We have develped a novel, multistage, method for registration of post mortem histology sections, to in vivo MRI sub-volumes of the same brains. Our method can be used to transfer cortical and laminar boundaries from the histology sections to the MRI volumes and therefore may facilitate analysis of cytoarchitectonically parcellated and therefore more functionally homogeneous regions of interest in the MRI scans. Combining the two techniques allows us to capitalize on the strengths of each method, that is, the precise delineation of functionally distinct units of brain structure as discernable on post mortem histology sections and the visualization of in vivo brain structure, undistorted by post mortem fixation and processing, on the MRI scans.
Our method has a potential application in human databases where both MRI scans and post mortem histological sections are available from the same subjects to analyze structural alteration in cytoarchitectonically parcellated, and therefore more functionally homogenous, ROIs. With respect to analysis of the cerebral cortex, it is all the more important to use cytoarchitectonic criteria to distinguish individual cortical areas in the human brain where the borders of areas show marked individual variability and exhibit little correspondence to sulcal landmarks. Moreover, in diseases thought to have a developmental origin, as for example schizophrenia, application of this method would make it possible to determine whether the expanse of a specific cortical region, for example, area 46, is altered relative to the size of the frontal lobe as a whole. Thus, the application of this registration method may allow for more detailed and functionally relevant analyses of neuropsychiatric illness that could significantly advance our understanding of these human diseases. This registration method also has more general utility in superimposition of any histologically based information onto the MRI volumes.