title: A quantitative spatial comparison of high-density diffuse optical tomography and fMRI cortical mapping.
abstract: Functional neuroimaging commands a dominant role in current neuroscience research. However its use in bedside clinical and certain neuro-scientific studies has been limited because the current tools lack the combination of being non-invasive, non-ionizing and portable while maintaining moderate resolution and localization accuracy. Optical neuroimaging satisfies many of these requirements, but, until recent advances in high-density diffuse optical tomography (HD-DOT), has been hampered by limited resolution. While early results of HD-DOT have been promising, a quantitative voxel-wise comparison and validation of HD-DOT against the gold standard of functional magnetic resonance imaging (fMRI) has been lacking. Herein, we provide such an analysis within the visual cortex using matched visual stimulation protocols in a single group of subjects (n=5) during separate HD-DOT and fMRI scanning sessions. To attain the needed voxel-to-voxel co-registration between HD-DOT and fMRI image spaces, we implemented subject-specific head modeling that incorporated MRI anatomy, detailed segmentation, and alignment of source and detector positions. Comparisons of the visual responses found an average localization error between HD-DOT and fMRI of 4.4+/-1mm, significantly less than the average distance between cortical gyri. This specificity demonstrates that HD-DOT has sufficient image quality to be useful as a surrogate for fMRI.
authors.affiliation: Department of Radiology, Washington University School of Medicine, 4525 Scott Ave, East Bldg. CB 8225, St Louis, MO, 63110, USA.
authors.forename: Adam T
authors.initials: AT
authors.lastname: Eggebrecht
authors.forename: Brian R
authors.initials: BR
authors.lastname: White
authors.forename: Silvina L
authors.initials: SL
authors.lastname: Ferradal
authors.forename: Chunxiao
authors.initials: C
authors.lastname: Chen
authors.forename: Yuxuan
authors.initials: Y
authors.lastname: Zhan
authors.forename: Abraham Z
authors.initials: AZ
authors.lastname: Snyder
authors.forename: Hamid
authors.initials: H
authors.lastname: Dehghani
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Culver
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D041622:Tomography, Optical / Q000379:methods*; D055815:Young Adult