3 T MR扩散张量纤维束成像在分析正常人脑内主要联合纤维中的价值

目的用扩散张量纤维束成像对健康成人脑内主要连合、联合纤维进行分析，为脑功能研究提供活体神经纤维束的功能解剖学依据。方法健康成人20名，利用西门子Trio 2003 T-3T及工作站，选择弓状束、下纵束、胼胝体、内囊后肢、外囊、额枕束等进行纤维束追踪分析。结果正常成人外囊纤维束左侧平均308束，右侧平均307束（t=0．138，P〉0．05）；额枕束纤维束左侧平均115束，右侧平均110束（t=1．174，P〉0．05）。部分各向异性分数（FA）外囊左侧平均为0．361，右侧平均0．362（t=-0．184，P〉0．05）；额枕束左侧平均0．352，右侧平均0．351（t=-0．816，P〉0．05）。内囊后肢纤维束左侧平均249束，右侧平均257束（t=-0．818，P〉0．05）；弓状束左侧平均198束，右侧平均204束（t=-0．465，P〉0．05）。部分FA内囊后肢左侧平均0．450，右侧平均0．444（t=2．771，P〈0．01）；弓状束左侧0．386，右侧0．375（t=1．912，P〈0．05）。下纵束纤维束左侧平均138束，右侧平均116束（t=1．739，P〈0．05）；部分FA左侧平均0．377，右侧平均0．359（t=2．606，P〈0．01）。半球内下部额、颞、顶和枕叶4个脑叶之间有联合纤维束，左侧平均126束，右侧平均133束（t=-0．791，P〉0．05）；部分FA左侧平均0．369，右侧平均0．370（t=-0．178，P〉0．05）。结论脑内主要连合、联合纤维束有明显的个体差异。大脑半球内除传统解剖学公认的联合纤维束外，还有联系四脑叶间的纤维束。

The value of 3 T MR diffusion tensor fiber tractography study of association fasciculus of normative human in vivo primarily

Objective To exhibit the fibers of association fascicules,aims at demonstrating the association fibers of brain with diffusion tensor fiber tracking technique.Methods Conventionality MRI, diffusion tensor imaging(DTI)and diffusion tensor fiber tractography(DT-FT)were performed in twenty healthy subjects,including eighteen right-handed(sixteen men and four women)and two left-handed(one male and one female)by 3 T Siemens Trio 2003 T MRI.To select arcuate faseicules,inferior longitudinal fascicules,frontal-occipital fascicules,corpus callosum,posterior limb of internal capsule and external capsule as seeds used to track fibers.Results Diffusion tensor fiber tracking exhibited bundles of external capsule left mean fibers were 308 bundles,right fibers were 307 bundles(t=0.138,P>0.05),frontal- occipital tracks left mean fibers were 115 bundles,right fibers were 110 bundles(t=1.174,P>0.05),and their fractional anisotropy(FA)valueextemal capsule mean FA left was 0.361,the fight was 0.362 (t= -0.184,P>0.05).Frontal-occipital tracks mean fractional anisotropy left was 0.352,the right was 0.351(t= -0.816,P>0.05).The difference between both sides were statistically insignificant(P> 0.05).The posterior limb of internal capsule left mean fibers were 249 bundles,fight fibers were 257 bundles(t= -0.818,P>0.05),arcuate fasciculesleft mean fibers were 198 bundles,right fibers were 204 bundles(t= -0.465,P>0.05)fibers difference between both sides were statistically insignificant (P>0.05),but the individual difference was significant,and their fractional anisotropy difference between both sides(posterior limb of internal capsule mean FA left was 0.450,the right was 0.444(t=2.771,P< 0.01).Arcuate fascicules mean FA left was 0.386,the right was 0.375(t=1.912,P<0.05)were statistically significant(P<0.05).Inferior longitudinal fascicules left mean fibers were 138 bundles,right fibers were 116 bundles(t=1.739,P<0.05)and fractional anisotropy difference between both sides mean FA left was 0.377,the right was 0.359(t=2.606,P<0.01)were statistically significant(P<0.05). There may be a new association fascicules inner 4 brain lobes,the fascicules in the same side hemisphere, associated with the frontal,temporal,parietal and occipital lobes,named the Frontal-Parietal-Occipital bundles(FPOB).The fibers left mean fibers were 126 bundles,right fibers were 133 bundles(t= -0.791, P>0.05).Mean FA left was 0.369,the right was 0.370(t= -0.178,P>0.05),difference between both sides was statistically insignificant(P>0.05).But the individual difference was significant.Some of them were the left larger than the right side.The frontal parts kept in touch with the Broca area of the left posterior of inferior frontal gyre.Conclusions There is individual difference both sides of association fascicules. There may be a new fiber bundle in the hemisphere,and associate with frontal lobe,temporal lobe,parietal lobe and occipital lobe.