MR měřicí techniky rychle přepínaných gradientních magnetických polí v MR tomografii

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26220%2F06%3APU54874" target="_blank" >RIV/00216305:26220/06:PU54874 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68081731:_____/05:00043851

Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

MR Measurement Technique of Rapidly Switched Gradient Magnetic Fields in MR Tomography

Popis výsledku v původním jazyce

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 pulseand 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 tomo

Název v anglickém jazyce

MR Measurement Technique of Rapidly Switched Gradient Magnetic Fields in MR Tomography

Popis výsledku anglicky

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 pulseand 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 tomo

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

JA - Elektronika a optoelektronika, elektrotechnika

OECD FORD obor

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Projekt

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Návaznosti

Z - Vyzkumny zamer (s odkazem do CEZ)

Rok uplatnění

2006

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Applied Magnetic Resonance (IF 0,665)

ISSN

0937-9347

e-ISSN

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Svazek periodika

29

Číslo periodika v rámci svazku

12

Stát vydavatele periodika

AT - Rakouská republika

Počet stran výsledku

12

Strana od-do

675-686

Kód UT WoS článku

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EID výsledku v databázi Scopus

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