Fast FLAIR sequence for detecting major vascular abnormalities during the hyperacute phase of stroke: a comparison with MR angiography.
In the hyperacute phase of stroke, occluded vessels can be seen as high signal on fast-FLAIR images or as absence of flow-related enhancement in maximum-intensity projection (MIP) MR angiography (MRA). To compare these techniques, we examined 53 patients within 6 h of a stroke, using a standardised MRI protocol including fast-FLAIR and 3D time-of-flight TOF MR to detect vessel occlusion or reduced flow corresponding to the suspected ischaemic territory. Brain infarcts were confirmed on MRI after 1-5 days in 41 cases (77%). The overall accuracy of 3D-TOF MRA was 68% and sensitivity, specificity, positive and negative predictive values were 67%, 71%, 87%, and 43% respectively. Values for the fast-FLAIR sequence were: 65%, 85%, 93% and 44%, with an overall accuracy of 70%. The fast-FLAIR sequence was thus able to show occluded vessels or reduced flow with about the same accuracy as 3D-TOF MRA and enabled better prediction of the ischaemic area.
Cosnard
G
G
Department of Radiology, Cliniques Universitaires Saint-Luc, Brussels, Belgium. cosnard@rdgn.ucl.ac.be
Duprez
T
T
Grandin
C
C
Smith
A M
AM
Munier
T
T
Peeters
A
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002560:Cerebrovascular Circulation; D002561:Cerebrovascular Disorders / Q000175:diagnosis*; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity