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Diffusion tensor imaging may help the determination of time at onset in cerebral ischaemia.
- Source :
-
Journal of Neurology, Neurosurgery & Psychiatry . Sep2009, Vol. 80 Issue 9, p986-14. 5p. - Publication Year :
- 2009
-
Abstract
- BACKGROUND AND AIM: The apparent diffusion coefficient (ADC) and anisotropy (eg, fractional anisotropy (FA)) of ischaemic tissue evolve over time. A reduction in diffusivity (ie, λ2and λ3) is an important marker for characterising hyperacute-stage infarction, as these parameters may reflect axonal membrane status. The study examines whether transverse diffusivity could be useful in assessing white matter infarcts of various ages. METHODS: Diffusion tensor imaging data from 44 adult patients (34 men, 10 women, aged 46 to 89 years, mean = 70.3) with acute white matter infarction (1–168 h) of the internal capsule were analysed. Relative eigenvalues were calculated as: (λipsi–λcontra)/λcontra. Lesions were classified based on theoretically expected evolution of diffusivity over time as follows: stage I, FA higher than the contralesional region of interest (ROI); stage II, diffusivity lower than the contralesional side for all eigenvalues; stage III, one of two transverse eigenvalues (λ2or λ3) higher than the contralesional ROI. RESULTS: Stage I infarcts (n = 5) were found primarily within 24 h of the onset of symptoms, with one case found on the third day. Stage II infarcts were found most commonly within 24 h (n = 18), and fewer after 24 h. After the first day, the ratio of stage III infarcts increased significantly. Thus, diffusivity-based classification of white matter infarcts seems to show a chronological trend. CONCLUSIONS: Diffusion anisotropy may be useful for defining the biological tissue clock of white matter infarctions. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00223050
- Volume :
- 80
- Issue :
- 9
- Database :
- Academic Search Index
- Journal :
- Journal of Neurology, Neurosurgery & Psychiatry
- Publication Type :
- Academic Journal
- Accession number :
- 44221183
- Full Text :
- https://doi.org/10.1136/jnnp.2008.163584