Kolta Sami, De Vernejoul Marie-Christine, Meneton Pierre, Fechtenbaum Jacques, Roux Christian
Rheumatology Department, Cochin Hospital, Assistance Publique, Hôpitaux de Paris René Descartes University, Paris, France.
J Clin Densitom. 2003 Fall;6(3):251-8. doi: 10.1385/jcd:6:3:251.
Animal models are widely used to explore the pathogenesis and management of osteoporosis. Mice are increasingly being used in animal models. We have evaluated the precision, accuracy, and ability to monitor changes in bone mineral measurements of mice with the Piximus and Hologic QDR 2000 devices. One hundred and twenty-two C57/BL6 mice were used in this study; 70 of them were put on a low calcium diet and followed prospectively for 14 wk. They were measured using both devices at baseline and at wk 14. Using the Piximus, we measured the whole body, the tibia, and two caudal vertebrae. Using the Hologic, we measured the tibia, which we divided into three equal parts. The remaining mice were used to evaluate the precision and accuracy of the measurement. The accuracy, which was determined only for the Hologic device, revealed a mean difference between the in vivo bone mineral content (BMC) and the ash weight of 0.1 mg. The precision, evaluated from the coefficient of variation (%) and the Smallest Detectable Difference (SDD, in absolute values) was good for both devices, confirming their ability to detect small differences in longitudinal studies: as little as 0.004 g for the BMC of the total tibia on both devices, and 0.003 g/cm2 for whole body bone mineral density (BMD) on the Piximus. The BMC found using the two devices was comparable, whereas the BMD obtained on the Hologic device was nearly double that found using the Piximus. The comparison of the results by Bland and Altman's method showed that the difference between the results was not dependent on the magnitude of the measurement. We concluded that bone density and bone-density changes in mice can be measured precisely in vivo using the Hologic and Piximus devices; the latter being able to measure the whole body BMD with good precision.
动物模型被广泛用于探究骨质疏松症的发病机制和治疗方法。小鼠越来越多地被用于动物模型。我们使用Piximus和Hologic QDR 2000设备评估了测量小鼠骨矿物质的精度、准确性以及监测其变化的能力。本研究使用了122只C57/BL6小鼠；其中70只采用低钙饮食，并进行了为期14周的前瞻性跟踪。在基线和第14周时使用这两种设备对它们进行测量。使用Piximus测量了全身、胫骨和两节尾椎。使用Hologic测量了胫骨，并将其分为三等份。其余小鼠用于评估测量的精度和准确性。仅针对Hologic设备确定的准确性显示，体内骨矿物质含量（BMC）与灰重之间的平均差异为0.1毫克。从变异系数（%）和最小可检测差异（SDD，绝对值）评估的精度对这两种设备来说都很好，证实了它们在纵向研究中检测微小差异的能力：两种设备对整个胫骨BMC的检测低至0.004克，Piximus对全身骨矿物质密度（BMD）的检测为0.003克/平方厘米。使用这两种设备测得的BMC具有可比性，而使用Hologic设备获得的BMD几乎是使用Piximus测得的两倍。通过Bland和Altman方法对结果进行比较表明，结果之间的差异不取决于测量值的大小。我们得出结论，使用Hologic和Piximus设备可以在体内精确测量小鼠的骨密度和骨密度变化；后者能够以良好的精度测量全身BMD。
