弥散张量成像量化指标与脑弥散加权成像的对照性研究

Comparative study of quantitative index between DWI and DTI in normal brain MRI

【目的】本研究旨在探索弥散加权成像与弥散张量成像、不同弥散数量的弥散张量成像的量化指标的一致性,从而确定其可比较性。【方法】收集我院正常健康体检患者随机分为4组,每组20例,所有研究对象均行常规头颅MRI扫描,采用DWI、20、30、64个梯度方向的DTI检查,对每个研究对象选6个固定位置ROI,分别为双侧丘脑、尾状核头部、胼胝体体部,对各组间的ADC值进行统计分析。对DTI组及各DWI组所获得的扩散图像质量进行对比分析。而DWI组采用b值分别为0、500、1000s/mm2,对不同b值间所得ADC值进行对比分析。【结果】在各同一解剖位置的DWI和DTI所得到的ADC值组间比较均无统计学差异(P>0.05)。各同一解剖位置不同梯度数量所得ADC值组间比较无统计学差异(P>0.05)。不同b值所测得ADC值对比有统计学差异(P<0.05)。DTI扩散方向越多,图像质量越好,而DWI扫描b值1000图像质量较500更好。【结论】DWI及DTI扫描所得的ADC值具有可比性和一致性,两种扫描方法所得量化指标可对照研究。

【Objective】To find out the consistency between diffusion weighted imaging and diffusion tensor imaging, and different diffusion amount of diffusion tensor imaging quantization.【Method】Healthy patients were randomly divided into 4 groups, 20 cases in each group. All of the subjects underwent routine head MRI scan, using DWI, 20, 30, 64 gradient direction DTI examination. Each subject selected 6 fixed position ROI, the head of the caudate nucleus, thalamus corpus callosum respectively. The ADC values between the groups were analyzed. DWI with 0、500、1000 s/mm 2 were applicated and different b values obtained ADC values were analyzed. 【Result】There was no statistical difference between the ADC value through DWI or DTI at the same position （P 0.05）. There was no statistical difference between ADC value through different gradients number at the same position（P 0.05）. There were significantly difference between different b value（P 0.05）. The more DTI diffusion directed, the better image quality, and imaging quality of DWI with 1000 was better than DWI with 500.【Conclusion】There is comparability and consistency between the ADC value through DWI and DTI scan ,the quantitative index obtained from the two scan methods can be comparatively studied.