论文标题
让您的朋友关闭和更远的敌人:在3D放射学图像中使用空间先验的对比度学习
Keep Your Friends Close & Enemies Farther: Debiasing Contrastive Learning with Spatial Priors in 3D Radiology Images
论文作者
论文摘要
对空间属性的理解对于有效的3D放射学图像分析至关重要,其中基于作物的学习是事实上的标准。给定图像贴片,其核心空间属性(例如位置和方向)通过固有的解剖一致性在预期对象,外观和结构上提供了有用的先验。特别是空间对应关系可以有效地衡量图像间区域之间的语义相似性,而它们的近似提取不需要注释或霸道的计算成本。但是,最近的3D对比学习方法要么忽略了信函,要么无法最大程度地利用它们。为此,我们提出了一个可扩展的3D对比框架(Spade,用于空间偏见),该框架利用了提取对应关系来选择更有效的正面和负面样本以进行表示。我们的方法学会了全球不变和本地模棱两可的表示,考虑到下游细分。我们还为全球和本地范围提出了单独的选择策略,以根据其各自的代表性要求进行量身定制。与最近的最新方法相比,黑桃在三个下游分割任务(CT腹部器官,CT心脏,MR心脏)上显示出显着改善。
Understanding of spatial attributes is central to effective 3D radiology image analysis where crop-based learning is the de facto standard. Given an image patch, its core spatial properties (e.g., position & orientation) provide helpful priors on expected object sizes, appearances, and structures through inherent anatomical consistencies. Spatial correspondences, in particular, can effectively gauge semantic similarities between inter-image regions, while their approximate extraction requires no annotations or overbearing computational costs. However, recent 3D contrastive learning approaches either neglect correspondences or fail to maximally capitalize on them. To this end, we propose an extensible 3D contrastive framework (Spade, for Spatial Debiasing) that leverages extracted correspondences to select more effective positive & negative samples for representation learning. Our method learns both globally invariant and locally equivariant representations with downstream segmentation in mind. We also propose separate selection strategies for global & local scopes that tailor to their respective representational requirements. Compared to recent state-of-the-art approaches, Spade shows notable improvements on three downstream segmentation tasks (CT Abdominal Organ, CT Heart, MR Heart).