MRI Brain Templates of the Male Yucatan Minipig

Abstract

The pig is growing in popularity as an experimental animal because its gyrencephalic brain is similar to humans. Currently, however, there is a lack of appropriate brain templates to support functional and structural neuroimaging pipelines. The primary contribution of this work is an average volume from an iterative, non-linear registration of 70 male Yucatan minipig subjects whose ages ranged from five to seven months. In addition, several aspects of this study are unique, including the comparison of linear and non-linear template generation, the characterization of a large and homogeneous cohort, an analysis of effective resolution after averaging, and the evaluation of potential within template bias as well as a comparison with a template from another minipig species using a "left-out" validation set. We found that within our highly homogeneous co-hort, non-linear registration produced better templates, but only marginally so. Although our T1-weighted data were resolution limited, we preserved effective resolution across the multi-subject average, produced templates that have high gray-white matter contrast, and demonstrated superior registration accuracy compared to the only known alternative minipig template.