Detail publikace

MR Perfusion Visualization in 3D Image

Originální název

MR Perfusion Visualization in 3D Image

Anglický název

MR Perfusion Visualization in 3D Image

Jazyk

en

Originální abstrakt

For monitoring of tissue structures of Euphorbia plants is used magnetic resonance imaging (MRI). In contrast with CT the MRI does not emit any harmful radiation. The images are obtained without any deformation or destruction of the plant. The principle of MRI techniqueis based on the measurement of the interaction of the electromagnetic waves with nuclei placed in the strong magnetic fields. Diffusion is random translational motion of molecules from a place of higher concentration to a location with lower concentrations, arising due to their thermal energy. The diffusion coeffcients measured by MRI method are describing the degrees of mobility of nuclei. Measurements of these coeffcients is performed by measuring the PFGSE sequence, it is a normal spin-echo sequence extended by two identical rectangular diffusion gradients. During measurements there are distinguished three time intervals. In the first interval the nuclei are dephased, in the next interval the nuclei diffuse (relaxation time). In the last interval the nuclei are phased in by gradient pulses. When not all magnetization vectors are phased, diffusion is non-zero, otherwise diffusion is zero and the maximum MRI signal is obtained. During the measurement of the diffusion coeffcient the static gradient is manifested as a result of magnetic properties of the substance. There are four gradients used for measurement for each axis. Evaluation of acquired images was performed in the program Marevisi. The images were evaluated separately for positive gradient ones and negative gradient ones. To obtain more accurate values in all directions averaged values were calculated.

Anglický abstrakt

For monitoring of tissue structures of Euphorbia plants is used magnetic resonance imaging (MRI). In contrast with CT the MRI does not emit any harmful radiation. The images are obtained without any deformation or destruction of the plant. The principle of MRI techniqueis based on the measurement of the interaction of the electromagnetic waves with nuclei placed in the strong magnetic fields. Diffusion is random translational motion of molecules from a place of higher concentration to a location with lower concentrations, arising due to their thermal energy. The diffusion coeffcients measured by MRI method are describing the degrees of mobility of nuclei. Measurements of these coeffcients is performed by measuring the PFGSE sequence, it is a normal spin-echo sequence extended by two identical rectangular diffusion gradients. During measurements there are distinguished three time intervals. In the first interval the nuclei are dephased, in the next interval the nuclei diffuse (relaxation time). In the last interval the nuclei are phased in by gradient pulses. When not all magnetization vectors are phased, diffusion is non-zero, otherwise diffusion is zero and the maximum MRI signal is obtained. During the measurement of the diffusion coeffcient the static gradient is manifested as a result of magnetic properties of the substance. There are four gradients used for measurement for each axis. Evaluation of acquired images was performed in the program Marevisi. The images were evaluated separately for positive gradient ones and negative gradient ones. To obtain more accurate values in all directions averaged values were calculated.

BibTex


@inproceedings{BUT90946,
  author="Martin {Čáp} and Petr {Marcoň} and Eva {Gescheidtová} and Karel {Bartušek} and Eva {Kroutilová}",
  title="MR Perfusion Visualization in 3D Image",
  annote="For monitoring of tissue structures of Euphorbia plants is used magnetic resonance imaging (MRI). In contrast with CT the MRI does not emit any harmful radiation. The images are obtained without any deformation or destruction of the plant. The principle of MRI techniqueis based on the measurement of the interaction of the electromagnetic waves with nuclei placed in the strong magnetic fields. Diffusion is random translational motion of molecules from a place of higher concentration to a location with lower concentrations, arising due to their thermal energy. The diffusion coeffcients measured by MRI method are describing the degrees of mobility of nuclei. Measurements of these coeffcients is performed by measuring the PFGSE sequence, it is a normal spin-echo sequence extended by two identical rectangular diffusion gradients. During measurements there are distinguished three time intervals. In the first interval the nuclei are dephased, in the next interval the nuclei diffuse (relaxation time). In the last interval the nuclei are phased in by gradient pulses. When not all magnetization vectors are phased, diffusion is non-zero, otherwise diffusion is zero and the maximum MRI signal is obtained. During the measurement of the diffusion coeffcient the static gradient is manifested as a result of magnetic properties of the substance. There are four gradients used for measurement for each axis. Evaluation of acquired images was performed in the program Marevisi. The images were evaluated separately for positive gradient ones and negative gradient ones. To obtain more accurate values in all directions averaged values were calculated.",
  booktitle="Progress in Electromagnetics Research Symposium Proceedings, KL, Malaysia",
  chapter="90946",
  howpublished="electronic, physical medium",
  year="2012",
  month="march",
  pages="380--384",
  type="conference paper"
}