Quantification of fibrosis extend and airspace availability in lung: A semi-automatic ImageJ/Fiji toolbox

PLoS One. 2024 Feb 29;19(2):e0298015. doi: 10.1371/journal.pone.0298015. eCollection 2024.

Abstract

The evaluation of the structural integrity of mechanically dynamic organs such as lungs is critical for the diagnosis of numerous pathologies and the development of therapies. This task is classically performed by histology experts in a qualitative or semi-quantitative manner. Automatic digital image processing methods appeared in the last decades, and although immensely powerful, tools are highly specialized and lack the versatility required in various experimental designs. Here, a set of scripts for the image processing software ImageJ/Fiji to easily quantify fibrosis extend and alveolar airspace availability in Sirius Red or Masson's trichrome stained samples is presented. The toolbox consists in thirteen modules: sample detection, particles filtration (automatic and manual), border definition, air ducts identification, air ducts walls definition, parenchyma extraction, MT-staining specific pre-processing, fibrosis detection, fibrosis particles filtration, airspace detection, and visualizations (tissue only or tissue and airspace). While the process is largely automated, critical parameters are accessible to the user for increased adaptability. The modularity of the protocol allows for its adjustment to alternative experimental settings. Fibrosis and airspace can be combined as an evaluation of the structural integrity of the organ. All settings and intermediate states are saved to ensure reproducibility. These new analysis scripts allow for a rapid quantification of fibrosis and airspace in a large variety of experimental settings.

MeSH terms

  • Coloring Agents*
  • Filtration
  • Lung
  • Reproducibility of Results
  • Thorax*

Substances

  • Coloring Agents

Grants and funding

All authors of the present article are current or former employees of Metcela Inc. This study was funded by grants from Kawasaki City (https://www.city.kawasaki.jp/en/index.html), namely “Kawasaki City New Technology/New Product Development Support Project Subsidy” (Grant No. 84; awarded to TIw) and “Kawasaki City “New Normal” Research and Development Subsidy” (Grant No. 225; awarded to TIw). Sample preparation, imaging, and method development were financed by these grants. Metcela provided support in the form of salaries for authors BDS, KK, YM, TIm, AI, and Tiw. Funders did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the “author contributions” section.