健康老年妇女近段股骨骨密度和结构的定量CT研究

目的 采用定量CT(QCT)和双能X线吸收测量(DXA)仪对健康老年妇女近段股骨骨密度(BMD)和骨结构进行研究,并对2种测量方法的结果进行比较.方法 对66名65岁以上健康妇女左侧髋关节进行DXA测量,计算出股骨颈和粗隆区BMD;对其双侧近段股骨进行QCT测量,计算出股骨颈、粗隆区和整体股骨ROI的皮质骨、松质骨和总体骨的BMD和体积;并将QCT三维图像模拟DXA的平面投影计算出模拟DXA股骨颈BMD和模拟DXA股骨粗隆区BMD.对所获数据进行配对t检验或非参数秩和检验,并用Pearson法分析DXA和QCT相对应ROI的相关性.结果 用QCT可以对股骨近段不同ROI(股骨颈、粗隆区和整体股骨区)及不同骨成分(皮质骨、松质骨和总体骨)的BMD及体积等参数进行精确的定量分析.除右侧股骨颈皮质骨BMD(0.52±0.04)g/cm3]、股骨粗隆区皮质骨BMD(0.49±0.03)g/cm3]、股骨粗隆区综合骨BMD(0.22±0.04)g/cm3]大于左侧相应参数分别为(0.51±0.04)、(0.48±0.03)、(0.21±0.04)g/cm3],差异均有统计学意义(P值均<0.05),但差别均<3.3%;而模拟DXA股骨颈BMD、模拟DXA股骨粗隆区BMD、股骨颈皮质骨体积、股骨颈松质骨BMD、股骨颈松质骨体积、股骨颈综合骨BMD、股骨颈综合骨体积、股骨粗隆区皮质骨体积、股骨粗隆区松质骨BMD、股骨粗隆区松质骨体积、股骨粗隆区综合骨体积左侧参数分别为(0.52±0.10)g/cm2、(0.78±0.13)g/cm2、5.80 cm3、(0.06±0.03)g/cm3、(5.19±1.40)cm3、(0.25±0.04)g/cm3、15.66 cm3、(21.74±3.43)cm3、(0.08±0.03)g/cm3、(34.27±6.09)cm3、(76.12±11.11)cm3,右侧分别为(0.52±0.10)g/cm2、(0.78±0.13)g/cm2、6.01 cm3、(0.06±0.02)g/cm3、(5.17±1.27)cm3、(0.25±0.04)g/cm3、15.62 cm3、(22.12±3.60)cm3、(0.09±0.03)g/cm3、(34.17±5.94)cm3、(76.53±10.71)cm3,差异均无统计学意义(P值均>0.05).左右两侧近段股骨QCT各相对应参数之间的r值范围在0.656～0.955,均具有相关性(P<0.05).QCT模拟DXA股骨颈和粗隆区BMD与真正DXA测量的相应值之间r值分别为0.685和0.855,具有相关性(P<0.05).结论 利用QCT技术可以对老年妇女近段股骨不同区域和不同成分的BMD和结构进行精确定量分析,QCT是骨质疏松研究中非常有用的测量技术.

The study of bone mineral density and structure in proximal femur by quantitative CT in elderly Chinese women

Objective To evaluate the bone mineral density (BMD) and structure of proximal femur in elderly Chinese women by quantatitive computed tomography (QCT) and dual energy X-ray absorptiometry (DXA), and to further compare the results of these two methods. Methods Sixty-six healthy Chinese women over 65 years old participated in this study. The left hips of all subjects were measured with DXA and the BMD of femoral neck and trochanteric region were calculated. With QCT, the BMD and tissue volume of cortical, trabecular and integral bone were calculated for femoral neck, trochanteric and total femur regions in both hips. Appropriate statistical analyses were performed with SPSS 11.5. Results The BMD and structural parameters in different regions and different compartments of the proximal femur could be precisely assessed with QCT technique. The BMD of cortical bone in femoral neck ( 0. 52 ± 0. 04) g/cm3 ], BMD of cortical bone in troehanterie region (0. 49 ± 0. 03 ) g/cm3 ] and BMD of integral bone in trochanteric region (0. 22 ± 0. 04 ) g/cm3 ] were greater in the right than those in the left (0. 51 ± 0. 04), (0. 48±0. 03), (0. 21±0. 04) g/cm3 ]. The difference had statistical signification (P <0. 05). However, the difference was less than 3. 3%. In the left the parameters of analogue DXA BMD of femoral neck, analogue DXA BMD of trochanteric region, cortical bone volume of femoral neck, BMD of trabecular bone in femoral neck, trabecular bone volume of femoral neck, BMD of integral bone in femoral neck, integral bone volume of femoral neck, cortical bone volume of trochanteric region, BMD of trabecular bone in trochanteric region, trabecular bone volume of trochanteric region and integral bone volume of trochanteric region were ( 0. 5,2 ± 0. 10 ) g/cm2, (0. 78 ± 0. 13 ) g/cm2, 5.80 cm3, ( 0. 06 ± 0. 03 ) g/cm3, (5. 19 ± 1.40 ) cm3, ( 0. 25 ± 0. 04 ) g/cm3, 15.66 cm3, ( 21.74 ± 3.43 ) cm3, ( 0. 08 ± 0. 03 ) g/cm3, (34. 27 ± 6. 09) cm3 and (76. 12 ± 11.11 ) cm3 respectively, in the right the corresponding parameters being (0.52±0. 10) g/cm2, (0.78 ± 0. 13) g/cm2,6.01 cm3, (0.06 ± 0.02) g/cm3, (5.17 ± 1.27) cm3, (0. 25 ± 0. 04) g/cm3, 15.62 cm3, ( 22. 12 ± 3.60 ) cm3, ( 0. 09 ± 0. 03 ) g/cm3, ( 34. 17 ± 5.94 )cm3 and (76. 53 ± 10. 71 )cm3 respectively. There were no significant difference between the left and right parameters above (P > 0. 05). All QCT parameters of the right hip correlated well with their corresponding ones of left hip with correlation coefficients ranging from 0. 656---0. 955, P < 0. 05. QCT-derived simulated DXA femoral neck and trochanteric BMD were correlated well with real DXA measurements ( r 0. 685 and 0. 855, P < 0. 05). Conclusion With QCT technique the BMD and structural parameters in different regions and different compartments of the proximal femur can be precisely assessed. QCT is a powerful technique in the researches of osteoporosis.