title: Automated assessment of exclusion criteria for DXA lumbar spine scans.
abstract: Modern bone densitometry systems using dual-energy X-ray absorptiometry (DXA) automatically analyze lumbar spine scans and provide clinically important information concerning spine bone mineral density (BMD) and fracture risk. Lumbar spine BMD accurately reflects skeletal health and fracture risk in most cases, but degenerative diseases associated with aging may lead to the formation of reactive bone (osteophytes) and other confounding conditions that elevate BMD without a concomitant increase in bone strength or decrease in fracture risk. Automated densitometry software known as computer-aided densitometry (CAD) (GE Medical Systems Lunar) assists the user in identifying scans with common acquisition and analysis irregularities known to influence BMD values. Visual examination of 231 female spine scans measured with DXA found abnormal conditions that could influence BMD results in 29% of scans. The sensitivity and specificity of several criteria for identifying scans with conditions that could influence BMD were determined. A good criterion for identifying scans with abnormal conditions was a T-score difference of greater than 0.9 or 1.0 between L1-L4 mean and individual vertebrae. Criteria for excluding affected vertebrae were determined. Exclusion of affected vertebrae resulted in a mean BMD decrease of nearly 0.6 SD (T-score) among affected scans.
authors.affiliation: GE Medical Systems Lunar, Madison, Wisconsin 53717, USA. howard.barden@med.ge.com
authors.forename: Howard S
authors.initials: HS
authors.lastname: Barden
authors.forename: Paul
authors.initials: P
authors.lastname: Markwardt
authors.forename: Randy
authors.initials: R
authors.lastname: Payne
authors.forename: Brent
authors.initials: B
authors.lastname: Hawkins
authors.forename: Matt
authors.initials: M
authors.lastname: Frank
authors.forename: Kenneth G
authors.initials: KG
authors.lastname: Faulkner
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods*; D000368:Aged; D015519:Bone Density; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging*; D010024:Osteoporosis / Q000175:diagnosis; D012680:Sensitivity and Specificity; D012984:Software