Apparatus and method for magnetic resonance measurement and mapping of electrical impedance, complex permittivity and complex conductivity as applied to detection and evaluation of sample pathology

摘要

A method of measurement of or mapping the distribution of complex permittivity, complex conductivity, complex impedance, or electric loss angle during magnetic resonance imaging or analysis. The method includes applying a time-varying electric field of a Faraday shield to a sample and cross-correlating the line spectrum signal so produced with the voltage applied to the Faraday shield in a detection circuit. The method permits non-contrast magnetic resonance screening for breast cancer in vivo and/or continuous measurement of electrical characteristics of materials at variable frequencies in vitro. A system of detecting and evaluating sample pathology includes a Faraday shield device that includes parallel electrodes oriented orthogonal to the static magnetic field of a MRI device to produce a time varying electric field. A detector is coupled to the MRI device to detect at least one of a complex permittivity, a complex conductivity, and an electrical impedance of the sample.

主权项

1. A method of detecting and evaluating sample spatially ordered pathology, comprising:
placing an in-vivo human tissue sample to be evaluated within a magnetic resonance imaging device in proximity to a Faraday shield device, wherein the Faraday shield device comprises Faraday shields oriented so as not to significantly affect a radio frequency field generated within the magnetic resonance imaging device, and an insulating material that insulates the in-vivo human tissue sample from the Faraday shields, whereby the Faraday shield device is configured to apply a time varying potential difference to the in-vivo human tissue sample; applying a time varying potential difference to the Faraday shield device, so as to create a time varying electric field in the in-vivo human tissue sample and a local time varying current field in the in-vivo human tissue sample essentially orthogonal to the main magnetic field generated by the magnetic resonance imaging device which results in a periodic aberration in a local magnetic field that periodically varies a phase of spins within the in-vivo human tissue sample; and imaging at least one of a complex permittivity, a complex conductivity, and an electrical impedance of the in-vivo human tissue sample during the application of the time varying potential difference to the Faraday shield device.