[Echo-planar diffusion-weighted MRI in the diagnosis of acute ischemic stroke: characterisation of tissue abnormalities and limitations in the interpretation of imaging findings].
BACKGROUND
An accurate diagnosis is frequently difficult in early stroke. Diffusion-weighted (DW) magnetic resonance imaging (MRI) allows visualization of ischemic parenchyma and quantitative assessment of tissue changes before unequivocal abnormalities appear on T(2)-weighted MRI.


METHODS
We analyzed 105 MRI examinations of patients with acute stroke (<24 h) with regard to patterns of abnormalities in T(2)-weighted and DW MRI. Furthermore we assessed the influence of artifacts related to DW echo-planar single-shot MRI on image interpretation.


RESULTS
Depending on the time of patient assessment there were three partly overlapping T(2)/DW patterns: (1) in the very early phase (</=1.5 h after symptom onset) there was no T(2) abnormality and no definite abnormality of diffusion; (2) no T(2) abnormality and restricted diffusion (1.5-4 h); (3) T(2) hyperintensity and restricted diffusion (>/=3 h). Typical artifacts (susceptibility distortions, N/2 artifact, chemical shift artifact and eddy currents artifact) had to be considered when interpreting images.


CONCLUSIONS
Provided typical artifacts are taken into consideration, echo-planar DW MRI allows a more precise diagnostic assessment in acute stroke.
Gass
A
A
Neurologische Klinik, Klinikum Mannheim, Universität Heidelberg.
Gaa
J
J
Sommer
A
A
Hirsch
J
J
Georgi
M
M
Hennerici
M G
MG
Schwartz
A
A
D000208:Acute Disease; D000328:Adult; D000368:Aged; D002545:Brain Ischemia / Q000175:diagnosis*; D002561:Cerebrovascular Disorders / Q000175:diagnosis*; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000592:standards; D008297:Male; D008875:Middle Aged