SYSTEM AND METHOD FOR MEASURING INDUCED RADIO FREQUENCY CURRENT USING PHASE CONTRAST MAGNETIC RESONANCE IMAGING

摘要

A method for automatically measuring currents induced on conducting structures positioned in the bore of a magnetic resonance imaging (“MRI”) scanner using a single magnetic resonance image is provided. A conductive structure is positioned within the bore of the MRI scanner during imaging. When the MRI system is transmitting an RF field, a current is induced in the conductive structure. The current creates a magnetic field at the Larmor frequency, which couples to the RF magnetic field in the vicinity of the conductive structure. The modified magnetic field results in an artifact being generated in phase images. The artifact in the phase image is then analyzed to determine the current induced in the conductive structure.

主权项

1. A method for using a magnetic resonance imaging (“MRI”) system to measure a current induced on a conductive structure by the MRI system, the steps of the method comprising:
a) acquiring with the MRI system, data from a volume-of-interest that contains at least a portion of a conductive structure using a pulse sequence that includes generating a radio frequency (RF) field that induces a current in the conductive structure; b) reconstructing from the data acquired in step a), an image that depicts the portion of the conductive structure; c) producing a phase image from the image reconstructed in step b) by extracting phase information from the reconstructed image; d) fitting the phase information in the phase image to a model that relates a phase of the generated RF field to a phase of a magnetic field generated by the current induced in the conductive structure; and e) determining a quantitative measurement of the current induced in the conductive structure from the fitting performed in step d).