Yamada M, Ito M, Hayashi K, Nakamura T
Department of Radiology, Nagasaki University School of Dentistry, Japan.
AJR Am J Roentgenol. 1993 Sep;161(3):621-7. doi: 10.2214/ajr.161.3.8352120.
The value of calcaneal dual-energy X-ray absorptiometry for monitoring changes in bone mineral density has not yet been established. Accordingly, the focus of this study was to determine the usefulness of the calcaneus as the site for bone mineral density measurement with dual-energy X-ray absorptiometry.
Dual-energy X-ray absorptiometry of the calcaneus was performed in 19 specimens derived from 11 cadavers and 337 healthy volunteers to assess accuracy, in vivo precision, and age-related changes in bone mineral density. We also compared calcaneal bone mineral density determined by dual-energy X-ray absorptiometry with lumbar spine bone mineral density determined by dual-energy X-ray absorptiometry (L1-L4) or quantitative CT (L3).
Studies of specimens showed that dual-energy X-ray absorptiometry had an error rate of 6%. In addition, strong correlations were found between bone mineral content and ash weight (r = .97, p < .0001) and between bone mineral density and ash density (r = .87, p < .0001). In vivo studies showed moderate correlations between calcaneal bone mineral density determined by dual-energy X-ray absorptiometry and lumbar spine bone mineral density determined by dual-energy X-ray absorptiometry (men, r = .77, p < .0001; women, r = .76, p < .0001) and lumbar spine bone mineral density by quantitative CT (men, r = .68, p < .0001; women, r = .68, p < .0001). Calcaneal bone mineral density measured by dual-energy X-ray absorptiometry and lumbar spine bone mineral density measured by quantitative CT continued to decrease throughout the postmenopausal period. However, lumbar spine bone mineral density determined by dual-energy X-ray absorptiometry did not show further decreases in subjects more than 70 years old.
Taken together, these results suggest that the calcaneus can be used as an additional site for determining bone mineral density to assess osteopenia in patients when deformities of the spine make quantitative CT or other methods of density measurement impossible.
跟骨双能X线吸收法用于监测骨矿物质密度变化的价值尚未确立。因此，本研究的重点是确定跟骨作为双能X线吸收法测量骨矿物质密度部位的实用性。
对来自11具尸体的19个标本和337名健康志愿者进行跟骨双能X线吸收法检测，以评估准确性、体内精密度以及骨矿物质密度的年龄相关变化。我们还将双能X线吸收法测定的跟骨骨矿物质密度与双能X线吸收法（L1-L4）或定量CT（L3）测定的腰椎骨矿物质密度进行了比较。
对标本的研究表明，双能X线吸收法的误差率为6%。此外，在骨矿物质含量与灰重之间（r = 0.97，p < 0.0001）以及骨矿物质密度与灰密度之间（r = 0.87，p < 0.0001）发现了强相关性。体内研究表明，双能X线吸收法测定的跟骨骨矿物质密度与双能X线吸收法测定的腰椎骨矿物质密度之间（男性，r = 0.77，p < 0.0001；女性，r = 0.76，p < 0.0001）以及与定量CT测定的腰椎骨矿物质密度之间（男性，r = 0.68，p < 0.0001；女性，r = 0.68，p < 0.0001）存在中度相关性。双能X线吸收法测定的跟骨骨矿物质密度和定量CT测定的腰椎骨矿物质密度在整个绝经后期持续下降。然而，双能X线吸收法测定的腰椎骨矿物质密度在70岁以上的受试者中未显示出进一步下降。
综上所述，这些结果表明，当脊柱畸形使定量CT或其他密度测量方法无法进行时，跟骨可作为确定骨矿物质密度的额外部位，用于评估患者的骨质减少情况。
