The morphological characteristics of cerebral contusions in head trauma patients suggest that an increase in cerebrovascular permeability is responsible for the contusion edema which develops within 1-3 days posttrauma. In the present study, 10 patients with cerebral contusions (mean age, 38 years old; 8 males and 2 females) were examined by gadolinium (Gd)-DTPA enhanced magnetic resonance imaging (MRI) at 1-2 days after trauma. Gd-DTPA (0.3 mmol/kg) was infused intravenously over a period of 30 min. MRIs were taken before, and at 2 and 4 hours after initiation of the Gd-DTPA administration. It was found that contusion edema areas were frequently enhanced by Gd-DTPA at 2 hours. The enhancement diminished at 4 hours. These findings appear to be inconsistent with the results of previously reported similar studies in which enhancement was detected at 6-9 days posttrauma but not during the period earlier than 6 days. This discrepancy may be attributable to the presence of a high blood concentration of Gd-DTPA for a longer period of time and a delay in the time at which MRIs were taken in the present study. The present data indicate that an increased cerebrovascular permeability occurs at as early as 1-2 days posttrauma, and suggest that contusion edema which progresses during the initial 1-3 days may be at least partially vasogenic in nature.