T2- and diffusion-weighted magnetic resonance imaging of a focal ischemic lesion in rat brain.
OBJECTIVE
We sought to evaluate the application of T2-weighted and diffusion-weighted magnetic resonance imaging techniques in the study of a focal ischemic lesion in the rat brain.


METHODS
Unilateral cortical infarcts were induced using the photosensitive dye rose bengal and 560 nm light irradiation. Magnetic resonance images were recorded from a total of 11 rats at selected intervals from 1.5 hours to several days after induction of the lesion. Parallel experiments were performed in which Evans blue dye was injected into the lesioned animals either immediately after lesion induction (n = 11) or 1 hour before the animals were killed (n = 11). The second procedure was designed to show regions of blood-brain barrier permeability to plasma proteins at the time of sacrifice, whereas the first procedure showed the accumulation and subsequent dispersion of plasma protein following disruption of the blood-brain barrier.


RESULTS
Regions of the cortex highlighted by the T2-weighted images corresponded well to the pattern of dye staining seen from the first procedure while the diffusion-weighted images showed visual correspondence with the staining pattern obtained using the second procedure.


CONCLUSIONS
These results illustrate the complementary use of T2-weighted and diffusion-weighted magnetic resonance imaging in discerning the pathophysiology of developing lesions.
Department of Biophysics, Hunterian Institute, Royal College of Surgeons of England, London.
N
N
van Bruggen
B M
BM
Cullen
M D
MD
King
M
M
Doran
S R
SR
Williams
D G
DG
Gadian
J E
JE
Cremer
D000818:Animals; D001921:Brain / Q000378:metabolism / Q000473:pathology*; D002545:Brain Ischemia / Q000175:diagnosis* / Q000378:metabolism; D005070:Evans Blue; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012709:Serum Albumin / Q000493:pharmacokinetics; D013194:Staining and Labeling; D014018:Tissue Distribution
D012709:Serum Albumin; D005070:Evans Blue