Stroke, Vol 17, 328-331, Copyright © 1986 by American Heart Association
LD DeWitt
There are many positive aspects to the use of MRI in the evaluation of
cerebrovascular disease. First, the MR imaging technique appears to be
essentially without hazard. It does not rely on ionizing radiation, and no
intravenous injections of contrast agent are necessary. MRI exploits the
tissue's inherent biophysical characteristics to provide superior contrast.
Infarctions are well delineated by MRI, often better and earlier than CT.
Because of the lack of MRI signal from bone and thus the lack of transverse
artifact from bone often seen with CT, lesions in the posterior fossa are
very well visualized. With MRI it is possible to obtain images in the
transverse, coronal, and sagittal planes, which provides for good
evaluation of lesion size and extent. Arteriovenous malformations have been
visualized by MRI, but it is still too early to know whether MRI has any
detection capability over CT in this disorder. Subdural hematomas have been
well visualized by MRI, including cases of isodense subdurals not
visualized by CT. On the other hand, MRI has not proven to have any
advantage over CT in the evaluation of intracerebral hemorrhage,
hemorrhagic infarction, and subarachnoid hemorrhage. In fact, for detection
of intracerebral hemorrhage and subarachnoid hemorrhage, CT may be better
at the present time. In chronic infarction the surrounding area of
Wallerian degeneration may cause the area of infarction to appear larger
than it actually is. Hopefully, with further research into the use of
different pulse sequence techniques and with good neuropathological
correlation, the present limitations of MRI can be eliminated.(ABSTRACT
TRUNCATED AT 250 WORDS)
ARTICLES
Clinical use of nuclear magnetic resonance imaging in stroke
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