GADOLINIUM DTPA-ENHANCED MAGNETIC-RESONANCE-IMAGING OF CEREBRAL CONTUSIONS

The morphological characteristics of cerebral contusions in head traum a patients suggest that an increase in cerebrovascular permeability is responsible for the contusion edema which develops within 1-3 days po sttrauma. In the present study, 10 patients with cerebral contusions ( mean age, 38 years old; 8 males and 2 females) were examined by gadoli nium (Gd)-DTPA enhanced magnetic resonance imaging (MRI) at 1-2 days a fter trauma. Gd-DTPA (0.3 mmol/kg) was infused intravenously over a pe riod of 30 min. MRIs were taken before, and at 2 and 4 hours after ini tiation of the Gd-DTPA administration. It was found that contusion ede ma areas were frequently enhanced by Gd-DTPA at 2 hours. The enhanceme nt diminished at 4 hours. These findings appear to be inconsistent wit h the results of previously reported similar studies in which enhancem ent was detected at 6-9 days posttrauma but not during the period earl ier 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 a nd a delay in the time at which MRIs were taken in the present study. The present data indicate that an increased cerebrovascular permeabili ty occurs at as early as 1-2 days posttrauma, and suggest that contusi on edema which progresses during the initial 1-3 days may be at least partially vasogenic in nature.