Application of stereological methods to estimate post-mortem brain surface area using 3T MRI

The Cavalieri and Vertical Sections methods of design based stereology were applied in combination with 3 tesla (i.e. 3T) Magnetic Resonance Imaging (MRI) to estimate cortical and subcortical volume, area of the pial surface, area of the grey-white matter boundary, and thickness of the cerebral cortex. The material comprises eight human cadaveric cerebri which had been separated into sixteen cerebral hemisphere specimens prior to embedding in agar gel. The results from MRI were compared with corresponding 'gold standard' values subsequently obtained by application of the same methodology using physical sectioning of the specimens. 95% agreement intervals revealed poor agreement between MR imaging and physical sectioning, specially for pial surface and thickness, as well as cerebral cortex and subcortex volumes. On average, pial surface area was estimated to be almost half the extent using MRI compared to physical sectioning (i.e. 45%, p