Early ischemic edema on cerebral computed tomography: its relation to diffusion changes and hypoperfusion within 6 h after human ischemic stroke. A comparison of CT, MRI and PET

Cerebrovasc Dis. 2006;21(5-6):336-9. doi: 10.1159/000091539. Epub 2006 Feb 14.


Background: Brain tissue hypoattenuation on early computed tomography is frequently included in decision making in acute stroke management. However, its pathophysiological counterpart needs further evaluation.

Methods: By comparative imaging with diffusion-weighted imaging and 15O-water positron emission tomography we aimed to interpret early (<6 h) hypoattenuation.

Results: In 11 patients, the hypoattenuation corresponded to a decreased proton diffusion (median 115.9% relative DWI value) measured by magnetic resonance imaging and to a severe hypoperfusion (below 12 ml/100 g/ min) assessed by positron emission tomography. The volume of parenchymal hypoattenuation correlated to the tissue with disturbed diffusion (Spearman's rho=0.73), but largely underestimated the hypoperfusion below 20 ml/100 g/min.

Conclusions: Early hypoattenuation reflects the coupling of the severity of ischemia and resulting diffusion changes. It allows an estimate of the infarct core but underestimates the penumbral hypoperfusion.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Brain Edema / diagnosis
  • Brain Edema / etiology*
  • Brain Edema / metabolism*
  • Cerebrovascular Circulation / physiology*
  • Diffusion Magnetic Resonance Imaging
  • Follow-Up Studies
  • Humans
  • Infarction, Middle Cerebral Artery / complications*
  • Infarction, Middle Cerebral Artery / diagnosis
  • Infarction, Middle Cerebral Artery / metabolism*
  • Middle Aged
  • Positron-Emission Tomography
  • Time Factors
  • Tomography, X-Ray Computed