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arXiv 2603.24985cs.CV

基于元学习的3D LGE MRI左心房壁少样本分割

Few-Shot Left Atrial Wall Segmentation in 3D LGE MRI via Meta-Learning

Department of Systems and Computer Engineering, Carleton University(系统与计算机工程系,卡尔顿大学);Department of Radiology, Radiation Oncology, and Medical Physics, University of Ottawa(放射科、放射肿瘤学与医学物理系,渥太华大学);Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute(心内科,医学系,渥太华心脏研究所)

Yusri Al-Sanaani, Rebecca Thornhill, Pablo Nery, Elena Pena, Robert deKemp, Calum Redpath, David Birnie, Sreeraman Rajan

AI总结:

提出基于模型无关元学习(MAML)和3D残差U-Net的框架,通过边界感知复合损失和辅助任务实现左心房壁的少样本分割,在5-shot下Dice达0.54,接近全监督性能。

摘要:

从晚期钆增强磁共振成像(LGE-MRI)中分割左心房(LA)壁因其薄几何结构、低对比度和有限的专家标注而具有挑战性。我们提出了一种基于模型无关元学习(MAML)的框架,采用3D残差U-Net骨干网络,用于K-shot(K=5, 10, 20)左心房壁分割。该框架在左心房壁任务以及辅助的左心房和右心房(RA)腔任务上进行元训练,并使用边界感知复合损失来改善薄结构描绘。我们在一个保留的干净测试集上评估了MAML,并在未见过的合成域偏移和本地队列上评估了其鲁棒性。在保留的干净测试集上,MAML在5-shot下优于少样本微调基线,Dice系数(DSC)=0.54对比0.48,豪斯多夫距离(HD95)=4.60对比6.40毫米。在20-shot下,MAML接近从头训练的完全监督模型,DSC=0.59对比0.61。在未见过的偏移下,性能相对于干净测试有所下降,但随K增加而持续改善。在5-shot下,MAML在未见过的合成偏移下达到DSC=0.52和HD95=5.02毫米,在本地队列上达到DSC=0.50和HD95=5.43毫米。这些结果表明,元学习可以改善低样本适应中的薄壁描绘,并可能减少心房重构评估的标注负担。

英文摘要:

Segmenting the left atrial (LA) wall from late gadolinium enhancement magnetic resonance imaging (LGE-MRI) is challenging because of its thin geometry, low contrast, and limited expert annotations. We propose a model-agnostic meta-learning (MAML) framework with a 3D residual U-Net backbone for K-shot (K = 5, 10, 20) LA wall segmentation. The framework is meta-trained on LA wall tasks together with auxiliary LA and right atrial (RA) cavity tasks and uses a boundary-aware composite loss to improve thin-structure delineation. We evaluated MAML on a held-out clean test set and assessed its robustness under an unseen synthetic domain shift and on a local cohort. On the held-out clean test set, MAML outperformed the K-shot fine-tuning baseline at 5-shot, achieving Dice coefficient (DSC) = 0.54 versus 0.48 and Hausdorff distance (HD95) = 4.60 versus 6.40 mm. At 20-shot, MAML approached the fully supervised model trained from scratch, with DSC = 0.59 versus 0.61. Under unseen shifts, performance decreased relative to clean testing but improved consistently as K increased. At 5-shot, MAML achieved DSC = 0.52 and HD95 = 5.02 mm under the unseen synthetic shift, and DSC = 0.50 and HD95 = 5.43 mm on the local cohort. These results suggest that meta-learning can improve thin-wall delineation in low-shot adaptation and may reduce the annotation burden for atrial remodeling assessment.

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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