We show that electrical impedance tomography (EIT) image reconstruction algorithms with regularization based on the total variation (TV) functional are suitable for in vivo imaging of physiological data. This reconstruction approach helps to preserve discontinuities in reconstructed profiles, such as step changes in electrical properties at interorgan boundaries, which are typically smoothed by traditional reconstruction algorithms. The use of the TV functional for regularization leads to the minimization of a nondifferentiable objective function in the inverse formulation. This cannot be efficiently solved with traditional optimization techniques such as the Newton method. We explore two implementations methods for regularization with the TV functional: the lagged diffusivity method and the primal dualinterior point method (PD-IPM). First we clarify the implementation details of these algorithms for EIT reconstruction. Next, we analyze the performance of these algorithms on noisy simulated data. Finally, we show reconstructed EIT images of in vivo data for ventilation and gastric emptying studies. In comparison to traditional quadratic regularization, TV regulariza tion shows improved ability to reconstruct sharp contrasts.

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Keywords Electrical impedance tomography (EIT), Lagged diffusivity, Primal dual interior point method, Regularization, Total variation (TV)
Persistent URL dx.doi.org/10.1109/TMI.2009.2022540
Journal IEEE Transactions on Medical Imaging
Borsic, A. (Andrea), Graham, B.M. (Brad M.), Adler, A, & Lionheart, W.R.B. (William R. B.). (2010). In vivo impedance imaging with total variation regularization. IEEE Transactions on Medical Imaging, 29(1), 44–54. doi:10.1109/TMI.2009.2022540