title: Hemorrhagic transformation in acute cerebellar infarction.
abstract: BACKGROUND
  Hemorrhagic transformation (HT) is a well-known consequence of acute ischemic stroke, but little is known about HT in cerebellar infarction.
  
  
  METHODS
  Patients with acute cerebellar infarction within 48 h of onset were retrospectively recruited. MRI, including diffusion-weighted imaging (DWI) and T(2)*-gradient echo imaging (T(2)*), was performed twice (upon admission and 2 weeks after stroke onset). Infarct diameter and volume were measured by manual tracing on initial DWI. HT was evaluated with follow-up T(2)*, and all patients were divided into two groups according to the presence of HT (HT group and non-HT group). The frequency of HT and the factors associated with HT were investigated.
  
  
  RESULTS
  Ninety-six patients (64 males, median age 74 years, IQR 65-81 years, and National Institute of Health Stroke Scale score 5, IQR 1-14) were enrolled. Forty-two patients (43%) showed HT on follow-up T(2)* (HT group). Infarct diameter and volume were larger in the HT group than in the non-HT group (3.2 vs. 1.6 cm, respectively, p < 0.001, for infarct diameter and 8.0 vs. 1.7 cm(3), respectively, p < 0.001 for infarct volume). Multivariate logistic regression analysis revealed that both infarct diameter >2.7 cm (OR 7.58, 95% CI 2.82-20.4, p < 0.001) and volume >4.5 cm(3) (OR 11.5, 95% CI 3.80-34.8, p < 0.001) were independent factors associated with HT.
  
  
  CONCLUSIONS
  Half of the patients with acute cerebellar infarcts had HT on follow-up T(2)*. Initial infarct diameter and volume on DWI were independent factors associated with HT.
authors.affiliation: Department of Stroke Medicine, Kawasaki Medical School, Kurashiki, Okayama 701-0192, Japan. ysakamoto02@gmail.com
authors.forename: Yuki
authors.initials: Y
authors.lastname: Sakamoto
authors.forename: Kazumi
authors.initials: K
authors.lastname: Kimura
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Iguchi
authors.forename: Kensaku
authors.initials: K
authors.lastname: Shibazaki
authors.forename: Junya
authors.initials: J
authors.lastname: Aoki
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D002543:Cerebral Hemorrhage / Q000175:diagnosis / Q000453:epidemiology* / Q000473:pathology; D002544:Cerebral Infarction / Q000150:complications*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D005500:Follow-Up Studies; D006406:Hematoma / Q000175:diagnosis / Q000453:epidemiology* / Q000473:pathology; D006801:Humans; D015994:Incidence; D008297:Male; D012044:Regression Analysis; D012189:Retrospective Studies