Papanikolaou Nickolas, Karampekios Spyros, Papadaki Efrosyni, Malamas Menelaos, Maris Thomas, Gourtsoyiannis Nicholas
Department of Radiology, University Hospital of Heraklion, Medical School, University of Crete, Heraklion, Crete, Greece.
Eur Radiol. 2006 Jan;16(1):187-92. doi: 10.1007/s00330-005-2833-7. Epub 2005 Jul 5.
Non-invasive in vivo visualization of white matter fiber tracts is currently feasible by means of diffusion tensor imaging (DTI) techniques. DTI-derived metrics, like fractional anisotropy (FA) and mean diffusivity (MD), have the potential to improve tissue characterization. Technical optimization of diffusion tensor sequences, including signal-to-noise ratio and spatial resolution, was performed for 20 normal subjects. High- and low-resolution DTI sequences were applied on all subjects and FA, MD parametric maps were reconstructed for both protocols. Voxel-based statistical analysis revealed regions with significantly different FA and MD values between the two sequences, while the same type of analysis was performed to illustrate regions with significantly different signal-to-noise ratio. In conclusion, optimized DTI sequences may be applied routinely in clinical practice with a standard MR scanner, while accurate quantification of FA and MD may improve lesion characterization.
目前，通过扩散张量成像（DTI）技术可以在体内对白质纤维束进行无创可视化。DTI衍生的指标，如分数各向异性（FA）和平均扩散率（MD），有可能改善组织特征描述。对20名正常受试者进行了扩散张量序列的技术优化，包括信噪比和空间分辨率。对所有受试者应用了高分辨率和低分辨率DTI序列，并为两种方案重建了FA、MD参数图。基于体素的统计分析揭示了两个序列之间FA和MD值有显著差异的区域，同时进行了相同类型的分析以说明信噪比有显著差异的区域。总之，优化后的DTI序列可以在标准MR扫描仪的临床实践中常规应用，而FA和MD的准确量化可能会改善病变特征描述。
