两种1.5TMRI仪对肝扩散加权成像表观扩散系数及可重复性的影响  

Effect of Two Different 1.5T MRI Scanners on the Apparent Diffusion Coefficient Measurement and its Reproducibility in Diffusion Weighted Imaging of the Liver

作　　者：陈世林[1,2,3] 陈鑫[1,2] 钟丽珊[2] 刘再毅[2] 梁长虹[2] 

机构地区：[1]南方医科大学,广东广州510515 [2]广东省人民医院(广东省医学科学院),广东广州510080 [3]湖南省永州市中心医院,湖南永州425006

出　　处：《中国医学影像学杂志》2013年第12期916-919,共4页Chinese Journal of Medical Imaging

基　　金：国家自然科学基金项目(81271569;81271654);广州市科技支撑项目(2010J-481)

摘　　要：目的探讨两种1.5T MRI仪对肝扩散加权成像(DWI)表观扩散系数(ADC)及其可重复性的影响。资料与方法使用两台不同的1.5T MRI仪(Siemens Espree和Philips Achieva),设置相同的序列和参数分别对两组正常志愿者(各33例)进行两次肝DWI扫描(b=0、800 s/mm2)。选取左、右肝中间连续3层ADC图测量ADC值,分别在左、右肝放置2个大小一致的感兴趣区测量ADC值,采用BlandAltman法评价两种机器ADC值测量的可重复性。结果 Siemens MRI仪测得的左、右肝ADC值均高于Philips MRI仪测得值(t=2.045~2.713,P<0.05);每种机器所测得左肝ADC值大于右肝(t=-10.561^-7.263,P<0.001);Bland-Altman结果显示,两种机型测得左、右肝ADC值的可重复性相似,且右肝的可重复性均较左肝好,其中Siemens MRI仪测得左、右肝ADC值的一致性分别为16.65%、7.55%,Philips MRI仪测得左、右肝的一致性分别为16.30%、7.85%。结论不同MRI仪对ADC值的测量有一定的影响,但可重复性相似。临床比较ADC值时应该充分考虑机型的影响。Purpose To investigate the effect of two different 1.5T MRI scanners on the apparent diffusion coefficient （ADC） measurement and its reproducibility in diflhsion weighted imaging （DWI） of the liver. Materials and Methods Two groups of volunteers （33 people in each group） underwent liver DWI examination twice by using the same DWI sequence with b value of 0 and 800 s/m㎡ on different MR1 scanners （1.5T Siemens Espree and 1.5T Philips Achieva）. On ADC maps, two region of interests were placed on three central slices of the left and right liver lobes, respectively. The ADC measurements of six region of interests on left and right liver lobes were averaged to represent the mean ADC values of the left and right liver lobe, respectively. The reproducibility of the ADC measurements was assessed by Bland-Altman method. Results The ADC values of the left and right liver lobes measured on Siemens MRI scanner were significantly higher than those on Philips MRI scanner （t=2.045-2.713, P〈0.05）; on both scanners, the ADC values of the left liver lobe were significantly higher than those of the right liver lobe （t=-10.561--7.263, P〈0.001）. The Bland-Altman results showed that the reproducibility of ADC measurement was similar on both MRI scanners, and both displayed higher reproducibility of right liver lobe than that of left liver lobe （on Siemens MRI scanner： the agreement were 16.65% and 7.55% for the left and right liver lobe, respectively; and on Philips MRI scanner： 16.30% and 7.85%, respectively. Conclusion Different MRI scanners may have influence on ADC values, but does not affect its reproducibility. Therefore, when ADC values obtained on different MR scanners are compared in clinical analysis, this influence should be considered.

关 键 词：肝脏 磁共振成像 弥散 扩散加权成像 表观扩散系数 可重复性 结果 

分 类 号：R445.2[医药卫生—影像医学与核医学]