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Abstract

A tonotopic organization of the human auditory cortex (AC) has been reliably found by neuroimaging studies. However, a full characterization and parcellation of the AC is still lacking. In this study, we employed pseudo-continuous arterial spin labeling (pCASL) to map tonotopy and voice selective regions using, for the first time, cerebral blood flow (CBF). We demonstrated the feasibility of CBF-based tonotopy and found a good agreement with BOLD signal-based tonotopy, despite the lower contrast-to-noise ratio of CBF. Quantitative perfusion mapping of baseline CBF showed a region of high perfusion centered on Heschl's gyrus and corresponding to the main high-low-high frequency gradients, co-located to the presumed primary auditory core and suggesting baseline CBF as a novel marker for AC parcellation. Furthermore, susceptibility weighted imaging was employed to investigate the tissue specificity of CBF and BOLD signal and the possible venous bias of BOLD-based tonotopy. For BOLD only active voxels, we found a higher percentage of vein contamination than for CBF only active voxels. Taken together, we demonstrated that both baseline and stimulus-induced CBF is an alternative fMRI approach to the standard BOLD signal to study auditory processing and delineate the functional organization of the auditory cortex. Hum Brain Mapp, 2016. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

Original languageEnglish
Pages (from-to)1140-1154
Number of pages15
JournalHuman Brain Mapping
Volume38
Issue number3
DOIs
Publication statusPublished - Mar 2017

Keywords

  • tonotopy
  • fMRI
  • ASL
  • CBF
  • quantitative perfusion
  • SWI
  • primary auditory cortex
  • INTERINDIVIDUAL VARIABILITY
  • SPATIAL-ORGANIZATION
  • NATURAL SOUNDS
  • VISUAL-CORTEX
  • RESOLUTION
  • PERFUSION
  • GRADIENT
  • AREAS
  • BOLD
  • FREQUENCY

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