Detection of the arcuate fasciculus in congenital amusia depends on the tractography algorithm
Detection of the arcuate fasciculus in congenital amusia depends on the tractography algorithm
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DOI：
10.3389/fpsyg.2015.00009
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发表时间：
2015-01-21
影响因子：
3.8
通讯作者：
Stewart, Lauren
中科院分区：
文献类型：
--
作者：
Chen, Joyce L.;Kumar, Sukhbinder;Stewart, Lauren
扩散磁共振成像（MRI）的出现使研究人员能够在活体中解剖大脑中的白质纤维通路。例如，这使我们能够描述和量化不同人群在健康和疾病方面的纤维束差异，以及随着训练的变化而变化。基于弥散MRI，先前的文献报道了在一些对照个体和先天性失音患者中弓状束（AF）的缺失。考虑到失音症的细微损伤，完全没有这样一个主要的解剖道是令人惊讶的。因此，我们假设在该人群中未能检测到房颤可能与所使用的跟踪算法有关，而不一定反映其表型。使用三种不同的跟踪算法分析控制和音乐个体的扩散数据：确定性和概率，后者要么建模两个或一个纤维种群。在这三种算法中，我们重复了先前的左侧心房颤动体积大于右侧心房颤动体积的发现，但没有发现组间差异或相互作用。我们使用概率2纤维模型检测所有个体的心房纤颤，然而，当使用确定性神经束造影时，一些对照和音乐个体的跟踪失败。这些发现表明，在我们的样本中检测AF的能力取决于束束造影算法的类型。这就提出了一个问题，即在先前的研究中未能检测到房颤是否与潜在的解剖学或表型无关。
The advent of diffusion magnetic resonance imaging (MRI) allows researchers to virtually dissect white matter fiber pathways in the brain in vivo. This, for example, allows us to characterize and quantify how fiber tracts differ across populations in health and disease, and change as a function of training. Based on diffusion MRI, prior literature reports the absence of the arcuate fasciculus (AF) in some control individuals and as well in those with congenital amusia. The complete absence of such a major anatomical tract is surprising given the subtle impairments that characterize amusia. Thus, we hypothesize that failure to detect the AF in this population may relate to the tracking algorithm used, and is not necessarily reflective of their phenotype. Diffusion data in control and amusic individuals were analyzed using three different tracking algorithms: deterministic and probabilistic, the latter either modeling two or one fiber populations. Across the three algorithms, we replicate prior findings of a left greater than right AF volume, but do not find group differences or an interaction. We detect the AF in all individuals using the probabilistic 2-fiber model, however, tracking failed in some control and amusic individuals when deterministic tractography was applied. These findings show that the ability to detect the AF in our sample is dependent on the type of tractography algorithm. This raises the question of whether failure to detect the AF in prior studies may be unrelated to the underlying anatomy or phenotype.