title: Perfusion-weighted MRI as a predictor of clinical outcomes following medullary infarctions.
abstract: BACKGROUND
  Perfusion-weighted imaging (PWI) is rarely used to evaluate cases of posterior circulation infarctions. We evaluated clinical outcomes, diffusion-weighted imaging (DWI) patterns and angiographic findings in patients experiencing medullary infarctions according to PWI results.
  
  
  METHODS
  Data from consecutive patients with acute ischemic lesions primarily involving the medulla were analyzed. All patients underwent MRI including DWI, PWI and MR angiography. The patients were grouped according to the presence or absence of a perfusion delay in the medulla and/or inferior cerebellum.
  
  
  RESULTS
  Among 35 patients, all but 1 had a PWI of interpretable quality. Of these 34 patients, 18 had a normal perfusion status, while 16 had perfusion defects in the medulla and/or inferior cerebellum. The abnormal PWI group had poor clinical outcomes at 7 days and 1 month after the onset of symptoms. There was no difference in DWI patterns between these 2 groups. The angiographic findings demonstrated that a stenosis of >or=50% or an occlusion of the ipsilesional vertebral artery was frequently observed in the abnormal PWI group (p = 0.001). Multivariate analysis revealed that abnormal PWI and DWI patterns were independently associated with poor early and late outcomes following medullary infarctions.
  
  
  CONCLUSIONS
  PWI may be a feasible modality for assessing the perfusion status of the posterior circulation and predicting clinical outcomes following medullary infarctions.
authors.affiliation: Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Suk Jae
authors.initials: SJ
authors.lastname: Kim
authors.forename: Sookyung
authors.initials: S
authors.lastname: Ryoo
authors.forename: Oh Young
authors.initials: OY
authors.lastname: Bang
authors.forename: Chin-Sang
authors.initials: CS
authors.lastname: Chung
authors.forename: Kwang Ho
authors.initials: KH
authors.lastname: Lee
authors.forename: Gyeong-Moon
authors.initials: GM
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001925:Brain Damage, Chronic / Q000453:epidemiology / Q000209:etiology; D002531:Cerebellum / Q000098:blood supply; D002533:Cerebral Angiography; D002560:Cerebrovascular Circulation; D038524:Diffusion Magnetic Resonance Imaging; D017352:Echo-Planar Imaging; D005260:Female; D006801:Humans; D020762:Infarction, Posterior Cerebral Artery / Q000150:complications / Q000473:pathology*; D018810:Magnetic Resonance Angiography; D008297:Male; D008526:Medulla Oblongata / Q000098:blood supply*; D008875:Middle Aged; D055420:Perfusion Imaging; D011379:Prognosis; D012307:Risk Factors; D012720:Severity of Illness Index; D014715:Vertebrobasilar Insufficiency / Q000150:complications / Q000175:diagnosis