title: A novel quantitative approach to the measurement of abdominal aortic calcification as applied to the Canadian Multicenter Osteoporosis Study (CaMOS).
abstract: Lateral spine radiographs provide an inexpensive resource for characterizing abdominal aortic calcification (AAC). A widely accepted measurement of AAC is the semi-quantitative technique generated by the Framingham Heart Study (F-AAC-24). We sought to develop an analytical method to quantify ACC (QAAC) on lateral spine radiographs and compare the finding to conventional subjective measurements.
  
  
  
  Severity of AAC was quantified by measuring pixel intensities in the user-defined region of the aorta with internal standardization to the vertebral endplates and background calibration to the density of the vertebral body. The association between bone mineral density (BMD) measured by dual energy X-ray absorptiometry (DXA) and AAC measured by QAAC, F-AAC-24 and a modified Framingham score (F-AAC-12) was determined in 110 participants of the Canadian Multicenter Osteoporosis Study (CaMOS).
  
  
  
  The inter-observer reliability for the QAACwas slightly higher than with the visual and semi-quantitative Framingham method and the pseudo-colored images illustrate the potential to meaningfully resolve severity of calcification. There was a significant negative association between QAACand BMD measures of the hip and spine. This association remained significant after adjustment for age, sex, estimated glomerular filtration rate, phosphate and hypertension. Significant predictors of F-ACC-12 and 24 included age and hypertension.
  
  
  
  The QAACis a reproducible approach to measuring AAC. Whether it is capable of monitoring subtle calcific changes over time requires further study. This technique could be applied to large studies that seek to determine the impact of interventions that modify bone density as a treatment for vascular calcification and cardiovascular disease in the general population.
authors.affiliation: Department of Biomedical and Molecular Science, Queen's University, Kingston, ON, Canada.
authors.forename: Mark
authors.initials: M
authors.lastname: Grant
authors.affiliation: Department of Biomedical and Molecular Science, Queen's University, Kingston, ON, Canada.
authors.forename: Mandy E
authors.initials: ME
authors.lastname: Turner
authors.affiliation: Department of Biomedical and Molecular Science, Queen's University, Kingston, ON, Canada.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Murray-Guenther
authors.affiliation: Department of Medicine, Queen's University, Kingston, ON, Canada.
authors.forename: Tassos
authors.initials: T
authors.lastname: Anastassiades
authors.affiliation: Clinical Research Centre, Kingston General Hospital, Department of Public Health Sciences, Queen's University, Kingston, ON, Canada.
authors.forename: Wilma M
authors.initials: WM
authors.lastname: Hopman
authors.affiliation: Department of Biomedical and Molecular Science, Queen's University, Kingston, ON, Canada.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Adams
authors.affiliation: Department of Biomedical and Molecular Science, Queen's University, Kingston, ON, Canada.
authors.forename: Paul
authors.initials: P
authors.lastname: Jeronimo
authors.affiliation: Department of Radiology, Queen's University, Kingston, ON, Canada.
authors.forename: Robert
authors.initials: R
authors.lastname: Nolan
authors.affiliation: Department of Biomedical and Molecular Science, Queen's University, Kingston, ON, Canada.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Adams
authors.affiliation: Department of Biomedical and Molecular Science, Queen's University, Kingston, ON, Canada; Department of Medicine, Queen's University, Kingston, ON, Canada. Electronic address: holdenr@kgh.kari.net.
authors.forename: Rachel M
authors.initials: RM
authors.lastname: Holden
mesh_terms: D000368:Aged; D001012:Aorta, Abdominal / Q000473:pathology*; D015519:Bone Density; D002170:Canada; D003710:Demography; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D008297:Male; D015999:Multivariate Analysis; D010024:Osteoporosis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D012015:Reference Standards; D061205:Vascular Calcification / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology
keywords: Atherosclerosis; DXA; General population studies; Osteoporosis; Radiology; Vascular calcification