Koo Winston W K, Hockman Elaine M, Hammami Mouhanad
Department of Pediatrics, University of Tennessee, Memphis, USA.
J Am Coll Nutr. 2004 Jun;23(3):212-9. doi: 10.1080/07315724.2004.10719363.
To document the clinical and experimental situations that may affect DXA measurements in small subjects.
49 piglets (886g to 21100g) had measurements with either of two pencil beam densitometers (QDR 1000W and QDR 2000 Plus, Hologic Inc, Waltham, MA) using commercial infant (IWB) and adult whole body (AWB) software v5.71p and v5.71 respectively. AWB scans were analyzed with three additional software versions. 35 infants (2115 to 11564g) had IWB measurements.
DXA measurements of total weight, bone mineral content, bone area, bone mineral density, fat and lean mass from IWB scans (all piglets) and from AWB scans (piglets >12 kg) were highly reproducible (p < 0.001). A statistically significant change occurred in at least one of the DXA measurements from the use of different platforms, variations in the amount and placement of covering (e.g., blanket), placement of the external calibration standard, presence of radiographic contrast material, presence of movement artifact, delivery of an intravenous fluid bolus prior to scanning or improper delineation of external calibration standard during analysis. Additionally, results varied amongst different versions of software as well as between IWB and AWB softwares.
In small subjects, consistency in the DXA techniques is paramount for valid and meaningful comparison of DXA data in bone mass and body composition.
记录可能影响小受试者双能X线吸收法（DXA）测量结果的临床和实验情况。
49头仔猪（体重886克至21100克）分别使用两种笔束密度计（QDR 1000W和QDR 2000 Plus，Hologic公司，马萨诸塞州沃尔瑟姆）进行测量，分别使用商业婴儿（IWB）软件v5.71p和成人全身（AWB）软件v5.71。对AWB扫描结果使用另外三个软件版本进行分析。35名婴儿（体重2115克至11564克）进行了IWB测量。
IWB扫描（所有仔猪）和AWB扫描（体重>12千克的仔猪）得出的总重量、骨矿物质含量、骨面积、骨矿物质密度、脂肪和瘦肉质量的DXA测量结果具有高度可重复性（p<0.001）。使用不同平台、覆盖物数量和放置位置的变化（如毯子）、外部校准标准的放置、放射造影剂的存在、运动伪影的存在、扫描前静脉推注液体或分析期间外部校准标准的划定不当，这些情况中至少有一种会导致DXA测量结果发生统计学显著变化。此外，不同软件版本之间以及IWB和AWB软件之间的结果也有所不同。
对于小受试者，DXA技术的一致性对于有效且有意义地比较骨量和身体成分的DXA数据至关重要。
