Diagnostic evaluation of patients with disorders of consciousness with diffusion tensor imaging

Background:With the development of emergency and intensive medical technologies,the survival rate of traumatic brain injury has greatly increased.More and more patients have been converted from severe coma to alleviated state of consciousness,which can be subsequently classified within the framework of disorders of consciousness (DOC).We investigated the clinical application and characteristics of imaging indicators of diffusion tensor imaging (DTI) for the DOC patients.Methods:DTI was performed on a total of 75 cases with a clinical diagnosis of DOC from January 2014 to December 2015 in Beijing Tiantan Hospital and PLA Army General Hospital (including 66 cases of unresponsive wakefulness state (UWS) patients and 9 cases of minimally conscious state (MCS) patients).The data for the imaging indicators,such as fractional anisotropy (FA) and mean diffusivity (MD),were separately collected from three relevant regions of interest (ROIs):brainstem,thalamus,and subcortex.The indicators of two groups with different conscious states were statistically analyzed,and correlation analyses were conducted for the mean values of FA and MD in the ROIs evaluated through clinical Coma Recovery Scale-Revised (CRS-R) scores.Results:The FA value of the UWS group was evidentially lower than that of the MCS group (P ＜ 0.05),while the MD value of the UWS group was higher than that of the MCS group (P ＜ 0.05);the difference was statistically significant.The FA and MD values in the ROIs (locations:brainstem,thalamus,and subcortex) correlated with CRS-R scores,particularly in the thalamus.Conclusion:DTI has a certain clinical reference value for DOC imaging grading.The more severe the DOC,the higher the MD value and the lower the FA value.