Correlation between conductivity and prognostic factors in invasive breast cancer using magnetic resonance electric properties tomography (MREPT)

MR‐based electrical properties tomography converts the MRI transmit/receive RF field measurements to tissue electrical property maps through dedicated reconstruction algorithms. Recent reports showed that despite limitations, electrical properties tomography holds promise for generating additional contrast for tumor detection and patient‐specific modeling of tissue–RF field interactions. This review summarizes the available tissue electrical property contrasts and compares them with the capabilities of the most commonly used electrical properties tomography reconstruction method. Future directions and prospects of clinical translation are discussed.

Section: Clinical Applicationsmentioning

confidence: 99%

Electrical properties tomography: Available contrast and reconstruction capabilities

Hancu

Liu

Hua

et al. 2018

“…Recently, MR electrical property tomography (MREPT or EPT) was introduced, which noninvasively extracts the tissue electrical property from the distribution of the RF transmit field of an MRI system . Clinical applications of EPT have been reported, such as in stroke, glioma, pelvic cancer, and breast cancer . The physiological meanings of the measurements were also investigated in comparison with other imaging parameters and prognostic factors …”

Section: Introductionmentioning

confidence: 99%

“…Clinical applications of EPT have been reported, such as in stroke, glioma, pelvic cancer, and breast cancer . The physiological meanings of the measurements were also investigated in comparison with other imaging parameters and prognostic factors …”

Section: Introductionmentioning

confidence: 99%

“…3,4 Clinical applications of EPT have been reported, such as in stroke, 5,6 glioma, 7 pelvic cancer, 8 and breast cancer. 9,10 The physiological meanings of the measurements were also investigated in comparison with other imaging parameters 11 and prognostic factors. 10 Despite the potential of EPT as a useful biomarker, technical improvements-especially in signal processing-are still necessary.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Redesign of the Laplacian kernel for improvements in conductivity imaging using MRI

Shin

Kim

2018

Self Cite

Purpose To develop an electrical property tomography reconstruction method that achieves improvements over standard method by redesigning the Laplacian kernel. Theory and Methods A decomposition property of the governing PET equation shows the possibility of redesigning the Laplacian kernel for conductivity reconstruction. Hence, the discrete Laplacian operator used for electrical property tomography reconstruction is redesigned to have a Gaussian‐like envelope, which enables manipulation of the spatial and spectral response. The characteristics of the proposed kernel are investigated through numerical simulations and in vivo brain experiments. Results The proposed method reduces textured noise, which hampers observing features of the conductivity image. Furthermore, the proposed scheme can mitigate the propagation of local phase error such as flow‐induced phase. By doing so, the proposed method can recover feature information in conductivity (or resistivity) images. Lastly, the proposed kernel can be extended to other electrical property tomography reconstructions, improving the quality of images. Conclusion An alternative design of the Laplacian kernel for conductivity imaging has been developed to mitigate the textured noise and the propagation of local phase artifact.

“…High-frequency conductivity maps can be used to obtain local specific absorption rate maps (4), whereas low frequency conductivity maps can be used to monitor thermal therapeutic procedures (5), electroencephalogram source localization (6,7), and the planning of trans-cranial magnetic stimulation (8)(9)(10). Furthermore, both high-and low-frequency conductivities depend on the pathological state of tissues; for example, conductivity maps may be used for the detection and characterization of tumors (11)(12)(13)(14)(15)(16)(17)(18).…”

Section: Introductionmentioning

confidence: 99%

Feasibility of conductivity imaging using subject eddy currents induced by switching of MRI gradients

Oran

Ider

2016

Purpose: To investigate the feasibility of low-frequency conductivity imaging based on measuring the magnetic field due to subject eddy currents induced by switching of MRI zgradients. Methods: We developed a simulation model for calculating subject eddy currents and the magnetic fields they generate (subject eddy fields). The inverse problem of obtaining conductivity distribution from subject eddy fields was formulated as a convection-reaction partial differential equation. For measuring subject eddy fields, a modified spin-echo pulse sequence was used to determine the contribution of subject eddy fields to MR phase images. Results: In the simulations, successful conductivity reconstructions were obtained by solving the derived convectionreaction equation, suggesting that the proposed reconstruction algorithm performs well under ideal conditions. However, the level of the calculated phase due to the subject eddy field in a representative object indicates that this phase is below the noise level and cannot be measured with an uncertainty sufficiently low for accurate conductivity reconstruction. Furthermore, some artifacts other than random noise were observed in the measured phases, which are discussed in relation to the effects of system imperfections during readout. Conclusion: Low-frequency conductivity imaging does not seem feasible using basic pulse sequences such as spin-echo on a clinical MRI scanner. Magn Reson