title: Distance to thrombus on MR angiography predicts outcome of middle cerebral artery occlusion treated with IV thrombolysis.
abstract: BACKGROUND
  The distance to thrombus (DT) on CT angiography was recently proposed as a predictor of outcome in patients treated by intravenous thrombolysis (IVT) for stroke due to occlusion of the middle cerebral artery (MCA). The purpose of the present study was to validate its inter-rater reliability and its prognostic value on contrast-enhanced magnetic resonance angiography (CE-MRA). Furthermore, we investigated the relation between DT and FLAIR-vascular hyperintensities (FVH) as a surrogate of collateral circulation and hypoperfusion.
  
  
  METHODS
  Patients with acute MCA occlusions treated by IVT and diagnosed with magnetic resonance imaging (MRI) were included. Two readers measured DT. FVH and acute DWI lesion volumes were quantified. Clinical status was determined using the initial NIH stroke scale (NIHSS) and 90-day modified Rankin Scale (90d mRS).
  
  
  RESULTS
  Sixty-one patients showed a lesion on diffusion-weighted magnetic resonance images and an occlusion of the MCA on CE-MRA. We found significant inverse correlations between DT and NIHSS scores at admission (ρ = -0.29; P = 0.02), DT and mRS at 90 days (ρ = -0.29; P = 0.04), and between DT and FVH (ρ = -0.32; P = 0.01). For a DT <22 mm, the likelihood of an unfavorable outcome (90d mRS 3-6 or NIHSS score improvement of ≤10 points at discharge) was >50 %. Initial DWI lesion volumes showed no correlation with the outcome. Excellent inter-rater agreement for DT was observed (Cronbach's α = 0.98; P < 0.001).
  
  
  CONCLUSIONS
  DT on CE-MRA is reliably measurable, correlates inversely with FLAIR-vascular hyperintensities, and predicts outcome in patients with acute MCA occlusion treated with IVT.
authors.affiliation: Department of Neuroradiology, University Hospital Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany. matthias.gawlitza@medizin.uni-leipzig.de.
authors.forename: Matthias
authors.initials: M
authors.lastname: Gawlitza
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Friedrich
authors.affiliation: Department of Neuroradiology, University Hospital Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany.
authors.forename: Ulf
authors.initials: U
authors.lastname: Quäschling
authors.affiliation: Department of Neuroradiology, University Hospital Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schob
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Schaudinn
authors.affiliation: Department of Neurology, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Hobohm
authors.affiliation: Department of Neuroradiology, University Hospital Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany.
authors.forename: Karl-Titus
authors.initials: KT
authors.lastname: Hoffmann
authors.affiliation: Department of Neuroradiology, University Hospital Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany.
authors.forename: Donald
authors.initials: D
authors.lastname: Lobsien
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D059925:Anatomic Landmarks / Q000473:pathology; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D020244:Infarction, Middle Cerebral Artery / Q000188:drug therapy* / Q000473:pathology*; D007262:Infusions, Intravenous; D020767:Intracranial Thrombosis / Q000188:drug therapy* / Q000473:pathology*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D015912:Thrombolytic Therapy; D016896:Treatment Outcome
chemical_list: D005343:Fibrinolytic Agents
keywords: Distance to thrombus; MRI; Middle cerebral artery; Patient outcome; Stroke