Transient disappearance of cerebral infarcts on CT scan, the so-called fogging effect.
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.
D000368:Aged; D002544:Cerebral Infarction / Q000000981:diagnostic imaging*; D005069:Evaluation Studies as Topic; D005188:False Negative Reactions; D006801:Humans; D011446:Prospective Studies; D013997:Time Factors; D014057:Tomography, X-Ray Computed