Histopathologic correlates of abnormal water diffusion in cerebral ischemia: diffusion-weighted MR imaging and light and electron microscopic study.
OBJECTIVE
To correlate the findings on diffusion-weighted magnetic resonance (MR) images with the cytologic and histologic findings in ischemic tissue.


METHODS
A photochemical model of cerebral infarction in rats was studied with diffusion- and T2-weighted MR imaging. The development of lesions was followed from 20 minutes to 5 days after the onset of ischemia. Apparent water diffusion coefficient (ADC) maps were calculated and correlated with light and electron microscopic findings.


RESULTS
T2-weighted images clearly showed vasogenic edema but did not enable distinction between areas with cellular damage and the surrounding edematous regions. In contrast, the ADC, which was elevated in nonischemic edematous regions, was diminished in areas with histologic evidence of ischemic damage or necrosis. In the core of the infarct, the ADC became elevated when electron microscopy revealed cellular lysis.


CONCLUSIONS
Diffusion-weighted images may help ascertain the extent of cellular damage and death after stroke.
Pierpaoli
C
C
Neuroimaging Branch, National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, MD 20892.
Righini
A
A
Linfante
I
I
Tao-Cheng
J H
JH
Alger
J R
JR
Di Chiro
G
G
D000818:Animals; D001253:Astrocytes / Q000378:metabolism / Q000473:pathology; D001834:Body Water / Q000378:metabolism*; D001921:Brain / Q000378:metabolism / Q000473:pathology; D001929:Brain Edema / Q000378:metabolism / Q000473:pathology; D002545:Brain Ischemia / Q000378:metabolism* / Q000473:pathology*; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D002544:Cerebral Infarction / Q000378:metabolism / Q000473:pathology; D003593:Cytoplasm / Q000378:metabolism / Q000648:ultrastructure; D004058:Diffusion; D008027:Light; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008854:Microscopy, Electron; D009410:Nerve Degeneration; D009412:Nerve Fibers / Q000378:metabolism / Q000648:ultrastructure; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012395:Rose Bengal / Q000008:administration & dosage; D013997:Time Factors
D012395:Rose Bengal