Transient disappearance of cerebral infarcts on CT scan, the so-called fogging effect

Neuroradiology. 1981;22(2):61-5. doi: 10.1007/BF00344775.


The fogging effect, whereby initially hypodense infarcts become isodense during the second and third week after the onset of stroke, was investigated in a prospective and consecutive series comprising 50 cases with completed stroke. CT scans were performed approximately 3 days, 10 days and 6 months after stroke. The fogging effect was found in 54% of cases. The hypodense areas reappeared on all scans at 5 months. Cerebral infarcts therefore may be overlooked or grossly underestimated if the scan is performed during the second and third week after stroke.

MeSH terms

  • Aged
  • Cerebral Infarction / diagnostic imaging*
  • Evaluation Studies as Topic
  • False Negative Reactions
  • Humans
  • Prospective Studies
  • Time Factors
  • Tomography, X-Ray Computed*