CREATIS (UMR 5220 CNRS & U1206 INSERM), Université Claude Bernard Lyon 1, Université de Lyon, Villeurbanne, France.
Department of Mathematics and Computer Science, University of Calabria, Rende, Italy.
Comput Methods Programs Biomed. 2021 Jul;206:106113. doi: 10.1016/j.cmpb.2021.106113. Epub 2021 Apr 24.
Machine learning frameworks have demonstrated their potentials in dealing with complex data structures, achieving remarkable results in many areas, including brain imaging. However, a large collection of data is needed to train these models. This is particularly challenging in the biomedical domain since, due to acquisition accessibility, costs and pathology related variability, available datasets are limited and usually imbalanced. To overcome this challenge, generative models can be used to generate new data.
In this study, a framework based on generative adversarial network is proposed to create synthetic structural brain networks in Multiple Sclerosis (MS). The dataset consists of 29 relapsing-remitting and 19 secondary-progressive MS patients. T1 and diffusion tensor imaging (DTI) acquisitions were used to obtain the structural brain network for each subject. Evaluation of the quality of newly generated brain networks is performed by (i) analysing their structural properties and (ii) studying their impact on classification performance.
We demonstrate that advanced generative models could be directly applied to the structural brain networks. We quantitatively and qualitatively show that newly generated data do not present significant differences compared to the real ones. In addition, augmenting the existing dataset with generated samples leads to an improvement of the classification performance (F1 81%) with respect to the baseline approach (F1 66%).
Our approach defines a new tool for biomedical application when connectome-based data augmentation is needed, providing a valid alternative to usual image-based data augmentation techniques.
机器学习框架在处理复杂数据结构方面展现出了巨大的潜力,在包括脑成像在内的多个领域都取得了显著的成果。然而,这些模型的训练需要大量的数据。这在生物医学领域尤其具有挑战性,因为由于获取的便利性、成本以及与病理学相关的变异性,可用的数据集有限且通常不平衡。为了克服这一挑战,可以使用生成模型来生成新的数据。
本研究提出了一种基于生成对抗网络的框架,用于在多发性硬化症(MS)中创建合成结构脑网络。该数据集包含 29 例复发缓解型和 19 例继发进展型 MS 患者。使用 T1 和弥散张量成像(DTI)采集来获取每个受试者的结构脑网络。通过(i)分析其结构特性和(ii)研究其对分类性能的影响,对新生成的脑网络的质量进行评估。
我们证明了先进的生成模型可以直接应用于结构脑网络。我们定量和定性地表明,新生成的数据与真实数据没有显著差异。此外,通过在现有数据集上添加生成样本,可以提高分类性能(F1 为 81%),优于基线方法(F1 为 66%)。
当需要基于连接组的数据增强时,我们的方法为生物医学应用定义了一种新工具,为常用的基于图像的数据增强技术提供了有效的替代方案。