TY - JOUR
T1 - Atlas-based head modeling and spatial normalization for high-density diffuse optical tomography
T2 - In vivo validation against fMRI
AU - Ferradal, Silvina L.
AU - Eggebrecht, Adam T.
AU - Hassanpour, Mahlega
AU - Snyder, Abraham Z.
AU - Culver, Joseph P.
N1 - Funding Information:
This work was supported in part by NIH grants R01-EB009233 (J.P.C), Fulbright Science and Technology Ph.D. Award (S.L.F.), and Autism Speaks Postdoctoral Translational Research Fellowship 7962 (A.T.E.).
PY - 2014/1/15
Y1 - 2014/1/15
N2 - Diffuse optical imaging (DOI) is increasingly becoming a valuable neuroimaging tool when fMRI is precluded. Recent developments in high-density diffuse optical tomography (HD-DOT) overcome previous limitations of sparse DOI systems, providing improved image quality and brain specificity. These improvements in instrumentation prompt the need for advancements in both i) realistic forward light modeling for accurate HD-DOT image reconstruction, and ii) spatial normalization for voxel-wise comparisons across subjects. Individualized forward light models derived from subject-specific anatomical images provide the optimal inverse solutions, but such modeling may not be feasible in all situations. In the absence of subject-specific anatomical images, atlas-based head models registered to the subject's head using cranial fiducials provide an alternative solution. In addition, a standard atlas is attractive because it defines a common coordinate space in which to compare results across subjects. The question therefore arises as to whether atlas-based forward light modeling ensures adequate HD-DOT image quality at the individual and group level. Herein, we demonstrate the feasibility of using atlas-based forward light modeling and spatial normalization methods. Both techniques are validated using subject-matched HD-DOT and fMRI data sets for visual evoked responses measured in five healthy adult subjects. HD-DOT reconstructions obtained with the registered atlas anatomy (i.e. atlas DOT) had an average localization error of 2.7. mm relative to reconstructions obtained with the subject-specific anatomical images (i.e. subject-MRI DOT), and 6.6. mm relative to fMRI data. At the group level, the localization error of atlas DOT reconstruction was 4.2. mm relative to subject-MRI DOT reconstruction, and 6.1. mm relative to fMRI. These results show that atlas-based image reconstruction provides a viable approach to individual head modeling for HD-DOT when anatomical imaging is not available.
AB - Diffuse optical imaging (DOI) is increasingly becoming a valuable neuroimaging tool when fMRI is precluded. Recent developments in high-density diffuse optical tomography (HD-DOT) overcome previous limitations of sparse DOI systems, providing improved image quality and brain specificity. These improvements in instrumentation prompt the need for advancements in both i) realistic forward light modeling for accurate HD-DOT image reconstruction, and ii) spatial normalization for voxel-wise comparisons across subjects. Individualized forward light models derived from subject-specific anatomical images provide the optimal inverse solutions, but such modeling may not be feasible in all situations. In the absence of subject-specific anatomical images, atlas-based head models registered to the subject's head using cranial fiducials provide an alternative solution. In addition, a standard atlas is attractive because it defines a common coordinate space in which to compare results across subjects. The question therefore arises as to whether atlas-based forward light modeling ensures adequate HD-DOT image quality at the individual and group level. Herein, we demonstrate the feasibility of using atlas-based forward light modeling and spatial normalization methods. Both techniques are validated using subject-matched HD-DOT and fMRI data sets for visual evoked responses measured in five healthy adult subjects. HD-DOT reconstructions obtained with the registered atlas anatomy (i.e. atlas DOT) had an average localization error of 2.7. mm relative to reconstructions obtained with the subject-specific anatomical images (i.e. subject-MRI DOT), and 6.6. mm relative to fMRI data. At the group level, the localization error of atlas DOT reconstruction was 4.2. mm relative to subject-MRI DOT reconstruction, and 6.1. mm relative to fMRI. These results show that atlas-based image reconstruction provides a viable approach to individual head modeling for HD-DOT when anatomical imaging is not available.
KW - Anatomical atlas
KW - Brain mapping
KW - Diffuse optical tomography
KW - Functional magnetic resonance imaging
KW - Group analysis
KW - Non-linear registration
KW - Spatial normalization
UR - http://www.scopus.com/inward/record.url?scp=84889636384&partnerID=8YFLogxK
U2 - 10.1016/j.neuroimage.2013.03.069
DO - 10.1016/j.neuroimage.2013.03.069
M3 - Article
C2 - 23578579
AN - SCOPUS:84889636384
VL - 85
SP - 117
EP - 126
JO - NeuroImage
JF - NeuroImage
SN - 1053-8119
ER -