容积性定量CT测量股骨近端骨密度准确性研究

The study of accuracy of volumetric quantitative computed tomography in measuring bone mineral density of the proximal femur

目的通过分别对比容积性定量CT(vQCT)、双能X射线吸收法(DXA)与灰化法测量股骨近端骨密度结果,确定并对比相关性,进行指导临床骨质疏松诊断及治疗。方法选取20个尸体股骨近端标本,先使用DXA骨密度仪扫描,测得骨矿含量(BMC)及骨密度(BMD)。再对标本相同部位行64层螺旋CT扫描,数据导入OsteoCAD软件自动分析得出骨密度值。应用灰化法得出标本灰质量密度。所有资料进行统计分析分别确定并对比vQCT及DXA测量的骨密度值与灰密度之间的相关性。结果vQCT测量股骨颈骨密度与灰质量密度线性相关性较好(r=0.852,P<0.01),DXA与灰质量密度的相关性略差(r=0.807,P<0.01)。结论vQCT测得的骨密度较DXA与灰质量密度线性相关性更好,可靠性高,对于诊断骨质疏松,预测骨质疏松性骨折,评价、指导骨质疏松骨折手术更有应用价值。

Objective To compare the data of volumetric quantitative computed tomography（vQCT） and of dual energy radiograph absorptiometry （DXA） with of bone ash analysis respectively in measuring bone mineral density of the proximal femur, to determine and compare the correlation, and then to guide the diagnosis and treatment of osteoporosis. Methods 20 specimens of cadaveric proximal femur were recruited. BMD and BMC were measured by DXA. Then 64-slice spiral CT scanned the same specimens and the OsteoCAD software analysis the date from CT to get the BMD. After adjunct removed, the specimens were incinerated. After comparing the value of BMD and BMC measured by DXA and vQCT respectively with the value of bone ash density of incinerated proximal femur, we calculated the correlation between the BMD measured by vQCT and bone ash density and between BMD measured by DXA and bone ash density. Results The correlation of BMD measured by vQCT and the bone ash density was high（ r = 0. 852, P 〈 0. 01 ）, The correlation of BMD measured by DXA and the bone ash density was low relatively （ r = 0. 807, P 〈 0.01 ）. Conclusion The linear correlation of BMD measured by vQCT and bone ash density is higher than that by DXA. The measurement of BMD by vQCT is reliable and valuable for diagnosing osteoporosis, predicting fragile fracture, evaluating and guiding operative treatment.