title: Early detection of secondary damage in ipsilateral thalamus after acute infarction at unilateral corona radiata by diffusion tensor imaging and magnetic resonance spectroscopy.
abstract: BACKGROUND
  Traditional magnetic resonance (MR) imaging can identify abnormal changes in ipsilateral thalamus in patients with unilateral middle cerebral artery (MCA) infarcts. However, it is difficult to demonstrate these early changes quantitatively. Diffusion tensor imaging (DTI) and proton magnetic resonance spectroscopy (MRS) are potentially sensitive and quantitative methods of detection in examining changes of tissue microstructure and metabolism. In this study, We used both DTI and MRS to examine possible secondary damage of thalamus in patients with corona radiata infarction.
  
  
  METHODS
  Twelve patients with unilateral corona radiata infarction underwent MR imaging including DTI and MRS at one week (W1), four weeks (W4), and twelve weeks (W12) after onset of stroke. Twelve age-matched controls were imaged. Mean diffusivity (MD), fractional anisotropy (FA), N-acetylaspartate (NAA), choline(Cho), and creatine(Cr) were measured in thalami.
  
  
  RESULTS
  T1-weighted fluid attenuation inversion recovery (FLAIR), T2-weighted, and T2-FLAIR imaging showed an infarct at unilateral corona radiate but no other lesion in each patient brain. In patients, MD was significantly increased at W12, compared to W1 and W4 (all P< 0.05). NAA was significantly decreased at W4 compared to W1, and at W12 compared to W4 (all P< 0.05) in the ipsilateral thalamus. There was no significant change in FA, Cho, or Cr in the ipsilateral thalamus from W1 to W12. Spearman's rank correlation analysis revealed a significant negative correlation between MD and the peak area of NAA, Cho, and Cr at W1, W4, and W12 and a significant positive correlation of FA with NAA at W1.
  
  
  CONCLUSIONS
  These findings indicate that DTI and MRS can detect the early changes indicating secondary damage in the ipsilateral thalamus after unilateral corona radiata infarction. MRS may reveal the progressive course of damage in the ipsilateral thalamus over time.
authors.affiliation: Department of Neurology and Stroke Center, the First Affiliated Hospital, Sun Yat-Sen University, No 58, Zhongshan Road 2, Guangzhou 510080, China.
authors.forename: Chuo
authors.initials: C
authors.lastname: Li
authors.forename: Xueying
authors.initials: X
authors.lastname: Ling
authors.forename: Sirun
authors.initials: S
authors.lastname: Liu
authors.forename: Anding
authors.initials: A
authors.lastname: Xu
authors.forename: Yusheng
authors.initials: Y
authors.lastname: Zhang
authors.forename: Shihui
authors.initials: S
authors.lastname: Xing
authors.forename: Zhong
authors.initials: Z
authors.lastname: Pei
authors.forename: Jinsheng
authors.initials: J
authors.lastname: Zeng
mesh_terms: D002544:Cerebral Infarction / Q000150:complications* / Q000175:diagnosis*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D013788:Thalamus / Q000098:blood supply* / Q000473:pathology*