3.0T磁敏感加权成像与弥散成像对兔颅脑爆震伤的实验研究

The Experimental Study of Susceptibility Weighted Imaging and Diffusion Weighted Imaging in the Blast Injury to the Rabbits Brain at 3.0T MRI

目的:建立可靠、稳定的颅脑爆震伤模型,探讨磁敏感加权成像(susceptibility weighted imaging,SWI)及弥散加权成像(diffusion weighted imaging,DWI)序列对颅脑爆震伤早期出血灶及非出血灶的诊断价值及预后评估作用,旨在为临床治疗提供合理依据。方法:对30只新西兰大白兔执行兔颅脑爆震,炸后执行常规断层扫描(computed tomography,CT)、核磁共振成像(nuclear magnetic resonance imaging,MRI)、SWI及DWI扫描,SWI、DWI图像及数据处理通过SWI、DWI后处理软件自动得到,对病灶进行量化分析;采用functool 2软件对感兴趣区进行量化分析得到其表观弥散系数(apparent diffusion coefficient,ADC);解剖兔颅脑,进行病理学检查,与其同一层面SWI及DWI图像对照分析。结果:30只实验兔中,6只兔的CT、T1WI、T2WI序列显示脑内未见任何异常信号影。SWI序列显示点状(315/42.7%)、片状(218/29.5%)及线样(205/27.8%)低信号影,比其他序列检出出血灶多(χ2=10.00,P<0.01)。DWI显示非出血灶呈点状(102/54.0%)、片样(33/17.5%)高信号影,边缘清晰。DWI序列检出非出血灶数目多于常规T1WI、T2WI序列(χ2=10.01,P<0.01),ADC值降低程度与生存时间呈线性相关(分别为:r=0.53,P=0.05)。结论:SWI能够检出较多隐匿出血灶,DWI明显提高对非出血灶检出率,尤其小片状非出血灶检出率,并且通过测定ADC值降低程度对预后评估具有作用,因此为临床诊治提供指导依据。

Objective:To establish a reliable model of craniocerebral injury by shock wave for experimental study. The goal was to assess the diagnostic and the prognosis value of Susceptibility weighted imaging(SWI)and Diffusion Weighted Imaging(DWI)to prophase bleeding lesion and no bleeding lesion injury. Methods:Thirty rabbits underwent blast injury and then routine CT,MRI,SWI,DWI scanning were conducted. Functool 2 technology was used to conduct quantitative analysis of region of interest. Pathological examination was followed to compare against the SWI,DWI imaging data. Results:CT,T1WI and T2WI showed no abnormality on the encephalon in 6 of the 30 rabbits,SWI imaging identified signal hypointensity at punctiform(315/42.7%),plaque(218/29.5%)and linar(205/27.8%). DWI imaging showed hypointensity at punctiform(102/54%),plaque(33/17.5%)and detected more bleeding lesions than others subsequences(χ2=10.00,P<0.01). DWI imaging detected more no hemorrhagic focus than routine T1WI and T2WI(χ2=10.01,P<0.01). There is a linear correlation between dispersion coefficien(tADC)value decrease and the survival time of the rabbits(r=0.53,P=0.05).Conclusion:SWI can detect more delitescent prophase bleeding,DWI imaging can significantly improve the detection rate for no bleeding lesions especially small lamellar no bleeding lesions and pass survey ADC value decrease degree to the prognosis evaluation,so for the diagnosis and therapy of clinic provids more directions value.