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Abstract #3138

Monte-Carlo Simulation of Susceptibility Effects on the PGSE Signal and Diffusion Measures

Pim Pullens1, 2, Alard Roebroeck2, Rainer Goebel2, Kamil Uludag2

1Biomedical MR Imaging and Spectroscopy Group, Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands; 2Maastricht Brain Imaging Center, Maastricht, Netherlands

The susceptibility in white matter fiber is orientation-dependent and, thus, affects the gradient-echo signal. Rotating a fibrous phantom in the magnetic field, we also observed signal changes in diffusion-weighted spin-echo experiments. Consequently, diffusion parameters, such as FA and ADC, can be distorted by these orientation-dependent effects. In the study, Monte-Carlo simulations were performed to investigate the effect of susceptibility changes in a PGSE experiment. We found in our simulations that diffusion-weighted signal, FA and ADC change as a result of susceptibility differences. This could have an impact on human DW-MRI measurements especially at high and ultra-high fields.

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Keywords

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