ABSTRACT
Objective To evaluate the clinical application of SWI and DTI of MRI in the diagnosis and prognosis of diffuse axonal injury (DAI).Methods A retrospective case series study was conducted on the clinical data of 16 patients with DAI admitted from January 2015 to December 2017.There were nine males and seven females,aged (56.3 ± 4.1) years.According to Glasgow Coma Scale (GCS),there were seven patients with 3-8 points,eight with 9-12 points,and one with 13 points.All patients received head CT examination on admission and then received head MRI examination within one week to record the number of lesions on T1WI,T2WI,DWI,and SWI in CT and MRI examination.On the DTI sequence,five regions including the subcortical white matter,the corpus callosum,the thalamus,the cerebellum,and the brain stem were selected for measurement of the apparent diffusion coefficient (ADC) and partial fraction of anisotropy (FA) values.The Glasgow outcome scale (GOS) was evaluated 6 months after injury.The linear correlation between ADC,FA values,GCS,and GOS on admission and after 6 months were analyzed.Results The statistical analysis of CT,T1WI,T2WI,DWI and SWI in 16 patients showed that the detection rates of DAI lesions were 25.6％ (43/168),30.4％ (51/168),44.0％ (74/168),51.8％ (87/168),and 100％,respectively (P ＜0.01).The ADC values of the subcortical white matter,the corpus callosum,the thalamus,the cerebellum,and the brain stem were 0.830 ± 0.148,0.536 ± 0.169,0.838 ± 0.596,0.708 ± 0.157,and 0.713 ± 0.135,respectively,and FA values were 0.487 ± 0.103,0.142 ± 0.040,0.293 ± 0.089,0.212 ± 0.045,and 0.366 ± 0.797,respectively.The GCS on admission was (8.9 ± 3.3)points,and GOS was (4.2 ± 1.0)points six months after injury.The correlation analysis showed that the ADC value and FA value of subcortical white matter and cerebellum were not related to GCS and GOS (P ＞ 0.05).The correlation strength of ADC values in each region with the GCS score in descending order was the thalamus,the corpus callosum,and the brain stem (P ＜ 0.05 or 0.01);for ADC with the GOS score,it was the corpus callosum,the thalamus and the brain stem (P ＜0.05 or 0.01);for FA with GCS and GOS scores,it was thalamus,corpus callosum,and brainstem (P ＜ 0.05 or 0.01).Conclusion The SWI has better sensitivity to detect DAI lesions than CT and conventional MRI sequences.DTI can accurately,objectively and visually detect the integrity of cerebral white matter fibers.Both SWI and DTI can help make early diagnosis and evaluate the prognosis of DAI patients accurately.