Quantitative Imaging for Interstitial Lung Disease

Quantitative imaging has emerged as a promising tool for the diagnosis, classification, and prognostication of interstitial lung disease (ILD). Both global and regional lung abnormalities can be objectively and reproducibly measured using quantitative imaging, which is particularly useful for early disease evaluation and assessment of subtle changes. Accurate ILD classification and identification of inconspicuous changes allow for more personalized treatment decisions and, ultimately, improved patient outcomes. Because CT is the primary imaging modality for ILD evaluation, most of the computer-aided support systems have been developed for this modality and are referred to as <i>quantitative CT</i>. While CT continues to advance with functional capability using dual-energy technology, new MRI techniques are being developed that offer the ability to further improve ILD evaluation. Recent advancements in the field of artificial intelligence underly the development of these new quantitative imaging tools. As quantitative imaging for ILD evaluation becomes more common, it will likely play an increasingly important role in the general clinical radiology workflow, necessitating a familiarity of its use for the general radiologist. This review summarizes current applications of quantitative CT in the evaluation of fibrotic ILDs, including idiopathic pulmonary fibrosis, hypersensitivity pneumonitis, and connective tissue disease-related ILD, and highlights emerging quantitative MRI techniques for ILD assessment. <b>Keywords:</b> Applications-CT, Deep Learning, Machine Learning, Radiomics, CT-Quantitative, Thorax, Lung © RSNA, 2025.