Despite the advantageous resolution of electron tomography (ET), reconstruction of three-dimensional (3D) images from multiple two-dimensional (2D) projections presents several challenges, including small signal-to-noise ratios, and a limited projection range. This study evaluates the capabilities of ET for thin sections of shale, a complex nanoporous medium. A numerical phantom with 1.24 nm pixel size is constructed based on the tomographic reconstruction of a Barnett shale. A dataset of 2D projection images is numerically generated from the 3D phantom and studied over a range of conditions. First, common reconstruction techniques are used to reconstruct the shale structure. The reconstruction uncertainty is quantified by comparing overall values of storage and transport metrics, as well as the misclassification of pore voxels compared to the phantom. We then select the most robust reconstruction technique and we vary the acquisition conditions to quantify the effect of artifacts. We find a strong agreement for large pores over the different acquisition workflows, while a wider variability exists for nanometer-scale features. The limited projection range and reconstruction are identified as the main experimental bottlenecks, thereby suggesting that sample thinning, advanced holders, and advanced reconstruction algorithms offer opportunities for improvement.

中文翻译：

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页岩成像电子断层扫描能力评估。

尽管电子断层扫描 (ET) 具有有利的分辨率，但从多个二维 (2D) 投影重建三维 (3D) 图像仍面临一些挑战，包括信噪比小和投影范围有限。本研究评估了 ET 对页岩（一种复杂的纳米多孔介质）薄片的能力。基于 Barnett 页岩的断层扫描重建，构建了像素大小为 1.24 nm 的数值模型。2D 投影图像数据集是根据 3D 模型以数字方式生成的，并在一系列条件下进行研究。首先，使用常见的重建技术来重建页岩结构。通过比较存储和运输指标的总体值以及与模型相比的孔隙体素的错误分类来量化重建不确定性。然后，我们选择最稳健的重建技术，并改变采集条件来量化伪影的影响。我们发现不同采集工作流程中的大孔隙具有很强的一致性，而纳米级特征存在更大的可变性。有限的投影范围和重建被认为是主要的实验瓶颈，因此表明样本稀疏、先进的支架和先进的重建算法提供了改进的机会。