학술논문

A method for NMR imaging of a magnetic field generated by electric current
Document Type
Periodical
Source
IEEE Transactions on Magnetics IEEE Trans. Magn. Magnetics, IEEE Transactions on. 40(4):2188-2190 Jul, 2004
Subject
Fields, Waves and Electromagnetics
Magnetic resonance imaging
Magnetic fields
Current
Magnetic field measurement
Radio frequency
Nuclear magnetic resonance
Nuclear power generation
Signal generators
Wire
Magnetization
Language
ISSN
0018-9464
1941-0069
Abstract
This paper proposes a method to detect electric currents using nuclear magnetic resonance (NMR) imaging. The motion of magnetization during applications of electric current and radio-frequency (RF) pulses was formulated based on the rotating-frame Bloch equation. The relationship between a magnetic field generated by electric current and the signal intensity of an NMR image was calculated for a Gaussian RF pulse with a duration of 10 ms. Images of a phantom were obtained with and without application of electric current to a straight wire. The magnetic field generated by the electric current caused a decrease in the signal intensity around the wire. The magnetic field measured from the images was in good agreement with the theoretically calculated magnetic field. In the case of an RF pulse duration of 10 ms, a maximum sensitivity of 3.0/spl times/10/sup 5/ T/sup -1/ was obtained at a magnetic field intensity of 2.7/spl times/10/sup -6/ T.