title: Extracoronary Thoracic and Coronary Artery Calcifications on Chest CT for Lung Cancer Screening: Association with Established Cardiovascular Risk Factors - The "CT-Risk" Trial.
abstract: OBJECTIVE
  To investigate the correlation between prevalence and degree of coronary artery calcification (CAC) and extracoronary calcifications (ECCs), scored quantitatively according to Agatston and semiquantitatively by visual analysis, in chest computed tomography (CT) studies obtained for lung cancer screening in asymptomatic subjects and in patients with known coronary heart disease (CHD), and to compare the association of ECC and CAC to established cardiovascular risk factors.
  
  
  METHODS
  Prospective study on 501 males (67 ± 8 years) with a history of working dust exposure who underwent nongated low-dose chest CT for lung cancer screening. Of these, 63 (12.6%) had a history of CHD, the remaining 438 subjects (87.4%) were clinically asymptomatic and without a history of CHD. On the day of the CT study, subjects underwent a thorough clinical examination including blood tests and completed a standardized questionnaire to establish a complete medical history. ECC and CAC scores were quantified according to Agatston and, in addition, by visual rating of calcium load of individual vessel territories on a five-point scale from "absent" to "extensive." Results were correlated with the respective subjects' cardiovascular risk factors and with the presence or absence of CHD.
  
  
  RESULTS
  ECC scores correlated significantly with CAC scores (two-sided Spearman 0.515; P < .001). ECC scores were associated significantly (P < .001) with cardiovascular risk factors (smoking history, hypertension, diabetes, and hypercholesterolemia) and with subjects' Framingham/prospective cardiovascular münster study scores, whereas CAC scores were associated only with the presence of hypercholesterolemia. CAC scores were strongly associated with CHD than ECC scores (area under the curve, 0.88 vs. 0.66 at receiver operating characteristic analysis). Visual scoring of ECC/CAC load correlated closely with the respective Agatston values (P < .001) and revealed the same association (or lack thereof) with cardiovascular risk factors/CHD.
  
  
  CONCLUSIONS
  In nongated low-dose CT for lung cancer screening, CAC and ECC load can be accurately established by visual analysis. ECC and CAC scores correlate closely, but not perfectly. There is a strong association between established cardiovascular risk factors and ECC load, but not CAC load, providing further evidence that ECC scoring may complement CAC scoring for broader risk assessment, for example, regarding prediction of extracoronary vascular events.
authors.affiliation: Department of Diagnostic and Interventional Radiology, RWTH Aachen University Hospital, Pauwelsstrasse 30, Aachen, 52074, Germany.
authors.forename: Timm
authors.initials: T
authors.lastname: Dirrichs
authors.affiliation: Department of Diagnostic and Interventional Radiology, RWTH Aachen University Hospital, Pauwelsstrasse 30, Aachen, 52074, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Penzkofer
authors.affiliation: Department of Diagnostic and Interventional Radiology, RWTH Aachen University Hospital, Pauwelsstrasse 30, Aachen, 52074, Germany.
authors.forename: Sebastian D
authors.initials: SD
authors.lastname: Reinartz
authors.affiliation: Institute for Occupational and Social Medicine, RWTH Aachen University Hospital, Aachen, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kraus
authors.affiliation: Department of Diagnostic and Interventional Radiology, Philipps University Marburg, Marburg, Germany.
authors.forename: Andreas H
authors.initials: AH
authors.lastname: Mahnken
authors.affiliation: Department of Diagnostic and Interventional Radiology, RWTH Aachen University Hospital, Pauwelsstrasse 30, Aachen, 52074, Germany. Electronic address: hb@bieling.com.
authors.forename: Christiane K
authors.initials: CK
authors.lastname: Kuhl
mesh_terms: D000368:Aged; D001013:Aorta, Thoracic; D001018:Aortic Diseases / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D002114:Calcinosis; D015897:Comorbidity; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D055088:Early Detection of Cancer / Q000706:statistics & numerical data; D005858:Germany / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D033162:Incidental Findings; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology; D008297:Male; D013902:Radiography, Thoracic / Q000706:statistics & numerical data; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*
keywords: Cardiac; computed tomography; risk stratification