINSFitHelper.h, where it appears the code to retrieve the metric value has been commented out and replaced with (line 500)
this->m_FinalMetricValue = -123.456789;