Our goal was to use lesions identified on MRI to guide the histological analysis of postmortem brains. After fixation, the postmortem brains were sectioned into 5 mm thick coronal slices and photographed, and the resulting slides were scanned into a computer graphics file format. The slices were co- registered to each other and assembled into a postmortem brain volume. We next co-registered the oblique coronal T1-weighted MRI to the postmortem brain volume. The transformation defined by this co-registration was used to transform the MRI lesion markings onto the postmortem brain. These transformed lesion markings were used to guide the histological analysis. Only rigid body transformations were used in this analysis. The postmortem brain volume looked most correct near the center slices, probably due to the deformations undergone by the postmortem brain during slicing, fixation, and movement. Despite this limitation and our use of rigid body transformations, the co-registered MRI and postmortem brain were reasonably well matched at the surface, at the ventricles, and at structures of interest such as the hippocampus. More precise localization of the MRI lesion markings on the postmortem brain slice will only be achieved when a nonlinear method such as warping of the brain is used.
展开▼
