JAXA Repository / AIREX 未来へ続く、宙(そら)への英知

このアイテムに関連するファイルはありません。

タイトルThe X-ray attenuation characteristics and density of human calcaneal marrow do not change significantly during adulthood
著者(英)Wills, J. S.; Yan, C. H.; Cleek, T. M.; Les, C. M.; Whalen, R. T.; Beaupre, G. S.
発行日2002-05-01
言語eng
内容記述Changes in the material characteristics of bone marrow with aging can be a significant source of error in measurements of bone density when using X-ray and ultrasound imaging modalities. In the context of computed tomography, dual-energy computed techniques have been used to correct for changes in marrow composition. However, dual-energy quantitative computed tomography (DE-QCT) protocols, while increasing the accuracy of the measurement, reduce the precision and increase the radiation dose to the patient in comparison to single-energy quantitative computed tomography (SE-QCT) protocols. If the attenuation properties of the marrow for a particular bone can be shown to be relatively constant with age, it should be possible to use single-energy techniques without experiencing errors caused by unknown marrow composition. Marrow was extracted by centrifugation from 10 mm thick frontal sections of 34 adult cadaver calcanei (28 males, 6 females, ages 17-65 years). The density and energy-dependent linear X-ray attenuation coefficient of each marrow sample were determined. For purposes of comparing our results, we then computed an effective CT number at two GE CT/i scan voltages (80 and 120 kVp) for each specimen. The coefficients of variation for the density, CT number at 80 kVp and CT number at 120 kVp were each less than 1%, and the parameters did not change significantly with age (p > 0.2, r2 < 0.02, power > 0.8 where the minimum acceptable r2 = 0.216). We could demonstrate no significant gender-associated differences in these relationships. These data suggest that calcaneal bone marrow X-ray attenuation properties and marrow density are essentially constant from the third through sixth decades of life.
NASA分類Aerospace Medicine
権利Copyright
URIhttps://repository.exst.jaxa.jp/dspace/handle/a-is/302009


このリポジトリに保管されているアイテムは、他に指定されている場合を除き、著作権により保護されています。