title: Clinical diffusion mismatch better discriminates infarct growth than mean transit time-diffusion weighted imaging mismatch in patients with middle cerebral artery-M1 occlusion and limited infarct core.
abstract: OBJECTIVE
  Our purpose was to compare clinical diffusion mismatch (CDM) and mean transit time (MTT)-diffusion mismatch as predictors of infarct growth in patients with proximal middle cerebral artery (MCA) occlusion and small infarct core on presentation.
  
  
  METHODS
  Retrospective analysis of consecutive stroke patients with: (1) MCA-M1 occlusion; (2) MRI performed ≤10 h from symptoms onset; and (3) baseline MRI-diffusion weighted imaging (DWI) volume ≤25 mL. Definitions included: CDM=baseline National Institutes of Health Stroke Scale (NIHSS) score ≥8 and DWI volume ≤25 mL; MTT-DWI mismatch=visually assessed unthresholded MTT lesion ((MTT-DWI))/DWI) ≥20% and ≥10 mL larger than the DWI lesion; and significant infarct growth (>20% (≥5 mL) increase in infarct volume on follow-up). Uni-/multivariate analyses were performed to define the predictors of infarct growth.
  
  
  RESULTS
  63 stroke patients with MCA-M1 occlusions and MRI within 10 h of onset were evaluated. 20 patients were excluded on the basis of DWI volume >25 mL leaving 43 patients (mean age 75.8 years; median NIHSS=13) in the study cohort. On univariate analysis, larger admission DWI volume (p<0.0001), baseline NIHSS score ≥8 (p=0.001), lack of IV and/or endovascular treatment (p=0.021), glucose levels >125 mg/dL (p=0.024), poor CT angiography collaterals (p=0.046), and lower admission Alberta Stroke Program Early CT score (ASPECTS) (p=0.049) predicted infarct growth. Baseline NIHSS score ≥8 was the only independent predictor of stroke growth in the multivariate analysis (p=0.001). All patients had MTT-DWI mismatch >20%. There was no significant association between the amount of MTT-DWI mismatch and infarct growth (p=0.33).
  
  
  CONCLUSIONS
  CDM is the most powerful predictor of infarct growth in patients with MCA-M1 occlusion and small infarct core. Most of these patients will have a significant oligemic MTT lesion regardless of admission NIHSS score.
authors.affiliation: Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.|Departments of Neurology, Neurosurgery, and Radiology, Emory University School of Medicine, Marcus Stroke and Neuroscience Center, Grady Memorial Hospital, Atlanta, Georgia, USA.
authors.forename: Raul G
authors.initials: RG
authors.lastname: Nogueira
authors.affiliation: Department of Neuroradiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Andre
authors.initials: A
authors.lastname: Kemmling
authors.affiliation: Department of Neuroradiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Leticia M
authors.initials: LM
authors.lastname: Souza
authors.affiliation: Department of Neuroradiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Seyedmehdi
authors.initials: S
authors.lastname: Payabvash
authors.affiliation: Department of Neuroradiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Hirsch
authors.affiliation: Department of Neuroradiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Albert J
authors.initials: AJ
authors.lastname: Yoo
authors.affiliation: Department of Neuroradiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Lev
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002533:Cerebral Angiography; D002544:Cerebral Infarction / Q000000981:diagnostic imaging*; D002560:Cerebrovascular Circulation; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D020244:Infarction, Middle Cerebral Artery / Q000000981:diagnostic imaging*; D008297:Male; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D020521:Stroke / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed
keywords: CT perfusion; MRI; Stroke; Thrombectomy; Thrombolysis