English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
 
 
DownloadE-Mail
  Water diffusion in rat brain in vivo as detected at very large b values is multicompartmental

Pfeuffer, J., Provencher, S. W., & Gruetter, R. (1999). Water diffusion in rat brain in vivo as detected at very large b values is multicompartmental. MAGMA: Magnetic Resonance Materials in Physics, Biology and Medicine, 8, 98-108.

Item is

Files

show Files
hide Files
:
600616.pdf (Publisher version), 213KB
Name:
600616.pdf
Description:
-
Visibility:
Public
MIME-Type / Checksum:
application/pdf / [MD5]
Technical Metadata:
Copyright Date:
-
Copyright Info:
-
License:
-

Locators

show

Creators

show
hide
 Creators:
Pfeuffer, J., Author
Provencher, S. W.1, Author              
Gruetter, R., Author
Affiliations:
1Abteilung Experimentelle Methoden, MPI for biophysical chemistry, Max Planck Society, ou_578551              

Content

show
hide
Free keywords: multiexponential decay; restricted diffusion; diffusion time dependence; anisotropy; rat brain; diffusogram
 Abstract: The diffusion-weighted signal attenuation of water in rat brain was measured with pulsed-field gradient nuclear magnetic resonance methods in a single voxel under in vivo and global ischemic conditions. The diffusion-attenuated water signal was observed in vivo at b values of 300 ms/ mu m/sup 2/ (strength of diffusion weighting) and diffusion times up to 400 ms. A series of constant diffusion time (CT) experiments with varied gradient directions and diffusion times revealed a multiexponential decay with apparent diffusion coefficients (ADC) covering two orders of magnitude from I to 0.01 mu m/sup 2//ms. In a four-exponential fit, the observed changes during global ischemia could be fully explained by changes in the relative volume fractions only with unchanged ADCs. An anisotropy of the ADC, detected at small b values, was not observed for the ADC at large b values, but for the concomitant volume fractions. An inverse Laplace Transform of the CT curves, performed with CONTIN, resulted in continuously distributed diffusion coefficients, for which the term `diffusogram' is proposed. This approach was more appropriate than a discrete exponential model with four to six components, being related to the morphology of brain tissue and its cell size distribution. On the basis of an analytical, quantitative model, it is suggested that the measured ADC at small b values reflects mainly properties of the restricting boundaries, i.e. the relative volume fractions and the extracellular tortuosity, while the intrinsic intracellular diffusion constant and the exchange time are predicted to have minor influence.

Details

show
hide
Language(s): eng - English
 Dates: 2005-08-161999
 Publication Status: Published in print
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Type: -
 Identifiers: eDoc: 233602
Other: 11491
 Degree: -

Event

show

Legal Case

show

Project information

show

Source 1

show
hide
Title: MAGMA: Magnetic Resonance Materials in Physics, Biology and Medicine
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: -
Pages: - Volume / Issue: 8 Sequence Number: - Start / End Page: 98 - 108 Identifier: -