Anisotropic phantoms for quantitative diffusion tensor imaging and fiber-tracking validation
Anisotropic phantoms for quantitative diffusion tensor imaging and fiber-tracking validation
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DOI：
10.1007/s00723-008-0087-7
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发表时间：
2008-05-01
影响因子：
1
通讯作者：
Il'yasov, K. A.
中科院分区：
文献类型：
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作者：
Lorenz, R.;Bellemann, M. E.;Il'yasov, K. A.
不同的纤维材料（大麻，亚麻，粘胶人造丝，聚酰胺和dyneema纤维）进行了测试，其适用性作为纤维体模的扩散张量成像（DTI）校准临床磁共振成像系统与常见的扩散加权回波平面成像序列。此外，还研究了这些纤维体模的纤维跟踪验证潜力。对于体模制造，将纤维缠绕成由塑料带包裹的平行纤维束。在dyneema和聚酰胺（0.3 +/-0.1）纤维体模中确定了分布最均匀的各向异性分数（FA）值（0.63 +/- 0.10）。粘胶纤维、亚麻纤维和大麻纤维束中的FA值变化较大（约0.2 +/-0.10）。聚酰胺和dyneema体模的主特征向量方向离散度小于7度，而纤维体模的主特征向量方向离散度大于30度。因此，所呈现的结果可能表明，基于聚酰胺和dyneema的纤维体模提供了在临床扫描仪上验证和确认DTI序列的机会。此外，它们还可用于测试光纤跟踪算法的准确性。通过机械制造生产，可以实现纤维的强平行排列以及纤维束的恒定压缩等级。这也可以在各向异性纤维体模内提供高度可再现的扩散性质。
Different fiber materials (hemp, linen, viscose rayon, polyamide and dyneema twine) were tested for their suitability as fiber phantoms for diffusion tensor imaging (DTI) calibration on clinical magnetic resonance imaging systems with common diffusion-weighted echo planar imaging sequences. Additionally, the potential for fiber tracking validation of these fiber phantoms was investigated. For phantom manufacturing the fibers were wound up into a bundle of parallel fibers enwrapped by plastic ribbon. The most homogenously distributed fractional anisotropy (FA) values (0.63 +/- 0.10) were determined in the dyneema and polyamide (0.3 +/- 0.1) fiber phantom. FA values in the viscose, linen and hemp bundles were at high variations (about 0.2 +/- 0.10). The dispersion of the direction of the principal eigenvector in the polyamide and dyneema phantom was less than 7 degrees, for the other fiber phantoms it was over 30 degrees. Thus, the presented results may indicate that polyamide- and dyneema-based fiber phantoms provide the opportunity for verification and validation of DTI sequences on clinical scanner. Additionally, they can be applicable for testing the accuracy of fiber tracking algorithms. A strong parallel alignment of the fibers with a constant compression grade of the fiber bundles could be achieved by machine-made production. This could also provide highly reproducible diffusion properties within the anisotropic fiber phantoms.