2015 年 38 巻 2 号 p. 75-80
Purpose: The prediction of outcome in patients with diffuse axonal injury (DAI) is usually difficult in the acute phase. Although several prognostic factors of DAI have been reported previously, conventional neuroimaging techniques like computed tomography and magnetic resonance imaging (MRI) are limited in their outcome prediction. The purpose of this study is to determine whether brainstem injury and the number of injured regions identified using susceptibility-weighted imaging (SWI) are useful in predicting the outcome of acute phase DAI patients.
Materials and Methods: Eight patients with DAI (median age 19 years, mean GCS score 8.9) were examined retrospectively with MRI, including fluid-attenuated inversion recovery and SWI, and the number and distribution of injured regions was evaluated. To evaluate injured regions, the brain was divided into 14 regions: brainstem, corpus callosum, bilateral frontal, parietal, temporal, occipital lobe, bilateral basal ganglia, and bilateral cerebellar hemisphere. Patients were divided into three groups, according to the Adams et al. classification. Outcome was assessed at 30 days post-injury using the modified Rankin Scale (mRS).
Results: Grade 3 DAI was found in four patients using SWI and two patients using FLAIR. On SWI only, grade 3 DAI patients showed significantly higher mRS than grades 1 and 2 (p=0.02). A large number of injured regions on SWI correlated significantly with poor mRS (p=0.0004). The median mRS was 3.5.
Conclusion: SWI is useful for evaluating the number and distribution of injured regions in DAI patients, and correlates with mRS 30 days post-injury.
