| タイトル | Accurate Measurement of Bone Density with QCT |
| 著者（英） | Dalton, Bonnie P.; Cleek, Tammy M.; Matsubara, Miki; Whalen, Robert T.; Beaupre, Gary S. |
| 著者所属（英） | NASA Ames Research Center |
| 発行日 | 2002-01-01 |
| 言語 | eng |
| 内容記述 | The objective of this study was to determine the accuracy of bone density measurement with a new OCT technology. A phantom was fabricated using two materials, a water-equivalent compound and hydroxyapatite (HA), combined in precise proportions (QRM GrnbH, Germany). The phantom was designed to have the approximate physical size and range in bone density as a human calcaneus, with regions of 0, 50, 100, 200, 400, and 800 mg/cc HA. The phantom was scanned at 80, 120 and 140 KVp with a GE CT/i HiSpeed Advantage scanner. A ring of highly attenuating material (polyvinyl chloride or teflon) was slipped over the phantom to alter the image by introducing non-axi-symmetric beam hardening. Images were corrected with a new OCT technology using an estimate of the effective X-ray beam spectrum to eliminate beam hardening artifacts. The algorithm computes the volume fraction of HA and water-equivalent matrix in each voxel. We found excellent agreement between expected and computed HA volume fractions. Results were insensitive to beam hardening ring material, HA concentration, and scan voltage settings. Data from all 3 voltages with a best fit linear regression are displays. |
| NASA分類 | Aerospace Medicine |
| 権利 | No Copyright |
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