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Large-Scale Non-Linear 3D Reconstruction Algorithms for Electrical Impedance Tomography of the Human Head

Horesh, L; Schweiger, M; Arridge, SR; Holder, DS; (2007) Large-Scale Non-Linear 3D Reconstruction Algorithms for Electrical Impedance Tomography of the Human Head. In: Kim, SI and Suh, TS, (eds.) WORLD CONGRESS ON MEDICAL PHYSICS AND BIOMEDICAL ENGINEERING 2006, VOL 14, PTS 1-6. (pp. 3862 - 3865). SPRINGER-VERLAG BERLIN

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Abstract

Non-linear image reconstruction methods are desirable for applications in electrical impedance tomography (EIT) such as brain or breast imaging where the assumptions of linearity are violated. We present a novel non-linear Newton-Krylov method for solving large-scale EIT inverse problems, which has the potential advantages of improved robustness and computational efficiency over previous methods. This combines Krylov-subspace efficiency in the production of an implicit Hessian inverse together with the Newton-type search direction effectiveness. The computational cost was assessed by comparing the objective function value and image error norm with respect to run-time, iteration count and memory consumption with six other non-linear methods, including Damped Newton-Gauss, Levenberg-Marquardt, Variable Metric and non-linear Conjugated Gradients, using realistic layered head models with meshes of 4, 12 and 31K elements. For the small-scale model, Newton-type methods slightly outperformed the Krylov-Newton approach, while the other large-scale methods performed poorly. For the larger two models, the Newton-Krylov approach converged much more rapidly than the Krylov-subspace and quasi-Newton methods; Newton-type methods failed to converge in the time available. This approach opens a new frontier for non-linear FIT image reconstruction, as it allows production of accurate solutions of large-scale realistic models using modest computational resources.

Type:Proceedings paper
Title:Large-Scale Non-Linear 3D Reconstruction Algorithms for Electrical Impedance Tomography of the Human Head
Event:World Congress on Medical Physics and Biomedical Engineering
Location:Seoul, SOUTH KOREA
Dates:2006-08-27 - 2006-09-01
ISBN-13:978-3-540-36839-7
Keywords:Large-scale, Newton-Krylov, Non-linear reconstruction, Monopolar sources
UCL classification:UCL > School of BEAMS > Faculty of Engineering Science > Computer Science
UCL > School of BEAMS > Faculty of Engineering Science > Medical Physics and Bioengineering

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