title: Hypointense Vessels Detected by Susceptibility-Weighted Imaging Identifies Tissue at Risk of Infarction in Anterior Circulation Stroke.
abstract: The diagnostic value of susceptibility-weighted magnetic resonance imaging of acute stroke patients has shown potential as a surrogate marker of impaired hemodynamics. We investigate the value of asymmetrical hypointense cerebral vessels (HV) for the identification of vessel status and tissue at risk of infarction (TaR).
  
  
  
  Symmetry of HV was visually rated on SWI data from a well-defined population of acute anterior circulation stroke with onset <24 hours. MRI perfusion data was analyzed and volumes of tissue at risk segmented using a delay threshold of Tmax> 6 seconds. Status of the extra- and intracranial arteries was assessed by ultrasound and MR angiography.
  
  
  
  35 patients were included (12 women; median age 69 years, IQR 61-77; median NIHSS at admission 10, IQR 6-20). Asymmetrically distributed HV were detected at the stroke hemisphere in 25 patients (71%). Of those, 12 patients displayed occlusion of the middle cerebral artery, whereas occlusion of the extracranial ICA was detected in 6 patients. TaR was larger, yet not significantly different in patients with asymmetrically HV (mean volume 38.9 ml, SD 52.9 ml) compared to patients showing symmetrical HV (4.2 ml; SD 10.7 ml, p-value 0.081). Significant differences where, however, found after excluding patients with extracranial ICA occlusions (42.9 ml; SD 50.4 ml vs. 4.2 ml, SD 10.8 ml, p-value 0.025).
  
  
  
  Visual analysis of HV in SWI identifies tissue at risk in patients with anterior circulation stroke. Potentially pre-existing extracranial ICA occlusions leading to prominent HV have to be considered as a confounding factor.
authors.affiliation: Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Bastian
authors.initials: B
authors.lastname: Cheng
authors.affiliation: Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Schröder
authors.affiliation: Department of Radiology and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N4N1, Canada.
authors.forename: Nils Daniel
authors.initials: ND
authors.lastname: Forkert
authors.affiliation: Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Ludewig
authors.affiliation: Department of Neuroradiology, University Clinic Schleswig-Holstein, Lübeck, Germany.
authors.forename: André
authors.initials: A
authors.lastname: Kemmling
authors.affiliation: Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Tim
authors.initials: T
authors.lastname: Magnus
authors.affiliation: Department of Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Fiehler
authors.affiliation: Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Gerloff
authors.affiliation: Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Götz
authors.initials: G
authors.lastname: Thomalla
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000000981:diagnostic imaging* / Q000473:pathology; D002545:Brain Ischemia / Q000000981:diagnostic imaging* / Q000473:pathology; D002560:Cerebrovascular Circulation / Q000502:physiology; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D020521:Stroke / Q000000981:diagnostic imaging* / Q000473:pathology; D014463:Ultrasonography
keywords: Ischemic stroke; hypointense vessels; magnetic resonance imaging; susceptibility-weighted imaging; tissue at risk of infarction