title: Lines of Baillarger in vivo and ex vivo: Myelin contrast across lamina at 7T MRI and histology.
abstract: The human cerebral cortex is characterized by a number of features that are not uniformly distributed, such as the presence of multiple cytoarchitectonic elements and of myelinated layers running tangentially to the cortex surface. The presence and absence of these features are the basis of the parcellation of the cerebral cortex in several areas. A number of areas show myelin increases localized within the cortex, e.g., the stria of Gennari located in layer IV of the primary visual cortex. Sub-millimeter MRI can resolve myelin variations across the human cortex and may allow in vivo parcellation of these brain areas. Here, we image within-area myelination. We modified a T1-weighted (T1-w) MPRAGE sequence to enhance myelin visualization within the cortex. First, we acquired images from an ex vivo sample, and compared MRI laminar profiles from calcarine (corresponding to primary visual cortex) and extra-calcarine areas with histology sections from the same locations. Laminar profiles between myelin stained sections and the T1-w images were similar both in calcarine as well as extra-calcarine cortex. In calcarine cortex, the profile reveals the stria of Gennari. In extra-calcarine cortex, a similar profile exists which we suggest corresponds to the lines of Baillarger. Next, we adapted the same sequence to image within-area myelination in vivo. Also in in vivo data, we discriminated similar laminar profiles in calcarine and extra-calcarine cortex, extending into parietal and frontal lobes. We argue that this myelin pattern outside the calcarine cortex represents the lines of Baillarger.
authors.affiliation: Experimental Psychology, Helmholtz institute, Utrecht University, Utrecht, Netherlands; Radiology, Imaging Division, University Medical Center, Utrecht, Netherlands; Spinoza Centre for Neuroimaging, Amsterdam, Netherlands. Electronic address: alessio.fracasso@gmail.com.
authors.forename: Alessio
authors.initials: A
authors.lastname: Fracasso
authors.affiliation: Neurology, Brain Center Rudolf Magnus, University Medical Center, Utrecht, Netherlands.
authors.forename: Susanne J
authors.initials: SJ
authors.lastname: van Veluw
authors.affiliation: Radiology, Imaging Division, University Medical Center, Utrecht, Netherlands; Philips Medical Systems, Best, Netherlands.
authors.forename: Fredy
authors.initials: F
authors.lastname: Visser
authors.affiliation: Radiology, Imaging Division, University Medical Center, Utrecht, Netherlands.
authors.forename: Peter R
authors.initials: PR
authors.lastname: Luijten
authors.affiliation: Pathology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Wim
authors.initials: W
authors.lastname: Spliet
authors.affiliation: Radiology, Imaging Division, University Medical Center, Utrecht, Netherlands.
authors.forename: Jaco J M
authors.initials: JJM
authors.lastname: Zwanenburg
authors.affiliation: Experimental Psychology, Helmholtz institute, Utrecht University, Utrecht, Netherlands; Spinoza Centre for Neuroimaging, Amsterdam, Netherlands.
authors.forename: Serge O
authors.initials: SO
authors.lastname: Dumoulin
authors.affiliation: Radiology, Imaging Division, University Medical Center, Utrecht, Netherlands.
authors.forename: Natalia
authors.initials: N
authors.lastname: Petridou
mesh_terms: D000328:Adult; D002102:Cadaver; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000648:ultrastructure*; D009415:Nerve Net / Q000166:cytology / Q000000981:diagnostic imaging; D009778:Occipital Lobe / Q000166:cytology* / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014793:Visual Cortex / Q000166:cytology* / Q000000981:diagnostic imaging*