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arXiv 2206.05289eess.IVcs.CVcs.LG

压缩感知MRI的局部化对抗伪影

Localized adversarial artifacts for compressed sensing MRI

ETH Zürich(苏黎世联邦理工学院);University of Genoa(热那亚大学)

Rima Alaifari, Giovanni S. Alberti, Tandri Gauksson

AI总结:

本文针对压缩感知MRI,提出在频域构造对抗扰动以诱发TV重建中的严重局部伪影,并证明该现象是ℓ¹/TV最小化等可保证精确恢复方法所固有的,而DNN重建对此类攻击更具鲁棒性。

摘要:

随着深度神经网络(DNNs)在图像重建任务中的兴趣日益增长,其可靠性受到质疑(Antun et al., 2020; Gottschling et al., 2020)。然而,近期工作表明,与全变分(TV)最小化相比,在适当正则化下,DNN在ℓ²重建误差方面表现出类似的对抗噪声鲁棒性(Genzel et al., 2022)。我们考虑一种不同的鲁棒性概念,使用ℓ∞范数,并论证局部化重建伪影比ℓ²误差是更相关的缺陷。我们对欠采样的磁共振成像测量(在频域中)创建对抗扰动,这些扰动在TV正则化重建中诱发严重的局部化伪影。值得注意的是,相同的攻击方法对基于DNN的重建并不那么有效。最后,我们表明这一现象是那些可以保证精确恢复的重建方法所固有的,例如采用ℓ¹或TV最小化的压缩感知重建。

英文摘要:

As interest in deep neural networks (DNNs) for image reconstruction tasks grows, their reliability has been called into question (Antun et al., 2020; Gottschling et al., 2020). However, recent work has shown that, compared to total variation (TV) minimization, when appropriately regularized, DNNs show similar robustness to adversarial noise in terms of $\ell^2$-reconstruction error (Genzel et al., 2022). We consider a different notion of robustness, using the $\ell^\infty$-norm, and argue that localized reconstruction artifacts are a more relevant defect than the $\ell^2$-error. We create adversarial perturbations to undersampled magnetic resonance imaging measurements (in the frequency domain) which induce severe localized artifacts in the TV-regularized reconstruction. Notably, the same attack method is not as effective against DNN based reconstruction. Finally, we show that this phenomenon is inherent to reconstruction methods for which exact recovery can be guaranteed, as with compressed sensing reconstructions with $\ell^1$- or TV-minimization.

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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