Department of Medical and Surgical Sciences, Magna Graecia University of Catanzaro, Italy.
IBFM, National Research Council, Germaneto, Catanzaro, Italy; Institute of Neurology, University "Magna Graecia", Germaneto, Catanzaro, Italy.
J Neurosci Methods. 2014 Mar 15;224:79-87. doi: 10.1016/j.jneumeth.2013.12.014. Epub 2014 Jan 6.
Diffusion tensor imaging (DTI) is one of the most sensitive MRI tools for detecting subtle cerebral white matter abnormalities in amyotrophic lateral sclerosis (ALS). Nowadays a plethora of DTI tools have been proposed, but very few methods have been translated into clinical practice.
The aim of this study is to validate the objective measurement of fiber tracts as provided by a new unbiased and automated tractography reconstruction tool named as TRActs Constrained by UnderLying Anatomy (TRACULA). The reliability of this tract-based approach was evaluated on a dataset of 14 patients with definite ALS compared with 14 age/sex-matched healthy controls. To further corroborate these measurements, we used a well-known voxelwise approach, called tract-based spatial statistics (TBSS), on the same dataset.
TRACULA showed specific significant alterations of several DTI parameters in the corticospinal tract of the ALS group with respect to controls.
The same finding was detected using the well-known TBSS analysis. Similarly, both methods depicted also additional microstructural changes in the cingulum.
DTI tractography metrics provided by TRACULA perfectly agree with those previously reported in several post-mortem and DTI studies, thus demonstrating the accuracy of this method in characterizing the microstructural changes occurring in ALS. With further validation (i.e. considering the heterogeneity of other clinical phenotypes), this method has the potential to become useful for clinical practice providing objective measurements that might aid radiologists in the interpretation of MR images and improve diagnostic accuracy of ALS.
弥散张量成像（DTI）是检测肌萎缩侧索硬化症（ALS）中脑白质细微异常的最敏感的 MRI 工具之一。如今已经提出了大量的 DTI 工具，但很少有方法被转化为临床实践。
本研究旨在验证一种新的客观测量纤维束的方法，该方法基于一种新的无偏且自动化的束追踪重建工具，称为受底层解剖结构约束的纤维束（TRACULA）。该基于束的方法的可靠性在 14 名确诊 ALS 患者和 14 名年龄/性别匹配的健康对照者的数据集上进行了评估。为了进一步证实这些测量值，我们在同一数据集上使用了一种称为基于体素的空间统计学（TBSS）的知名体素方法。
TRACULA 在 ALS 组的皮质脊髓束中显示出几个 DTI 参数的特定显著改变，与对照组相比。
使用知名的 TBSS 分析也检测到了相同的发现。同样，这两种方法也在扣带回中描绘了额外的微观结构变化。
TRACULA 提供的 DTI 束追踪指标与之前在几个尸检和 DTI 研究中报道的指标完全一致，从而证明了该方法在描述 ALS 中发生的微观结构变化方面的准确性。通过进一步验证（即考虑其他临床表型的异质性），该方法有可能成为一种有用的临床实践方法，提供可能有助于放射科医生解释磁共振图像并提高 ALS 诊断准确性的客观测量值。
