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Dynamic dephasing changes in developing ischemic cerebral infarction in rats studied by Carr–Purcell T 2 magnetic resonance imaging
Author(s) -
Kavec Martin,
Gröhn Olli H. J.,
Gröhn Heidi I.,
Garwood Michael,
Kauppinen Risto A.
Publication year - 2005
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.20409
Subject(s) - dephasing , magnetic resonance imaging , nuclear magnetic resonance , striatum , hyperintensity , contrast (vision) , nuclear medicine , chemistry , medicine , physics , radiology , dopamine , optics , quantum mechanics
Carr–Purcell (CP) T 2 MRI with adiabatic pulses, acquired with varying interecho interval (τ CP ), was used to study the time course of T 2 and relative dynamic‐dephasing contrast in the rat brain. Exposure to 30 min of middle cerebral artery occlusion (MCAo) resulted in an irreversible increase in absolute CP‐ T 2 relaxation times. This was not associated with signal change in the relative dynamic‐dephasing images, as computed by subtracting short τ CP CP‐ T 2 images from long τ CP images and normalizing for long τ CP images. A day after MCAo strong CP‐ T 2 hyperintensity and low apparent diffusion coefficient were evident in the striatum with a decline in relative dynamic‐dephasing contrast. Low dynamic dephasing contrast prevailed in striatum until day 5 post‐MCAo, returning to control levels with similar time course to normalizing T 2 and diffusion. The present results show a novel behavior of dynamic‐dephasing contrast in poststroke brain tissue, providing data to assess the age of infarction in association to T 2 images. Magn Reson Med 53:960–964, 2005. © 2005 Wiley‐Liss, Inc.