π€ AI Summary
This study addresses the lack of efficient, unsupervised, and scalable methods for evaluating registration quality in multi-stain whole-slide images, such as H&E and IHC. To this end, the authors propose a fast, annotation-free evaluation framework that jointly leverages downsampled tissue masks and deformation field metrics to assess global structural consistency and local transformation smoothness and plausibility, respectively. The method incurs low computational overhead and enables real-time assessment. Extensive validation across multiple IHC markers and with input from several pathologists demonstrates that the proposed automated metrics exhibit strong correlation with human expert ratings, confirming the approachβs reliability, generalizability, and clinical applicability.
π Abstract
High-fidelity registration of histopathological whole slide images (WSIs), such as hematoxylin&eosin (H&E) and immunohistochemistry (IHC), is vital for integrated molecular analysis but challenging to evaluate without ground-truth (GT) annotations. Existing WSI-level assessments -- using annotated landmarks or intensity-based similarity metrics -- are often time-consuming, unreliable, and computationally intensive, limiting large-scale applicability. This study proposes a fast, unsupervised framework that jointly employs down-sampled tissue masks- and deformations-based metrics for registration quality assessment (RQA) of registered H&E and IHC WSI pairs. The masks-based metrics measure global structural correspondence, while the deformations-based metrics evaluate local smoothness, continuity, and transformation realism. Validation across multiple IHC markers and multi-expert assessments demonstrate a strong correlation between automated metrics and human evaluations. In the absence of GT, this framework offers reliable, real-time RQA with high fidelity and minimal computational resources, making it suitable for large-scale quality control in digital pathology.