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arXiv 2408.02462eess.IVcs.AIcs.CV

基于人工智能的电影心脏磁共振分割中种族偏差成因的研究

An investigation into the causes of race bias in AI-based cine CMR segmentation

School of Biomedical Engineering & Imaging Sciences, King's College London(伦敦国王学院生物医学工程与影像科学学院);HeartFlow Inc(HeartFlow公司);Guy’s and St Thomas’ Hospital(盖伊和圣托马斯医院);College of Electronic and Information Engineering, Tongji University(同济大学电子与信息工程学院)

Tiarna Lee, Esther Puyol-Anton, Bram Ruijsink, Sebastien Roujol, Theodore Barfoot, Shaheim Ogbomo-Harmitt, Miaojing Shi, Andrew P. King

AI总结:

本文通过分类、分割实验和可解释性方法,探究AI电影CMR分割中种族偏差的根源,发现偏差主要源于图像层面的分布偏移,且种族信息被编码在模型中,紧密裁剪心脏区域可减少但不能消除该偏差。

摘要:

人工智能(AI)方法正越来越多地用于电影心脏磁共振(CMR)成像的自动分割。然而,这些方法已被证明存在种族偏差,即根据用于训练AI模型的数据的(不)平衡程度,它们对不同种族表现出不同的性能水平。本文研究了这种偏差的来源,试图理解其根本原因,以便能够有效缓解。我们对来自英国生物银行(UK Biobank)的黑人和白人受试者的短轴电影CMR图像进行了一系列分类和分割实验,并应用AI可解释性方法来理解结果。在分类实验中,我们发现仅从图像本身就能以高准确率预测种族,但从真实标注分割中预测的准确率较低,这表明种族之间的分布偏移(通常是AI偏差的原因)主要是基于图像而非基于分割的。可解释性方法显示,分类模型中的大部分注意力集中在非心脏区域,例如皮下脂肪。将图像紧密裁剪到心脏周围后,分类准确率降低到接近随机水平。类似地,可以从有偏差的分割模型的潜在表示中预测种族,这表明种族信息被编码在模型中。将图像紧密裁剪到心脏周围可以减少但不能消除分割偏差。我们还研究了可能的混杂因素对所观察到的偏差的影响。

英文摘要:

Artificial intelligence (AI) methods are being used increasingly for the automated segmentation of cine cardiac magnetic resonance (CMR) imaging. However, these methods have been shown to be subject to race bias, i.e. they exhibit different levels of performance for different races depending on the (im)balance of the data used to train the AI model. In this paper we investigate the source of this bias, seeking to understand its root cause(s) so that it can be effectively mitigated. We perform a series of classification and segmentation experiments on short-axis cine CMR images acquired from Black and White subjects from the UK Biobank and apply AI interpretability methods to understand the results. In the classification experiments, we found that race can be predicted with high accuracy from the images alone, but less accurately from ground truth segmentations, suggesting that the distributional shift between races, which is often the cause of AI bias, is mostly image-based rather than segmentation-based. The interpretability methods showed that most attention in the classification models was focused on non-heart regions, such as subcutaneous fat. Cropping the images tightly around the heart reduced classification accuracy to around chance level. Similarly, race can be predicted from the latent representations of a biased segmentation model, suggesting that race information is encoded in the model. Cropping images tightly around the heart reduced but did not eliminate segmentation bias. We also investigate the influence of possible confounders on the bias observed.

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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