Diffusion tensor imaging of in vivo and excised rat spinal cord at 7 T with an icosahedral encoding scheme
Diffusion tensor imaging of in vivo and excised rat spinal cord at 7 T with an icosahedral encoding scheme
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DOI：
10.1002/mrm.20304
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发表时间：
2005-01-01
影响因子：
3.3
通讯作者：
Narayana, PA
中科院分区：
文献类型：
--
作者：
Madi, S;Hasan, KM;Narayana, PA
采用基于21个均匀分布和交替梯度方向的等面体编码方案和回波平面成像（EPI）读数，测量了活体和切除大鼠脊髓的分数各向异性（FA）和平均扩散率（D-av）的区域值。基于水影研究，该方案可提供无偏FA估计。对扫描仪在获取扩散张量成像（DTI）数据过程中的稳定性进行了评价。经Bland-Altman分析评估，FA值的重复测量显示出极好的再现性。这些研究表明，相对于活体脐带，切除样本的各向异性降低了。脊髓灰质的扩散呈各向异性。背侧白质（WM）的FA值高于腹侧白质。这些研究的结果将为损伤脊髓的一系列体内DTI提供必要的基线数据。(C) 2004 Wiley-Liss, Inc。
Regional values of fractional anisotropy (FA) and mean diffusivity (D-av) of in vivo and excised rat spinal cords were measured using an iscosahedral encoding scheme that is based on 21 uniformly distributed and alternating gradient directions with an echo planar imaging (EPI) readout. Based on the water phantom studies, this scheme was shown to provide unbiased estimation of FA. The stability of the scanner during the acquisition of diffusion tensor imaging (DTI) data was evaluated. Repeated measurements of the FA values demonstrated excellent reproducibility, as assessed by the Bland-Altman analysis. These studies demonstrated a reduced anisotropy in excised samples relative to in vivo cords. Diffusion in the spinal cord gray matter was shown to be anisotropic. The FA value in the dorsal white matter (WM) was found to be higher relative to the ventral WM. Results from these studies should provide the necessary baseline data for serial in vivo DTI of injured spinal cord. (C) 2004 Wiley-Liss, Inc.