Imaging cortical anatomy by high-resolution MR at 3.0T: Detection of the stripe of Gennari in visual area 17

The brain can be parcellated into numerous anatomical and functional subunits. The classic work by Brodmann (Vergleichende Lokalisationslehre der Grosshirnrinde in ihren Prinzipien dargestellt auf Grund des Zellenbaues. Leipzig: Barth; 1909) identified areas of the cerebral cortex based on histological differences. An alternative to his cytoarchitectonic approach is the myeloarchitectonic approach. MRI has excellent white/gray matter contrast in the brain due to the presence of myelin, and thus seems uniquely suited for in vivo studies of cortical myeloarchitecture. Here it is demonstrated that the stripe or stria of Gennari can be consistently detected in human occipital cortex. T₁-weighted images obtained at 3T from six of 10 normal volunteers, with resolutions of 350 × 350 × 600 μ, clearly demonstrate this myelin-rich intracortical layer. It is concluded that the striate cortex (area 17 of Brodmann) of the human brain can be delineated in vivo on T₁-weighted images, potentially enabling detection of specific cortical boundaries within individual brains.