title: Nonlinear approach to difference imaging in diffuse optical tomography.
abstract: Difference imaging aims at recovery of the change in the optical properties of a body based on measurements before and after the change. Conventionally, the image reconstruction is based on using difference of the measurements and a linear approximation of the observation model. One of the main benefits of the linearized difference reconstruction is that the approach has a good tolerance to modeling errors, which cancel out partially in the subtraction of the measurements. However, a drawback of the approach is that the difference images are usually only qualitative in nature and their spatial resolution can be weak because they rely on the global linearization of the nonlinear observation model. To overcome the limitations of the linear approach, we investigate a nonlinear approach for difference imaging where the images of the optical parameters before and after the change are reconstructed simultaneously based on the two datasets. We tested the feasibility of the method with simulations and experimental data from a phantom and studied how the approach tolerates modeling errors like domain truncation, optode coupling errors, and domain shape errors.
authors.affiliation: University of Eastern Finland, Department of Applied Physics, P.O. Box 1627, Kuopio 70211, Finland.
authors.forename: Meghdoot
authors.initials: M
authors.lastname: Mozumder
authors.affiliation: University of Eastern Finland, Department of Applied Physics, P.O. Box 1627, Kuopio 70211, FinlandbUniversity College London, Department of Computer Science, Gower Street, London WC1E 6BT, United Kingdom.
authors.forename: Tanja
authors.initials: T
authors.lastname: Tarvainen
authors.affiliation: University of Eastern Finland, Department of Applied Physics, P.O. Box 1627, Kuopio 70211, Finland.
authors.forename: Aku
authors.initials: A
authors.lastname: Seppänen
authors.affiliation: Aalto University School of Science, Department of Neuroscience and Biomedical Engineering, P.O. Box 12200, Aalto 00076, FinlanddHelsinki University Central Hospital, HUS Medical Imaging Center, BioMag Laboratory, P.O. Box 340, HUS 00029, Finland.
authors.forename: Ilkka
authors.initials: I
authors.lastname: Nissilä
authors.affiliation: University College London, Department of Computer Science, Gower Street, London WC1E 6BT, United Kingdom.
authors.forename: Simon R
authors.initials: SR
authors.lastname: Arridge
authors.affiliation: University of Eastern Finland, Department of Applied Physics, P.O. Box 1627, Kuopio 70211, Finland.
authors.forename: Ville
authors.initials: V
authors.lastname: Kolehmainen
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D000069416:Intravital Microscopy / Q000379:methods*; D017711:Nonlinear Dynamics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D041622:Tomography, Optical / Q000379:methods*