Detection of ultra-early brain damage after acute subdural hematoma in therat by magnetic resonance imaging

We measured serial changes in diffusion-weighted magnetic resonance imaging (DW) and in apparent diffusion coefficient (ADC) 1 to 3 hours after induct ion of acute subdural hematoma (ASDH) in rats, to assess the rate of develo pment of cytotoxic edema and ischemic brain damage observed in this model. Cortical ADC values underneath the hematoma in ASDH rats (n = 12) were sign ificantly lower than those in sham-operated rats (n = 5) at 1 hour. By 3 ho urs, the area of ADC abnormality had further increased. The lesion areas, a s percentage of hemispheric areas on 1- and 3-hour ADC maps, correlated sig nificantly with those on the histologic sections stained with hematoxylin a nd eosin, The results indicate that DWI with ADC mapping may provide a valu able diagnostic tool for monitoring of early pathologic changes following s ubdural hematoma in head-injured patients.