"Z(MSM0021630513)" . . . "Checking the quality of gradient magnetic fields in MR tomography" . "[B9FCF2DBE396]" . "468495" . . . . . . "189-193" . . . "Checking the quality of gradient magnetic fields in MR tomography"@en . "Bartu\u0161ek, Karel" . "80-214-3246-2" . "M\u011B\u0159en\u00ED kvality gradientn\u00EDch magnetick\u00FDch pol\u00ED v MR tomografii"@cs . "26220" . "Kub\u00E1sek, Radek" . "Checking the quality of gradient magnetic fields in MR tomography" . "3"^^ . "Brno" . . "2006-09-14+02:00"^^ . . "Brno" . "RIV/00216305:26220/06:PU61606!RIV07-MSM-26220___" . "5"^^ . "M\u011B\u0159en\u00ED kvality gradientn\u00EDch magnetick\u00FDch pol\u00ED v MR tomografii"@cs . . . "3"^^ . "Gescheidtov\u00E1, Eva" . . "Electronic Devices and Systems" . "Imaging techniques based on the principle of nuclear magnetic resonance (MRI) can be used in the study of molecular transport phenomena in biological systems such as self-diffusion processes. The precision of determining the diffusion constants depends on generating the gradient pulse with high precision. For the purpose of determining the characteristics of time behavior of gradient pulses a simple measuring method was developed and experimentally tested on a 4.7 T tomograph. The method is based on the principle of measuring the instantaneous frequency of MR signal in the presence of gradient pulse after the excitation of a thin defined layer of the examined specimen placed outside the gradient field centre. Using the above method, errors were found in the amplitude and time integral of generated gradient fields and in determining the diffusion constants for biological tissues." . "Imaging techniques based on the principle of nuclear magnetic resonance (MRI) can be used in the study of molecular transport phenomena in biological systems such as self-diffusion processes. The precision of determining the diffusion constants depends on generating the gradient pulse with high precision. For the purpose of determining the characteristics of time behavior of gradient pulses a simple measuring method was developed and experimentally tested on a 4.7 T tomograph. The method is based on the principle of measuring the instantaneous frequency of MR signal in the presence of gradient pulse after the excitation of a thin defined layer of the examined specimen placed outside the gradient field centre. Using the above method, errors were found in the amplitude and time integral of generated gradient fields and in determining the diffusion constants for biological tissues."@en . "Checking the quality of gradient magnetic fields in MR tomography"@en . "RIV/00216305:26220/06:PU61606" . "Vysok\u00E9 u\u010Den\u00ED technick\u00E9 v Brn\u011B" . . . "Zobrazovac\u00ED techniky pracuj\u00EDc\u00ED na b\u00E1zi magnetick\u00E9 resonance mohou b\u00FDt vyu\u017Eity pro studium transportn\u00EDch d\u011Bj\u016F v biologick\u00FDch syst\u00E9mech pomoc\u00ED dif\u00FAzn\u00EDch proces\u016F. P\u0159esn\u00E9 ur\u010Den\u00ED dif\u00FAzn\u00EDch konstant z\u00E1vis\u00ED na p\u0159esnosti gradientn\u00EDch puls\u016F. Pro ur\u010Den\u00ED \u010Dasov\u00FDch charakteristik gradientn\u00EDch puls\u016F byla vyvinuta a experiment\u00E1ln\u011B ov\u011B\u0159ena m\u011B\u0159ic\u00ED metoda. Ta je zalo\u017Eena na m\u011B\u0159en\u00ED okam\u017Eit\u00E9 frekvence MR sign\u00E1lu za p\u0159\u00EDtomnosti gradientn\u00EDho pulsu po excitaci tenk\u00E9 vrstvy vy\u0161et\u0159ovan\u00E9ho vzorku v poloze mimo st\u0159ed gradientu. Touto metodou byly zji\u0161t\u011Bny chyby v amplitud\u011B a integr\u00E1lu gradien\u00EDho pulsu a p\u0159i stanoven\u00ED dif\u00FAzn\u00EDho koeficientu v biologick\u00FDch tk\u00E1n\u00EDch."@cs . "MR, NMR, gradient magnetic field"@en . . .