Calibration of dual-energy X-ray absorptiometry for bone density
| Autor: | Didier Hans, James A. Hanson, Joel A. Trempe, Joseph P. Bisek, Richard B. Mazess |
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| Rok vydání: | 2009 |
| Předmět: |
Materials science
Bone density Endocrinology Diabetes and Metabolism Imaging phantom Absorptiometry Photon Bone Density Calibration medicine Humans Orthopedics and Sports Medicine Densitometer Dual-energy X-ray absorptiometry Bone mineral Polycarboxylate Cement medicine.diagnostic_test business.industry Soft tissue Lipids Models Structural Paraffin Anthropomorphic phantom Hydroxyapatites Nuclear medicine business Algorithms |
| Zdroj: | Journal of Bone and Mineral Research. 6:799-806 |
| ISSN: | 0884-0431 |
| DOI: | 10.1002/jbmr.5650060804 |
| Popis: | Bone mineral content (BMC, g) using DEXA (Lunar DPX) was measured on known hydroxyapatite samples in a water bath in the presence of uniform and nonuniform covering of fat-equivalent materials. Selective placement of paraffin over bone had a greater effect than lard in reducing apparent BMC, and polycarbonate plastic had a lesser effect. Measured BMC was 100.1 +/- 1.1% of actual hydroxyapatite weight when (1) fat over bone was about twice the mass of hydroxyapatite, and (2) the surrounding soft tissue was 15-30% fat. There was a linear relationship between observed and expected BMC, area (cm2), and bone mineral density (BMD, g/cm2) measured on an aluminum phantom using either the Lunar DPX or the Hologic QDR-1000. The measured area with the two densitometers was identical, but BMC differed. For both an anthropomorphic phantom and human subjects, use of a constant-threshold (0.2 g/cm2) edge-detection algorithm excluded less low-density bone from the transverse processes than the standard DPX edge-detection algorithm. Differences in edge detection could influence the results obtained with phantoms and in vivo and make system intercomparison difficult. |
| Databáze: | OpenAIRE |
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