Systematic Evaluation of Vision Transformers for Automated Cervical Cancer Classification: Optimization, Statistical Validation, and Clinical Interpretability
对视觉变换器在自动化宫颈癌分类中的系统评估:优化、统计验证与临床可解释性
Nisreen Albzour, Sarah S. Lam
AI总结 本文研究了视觉变换器在自动化宫颈癌分类中的应用,通过优化和统计验证,展示了其在临床可解释性方面的优势。
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手动宫颈癌筛查的巴氏涂片分析受到观察者间差异、时间限制和专家资源有限的限制。尽管卷积神经网络(CNNs)已自动化了宫颈细胞分类,但它们在建模长距离空间依赖性和缺乏临床可解释性方面仍有局限。在本研究中,视觉变换器(ViT)架构被系统优化以提高自动化宫颈癌筛查的性能,从而提高了可解释性。通过赫尔勒夫数据集(917张图像:242张正常,675张异常)对ViT-Tiny进行优化,这是一种轻量级视觉变换器架构,旨在减少计算复杂性。通过全面评估增强策略、类别加权和超参数,最佳配置实现了94.9%-95.2%的交叉验证准确率,其中随机水平翻转和类别加权(0.7 x 1.3)被确定为最有效的因素。梯度加权类激活映射(Grad-CAM)分析证实,模型注意力对应于临床相关形态学特征,包括核区域、细胞边界和染色质纹理,这与细胞病理学标准一致。这些发现表明,视觉变换器可以提供准确且可解释的决策支持,以用于宫颈癌筛查,这满足了医疗AI部署所需的临床性能和透明性要求。
Manual Pap smear analysis for cervical cancer screening is limited by inter-observer variability, time constraints, and restricted expert availability. Although convolutional neural networks (CNNs) have automated cervical cell classification, they remain limited in modeling long-range spatial dependencies and often lack clinical interpretability. In this study, Vision Transformer (ViT) architectures were systematically optimized to enhance automated cervical cancer screening, which resulted in improved interpretability. The Herlev dataset (917 images: 242 normal, 675 abnormal) was utilized to optimize ViT-Tiny, a lightweight Vision Transformer architecture designed for reduced computational complexity, through a comprehensive evaluation of augmentation strategies, class weighting, and hyperparameters. The optimal configuration achieved 94.9%-95.2% cross-validation accuracy, in which random horizontal flipping and class weighting (0.7 x 1.3) were identified as most effective. Gradient-weighted Class Activation Mapping (Grad-CAM) analysis confirmed that model attention corresponded to clinically relevant morphological features, which include nuclear regions, cell boundaries, and chromatin texture, which align with cytopathological criteria. These findings indicate that Vision Transformers can deliver accurate and interpretable decision support for cervical cancer screening, which fulfills both clinical performance and transparency requirements essential for medical AI deployment.