Developments in Electrical-Property Tomography Based on the Contrast-Source Inversion Method

Abstract

The main objective of electrical-property tomography (EPT) is to retrieve dielectric tissue parameters from B ^ 1 + data as measured by a magnetic-resonance (MR) scanner. This is a so-called hybrid inverse problem in which data are defined inside the reconstruction domain of interest. In this paper, we discuss recent and new developments in EPT based on the contrast-source inversion (CSI) method. After a short review of the basics of this method, two- and three-dimensional implementations of CSI–EPT are presented along with a very efficient variant of 2D CSI–EPT called first-order induced current EPT (foIC-EPT). Practical implementation issues that arise when applying the method to measured data are addressed as well, and the limitations of a two-dimensional approach are extensively discussed. Tissue-parameter reconstructions of an anatomically correct male head model illustrate the performance of two- and three-dimensional CSI–EPT. We show that 2D implementation only produces reliable reconstructions under very special circumstances, while accurate reconstructions can be obtained with 3D CSI–EPT.

An Overview of Microwave Imaging for Breast Tumor Detection

“…Here the vectorial nature of the fields has to be tackled. 3D forward models and inversion methods implemented within the contrast source inversion framework have been reported in 2019 like Multi-Task Bayesian Compressive Sensing (MT-BCS) [95], Twofold Subspace-based Optimization Method (TSOM) [96], 3D Electrical-Property Tomography (3D-EPT) [97], Newton-CG Method in l p Spaces [98], etc. Development of direct 3D models helps in more accurate modeling and imaging.…”

Transceive phase corrected 2D contrast source inversion‐electrical properties tomography

“…In Ref. [40], the effects of reconstructing fully 3D contrasts with a 2D CSI‐EPT algorithm are shown.…”

“…In Ref. [40], the effects of reconstructing fully 3D contrasts with a 2D CSI-EPT algorithm are shown. Possible solutions for the underestimation of the dielectric properties are to formulate the CSI-EPT algorithm for 3D RF fields.…”

Electrical Properties Tomography: A Methodological Review

“…Contrast-Source Inversion EPT (CSI-EPT) formulates the inversion problem as a purely optimization problem in which a single functional is iteratively minimized [67,68]. CSI-EPT combines the multiplication of the contrast function and the electric field strength into a single variable, the so-called contrast sourceŵ = χÊ.…”