title: Hounsfield units for assessing bone mineral density and strength: a tool for osteoporosis management.
abstract: BACKGROUND
  Measurements obtained from clinical computed tomography examinations may yield information leading to the diagnosis of decreased bone mineral density, without added expense to the patient. The purpose of the present study was to determine if Hounsfield units, a standardized computed tomography attenuation coefficient, correlate with bone mineral density and compressive strength.
  
  
  METHODS
  Twenty-five patients (including eighteen female and seven male patients with a mean age of 71.3 years) undergoing both lumbar spine dual x-ray absorptiometry scans and computed tomography imaging were evaluated to determine if Hounsfield units correlated with bone mineral density and T-scores. Normative data were generated from lumbar spine computed tomography examinations for eighty consecutive trauma patients and were stratified by age and sex. Separately, polyurethane foam blocks of varying densities were imaged with computed tomography and were subjected to mechanical testing to determine compressive strength. Compressive strength values and Hounsfield units were analyzed for correlation.
  
  
  RESULTS
  Significant correlations were found between Hounsfield units and bone mineral density, age, and T-scores and between Hounsfield units and compressive strength (p < 0.001).
  
  
  CONCLUSIONS
  Hounsfield units obtained from clinical computed tomography scans that are made for other purposes correlate with dual x-ray absorptiometry scores as well as compressive strengths based on osseous models and potentially provide an alternative method for determining regional bone mineral density at no additional cost to the patient. The information could conceivably be applied toward fracture risk assessment, diagnosis of osteoporosis, and early initiation of needed treatment.
authors.affiliation: Department of Orthopedics and Rehabilitation, University of Wisconsin, Madison, Wisconsin, USA.
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Schreiber
authors.forename: Paul A
authors.initials: PA
authors.lastname: Anderson
authors.forename: Humberto G
authors.initials: HG
authors.lastname: Rosas
authors.forename: Avery L
authors.initials: AL
authors.lastname: Buchholz
authors.forename: Anthony G
authors.initials: AG
authors.lastname: Au
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D015519:Bone Density / Q000502:physiology*; D001842:Bone and Bones / Q000000981:diagnostic imaging*; D019245:Compressive Strength / Q000502:physiology*; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008297:Male; D010024:Osteoporosis / Q000000981:diagnostic imaging*