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BARTUŠEK, K. GESCHEIDTOVÁ, E.
Original Title
MR Measurement Technique of Rapidly Switched Gradient Magnetic Fields in MR Tomography
Type
journal article in Web of Science
Language
English
Original Abstract
Gradient eddy currents, induced in the surrounding conductive structures in a MR magnet, are a major problem in MRI, in localized MR spectroscopy and in many other MR experiments. We present a comparison of three methods of measuring the gradient time characteristics and the time changes of basic magnetic field B0 after the gradient is switched off. The methods are based on a selective excitation of a thin layer of the specimen and on acquiring the MR signal obtained after the and of the gradient pulse and on the computation of the instantaneous frequency of the signal. At this point, the time gradient characteristic is proportional to the instantaneous frequency of the MR signal, which has a small signal to noise (S/N) ratio. We use the characteristics measured to set the pre-emphasis parameters in a 200 MHz/200 mm MR scanner. From the results obtained by measurement it follows that all methods are convenient for simple and quick characterization of gradient magnetic filed in MR tomographic magnets.
Keywords
MR tomography, gradiernt magnetic field, IF method, IFSE method, IFSES method, spin echo
Authors
BARTUŠEK, K.; GESCHEIDTOVÁ, E.
RIV year
2006
Released
1. 12. 2006
Publisher
Springer
ISBN
0937-9347
Periodical
Applied Magnetic Resonance (IF 0,665)
Year of study
29
Number
12
State
Republic of Austria
Pages from
675
Pages to
687
Pages count
BibTex
@article{BUT46129, author="Karel {Bartušek} and Eva {Gescheidtová}", title="MR Measurement Technique of Rapidly Switched Gradient Magnetic Fields in MR Tomography", journal="Applied Magnetic Resonance (IF 0,665)", year="2006", volume="29", number="12", pages="675--687", issn="0937-9347" }