Associations With Clinical and Other MRI Findings

I n MRI of patients with acute ischemic stroke, use of fluidattenuated inversion recovery (FLAIR) sequences has recently gained importance as a tool to assess lesion age. A separate finding on FLAIR images has been termed “hyperintense vessels” (HVs) and describes hyperintensities corresponding to an arterial course most conspicuous in the sylvian fissure and cortical sulci. Most likely, HVs result from retrograde flow through collateral arterial circulation, as has been shown by concurrent angiographic examinations. Pathophysiologically, sluggish blood flow is thought to result in an absence of flow void in these arteries causing increased signal intensities. We investigated whether clinical and Background and Purpose—Hyperintense vessels (HVs) have been observed in fluidattenuated inversion recovery imaging of patients with acute ischemic stroke and been linked to slow flow in collateral arterial circulation. Given the potential importance of HV, we used a large, multicenter data set of patients with stroke to clarify which clinical and imaging factors play a role in HV. Methods—We analyzed data of 516 patients from the previously published PREFLAIR study (PREdictive value of FLAIR and DWI for the identification of acute ischemic stroke patients ≤3 and ≤4.5 hours of symptom onset—a multicenter study) study. Patients were studied by MRI within 12 hours of symptom onset. HV were defined as hyperintensities in fluidattenuated inversion recovery corresponding to the typical course of a blood vessel that was not considered the proximal, occluded main artery ipsilateral to the diffusion restriction. Presence of HV was rated by 2 observers and related to clinical and imaging findings. Results—Presence of HV was identified in 240 of all 516 patients (47%). Patients with HV showed larger initial ischemic lesion volumes (median, 12.3 versus 4.9 mL; P<0.001) and a more severe clinical impairment (median National Institutes of Health Stroke Scale 10.5 versus 6; P<0.001). In 198 patients with MR angiography, HVs were found in 80% of patients with vessel occlusion and in 17% without vessel occlusion. In a multivariable logistic regression model, vessel occlusion was associated with HV (OR, 21.7%; 95% CI, 9.6–49.9; P<0.001). HV detected vessel occlusion with a specificity of 0.86 (95% CI, 0.80–0.90) and sensitivity of 0.76 (95% CI, 0.69–0.83). Conclusions—HVs are a common finding associated with proximal arterial occlusions and more severe strokes. HVs predict arterial occlusion with high diagnostic accuracy. (Stroke. 2012;43:2957-2961.)