不同回波时间对扩散加权成像人脑体素不相干运动参数的影响  

Effects of different echo times on parameters of diffusion weighted imaging intravoxel incoherent motion in human brain

作　　者：林园凯 王奕[1,2] 张宗军[1] 

机构地区：[1]南京军区南京总医院医学影像科,江苏南京210002 [2]徐州医学院研究生学院,江苏徐州221000

出　　处：《中国医学影像技术》2015年第12期1902-1906,共5页Chinese Journal of Medical Imaging Technology

摘　　要：目的探讨不同回波时间(TE)对DWI人脑体素不相干运动(IVIM)参数的影响。方法对14名健康志愿者行多b值磁共振扩散加权成像(MB-DWI),采用0~1000 s/mm^2共16个b值,TE分别为65、85、105 ms,经双指数模型处理后获得f、D*及D参数图,测量双侧尾状核头、壳核和半卵圆中心的f、D*和D值,并进行统计学分析。结果随着TE的增加,基底核区灰质核团信号逐渐减低,半卵圆中心白质信号增强。尾状核头、壳核及半卵圆中心的f值逐渐升高(P均<0.001);尾状核头及壳核的D*值逐渐减低(P均<0.05),半卵圆中心D*值的差异无统计学意义(P>0.05)。不同TE时,尾状核头、壳核及半卵圆中心的D值差异均无统计学意义(P均>0.05)。相同TE时,尾状核头、壳核及半卵圆中心的D值依次减低(P均<0.001)。结论 TE对f值和D*值影响较大,而对D值影响较小,针对不同的脑组织选择合适的TE可获得更准确的IVIM参数。Objective To explore the effects of different echo times（TE） on the parameters of DWI intravoxel incoherent motion（IVIM） in human brain.Methods Totally 14 healthy subjects underwent multi-b diffusion weighted imaging（MB-DWI）scanning with f 6 b values（range 0—1000 s/mm^2）.TE was set as 65,85 and 105 ms,respectively.MB-DWI data were processed by bi-exponential model to generate parametric images of f,D＊ and D.The f,D＊ and D values of bilateral caput nuclei caudati,putamina and semi-oval centers were measured.And the statistical analysis was performed.Results With the increase of TE,the signals in nucleus of basal ganglia decreased,while the signals of semi-oval centers increased.The f values in caput nuclei caudati,putamina and semi-oval centers increased（all P〈0.001）,while the D＊ values in caput nuclei caudati and putamina decreased（both P〈0.05） with the increasing TE.There was no statistically significant difference of D＊ value in semi-oval centers（P〉0.05）.And no statistical difference of D values was found in caput nuclei caudati,putamina and semi-oval centers at different TE（all P〈0.05）.At the same TE,D values in caput nuclei caudati,putamina and semi-oval centers successively reduced（all P〈0.001）.Conclusion TE has greater impact on f and D＊ value and smaller impact on D value.Selecting appropriate TE for specific brain tissue is helpful to get more accurate IVIM parameters.

关 键 词：体素不相干运动 脑 扩散磁共振成像 

分 类 号：R322.81[医药卫生—人体解剖和组织胚胎学] R445.2[医药卫生—基础医学]