Publication detail

Testing the quality of magnetic gradient fields for studying self-diffusion processes by magnetic resonance methods

BARTUŠEK, K. GESCHEIDTOVÁ, E.

Original Title

Testing the quality of magnetic gradient fields for studying self-diffusion processes by magnetic resonance methods

Type

journal article in Web of Science

Language

English

Original Abstract

Imaging techniques based on the principle of nuclear magnetic resonance (NMR) rank with the most advanced methods for studying chemical and biological properties of substances. Their universality makes them particularly suited for use in a wide range of scientific branches. NMR has found significant application in medicine. The diffusion effects of water molecules in tissues reduce the magnitude of spin echo in NMR measuring methods. Based on the amplitude change in the image, the diffusion coefficients and their distribution in the specimen being measured can be calculated. MR images of an object weighted by diffusion coefficients require a defined sequence of gradient pulses and an accurate knowledge of their time behaviour. Methods for measuring the diffusion coefficients require the knowledge of the minimum length of leading and trailing edges, the defined magnitude of the magnetic field gradient being excited, and also the symmetry of positive and negative gradient pulses (the zero integral of pulses of the same magnitude with opposite polarity). To determine the above characteristics of the time behaviour of gradient pulses of both polarities a simple measuring method was developed and experimentally tested on a tomograph with 4.7 T induction of basic magnetic field. This method is based on the principle of measuring the instantaneous frequency of MR signal in the presence of a gradient pulse subsequent to exciting a thin defined layer of the specimen under examination outside the gradient field centre.

Keywords

Nuclear magnetic resonance, diffusion coefficients, gradient pulse, spin echo, gradient pulses symmetry.

Authors

BARTUŠEK, K.; GESCHEIDTOVÁ, E.

RIV year

2006

Released

13. 7. 2006

Publisher

IOP publishing

Location

Bristol

ISBN

0957-0233

Periodical

Measurement Science and Technology

Year of study

2006

Number

17

State

United Kingdom of Great Britain and Northern Ireland

Pages from

2256

Pages to

2262

Pages count

7

BibTex

@article{BUT43263,
  author="Karel {Bartušek} and Eva {Gescheidtová}",
  title="Testing the quality of magnetic gradient fields for studying self-diffusion processes by magnetic resonance methods",
  journal="Measurement Science and Technology",
  year="2006",
  volume="2006",
  number="17",
  pages="2256--2262",
  issn="0957-0233"
}