title: Correspondence of human visual areas identified using functional and anatomical MRI in vivo at 7 T.
abstract: OBJECTIVE
  To study the correspondence of anatomically and functionally defined visual areas (primary visual cortex, V1, and motion selective area V5/human MT+) by using structural magnetic resonance imaging (MRI) and functional MRI (fMRI) in vivo at 7 T.
  
  
  METHODS
  Four subjects participated in this study. High-resolution (≈0.4 mm isotropic) anatomical MRI was used to identify cortical regions based on their distinct cortical lamination. The optimal contrast for identifying heavily myelinated layers within gray matter was quantitatively assessed by comparing T(1)-weighted magnetization-prepared rapid gradient echo (MPRAGE) and T(2)*-weighted, 3D fast-low angle shot (FLASH) imaging. Retinotopic mapping was performed using GE-based fMRI at 1.5 mm isotropic resolution to identify functional areas.
  
  
  RESULTS
  T(2)*-weighted FLASH imaging was found to provide a significantly higher contrast-to-noise ratio, allowing visualization of the stria of Gennari in every slice of a volume covering the occipital cortex in each of the four subjects in this study. The independently derived boundary of V1, identified in the same subjects using retinotopic mapping by fMRI, closely matched the border of anatomically defined striate cortex in the human brain. Evidence of banding was also found within the functionally defined V5 area; however, we did not find a good correlation of this area, or the functionally identified subregion (MT), with the banded area.
  
  
  CONCLUSIONS
  High-resolution T(2)*-weighted images acquired at 7 T can be used to identify myelinated bands within cortical gray matter in reasonable measurement times. Regions where a myelinated band was identified show a high degree of overlap with the functionally defined V1 area.
authors.affiliation: Sir Peter Mansfield Magnetic Resonance Center, School of Physics and Astronomy, University of Nottingham, Nottingham, UK. rosa.panchuelo@nottingham.ac.uk
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Sánchez-Panchuelo
authors.forename: Susan T
authors.initials: ST
authors.lastname: Francis
authors.forename: Denis
authors.initials: D
authors.lastname: Schluppeck
authors.forename: Richard W
authors.initials: RW
authors.lastname: Bowtell
mesh_terms: D001931:Brain Mapping / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D016018:Least-Squares Analysis; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010775:Photic Stimulation; D012984:Software; D014793:Visual Cortex / Q000033:anatomy & histology* / Q000502:physiology*