用放射吸收法(RA)测量指骨骨密度精确度和准确性的研究

Radiographic absorgtiometry for bone mineral measurement of the phalanges precision and accuracy study

目的评价放射吸收法(RA)测量2、3、4指骨中节骨密度的精确度和准确性。方法对19例尸体的双手,用铝制楔型标志物,分别进行了50kV 400mA和60kV 300mA两次X线照射,对每只手指的第二至第四节指骨的骨矿含量(BMC)和骨密度(BMD),以AU(指骨指数)为单位进行测量和分析。结果对于BMC-AU来说,这种方法的精密度误差是1.0%,对于BMD-AU来说,精密度误差是0.6%。通过5mm和6mm酒精厚度所获得的X射线图可以观察到BMD-AU有2.0%到2.4%的降低,与对照组相比有明显的统计学差异(P<0.01)。采用X射线吸收测定法得到的BMC-AU和前臂的BMC有良好的相关性(r=0.887),并且在指骨的BMC-AU与骨灰重量之间也有较好的相关性(r=0.983)。结论放射吸收法(RA)测量外周骨骨密度具有较高的精确度和准确性。

Objective To evaluate the accuracy and precision of a radiographic absorptiometry（RA） method for assessment of bone mineral of the middle phalanges. Methods Nineteen cadaveric hands were radiographed with an aluminum wedge, once at 50KVP and 400MA and once at 60KVP and 300MA. Bone mineral content（BMC） and bone mineral density（NMD） of the second to fourth middle phalanges, expressed in arbitrary units（ BMC-AU and BMD-AU） ,were analyzed and averaged in each hand.Results The precision error of this method was 1.0% for BMC-AU and 0.6% for BND-AU. A 2.0% - 2.4% reduction in BMD-AU seen on radiographs obtained through ethanol thicknesses of 5 and 6 mm compared with that seen on controls was statistically significant （ P 〈 0.01 ）.The correlation between BMC-AU and forearm BMC determined with dual x-ray abserptiometry was good（ r = 0. 887 ）, and that between BMC-AU and ash weight in the phalanges was excellent （r = 0. 983 ）. Conclusions The RA method is precise and accurate for bone mineral assessment of the peripherai appendicular skeleton.