Statistical analysis of the accuracy of water content‐based electrical properties tomography

Abstract

Water content-based electrical properties tomography (wEPT) can retrieve electrical properties (EPs) from water content maps, thereby eliminating the need for B 1 field measurement in the traditional magnetic resonance electrical properties tomography method. The wEPT is performed by conventional MR scanning, such as T 1 -weighted spin-echo imaging, and thus can be directly applied to clinical settings. However, the random noise propagation involved in wEPT causes inaccuracy in EP mapping. To guarantee the EP estimates desired for clinical practice, this study statically investigates the noise-specific uncertainty of wEPT through probability density function models. We calculated the probability distribution of EP maps with different noise levels and examined the effects of scan parameters on reconstruction accuracy with various flip angles (FAs) and repetition time (TR) settings. The theoretical derivation was validated by Monte Carlo simulations and human imaging experiment at 3 T.Results showed that a serious deviation could occur in tissues with large conductivity value at a low signal-to-noise ratio and quantitatively demonstrate that such deviation could be mitigated by increased FAs or TRs. This study provided useful information for the setup of scan parameters, evaluation of accuracy of the wEPT under specific SNR levels, and promote its clinical applications. K E Y W O R D Selectrical conductivity, electrical properties tomography, magnetic resonance imaging, probability density function, relative permittivity, water content

EPTlib: An Open-Source Extensible Collection of Electric Properties Tomography Techniques

“…A plethora of different techniques implementing EPT has been proposed in the literature [7]. Despite there exist some peculiar approaches to EPT, like the one based on the water content estimated by T 1 -weighted images [12][13][14], almost all the proposed techniques map the EPs by elaborating the distribution of the rotating component B + 1 of the radiofrequency magnetic field B 1 generated by the MRI scanner [7]. The magnitude |B + 1 |, namely the transmit (Tx) sensitivity, and the phase ϕ + , namely the Tx phase, of B + 1 are usually acquired separately.…”

Correlation analysis between the complex electrical permittivity and relaxation time of tissue mimicking phantoms in 7 T MRI

“…Another method has been proposed 14 , 21 to address the limitations of the Laplacian method. In this method, the Maxwell mixture theory, and the correlation between the water content of tissues and their electrical properties are used.…”