title: Topographic patterns of small subcortical infarcts associated with MCA stenosis: a diffusion-weighted MRI study.
abstract: OBJECTIVE
  Small subcortical infarcts (SSI, maximum lesion diameter < or =2.0 cm) are usually considered as infarcts caused by small vessel disease. However, SSI can also be associated with large artery occlusive disease such as middle cerebral artery (MCA) stenosis. We performed a prospective study to investigate the relationship between MCA stenosis and SSI distribution and further to investigate the mechanism of SSI caused by MCA stenosis.
  
  
  METHODS
  Magnetic resonance angiography (MRA) and diffusion-weighed MRI (DWI) of consecutive acute ischemic stroke patients with recent SSI were studied. The distribution of acute infarcts on DWI was categorized as cortical infarct (CI), border zone infarct (BI), or perforating artery infarct (PAI).
  
  
  RESULTS
  Totally, 93 cases were recruited, among which 12 had single SSI with MCA stenosis (group 1) and 26 patients had multiple SSI with MCA stenosis (group 2), while 55 patients without MCA stenosis had single SSI (group 3). For patients with single SSI and MCA stenosis, 6 had BI and 6 had PAI; for patients with multiple SSI and MCA stenosis, 25 had BI, 4 had PAI and 9 had CI (compared with group 1: P= .001); for patients with single SSI but without MCA stenosis, 20 had BI and 35 had PAI (compared with group 1: P= .58).
  
  
  CONCLUSIONS
  Multiple acute infarcts along the border zone are the commonest pattern in small infarcts with MCA stenosis, especially among those with multiple acute infarcts. Our data suggest that hemodynamic compromise and artery-to-artery embolism may be both important factors for infarcts in patients with MCA stenosis.
authors.affiliation: Department of Medicine and Therapeutics, Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.forename: Wynnie W M
authors.initials: WW
authors.lastname: Lam
authors.forename: Yu Hua
authors.initials: YH
authors.lastname: Fan
authors.forename: Colin A
authors.initials: CA
authors.lastname: Graham
authors.forename: Timothy H
authors.initials: TH
authors.lastname: Rainer
authors.forename: Ka Sing
authors.initials: KS
authors.lastname: Wong
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000473:pathology*; D016009:Chi-Square Distribution; D003251:Constriction, Pathologic / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000473:pathology*; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000473:pathology*; D011446:Prospective Studies