title: Diffusion tensor imaging correlates with lesion volume in cerebral hemisphere infarctions.
abstract: BACKGROUND
  Both a large lesion volume and abnormalities in diffusion tensor imaging are independently associated with a poor prognosis after cerebral infarctions. Therefore, we assume that they are associated. This study assessed the associations between lesion volumes and diffusion tensor imaging in patients with a right-sided cerebral infarction.
  
  
  METHODS
  The lesion volumes of 33 patients (age 65.9 ± 8.7, 26 males and 7 females) were imaged using computed tomography (CT) in the acute phase (within 3-4 hours) and magnetic resonance imaging (MRI) in the chronic phase (follow-up at 12 months, with a range of 8-27 months). The chronic-phase fractional anisotropy (FA) and mean diffusivity (MD) values were measured at the site of the infarct and selected white matter tracts. Neurological tests in both the acute and chronic phases, and DTI lateralization were assessed with the Wilcoxon signed-rank test. The effects of thrombolytic therapy (n = 10) were assessed with the Mann-Whitney U test. The correlations between the measured parameters were analysed with Spearman's rho correlation. Bonferroni post-hoc correction was used to compensate for the familywise error rate in multiple comparisons.
  
  
  RESULTS
  Several MD values in the right hemisphere correlated positively and FA values negatively with the lesion volumes. These correlations included both lesion area and healthy tissue. The results of the mini-mental state examination and the National Institutes of Health Stroke Scale also correlated with the lesion volume.
  
  
  CONCLUSIONS
  A larger infarct volume is associated with more pronounced tissue modifications in the chronic stage as observed with the MD and FA alterations.
authors.affiliation: Department of Radiology, Tampere University Hospital, Medical Imaging Centre, Tampere, Finland. maija.rossi@pshp.fi
authors.forename: Maija E
authors.initials: ME
authors.lastname: Rossi
authors.forename: Eeva
authors.initials: E
authors.lastname: Jason
authors.forename: Silvia
authors.initials: S
authors.lastname: Marchesotti
authors.forename: Prasun
authors.initials: P
authors.lastname: Dastidar
authors.forename: Jyrki
authors.initials: J
authors.lastname: Ollikainen
authors.forename: Seppo
authors.initials: S
authors.lastname: Soimakallio
mesh_terms: D000368:Aged; D000465:Algorithms; D002544:Cerebral Infarction / Q000473:pathology*; D054022:Cerebrum / Q000098:blood supply* / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic