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arXiv 2001.01330cs.CVcs.LGeess.IV

带有中间层损失的卷积神经网络用于CT和MRI扫描的3D超分辨率

Convolutional Neural Networks with Intermediate Loss for 3D Super-Resolution of CT and MRI Scans

University of Bucharest(布加勒斯特大学);``Carol Davila'' University of Medicine and Pharmacy(“卡罗尔·达维拉”医药大学);Colțea Hospital(科尔采亚医院)

Mariana-Iuliana Georgescu, Radu Tudor Ionescu, Nicolae Verga

AI总结:

提出一种基于10层卷积层和中间上采样层的深度CNN方法,用于CT和MRI扫描的3D超分辨率,通过中间损失和可变标准差高斯平滑提升性能,在2D和3D超分辨率任务上优于现有方法和插值基线。

摘要:

当今医院常用的CT扫描仪产生低分辨率图像,尺寸最大为512像素。图像中的一个像素对应于一毫米的组织块。为了准确分割肿瘤并制定治疗计划,医生需要更高分辨率的CT扫描。。同样的问题也出现在MRI中。在本文中,我们提出了一种针对3D CT或MRI扫描的图像超分辨率方法。我们的方法基于深度卷积神经网络(CNNs),由10个卷积层和一个中间上采样层组成,该层置于前6个卷积层之后。第一个CNN在两个轴(宽度和高度)上提高分辨率,随后由第二个CNN在第三个轴(深度)上提高分辨率。与其他方法不同,我们在上采样层之后立即针对真值高分辨率输出计算损失,此外还在最后一个卷积层之后计算损失。中间层损失迫使我们的网络产生更接近真值的更好输出。获得锐利结果的常用方法是使用固定标准差添加高斯模糊。为了避免对固定标准差过拟合,我们与其他方法不同,采用不同标准差的高斯平滑。我们在两个数据库的CT和MRI扫描的2D和3D超分辨率背景下评估我们的方法,使用2x和4x缩放因子,将其与文献中相关工作和基于各种插值方案的基线进行比较。实验结果表明,我们的方法优于所有其他方法。此外,我们的人类标注研究显示,医生和普通标注者在97.55%的情况下选择我们的方法而非Lanczos插值,在96.69%的情况下选择4x上采样因子。

英文摘要:

CT scanners that are commonly-used in hospitals nowadays produce low-resolution images, up to 512 pixels in size. One pixel in the image corresponds to a one millimeter piece of tissue. In order to accurately segment tumors and make treatment plans, doctors need CT scans of higher resolution. The same problem appears in MRI. In this paper, we propose an approach for the single-image super-resolution of 3D CT or MRI scans. Our method is based on deep convolutional neural networks (CNNs) composed of 10 convolutional layers and an intermediate upscaling layer that is placed after the first 6 convolutional layers. Our first CNN, which increases the resolution on two axes (width and height), is followed by a second CNN, which increases the resolution on the third axis (depth). Different from other methods, we compute the loss with respect to the ground-truth high-resolution output right after the upscaling layer, in addition to computing the loss after the last convolutional layer. The intermediate loss forces our network to produce a better output, closer to the ground-truth. A widely-used approach to obtain sharp results is to add Gaussian blur using a fixed standard deviation. In order to avoid overfitting to a fixed standard deviation, we apply Gaussian smoothing with various standard deviations, unlike other approaches. We evaluate our method in the context of 2D and 3D super-resolution of CT and MRI scans from two databases, comparing it to relevant related works from the literature and baselines based on various interpolation schemes, using 2x and 4x scaling factors. The empirical results show that our approach attains superior results to all other methods. Moreover, our human annotation study reveals that both doctors and regular annotators chose our method in favor of Lanczos interpolation in 97.55% cases for 2x upscaling factor and in 96.69% cases for 4x upscaling factor.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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