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 sig nal on fast-FLAIR images or as absence of flow-related enhancement in maxim um-intensity projection (MIP) MR angiography (MRA). To compare these techni ques, 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 ve ssel occlusion or reduced flow corresponding to the suspected ischaemic ter ritory. Brain infarcts: were confirmed on MRI after 1-5 days in 31 cases (7 7 %), The overall accuracy of 3D-TOF MRA was 68 % and sensitivity, specific ity, positive and negative predictive values were 67 %, 71 %, 87 %, and 43 % respectively. Values for the fast-FLAIR sequence were: 65 %, 85 %, 93 % a nd 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.