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.
Clinical Relevance: These data may have utility for the diagnosis and treatment of osteoporosis.
1Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021
2University of Wisconsin School of Medicine and Public Health (A.L.B.) and Department of Orthopedics & Rehabilitation (P.A.A.), UWMF Centennial Building, 1685 Highland Avenue, 6th Floor, Madison, WI 53705-2281. E-mail address for P.A. Anderson: firstname.lastname@example.org
3Department of Radiology, University of Wisconsin, Box 3252 Clinical Science Center-E3, 600 Highland Avenue, Madison, WI 53792
4Department of Mechanical Engineering, University of Wisconsin, 3046 Mechanical Engineering Building, 1513 University Avenue, Madison, WI 53706