{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,20]],"date-time":"2026-01-20T22:23:42Z","timestamp":1768947822328,"version":"3.49.0"},"reference-count":23,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2026,1,20]],"date-time":"2026-01-20T00:00:00Z","timestamp":1768867200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Canon Medical Systems Korea","award":["2019-CMSK-CT001"],"award-info":[{"award-number":["2019-CMSK-CT001"]}]},{"name":"Soonchunhyang University Research Fund","award":["2025-0044"],"award-info":[{"award-number":["2025-0044"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>Background\/Objectives: Ultra-low-dose computed tomography (ULD-CT) enables substantial radiation reduction compared with routine low-dose computed tomography (LD-CT), but its quantitative reliability across lung imaging biomarkers remains insufficiently characterized. This study aimed to assess the agreement and reliability of quantitative pulmonary imaging biomarkers between paired ULD-CT and LD-CT examinations. Methods: In this prospective study, 48 patients who underwent paired LD-CT and ULD-CT on the same day were analyzed. Whole-lung quantitative biomarkers were categorized into density-derived indices, airway structural metrics, and voxel-based functional biomarkers. Agreement between LD-CT and ULD-CT was evaluated using Bland\u2013Altman analysis and Pearson correlation. Results: Density-based biomarkers demonstrated high concordance, strong correlations, and small systematic biases, indicating robust dose stability. Airway structural metrics showed clinically acceptable agreement with near-perfect reproducibility for cluster-based indices. Voxel-based functional biomarkers exhibited greater dose sensitivity but preserved consistent directional bias. Total lung volume showed excellent reproducibility with minimal bias. Conclusions: ULD-CT enables reliable quantitative lung imaging with clinically acceptable agreement across major biomarker domains, supporting its use as a dose-efficient platform for longitudinal and screening applications.<\/jats:p>","DOI":"10.3390\/diagnostics16020327","type":"journal-article","created":{"date-parts":[[2026,1,20]],"date-time":"2026-01-20T09:24:34Z","timestamp":1768901074000},"page":"327","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Reliability and Agreement of Quantitative Pulmonary Imaging Biomarkers Between Ultra-Low-Dose and Low-Dose Chest CT: A Paired Intra-Individual Study"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0009-0009-4752-8973","authenticated-orcid":false,"given":"Da-Kyong","family":"Lee","sequence":"first","affiliation":[{"name":"Department of Radiology, Korea University Guro Hospital, Korea University College of Medicine, Seoul 08308, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8089-7396","authenticated-orcid":false,"given":"Zepa","family":"Yang","sequence":"additional","affiliation":[{"name":"Department of Computer Science, Soonchunhyang University, Asan 31538, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0247-8932","authenticated-orcid":false,"given":"Hwan-Seok","family":"Yong","sequence":"additional","affiliation":[{"name":"Department of Radiology, Korea University Guro Hospital, Korea University College of Medicine, Seoul 08308, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,1,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1007\/s00408-011-9353-9","article-title":"Quantitative Computed Tomography in COPD: Possibilities and Limitations","volume":"190","author":"Mets","year":"2012","journal-title":"Lung"},{"key":"ref_2","first-page":"483","article-title":"Comparison of Low- and Ultralow-Dose Computed Tomography of the Lung: Quantitative Evaluation of Image Quality and Pulmonary Emphysema","volume":"51","author":"Martini","year":"2016","journal-title":"Investig. 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