An Explanation of Signal Changes in DW-fMRI: Monte Carlo Simulation Study of Restricted Diffusion of Water Molecules Using 3D and Two-Compartment Cortical Cell Models

Shizue NAGAHARA; Takenori OIDA; Tetsuo KOBAYASHI

doi:10.1587/transinf.E96.D.1387

An Explanation of Signal Changes in DW-fMRI: Monte Carlo Simulation Study of Restricted Diffusion of Water Molecules Using 3D and Two-Compartment Cortical Cell Models

Shizue NAGAHARA, Takenori OIDA, Tetsuo KOBAYASHI

Full Text Views

0

Share
Cite this

Summary :

Diffusion-weighted (DW)-functional magnetic resonance imaging (fMRI) is a recently reported technique for measuring neural activities by using diffusion-weighted imaging (DWI). DW-fMRI is based on the property that cortical cells swell when the brain is activated. This approach can be used to observe changes in water diffusion around cortical cells. The spatial and temporal resolutions of DW-fMRI are superior to those of blood-oxygenation-level-dependent (BOLD)-fMRI. To investigate how the DWI signal intensities change in DW-fMRI measurement, we carried out Monte Carlo simulations to evaluate the intensities before and after cell swelling. In the simulations, we modeled cortical cells as two compartments by considering differences between the intracellular and the extracellular regions. Simulation results suggested that DWI signal intensities increase after cell swelling because of an increase in the intracellular volume ratio. The simulation model with two compartments, which respectively represent the intracellular and the extracellular regions, shows that the differences in the DWI signal intensities depend on the ratio of the intracellular and the extracellular volumes. We also investigated the MPG parameters, b-value, and separation time dependences on the percent signal changes in DW-fMRI and obtained useful results for DW-fMRI measurements.

Publication: IEICE TRANSACTIONS on Information Vol.E96-D No.6 pp.1387-1393

Publication Date: 2013/06/01

Publicized

Online ISSN: 1745-1361

DOI: 10.1587/transinf.E96.D.1387

Type of Manuscript: PAPER

Category: Biological Engineering

Authors

Shizue NAGAHARA
  Kyoto University,Japan Society for the Promotion of Science
Takenori OIDA
  Kyoto University
Tetsuo KOBAYASHI
  Kyoto University

Keyword

functional magnetic resonance imaging, diffusion-weighted imaging, restricted diffusion, Monte Carlo method

Cite this

Copy

Shizue NAGAHARA, Takenori OIDA, Tetsuo KOBAYASHI, "An Explanation of Signal Changes in DW-fMRI: Monte Carlo Simulation Study of Restricted Diffusion of Water Molecules Using 3D and Two-Compartment Cortical Cell Models" in IEICE TRANSACTIONS on Information, vol. E96-D, no. 6, pp. 1387-1393, June 2013, doi: 10.1587/transinf.E96.D.1387.
Abstract: Diffusion-weighted (DW)-functional magnetic resonance imaging (fMRI) is a recently reported technique for measuring neural activities by using diffusion-weighted imaging (DWI). DW-fMRI is based on the property that cortical cells swell when the brain is activated. This approach can be used to observe changes in water diffusion around cortical cells. The spatial and temporal resolutions of DW-fMRI are superior to those of blood-oxygenation-level-dependent (BOLD)-fMRI. To investigate how the DWI signal intensities change in DW-fMRI measurement, we carried out Monte Carlo simulations to evaluate the intensities before and after cell swelling. In the simulations, we modeled cortical cells as two compartments by considering differences between the intracellular and the extracellular regions. Simulation results suggested that DWI signal intensities increase after cell swelling because of an increase in the intracellular volume ratio. The simulation model with two compartments, which respectively represent the intracellular and the extracellular regions, shows that the differences in the DWI signal intensities depend on the ratio of the intracellular and the extracellular volumes. We also investigated the MPG parameters, b-value, and separation time dependences on the percent signal changes in DW-fMRI and obtained useful results for DW-fMRI measurements.
URL: https://globals.ieice.org/en_transactions/information/10.1587/transinf.E96.D.1387/_p

Copy

@ARTICLE{e96-d_6_1387,
author={Shizue NAGAHARA, Takenori OIDA, Tetsuo KOBAYASHI, },
journal={IEICE TRANSACTIONS on Information},
title={An Explanation of Signal Changes in DW-fMRI: Monte Carlo Simulation Study of Restricted Diffusion of Water Molecules Using 3D and Two-Compartment Cortical Cell Models},
year={2013},
volume={E96-D},
number={6},
pages={1387-1393},
abstract={Diffusion-weighted (DW)-functional magnetic resonance imaging (fMRI) is a recently reported technique for measuring neural activities by using diffusion-weighted imaging (DWI). DW-fMRI is based on the property that cortical cells swell when the brain is activated. This approach can be used to observe changes in water diffusion around cortical cells. The spatial and temporal resolutions of DW-fMRI are superior to those of blood-oxygenation-level-dependent (BOLD)-fMRI. To investigate how the DWI signal intensities change in DW-fMRI measurement, we carried out Monte Carlo simulations to evaluate the intensities before and after cell swelling. In the simulations, we modeled cortical cells as two compartments by considering differences between the intracellular and the extracellular regions. Simulation results suggested that DWI signal intensities increase after cell swelling because of an increase in the intracellular volume ratio. The simulation model with two compartments, which respectively represent the intracellular and the extracellular regions, shows that the differences in the DWI signal intensities depend on the ratio of the intracellular and the extracellular volumes. We also investigated the MPG parameters, b-value, and separation time dependences on the percent signal changes in DW-fMRI and obtained useful results for DW-fMRI measurements.},
keywords={},
doi={10.1587/transinf.E96.D.1387},
ISSN={1745-1361},
month={June},}

Copy

TY - JOUR
TI - An Explanation of Signal Changes in DW-fMRI: Monte Carlo Simulation Study of Restricted Diffusion of Water Molecules Using 3D and Two-Compartment Cortical Cell Models
T2 - IEICE TRANSACTIONS on Information
SP - 1387
EP - 1393
AU - Shizue NAGAHARA
AU - Takenori OIDA
AU - Tetsuo KOBAYASHI
PY - 2013
DO - 10.1587/transinf.E96.D.1387
JO - IEICE TRANSACTIONS on Information
SN - 1745-1361
VL - E96-D
IS - 6
JA - IEICE TRANSACTIONS on Information
Y1 - June 2013
AB - Diffusion-weighted (DW)-functional magnetic resonance imaging (fMRI) is a recently reported technique for measuring neural activities by using diffusion-weighted imaging (DWI). DW-fMRI is based on the property that cortical cells swell when the brain is activated. This approach can be used to observe changes in water diffusion around cortical cells. The spatial and temporal resolutions of DW-fMRI are superior to those of blood-oxygenation-level-dependent (BOLD)-fMRI. To investigate how the DWI signal intensities change in DW-fMRI measurement, we carried out Monte Carlo simulations to evaluate the intensities before and after cell swelling. In the simulations, we modeled cortical cells as two compartments by considering differences between the intracellular and the extracellular regions. Simulation results suggested that DWI signal intensities increase after cell swelling because of an increase in the intracellular volume ratio. The simulation model with two compartments, which respectively represent the intracellular and the extracellular regions, shows that the differences in the DWI signal intensities depend on the ratio of the intracellular and the extracellular volumes. We also investigated the MPG parameters, b-value, and separation time dependences on the percent signal changes in DW-fMRI and obtained useful results for DW-fMRI measurements.
ER -