Projections for handling uncertainties and enabling domain truncation in diffuse optical tomography

Fuente: arXiv
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Main Authors: Hakula, Aada, Hirvi, Pauliina, Hyvönen, Nuutti, Jääskeläinen, Altti, Kolehmainen, Ville
Format: Preprint
Published: 2026
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author Hakula, Aada
Hirvi, Pauliina
Hyvönen, Nuutti
Jääskeläinen, Altti
Kolehmainen, Ville
author_facet Hakula, Aada
Hirvi, Pauliina
Hyvönen, Nuutti
Jääskeläinen, Altti
Kolehmainen, Ville
contents This paper presents a projection-based technique to mitigate the impact of modeling errors related to domain truncation, changes in the optode coupling coefficients, and misspecified optical parameters of different tissue types in diffuse optical tomography. The approach considers the primary Jacobian matrix of the forward map in the image reconstruction scheme, linking the primary unknown, i.e., the per-voxel absorption coefficient changes in the region of interest, to the optode measurements, as well as the nuisance Jacobians that do the same for the auxiliary unknown parameters of secondary interest. To mitigate mismodeled coupling coefficients or domain truncation, the method projects the linearized forward model defined by the primary Jacobian onto the orthogonal complement of the range of a nuisance Jacobian, or onto the orthogonal complement of the span of a number of first left singular vectors for the nuisance Jacobian that has been weighted to account for prior information on the measurement setup. In the case of a misspecified baseline optical parameter for some tissue type, the nullspace of the utilized orthogonal projection is defined to be the span of first left singular vectors for a (weighted) difference of two Jacobian matrices evaluated at two different levels for the considered tissue-wise optical parameter. The reconstruction is formed by applying Bayesian inversion with Gaussian prior and noise models to the projected linearized equation. We evaluate the method on simulated brain activity data obtained via Monte Carlo simulations of the radiative transfer equation in a voxelized head anatomy for a neonate with combined gestational and chronological age of 41.7 weeks.
format Preprint
id arxiv_https___arxiv_org_abs_2604_26548
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Projections for handling uncertainties and enabling domain truncation in diffuse optical tomography
Hakula, Aada
Hirvi, Pauliina
Hyvönen, Nuutti
Jääskeläinen, Altti
Kolehmainen, Ville
Numerical Analysis
78A46, 15A29, 92C55, 62F15
This paper presents a projection-based technique to mitigate the impact of modeling errors related to domain truncation, changes in the optode coupling coefficients, and misspecified optical parameters of different tissue types in diffuse optical tomography. The approach considers the primary Jacobian matrix of the forward map in the image reconstruction scheme, linking the primary unknown, i.e., the per-voxel absorption coefficient changes in the region of interest, to the optode measurements, as well as the nuisance Jacobians that do the same for the auxiliary unknown parameters of secondary interest. To mitigate mismodeled coupling coefficients or domain truncation, the method projects the linearized forward model defined by the primary Jacobian onto the orthogonal complement of the range of a nuisance Jacobian, or onto the orthogonal complement of the span of a number of first left singular vectors for the nuisance Jacobian that has been weighted to account for prior information on the measurement setup. In the case of a misspecified baseline optical parameter for some tissue type, the nullspace of the utilized orthogonal projection is defined to be the span of first left singular vectors for a (weighted) difference of two Jacobian matrices evaluated at two different levels for the considered tissue-wise optical parameter. The reconstruction is formed by applying Bayesian inversion with Gaussian prior and noise models to the projected linearized equation. We evaluate the method on simulated brain activity data obtained via Monte Carlo simulations of the radiative transfer equation in a voxelized head anatomy for a neonate with combined gestational and chronological age of 41.7 weeks.
title Projections for handling uncertainties and enabling domain truncation in diffuse optical tomography
topic Numerical Analysis
78A46, 15A29, 92C55, 62F15
url https://arxiv.org/abs/2604.26548