Serial study of apparent diffusion coefficient and anisotropy in patients with acute stroke

Stroke. 1999 Nov;30(11):2382-90. doi: 10.1161/01.str.30.11.2382.


Background and purpose: We sought to characterize the evolution of apparent diffusion coefficient (ADC) and apparent diffusion anisotropy (ADA) in acute stroke and to evaluate their roles in predicting stroke evolution and outcome.

Methods: We studied 26 stroke patients acutely (<24 hours), subacutely (3 to 5 days), and at outcome (3 months). Ratios of the ADC and ADA within a region of infarction and the normal contralateral region were evaluated and compared with the Canadian Neurological Scale, Barthel Index, and Rankin Scale.

Results: Heterogeneity in ADC and ADA evolution was observed not only between patients but also within individual lesions. Three patterns of ADA evolution were observed: (1) elevated ADA acutely and subacutely; (2) elevated ADA acutely and reduced ADA subacutely; and (3) reduced ADA acutely and subacutely. At outcome, reduced ADA with elevated ADC was observed generally. We identified 3 phases of diffusion abnormalities: (1) reduced ADC and elevated ADA; (2) reduced ADC and reduced ADA; and (3) elevated ADC and reduced ADA. The ADA ratios within 12 hours correlated with the acute Canadian Neurological Scale (r=0.46, P=0.06), subacute Canadian Neurological Scale (r=0.55, P=0.02), outcome Barthel Index (r=0.62, P=0.01), and Rankin Scale (r=-0.77, P<0.0005) scores.

Conclusions: Combined ADC and ADA provide differential patterns of stroke evolution. Early ADA changes reflect cellular alterations in acute ischemia and may provide a potential marker to predict stroke outcome.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Disease
  • Adult
  • Aged
  • Aged, 80 and over
  • Biomarkers
  • Brain Ischemia / physiopathology
  • Cerebral Infarction / physiopathology
  • Cerebrovascular Circulation / physiology*
  • Contrast Media
  • Diffusion
  • Echo-Planar Imaging / methods
  • Female
  • Follow-Up Studies
  • Forecasting
  • Humans
  • Image Enhancement
  • Image Processing, Computer-Assisted / methods
  • Linear Models
  • Magnetic Resonance Angiography / methods
  • Magnetic Resonance Imaging / methods
  • Male
  • Middle Aged
  • Neurologic Examination
  • Stroke / classification
  • Stroke / physiopathology*
  • Time Factors


  • Biomarkers
  • Contrast Media