The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 23, 1990
Filed:
Aug. 11, 1989
Heinz Egloff, Fremont, CA (US);
Spectroscopy Imaging Systems, Fremont, CA (US);
Abstract
A method and apparatus for the compensation of an eddy current magnetic field in the magnetic field of a pulsed gradient coil in an MR scanning apparatus, wherein: an MR-active sample is positioned along a given coordinate axis within a magnetic field of the gradient coil and away from its isocenter; a plurality of time-sequential gradient coil pulses are applied to the gradient coil for generating a corresponding plurality of gradient magnetic field pulses; the sample is irradiated with an RF excitation pulse a given time delay which is increased following application of each of the gradient coil pulses, so as to generate a plurality of time-sequential MR signals; each of the MR signals are measured, Fourier transformed and stored as data, the data representative of the eddy current magnetic field; correction coefficients are calculated for compensating the magnetic field of the gradient coil with respect to the eddy current magnetic field using peak frequency shift data determined from the stored data; and the calculated correction coefficients are applied so as to generate a pre-distorted gradient coil pulse which will compensate for the affect of said eddy current magnetic field upon said gradient coil magnetic field.