【摘要】 目的:以磁共振锰离子强化纤维束跟踪结果为标准,对恒河猴脑白质不同激励次数扩散张量纤维束成像的结果进行验证。方法:取7只成年雄性恒河猴,先采集不同激励次数扩散张量图像,然后在猴脑额叶中央前回前肢运动中枢皮层内注射氯化锰,48h后采集三维T1WI。对比脑白质纤维束在FA图上的投影与Mn2+强化的部位、范围进行一致性。并通过DTI参数图,对比分析部分参数的变化对纤维束追踪结果的影响。结果:不同激励次数DTI纤维束分布与Mn2+强化结果在中脑以上水平相符;而中脑以下水平有显著性差别。激励次数不影响ADCmean和FA值的测量,但影响本征值的测量。结论:在本实验所用纤维束追踪算法的条件下,激励次数对脑白质纤维束追踪无明显影响,但锰离子增强验证结果证实,在中脑以下水平,不同激励次数DTI纤维束跟踪结果均不准确。更多还原

【Abstract】 Objective:Using manganese-enhanced MR imaging(ME-MRI)as standard to validate the accuracy of different number of excitations(NEX)of diffusion tensor tractogragphy(DTT)in the white matter of macaque monkey’s brain.Methods:Seven adult male macaque monkeys were scanned using diffuse tensor imaging(DTI)with different NEX.3μl of 0.8mol aqueous solution of MnCl2 was injected into the forelimb of primary motor cortex,3 dimensional T1W images were acquired 48h later representing results of ME-MRI.The location,range and consistency of fiber tract in white matter showed on DTI and ME-MRI were compared and analyzed.Impact of the changes of some parameters were measured and analyzed as well from the above-mentioned DTI images.Results:The results of the fiber tract distribution in different NEX of DTT and ME MRI were consistent in the positions above the level of midbrain and significant differences were existed below the level of midbrain.NEX had not affected the ADCmean and FA measurement,but affected the eigenvalue measurement.Conclusions:In this study,NEX does not significantly influence the effect of fiber tracking,yet with ME MRI,the results of DTI fiber tracking with different NEX were not accurate below the midbrain level.更多还原