Acquisition Strategy to Reduce Cerebrospinal Fluid Partial Volume Effects for Improved DTI Tractography
Acquisition Strategy to Reduce Cerebrospinal Fluid Partial Volume Effects for Improved DTI Tractography
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DOI：
10.1002/mrm.25226
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发表时间：
2015-03-01
影响因子：
3.3
通讯作者：
Beaulieu, Christian
中科院分区：
文献类型：
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作者：
Baron, Corey A.;Beaulieu, Christian
目的研究一种不增加扫描时间和比吸收率的采集方法，以减少脑脊液（CSF）部分容积效应对弥散张量成像（DTI）纤维束成像的不利影响。它是基于使用较短的重复时间（TR）通过切片采集重新排序，以减少长T-1 CSF的信号和非零的最小扩散加权（b值），以衰减快速扩散CSF信号相对于脑tissue.MethodsA的CSF/脑信号比从3.5到0.8的目标减少需要2.5 s的TR和425 s/mm（2）的最小b值.这是评估在4.7特斯拉在八个健康的年轻人的穹窿，其中有相当大的CSF污染，是难以跟踪从标准的DTI.ResultsThis方法有效地减少了CSF信号相对于大脑，并产生了更强大的纤维束造影，增加道体积，增加分数各向异性，结论通过降低TR和非零最小弥散加权，可以减轻DTI中CSF部分容积效应。RF吸收率或扫描时间增加的缺乏比其他CSF抑制方法（例如反转恢复）更有吸引力。Magn Reson Med 73：1075-1084，2015年。(c)2014 Wiley Periodicals，Inc.
PurposeAn acquisition method that does not increase scan time or specific absorption rate is investigated for reducing the deleterious effects of cerebrospinal fluid (CSF) partial volume effects on diffusion tensor imaging (DTI) tractography. It is based on using a shorter repetition time (TR) by means of slice acquisition re-ordering to reduce the signal of long T-1 CSF and a non-zero minimum diffusion weighting (b-value) to attenuate rapidly diffusing CSF signal with respect to brain tissue.MethodsA target reduction of the CSF/brain signal ratio from 3.5 to 0.8 required a TR of 2.5 s and minimum b-value of 425 s/mm(2). This was evaluated at 4.7 Tesla in eight healthy young adults for tractography of the fornix, which has considerable CSF contamination and is difficult to track from standard DTI.ResultsThis method effectively reduced CSF signal relative to brain and yielded more robust tractography, increased tract volume, increased fractional anisotropy, and decreased mean diffusivity in the fornix relative to standard DTI.ConclusionCSF partial volume effects in DTI can be mitigated in acquisition through reduced TR and non-zero minimum diffusion weighting. The lack of RF absorption rate or scan time increases is attractive over other CSF suppression methods such as inversion recovery. Magn Reson Med 73:1075-1084, 2015. (c) 2014 Wiley Periodicals, Inc.