Quantitative CT Measurements of Interstitial Lung Disease: Same-Day Variability Between Two Vendors—A Prospective Study

This prospective study evaluated the intervendor variability of Quantitative CT (QCT) measurements in patients with Interstitial Lung Disease (ILD). Forty-eight participants underwent chest CT examinations on the same day using both GE and Siemens scanners. The Aview Lung Texture software was utilized to perform automatic segmentation of lung regions and calculate the fibrosis score as the sum of reticular opacity and honeycombing volume percentages. When comparing each vendor's primary high-frequency kernels (LUNG and B60f), the fibrosis score showed a small mean raw difference of -0.80% and almost perfect agreement with a concordance correlation coefficient (CCC) of 0.989. In conclusion, QCT-derived fibrosis scores can be informative for longitudinal ILD assessment across different vendors when interpreted within the context of expected measurement variability. These results demonstrate the robustness of quantitative imaging biomarkers across different CT systems, supporting consistent longitudinal assessment in ILD. In this study, AVIEW Lung Texture software was used to automatically segment lung regions and quantify fibrosis patterns, enabling reproducible measurements across imaging environments.