Summary of studies describing FLAIR vascular hyperintensities

Author (Publication Year)Population StudiedNo.Age Range/Mean (yr)Criteria for FVH DiagnosisStudyConclusions
Cosnard et al (1999)3Acute cerebral ischemia imaged <6 hours from symptom onset5326–90/69High signal from vessels on FLAIR sequencesComparison of 3D-TOF MRA and FLAIR images for stroke diagnosisFVH corresponded to MRA evidence of stenosis/occlusion; FVH correlated to the territory of brain infarction on follow-up imaging in 85% of cases
Kamran et al (2000)4Retrospective blinded analysis of 304 MRIs of patients admitted for acute MCA stroke3052–81Tubular hyperintense signal relative to gray matter on FLAIRDetermined the clinical correlates of FVHFVH observed in 10% of cases; FVH associated with MCA occlusion or severe stenosis; Angiographic studies correlated FVH with slow flow in leptomeningeal collaterals; NIHSS scores higher in patients demonstrating greater burden of FVH in MCA territory
Maeda et al (2001)5Review of patients imaged within 6 hours of stroke-symptom onset1163–88/74Arterial hyperintensity on FLAIR imagesComparison of FVH with DWI for diagnosis of acute strokeFVH present in 8 of 11 patient MRIs; FVH can precede DWI abnormalities and may provide a clue to early detection of impending infarction
Toyoda et al (2001)6Imaging within 6 hours of onset of acute cerebral ischemia caused by intracranial arterial occlusion6027–93/70.3HVSDescribed FVH, MRA, flow voids on T2, and DWI findings in select groupFVH present in 98%; FVH seen in areas outside increased DWI signal; Final infarct volume intermediate to DWI signal area and FVH area
Iancu-Gontard et al (2003)8Cases with multiple intracerebral arterial stenoses imaged nonacutely with FLAIR and control group19 vs 19Study group (22–67/43), control group (42.2)HVS on FLAIR = focal or tubular hyperintensities in the subarachnoid space (within dark CSF signal)Determined whether HVS is more common in patients with known intracerebral arterial stenosisHigh inter-reader concordance in identifying FVH; FVH seen in 68% of cases and 5% of controls; Concordance of territorial distribution of stenoses on FVH highest in MCA distribution; FVH seen mostly in high-grade stenosis or occlusion
Schellinger et al (2005)12Review of 127 patients who received rtPA within 3 hours of stroke onset5663–89/76HVSComparison of HMCAS, GRE-BA, and FVH for diagnosis of stroke and predicting response to rtPAFVH associated with vessel occlusion but has little prognostic value; FVH more sensitive than HMCAS and GRE-BA in diagnosis if large-vessel occlusion (66% vs 40% vs 34%); HVS represents slow flow whereas the other 2 signs represent the thrombus; FVH not an independent predictor of intracranial hemorrhage, recanalization, and clinical outcome, including response to rtPA
Sanossian et al (2009)9Acute cerebral ischemia imaged within 6 hours of angiography7443–83/63Focal, tubular, or serpentine hyperintensity relative to gray matter in the subarachnoid space or extending into the parenchymaDescription of the correlates of FVH on concurrent angiographyFVH was present in 53/74 (72%) of all acute strokes with subsequent angiography; FVH was seen in areas of blood flow proximal and distal to stenosis or occlusion; FVH distal to high-grade arterial occlusion is associated with a high-grade leptomeningeal collateral blood flow
Lee et al. (2009)10Consecutive patients with MCA territory infarct imaged prior to treatment with rtPA5254–84/69Linear- or serpentine-appearing hyperintensity on FLAIR imaging, corresponding to a typical arterial course in the hemisphere of arterial occlusionStudy of the hemodynamic correlates of FVHFVH observed distal to arterial occlusion in 73% and proximal to 77% of patients; FVH due to collateral flow beyond the site of occlusion; FVH associated with smaller ischemic lesion volumes, as well as lower initial NIHSS scores; The presence of distal FVH before rtPA is associated with large diffusion-perfusion mismatch; FVH not an independent predictor of 5-day NIHSS