Consistency of automated coronary calcium score and extent of emphysema with different CT scanners and radiation dose protocols in lung cancer screening

Objective. To assess the consistency of automated measurements of coronary artery calcification (CAC) burden and emphysema extent on computed tomography (CT) images acquired with different scanners and radiation dose protocols in a lung cancer screening (LCS) population. Materials and Methods. The analysis included two LCS cohorts, named inter-scanner cohort, whose subjects underwent two consecutive screening rounds with two different dual-source CT scanners, and inter-dose cohort, whose subjects underwent a low-dose CT scan and an ultra-low dose CT scan. Exclusion criteria for CAC measurements were software failure, previous history of CVD and/or of coronary stenting, whereas for emphysema assessment software failure only. CT images were retrospectively analyzed by a fully automated AI software for CAC scoring, using three predefined Agatston score categories (0-99, 100-399, and ≥ 400), and emphysema quantification, using the percentage of low attenuation areas (%LAA). Demographic and clinical data were obtained from the written questionnaire completed by each participant at the first visit. Agreement for CAC and %LAA categories was measured by the k-Cohen Index with Fleiss-Cohen weights (Kw) and 95% Confidence Interval (CI). Results. In the inter-scanner cohort, an overlap of CAC strata was observed in 218/245 (90%) volunteers with an almost perfect agreement (Kw= 0.91, 95%CI 0.88-0.95), while an overlap of %LAA strata in 182/256 (71%) volunteers, with a substantial agreement (Kw= 0.70, 95%CI 0.63-0.76). In the inter-dose cohort, an overlap of CAC strata was observed in 275/327 (84%) volunteers, with an almost perfect agreement (Kw= 0.86, 95%CI 0.82-0.90), while an overlap of %LAA strata was found in 204/356 (57%) volunteers, with a moderate agreement (Kw= 0.57, 95%CI 0.51-0.63). Conclusion. Automated CAC and emphysema quantification showed consistent results when applied on CT images acquired with different scanners and different radiation dose CT protocols in two LCS cohorts. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study was funded by the Italian Association for Cancer Research (AIRC 5xmille IG 12162, IG 11991, and IG 18812), the Italian Ministry of Health (RF 2010-2306232, and 2010- 2310201), and Gensignia Life Science. The sponsors had no role in conducting and interpreting the study. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The Institutional Review Board of the Fondazione IRCCS Istituto Nazionale dei Tumori of Milan approval and written informed consent allowed the use of data for future research. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors