Hyperintense basilar artery on FLAIR MR imaging: diagnostic accuracy and clinical impact in patients with acute brain stem stroke

AJNR Am J Neuroradiol. 2014 Aug;35(8):1520-6. doi: 10.3174/ajnr.A3961. Epub 2014 May 8.

Abstract

Background and purpose: FLAIR-hyperintense vessels are known to be a sign of sluggish collateral blood flow in hemispheric vessel occlusion. Additionally, they seem to have a prognostic implication. The aim of the current study was to evaluate the hyperintense configuration of the basilar artery (FLAIR-hyperintense basilar artery) as a marker of basilar artery occlusion and as a predictor of patient outcome.

Materials and methods: We retrospectively identified 20 patients with basilar artery occlusion who initially underwent MR imaging with subsequent DSA. The diagnostic accuracy of the FLAIR-hyperintense basilar artery sign was tested by 4 independent readers in a case-control design, and the relation among FLAIR-hyperintense basilar artery and DWI posterior circulation-ASPECTS, patient outcome, and patient survival was evaluated. To grade the extent of the FLAIR-hyperintense basilar artery sign, we generated a score by counting the number of sections from the basilar tip to the foramen magnum in which a hyperintense signal in the vessel lumen was present multiplied by the section thickness.

Results: The FLAIR-hyperintense basilar artery sign showed moderate sensitivity (65%-95%) but very good specificity (95%-100%) and accuracy (85%-93%) for the detection of basilar artery occlusion. Substantial or excellent inter-reader agreement was observed (Cohen κ, 0.64-0.85). The FLAIR-hyperintense basilar artery inversely correlated with the posterior circulation-ASPECTS (r = -0.67, P = .01). Higher FLAIR-hyperintense basilar artery scores were associated with patient death (28.3 ± 13.7 versus 13.4 ± 11.1, P < .05).

Conclusions: The FLAIR-hyperintense basilar artery sign proved to be a valuable marker of vessel occlusion and may substantially support the diagnosis of basilar artery occlusion. The established FLAIR-hyperintense basilar artery score may be helpful for the prediction of individual patient survival.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Arterial Occlusive Diseases / complications
  • Arterial Occlusive Diseases / diagnosis*
  • Basilar Artery / pathology*
  • Brain Stem / pathology
  • Female
  • Humans
  • Magnetic Resonance Imaging / methods*
  • Male
  • Middle Aged
  • Retrospective Studies
  • Sensitivity and Specificity
  • Stroke / diagnosis*
  • Stroke / etiology*