MALDI IMS-Derived Molecular Contour Maps: Augmenting Histology Whole-Slide Images

Area of Science:

• Biomedical Imaging
• Molecular Pathology
• Analytical Chemistry

Background:

• Imaging mass spectrometry (IMS) generates multiplexed molecular distribution maps in tissues.
• Traditional heatmap visualizations with transparency blending obscure subtle quantitative details when overlaid with microscopy.
• Accurate visualization of molecular distributions is crucial for understanding tissue pathology.

Purpose of the Study:

• To develop a novel contour mapping approach for enhanced visualization of IMS data.
• To improve the interpretation of multimodal IMS-microscopy data.
• To better delineate molecular features in infected tissue environments.

Main Methods:

• Development of a contour mapping workflow integrating IMS ion intensity and microscopy data.
• Application of Pearson's correlation coefficient for selecting colocalizing lipids in univariate analysis.
• Utilized non-negative matrix factorization (NMF) for multivariate analysis of IMS data.
• Case study on Staphylococcus aureus-infected murine kidney tissue.

Main Results:

• Contour maps revealed enhanced visualization of lipid distributions and spatial gradients around bacterial abscesses compared to heatmaps.
• Univariate analysis identified specific lipids colocalizing with infection sites.
• Multivariate NMF-based contour maps highlighted distinct molecular profiles of abscesses and immune responses.
• The workflow visualized the host-pathogen interface molecular transition zone.

Conclusions:

• The developed contour mapping approach provides a more interpretable visualization of IMS-microscopy multimodal data.
• This technique enhances the understanding of molecular spatial dynamics in host-pathogen interactions.
• Contour mapping offers superior insights into tissue pathology compared to conventional heatmap overlays.