Susceptibility weighted imaging and diffusion weighted imaging in diagnostic and prognostic evaluation of diffuse axonal injury

Abstract

Objective To assess the diagnostic value of susceptibility weighted imaging (SWIl)and diffusion weighted imaging (DWI) for diffuse axonal injury (DAI) and their correlation with evaluation of injury severity and outcome.Methods Forty-nine patients with clinically diagnosed DAI underwent routine T1WI,T2WI,DWI,and SWI scanning.Respective signal characteristics and distribution features were detected.Number and volume of DAI lesions detected in each sequence were compared and analyzed for correlation with Glasgow coma score (GCS) and Glasgow outcome score (GOS).Results By contrast,SWI provided relatively better detection of intracranial micro-hemorrhage lesions (P ＜ 0.01),while DWI attained better presented edema lesions (P ＜ 0.01).Lesion volumes on SWI and DWI were significantly higher than those on TIWI and T2WI,but they were significantly different in Mann-Whitney test (P ＜ 0.01).SWI lesion number and volume,DWI lesion number as well as major lesion number at vulnerable zones of alba,cortex-medullar junction,cerebellum,brain stem,corpus callosum,and basal ganglia were negatively correlated with GCS on admission,GCS at 1 hour before examination and GOS at follow-up (P ＜ 0.05).Moreover,DWI lesion volume showed negative relation to GCS at 1 hour before examination and GOS at follow-up (P ＜ 0.01).Conclusion SWI and DWI can be pretty sensitive and effective to detect intracranial micro-hemorrhage and edema lesions in posttraumatic DAI patients and hence offer more help for early diagnosis and treatment of DAI as well as outcome evaluation. Key words: Diffuse axonal injury; Magnetic resonance imaging; Cerebral microbleeds