The traumatic penumbra of brain injury treated with RNAi:a multimodal magnetic resonance imaging study / 实用放射学杂志

ABSTRACT

Objective To investigate the dynamic images of traumatic penumbra(TP)in a rat model of traumatic brain injury (TBI)treated with AQP4-RNAi using multimodal MRI(MM-MRI)at 7.0 Tesla.Methods A rat model of TBI was established by the improved Feeney's method.MRI scans were performed including T2WI,DWI,ADC and SWI.The pathological changes in penumbra area were observed.All statistical analyses were performed using SPSS 21.0 software package.Results Over time rs-T2WI,rs-DWI and rs-SWI in TBI group were gradually increased.The r-ADC began to increase at one hour after trauma and reached the peak at 6 h. Then it began to fall and reached the bottom at 12 h.At each time point,the difference was statistically significant(P<0.05).Compared with RNA interference group,the rs-T2WI and rs-DWI in TBI group were decreased significantly at 6 h and 12 h(P<0.05),the r-ADC was not decreased significantly at 1 h(P>0.05)and decreased significantly at 6 h and 12 h(P<0.05).At each time point,there was no significant difference in rs-SWI(P>0.05).The area of mismatch between rs-SWI and rs-DWI was the most obvious at 6 h and 12 h,and the area of mismatch was decreased in size after treatment with AQP4-RNAi.There was no significant difference between TBI group and placebo group(P>0.05).In two groups,similar pathological changes were observed,which was depicted as vasogenic edema predominantly at 1 h and mixed edema at 6 h and 12 h. In RNA interference group,intracellular edema was markedly reduced at 6 h and 12 h,and the vasogenic edema was relieved to some extent at 12 h.Conclusion The treatment with APQ4-RNAi markedly alleviates cerebral edema.MM-MRI can reflect its pathological changes.The area of mismatch between SWI and DWI can prompt early detection of traumatic penumbra,which may provide useful information for clinical treatment.