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

Abstract

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). 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. Key words: Bone density; Tomography, X-ray computed ; Densitometry, X-ray