A Method for Eddy Current Field Measurement in Permanent Magnet Magnetic Resonance Imaging Systems

• Main Authors: SONG Rui, HE Yan-fa, ZHANG Bo
• Format: Article
• Language: zho
• Published: Science Press 2018-03-01
• Series: Chinese Journal of Magnetic Resonance
• Subjects: magnetic resonance imaging (MRI); gradient coil; eddy current field; measurement
• Online Access: http://121.43.60.238/bpxzz/EN/10.11938/cjmr20172593

Magnetic resonance imaging (MRI) is a widely used medical imaging technique. In MRI system, gradient magnetic fields are used to code spatial information. However, the fast-switching electric currents in the gradients coils used to generate gradient fields also induce vortex electric field, often referred as eddy current, in the surrounding metal conductors. In this paper, a method for eddy current field measurement was proposed. Based on the Faraday law of electromagnetic induction, an eddy current field measuring device was designed. Combining hardware acquisition and software processing, the eddy current field was obtained by subtracting the ideal gradient field from the magnetic field measured experimentally, whose waveform could be displayed in real time. The proposed method was verified by experimental results.