POSTMORTEM ANATOMY FROM CRYOSECTIONED WHOLE HUMAN BRAIN

A system of histologic and digital processing protocols are presented for the acquisition of high-resolution digital imagery from postmortem cryosectioned whole human brain and head for computer-based 3-dimensi onal (3D) representation and visualization. We designed and evaluated several protocols for optimal preparation of frozen specimens includin g fixation, decalcification, cryoprotection, freezing and sectioning p rocedures. High-resolution (1024(2) pixel) serial images were captured directly from the cryoplaned blockface using an integrated color digi tal camera and fiber optic illumination system mounted over a modified cryomacrotome. Specimens frozen and sectioned with the cranium intact preserved brain spatial relationships and anatomic bony landmarks. Co lor preservation was superior in unfixed tissue but unfixed heads were incompatible with decalcification and cryoprotection procedures and s ection collection from such specimens was complicated by bone fragment ation. Collection of 1024(2) images from whole brains resulted in a sp atial resolution of 200 mu m/pixel in a 1-3 Gbyte data space. Even hig her 3D spatial resolution was possible by primary image capture of sel ected regions such as hippocampus or brain stem. Discrete registration errors were corrected using image processing strategies such as cross -correlative and other algorithmic approaches. Data sets were amenable to resampling in multiple planes as well as scaling and transposition ing into standard coordinate systems. These methods enable quantitativ e measurements for comparison between subjects and to published atlas data. These techniques allow visualization and measurement at resoluti ons far higher than those available through other imaging technologies and provide greatly enhanced contrast for delineation of neuroanatomi c structures, pathways, and subregions.