Use of diffusion tensor imaging to assess the vasogenic edema in traumatic pericontusional tissue.

Background And Objective: Cerebral edema is a frequent and serious complication of traumatic brain injury (TBI). Diffusion tensor imaging (DTI) is considered a useful technique to assess white matter integrity after TBI. The objective of this prospective, observational study was to assess the characteristics of the vasogenic edema in the traumatic pericontusional tissue and compare it to the vasogenic edema found in brain tumors. We also included a control group.

Methods: Using DTI, the Apparent diffusion coefficient (ADC) and Fractional anisotropy (FA) were measured in the area of vasogenic edema in both TBI and tumor patients. The measurements in the control group were done in the gray and white matter. We included 15 TBI patients, 18 tumor patients and 15 controls.

Results: ADC and FA showed no differences between TBI and tumor patients (p=0.27 for AF; p=0.79 for ADC). Compared to healthy controls, TBI and tumor patients presented higher ADC values and lower FA values. The differences between TBI and controls were statistically significant (p<0.05).

Conclusions: In this prospective observational study using DTI-MRI in a selected group of mild and moderate TBI patients with vasogenic pericontusional edema we have shown that there were no significant differences of the ADC and FA values compared to brain tumor patients. Furthermore, healthy controls showed significant lower ADC values and higher FA values compared to TBI and tumor patients. Future studies, using DTI-MRI, should address whether any therapy has a favorable impact on the vasogenic edema of TBI patients with brain contusions.