FLAIR Distal Hyperintense Vessels as a Marker of Perfusion‐Diffusion Mismatch in Acute Stroke

Abstract

DHV may be a surrogate marker for PDM in patients with hyperacute ischemic stroke.

Do FLAIR Vascular Hyperintensities beyond the DWI Lesion Represent the Ischemic Penumbra?

“…In univariate analysis, patients with PWI-DWI mismatch had lower initial NIHSS scores (15 [range, [11][12][13][14][15][16][17][18][19][20] , P ϭ .01), and lower serum glucose levels at admission (6.7 Ϯ 1.2 versus 7.3 Ϯ 1.8 mmol/L, P ϭ .04). In multivariate analysis based on easily derivable admission variables, PWI-DWI mismatch was independently associated with FVH-DWI mismatch (OR, 7.63; 95% CI, 1.74 -33.43; P ϭ .007) after adjustment for onset-to-admission MR imaging time (OR, 0.98; 95% CI, 0.97-1.00; P ϭ .02) and DWI-ASPECTS (OR, 1.76; 95% CI, 1.22-2.53; P ϭ .003).…”

“…After an intracranial arterial occlusion, FLAIR vascular hyperintensities (FVHs) are seen in 45%-100% of patients with stroke. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] Although their pathophysiologic and clinical significance is not fully understood, FVHs might help in the management of patients with acute stroke. Beyond their diagnostic value regarding the detection of arterial occlusion, 11,14,15 FVHs may provide prognostic information, despite discrepancies among studies.…”

“…16 FVHs precede DWI abnormalities 17 and can be seen beyond the boundaries of the DWI lesion, and the final infarct volume falls between the initial DWI lesion and the area facing the FVHs. 14 Furthermore, FVHs beyond the clot are associated with perfusion-weighted imaging-DWI mismatch 3,8,13 and better outcome after IV-tPA. 3 Taken together, these data suggest that prominent/extended FVHs indicate large areas of salvageable tissue and greater potential benefit from recanalization.…”

Hyperintense Vessels on T2-PROPELLER-FLAIR in Patients with Acute MCA Stroke: Prediction of Arterial Stenosis and Perfusion Abnormality

“…Previous studies reported that FHVs are prominent within the Sylvian fissure. [6][7][8][9][10][11][12][13][14][15] This might be because the larger arteries have a slower flow speed than the smaller distal arteries under the same perfusion pressure. Hohenhaus et al 6 reported that…”

“…1,5 Recently, distal FHVs have been studied more due to their clinical importance. 6,7 Technically, in the setting of normal hemodynamics, the blood vessels show dark signal intensity on spin-echo sequences such as FLAIR because of the dephasing effect from mixed spinechoes and stimulated echoes, as well as the disrupted spin-echo mechanism due to through-plane blood motion. The retrograde slow flow results in the loss of this flow void phenomenon, and vessels appear hyperintense against the dark CSF background.…”