Characterising Heterogeneity and Subphenotyping Acute Respiratory Distress Syndrome with Computed Tomography

Authors: Roberta Garberi, Matthieu Jabaudon, Sam Bayat, Sarah E. Gerard, Aurora Magliocca, Mariangela Pellegrini, Alberto Bravin, Lorraine B. Ware, John J. Marini, Yi Xin, John G. Laffey, Maurizio Cereda, and Emanuele Rezoagli.

This review investigates the application of computed tomography in the characterisation of heterogeneity and the facilitation of subphenotyping in Acute Respiratory Distress Syndrome. It offers a comprehensive overview of qualitative, semi-quantitative, and quantitative imaging methodologies, including advanced techniques such as dual-energy computed tomography and computational analysis, to identify patterns of lung injury. Furthermore, it discusses the clinical significance, methodological limitations, and prospective developments related to CT-based phenotyping in ARDS.

ARDS is a heterogeneous clinical entity in which patients meeting similar diagnostic criteria may exhibit substantial differences in lung morphology, mechanical properties, biological injury, and clinical outcomes. Current classification systems, largely based on the severity of hypoxemia, do not adequately capture this variability, thereby limiting prognostic stratification and individualised therapeutic approaches. Computed tomography enables detailed regional assessment of lung aeration, density, weight, and perfusion, offering insights into the structural and functional determinants of differential responses to interventions such as positive end-expiratory pressure, prone positioning, and recruitment manoeuvres. These imaging-based strategies may contribute to improved phenotypic classification and more targeted management in ARDS.