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.