Comparison and investigation of bone mineral density in opposing femora by dual-energy X-ray absorptiometry

A dual-energy X-ray absorptiometry (DXA) machine was used to measure the bone mineral density (BMD) of both femora in 760 female volunteers. Each volunteer completed a questionnaire and exclusion criteria were applied such that only 480 of these were considered normal subjects. The remaining 280 women failed to comply with the criteria and were considered abnormal; their BMD results were analysed separately. Two abnormal subgroups, one with previous long bone fractures and one with radiologically diagnosed osteopenia, were studied. BMD values for femoral neck, Ward's triangle and trochanter were compared between the two femora in all the above groups. No dominance relationship was found when comparing left to right femur, averaged over any population studied, but large differences were found between the femora in individual volunteers. There was a high correlation between BMD in opposing femora of 0.91, 0.91 and 0.84 for the femoral neck, Ward's triangle and trochanter respectively. However, in normal subjects the percentage variation in these regions ranged up to 34%, 64% and 80% respectively at the different femoral sites. In addition, the normal population was divided into two subgroups, one in which the density difference between the femora was large, and the other in which the difference was statistically insignificant. The analytical and anatomical variations between these two groups were investigated. Only part of the difference appeared to be due to analytical problems and it seems that there is a genuine difference in femoral density. Poor correlation for femoral neck percentage density difference was found with average BMD, age, height and weight in the normal population. This study concludes that a measurement of BMD in one femur can not reliably predict the BMD in the contralateral femur. It is therefore recommended that routine density measurements should include scanning of both femora.     

跟骨超声骨质测量与双能量X线吸收骨密度测量的比较

我们试图通过对跟骨超声骨质测量仪与双能量Ｘ线吸收骨密度测量仪的临床对比，来评价跟骨超声骨质测量仪的敏感性。本文对５６名健康女性同时接受了超声骨质测量仪和双能量Ｘ线吸收骨密度仪的检测。３７例（年龄２６～７６岁）进行了跟骨超声和腰椎骨密度测量，１９例（年龄２６～７０岁）进行了跟骨超声和股骨颈骨密度测量。结果用ＳＹＳＴＡＴ统计软件包进行处理。结果表明：随着年龄的增加，腰椎、股骨颈骨密度及跟骨强度（Ｓｔｉｆｆｎｅｓｓ）均显著下降（Ｐ＜０．０５），两种仪器的阳性检出率无明显差异（Ｐ＜０．０５）。但腰椎和股骨颈ＢＭＤ与跟骨强度（Ｓｔｉｆｆｎｅｓｓ）的相关性适中ｒ＝０．４６５～０．５１３左右。通过逐步多元回归分析显示超声强度（Ｓｔｉｆｆｎｅｓｓ）与ＢＭＤ无关。这表明超声波测量仪主要测量骨的结构变化，而骨密度测量仪则是测量骨量的变化。两种方法相辅相承，共同测量，将更好地预测骨质疏松性骨折的发生。同时超声波具有无放射线损害、价格低廉及良好的敏感性，将越来越受到临床重视。     

Broadband ultrasound attenuation and dual energy X-ray absorptiometry in patients with hip fractures: Which technique discriminates fracture risk

There is considerable interest in predicting risk of hip fracture in order to allow targeting of preventive care. This study aimed to determine which of two methods best discriminates a hip fracture population from controls. Fifty women with fractured neck of femur, and 50 control subjects were scanned using dual energy X-ray absorptiometry (DXA) of the spine and hip and broadband ultrasound attenuation (BUA) of the os calcis. Significant differences between the two populations could be found for both DXA and BUA, with BUA showing the largest percentage difference (27%). The mean z-scores showed that BUA had the lowest, with the exception of DXA trochanter. However, no significant difference between BUA and DXA trochanter Z-scores was found. A receiver operator characteristic (ROC) analysis showed that BUA has a superior sensitivity and specificity compared with DXA measurements, with DXA of the hip being better than the spine. This retrospective study shows that BUA is a better discriminator of hip fracture than DXA lumbar spine of DXA hip, which may have important implications for predicting those at risk of future hip fracture.     

Influence of patient's weight on dual-photon absorptiometry and dual-energy X-ray absorptiometry measurements of bone mineral density

Lumbar spine bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DXA) (Hologic QDR 1000) and by¹⁵³Gd dual-photon absorptiometry (DPA) (Novo Lab 22a) in 120 postmenopausal women. Though a high correlation existed between the two techniques, the ratio between DXA and DPA values was not constant. Using DXA we observed a higher dependence of BMD on weight than in the DPA measurements. To investigate the different behaviour of DXA and DPA machines with weight, we analysed the effects of increasing thickness of soft tissue equivalents on the BMD of the Hologic spine phantom and on the BMD equivalent of an aluminium standard tube. Increasing tissue-equivalent thickness caused the phantom BMD measured by DPA to decrease significantly but had not effect on the DXA measurements. The different behaviour of DPA and DXA equipment with regard to the phantoms could account for the differences observed in the relations between BMD and weight in the patients. Using multiple regression we studied the influence of weight and body mass index on the relation between BMD measured by the two techniques. The introduction of either of these variables into the regression resulted in an improvement of the prediction of the DXA values from the DPA values. However, the residual standard error of the estimate was still higher than the combined precision errors of the two methods, so that no simple relation allows a conversion of BMD_DPA into BMD_DXA. Our results confirm that BMD is positively correlated with weight in postmenopausal women; the influence of weight on BMD is blunted when the Novo Lab 22a DPA machine is used for measuring bone mineral.     

Vertebral bone mineral density measured laterally by dual-energy X-ray absorptiometry

The bone mineral density (BMD) of lumbar vertebrae in the anteroposterior (AP) view may be overestimated in osteoarthritis or with aortic calcification, which are common in elderly. Furthermore, the risk of spinal crush fracture should be more closely related inversely to the BMD of the vertebral body than to that of the posterior arch. Therefore, we measured BMD of lumbar vertebrae in lateral (LAT) view (L2–L3), using a standard dual-energy X-ray absorptiometer (DEXA), thus eliminating most of the posterior spinal elements. The precision of BMD LAT measurement was determined both in vitro and in healthy volunteers. Then, we compared the capability of BMD LAT and BMD AP scans for monitoring bone loss related to age and for discriminating the BMD of postmenopausal women with nontraumatic vertebral fractures from that of young subjects. In vitro, when a spine phantom was placed in lateral position in the middle of 26 cm of water in order to simulate both soft-tissue thickness and X-ray source remoteness, the coefficient of variation (CV) of six repeated determinations of BMD was 1.0%. In vivo, the CV of paired BMD LAT measurements obtained in 20 healthy volunteers after repositioning was 2.8%. The age-related difference between a peak bone mass group estimated in a group of 27 healthy women aged 20 to 35 years and a group of 50 women aged 60 to 75 years, in whom neither vertebral fracture nor osteoporosis risk factors could be detected, were 21.7% and 37.6% in AP and LAT view, respectively. An arbitrary BMD fracture threshold was defined in AP and LAT views as the 90th percentile of the BMD value of a group of 22 osteoporotic women with vertebral fractures. The distribution of BMD AP and LAT above and below this threshold in 169 consecutively screened women without vertebral fracture was then analysed. In both AP and LAT views, 39.1% and 31.3% had BMD values above and below this threshold, respectively. Of the remaining, 16.0% had a BMD below this threshold only in AP and 13.6% only in LAT view. Thus, if BMD LAT was a better reflection of vertebral body bone mass than BMD AP, and thereby a better predictor of the resistance to crush fracture, our results would suggest that only the use of the standard AP view could under- or overestimate spinal fracture risk in about 30% of women screened for osteoporosis. In conclusion, our results indicate that BMD measurement in lateral view is feasible with a standard DEXA instrument. This mode of scanning, besides overcoming artefacts due to osteoarthritis of the posterior arch and aortic calcifications, appears to provide a greater sensitivity for assessing bone mass loss of the vertebral body than the standard anteroposterior scan.     

The relationship between bone mineral density and ultrasound in postmenopausal and osteoporotic women

The aim of this cross-sectional study was to use a novel method of data analysis to demonstrate that patients with osteoporosis have significantly lower ultrasound results in the heel after correcting for the effect of bone mineral density (BMD) measured in the spine or hip. Three groups of patients were studied: healthy early postmenopausal women, within 3 years of the menopause (n=104, 50%), healthy late postmenopausal women, more than 10 years from the menopause (n=75, 36%), and a group of women with osteoporosis as defined by WHO criteria (n=30, 14%). Broadband ultrasound attenuation (BUA), speed of sound (SOS) and Stiffness were measured using a Lunar Achilles heel machine, and BMD of the lumbar spine and left hip was measured using dual-energy X-ray absorptiometry (DXA). SOS, BUA and Stiffness were regressed against lumbar spine BMD and femoral BMD for all three groups combined. The correlation coefficients were in the range 0.52–0.58, in agreement with previously published work. Using a calculated ratio R, analysis of variance demonstrated that the ratio was significantly higher in the osteoporotic group compared with the other two groups. This implied that heel ultrasound values are proportionately lower in the osteoporotic group compared with the other two groups for an equivalent value of lumbar spine and femoral neck BMD. We conclude that postmenopausal bone loss is not associated with different ultasound values once lumbar spine or femoral neck BMD is taken into account. Ultrasound does not give additional information about patterns of bone loss in postmenopausal patients but is important in those patients with osteoporosis and fractures.     

上海市区居民3051例跟骨骨密度的测量

对上海市区居民３０５１人进行了跟骨骨密度测定。其中男１４４４人，女１６０７人，年龄１１～９５岁，按５岁为一年龄组将其分为１７组。结果：跟骨骨峰值出现在２０～２４岁组，女性骨峰值显著小于男性，中年开始出现跟骨骨量丢失，女性的骨丢失速度显著快于男性。女性骨累积丢失量也显著大于男性。女性的跟骨累积丢失量仅次于Ｗａｒｄ三角。跟骨骨密度除了随年龄变化外，也受身高、体重及体重指数的影响。６０岁以上老年女性骨质疏松症的患病率显著高于男性，男、女分别为１３．９％、５８．０％。结论：跟骨骨密度的测量能较好地反映人体骨矿含量的变化规律     

股骨近端骨密度的测量

双能X线骨密度仪检测骨密度是诊断骨质疏松症和疗效随访的金标准,特别是髋部骨密度的测量对于骨折的预测尤其测定部位本身骨折的预测作用较大.由于脊柱部位的骨密度测量值易受到脊柱退行性疾病的病理改变如退行性侧凸、骨赘增生、腰椎间盘突出等影响,测量的准确性下降.因而近年来欧美国家临床试验也好或者骨质疏松诊疗也好,大都以股骨近端的BMD测定为标准.本文就股骨近端解剖特点、骨密度测量的意义、方法以及测量的注意点作一个综述,以期帮助临床医生或技术员全面评估股骨近端骨密度测定的意义.     

Broadband ultrasound attenuation of the calcaneus predicts lumbar and femoral neck density in Caucasian women: A preliminary study

Recent studies have demonstrated the ability of ultrasound techniques to differentiate normal and osteoporotic women. To define the ability of broadband ultrasound attenuation (BUA) of the calcaneus to predict axial bone mass, the ultrasound value was correlated with lumbar vertebral and femoral neck density in 22 Caucasian women. The three measures of bone mass inversely correlated with age: lumbar density (r=0.54), femoral neck density (r=0.65), and BUA (r=0.73). BUA correlated with lumbar (r=0.83) and femoral neck (r=0.87) density. Lumbar vertebral density predicted femoral neck density with a standard error of estimate (SEE) of 0.07 g/cm², and femoral neck density predicted lumbar density with a SEE of 0.09 g/ cm². BUA of the calcaneus was as effective as either axial bone mass measure in predicting the other value: the SEE for lumbar density was 0.09 g/cm² while that for femoral neck density was only 0.06 g/cm². The results of this preliminary study indicate that this rapid, radiation-free technique can accurately predict axial bone mass, and may be of value as an initial procedure to discriminate those women warranting more extensive radiologic evaluations.     

Comparison of broadband ultrasound attenuation to single X-ray absorptiometry measurements at the calcaneus in postmenopausal women

Broadband ultrasound attenuation (BUA), a radiation-free and portable technology, may be useful in assessing bone density and fracture risk. In this study, we compared cross-sectional BUA measurements to the more established single energy X-ray absorptiometry measurements of bone mineral density (BMD) at the calcaneus in 259 healthy postmenopausal women, aged 45–76 years. Paired measurements with repositioning of the subject's dominant heel were made consecutively by each method. A coefficient of variation (CV) for each method was calculated for each individual from the paired scans. BUA and BMD of the heel were also compared with BMD of the lumbar spine and femoral neck, as measured by dual energy X-ray absorptiometry. BUA was significantly correlated with BMD at the calcaneus (r=0.66, P<0.01). Heel BUA was also correlated with lumbar spine BMD (r=0.43, P<0.01) and femoral neck BMD (r=0.43, P<0.01) but the correlations were lower than those between heel BMD and spine (r=0.63, P<0.01) or femoral neck BMD (r=0.62, P<0.01). The mean CV for heel BUA (3.60±3.50%) was significantly greater than that for heel BMD (1.06±0.99%, P<0.01). The moderate correlation of calcaneal BUA and BMD, the lower correlations of BUA than heel BMD with both spine and hip BMD, and lower precision of BUA indicate BUA does not predict bone density as effectively as absorptiometry, the current standard methodology.The contents of this publication do not necessarily reflect the views or policies of the U.S. Department of Agriculture, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government.     

Biochemical bone markers compared with bone density measurement by dual energy X-ray absorptiometry

In contrast to medical imaging, the biochemical markers allow a more frequent determination and are not as invasive as histomorphometric methods. We investigated biochemical markers of type I collagen compared with bone density measurements in 85 females between 41 and 89 years of age (median: 57 years). The bone density measurements were performed by dual-energy X-ray absorptiometry (DXA) on the lumbar spine (L_1–4). The bone density measurements were stated as percentage of the norm. All patients were divided into three groups: I=<80%; II=80–120%; III=>120%. Based on this classification the median concentration of the I-carboxyterminal propeptide of type I procollagen in serum (S-PICP) as an anabolic marker of type I collagen increased significantly with rising bone density: I 65.0^* g/liter (interquartile range: 52.1–78.0 g/liter); II 85.9^* g/liter (52.1–115.5 g/liter); III 81.4 g/liter (62.0–101.0 g/liter); ^* P<0.05. The concentration of urinary pyridinolines (U-PYR) as a marker for degradation of type I collagen decreased. The I-carboxyterminal telopeptide (S-ICTP) and osteocalcin (S-BGP) did not change. The multivariate regression analysis showed no relationship between bone density measurement and biochemical bone markers. Only the age significantly correlated negatively with bone density measurement. For a better assessment of type I collagen metabolism we created a b-quotient by dividing the sum of S-PICP and S-BGP by U-PYR. The median b-quotient increased significantly: I 1.55^*+ (0.97–2.04); II 2.09^* (1.57–2.86); III 2.46⁺ (1.58–3.22);^*+ P<0.05. Changes in bone metabolism cannot be identified by the determination of a single marker. However, the improved biochemical diagnostic measurement using the b-quotient may provide early information about the progression of a metabolic disorder within the interval of imaging.     

Relations between calcidiol serum levels and bone mineral density in postmenopausal women with low bone density

The relationship between vitamin D and bone density was studied in 150 selected, mature (45–74), postmenopausal women with a lumbar spine Z score below 0. Vitamin D status was evaluated using calcidiol serum levels. Serum calcitriol and parathyroid hormone (PTH) values were also evaluated in some subjects. Bone mass was evaluated by ascertaining bone density and Z and T scores in the lumbar spine and femur region. The reference group consisted of 25 premenopausal women. The postmenopausal group was divided into subgroups according to age, i.e., under or over 60 years old. Additionally, the whole group was also subdivided according to their lumbar spine Z scores into group I (Z>-1), group II (Z<-1; >-2), and group III (Z<-2). Group III of postmenopausal women had higher PTH and lower calcitriol levels than premenopausal women. Calcidiol serum levels were lower in postmenopausal women groups II or III than in the group I and premenopausal women. Calcidiol serum levels and the bone mass values for the lumbar spine were correlated positively in all the postmenopausal women; in the women over 60 years of age, calcidiol levels also correlated with the bone mass values expressed as the bone density in three femur regions: femoral neck, trocanter, and Ward's triangle. In conclusion, mature postmenopausal woman showed high PTH levels and low calcidiol and calcitriol values. Calcidiol status is significantly related to bone mineral density in the lumbar spine and in women over 60 years, calcidiol levels also correlated with bone density in the femur regions.     

A high dietary calcium intake is needed for a positive effect on bone density in Swedish postmenopausal women

The importance of dietary calcium for bone health is unclear, partly since most investigations have dealt only with a fairly narrow range of calcium intake. In the present population-based observational study with longitudinal dietary assessment, we investigated women with a mean age of 60 years and with a consistently high (range 1417–2417, mean 1645 mg,n=40), intermediate (800–1200, mean 1006 mg,n=35) or low (400–550, mean 465 mg,n=40) estimated daily consumption of calcium. Measurements of bone mineral density (BMD) of the lumbar spine, femoral neck and total body were performed by dual-energy X-ray absorptiometry, as well as ultrasound of the heel. In a multivariate analysis, with adjustment for energy intake the risk factors for osteoporosis (age, body mass index, physical activity, menopausal age, use of estrogens, smoking and former athletic activity), the group with the highest calcium intake had higher values for BMD than the others at all measured sites. The average mean difference compared with the low and the intermediate calcium group was 11% for the femoral neck, 8–11% for the lumbar spine and 5–6% for total body BMDs. In univariate analyses and multivariate models which did not include energy intake, the differences between the groups were less pronounced. The women in the intermediate calcium group had approximately the same mean BMD values as those in the low calcium group. These findings support the view that only a high calcium intake (3% highest percentiles in the studied population) protects against osteoporosis in Swedish postmenopausal women.     

Ultrasound and dual X-ray absorptiometry densitometry in women with hip fracture

To assess the usefulness of the measurement of the os calcis by ultrasound, a method that probably reflects bone quality as well as density, we have studied 54 women with hip fracture of the proximal femur and a control group. Ultrasound evaluation of the os calcis [broadband ultrasound attenuation (BUA), speed of the sound (SOS), and a combined index (stiffness)], and bone mineral density (BMD) determination over the proximal femur by dual X-ray absorptiometry (DXA) were performed. Weight, BMD, and ultrasound values in the hip fracture patients were significantly lower than controls (P<0.001). The Z-scores for BUA and stiffness were not different than that for femoral neck. Ward's triangle or trochanteric BMD (between-1.7 and -1.5). The odds ratios determined by receiver-operating characteristics (ROC) analysis were greater at the femoral neck (25.1) and BUA (24.4). Intermediate values were found at stiffness (16.9), Ward's triangle (12.8), and trochanter (11.1), and lower values were obtained at SOS (4.2). In turn, patients with trochanteric hip fractures had a significantly lower femoral neck and Ward's triangle BMD, stiffness, and BUA than patients with cervical hip fractures. Comparing a subgroup of 30 women with hip fractures without vertebral fractures with an age-matched group of 87 women with osteoporotic vertebral fractures, both groups were of similar weight and BMD but all ultrasound values were significantly lower in the hip fractures compared with vertebral fracture patients (P<0.05-P<0.01). Our findings suggest that in women with hip fractures, ultrasound evaluation of the os calcis has diagnostic sensitivity comparable to DXA of the femur and could be useful to predict hip fracture risk. Ultrasound values are lower in hip fractures compared with vertebral fracture, age-matched women and in older compared with younger hip fracture patients.     

Bone mineral density measured by dual-energy X-ray absorptiometry in healthy finnish women

Summary A cross-sectional study of 351 healthy Finnish women aged 20–76 years was done to establish reference values of bone mineral density (BMD) using dual-energy X-ray absorptiometry (DEXA). The effects of age and of several physical and lifestyle factors on BMD of the lumbar spine and proximal femur (femoral neck, trochanter, and Ward's triangle area) were investigated. Altogether 58 women were excluded from the final analysis due to significant spinal osteoarthritis or other diseases or drugs known to influence calcium or bone metabolism. The precision of the method was 0.9, 1.2, 2.7, and 2.4% in the lumbar, femoral neck, Ward's triangle and trochanter area, respectively. Lumbar BMD was increased by 30% (P<0.001) in 15 patients with osteoarthritis (21% of women 50 years or older), but it was apparently unaffected in 5 cases with aortic calcification. Except for the trochanter area, BMD diminished along with age, and this was significant after the menopause. The peak of mean BMD was observed at the age of 31–35 years in the spine and at the age of 20–25 years in the femoral neck and Ward's triangle. BMD was in a positive relationship to weight both in premenopausal and postmenopausal women and to the use of oral contraceptives in premenopausal women and to that of estrogen replacement therapy in postmenopausal women. Labors and pregnancies had a weak positive effect on BMD in premenopausal women. As compared with nonusers premenopausal women who had used alcohol showed a slightly decreased BMD of Ward's triangle. In postmenopausal women there was a positive correlation between alcohol intake and BMD.     

双能X线骨密度测定腰椎和股骨颈对诊断骨质疏松检出率的比较

目的探讨双能X线吸收法测量腰椎及股骨颈两个不同部位骨密度对骨质疏松诊断的检出率,寻找灵敏度高、更经济实用的筛查骨质疏松的有效方法方法 2011年1月至2012年12月在我院妇科及老年病科住院的女性患者共732人,分别测量腰椎及股骨颈的骨密度T值,进行SPSS统计研究。结果对同一人群通过股骨颈和腰椎不同部位检测发现骨质疏松的检出率分别为25.4%,32.0%;严重骨质疏松的检出率分别为9.0%,27.9%;两者之间差异有统计学意义(P=0.001),腰椎骨密度测量对骨质疏松诊断检出率明显优于股骨颈。根据4个年龄组的股骨颈和腰椎的骨密度T值比较差异均有统计学意义(P均0.01)。结论采用双能X线骨密度测定对诊断骨质疏松腰椎明显优于股骨颈。     

A comparison of two dual-energy X-ray absorptiometry systems for spinal bone mineral measurement

Summary Two dual-energy X-ray absorptiometry (DEXA) systems—the Hologic QDR-1000 and the Norland XR-26 bone densitometers—were evaluated in terms of precision, accuracy, linearity of response, X-ray exposure, and correlation of in vivo spinal measurements. In vitro precision and accuracy studies were performed using the Hologic anthropomorphic spine phantom; linearity of response was determined with increasing thicknesses of aluminum slabs and concentrations of Tums E-X in a constant-level water bath. Both systems were comparable in precision, achieving coefficients of variation (CVs) of less than 1% in bone mineral content (BMC, g), bone area (cm²), and bone mineral density (BMD, g/cm²). Both were accurate in their determination of BMC, bone area, and BMD with reference to the Hologic spine phantom. Both systems also showed good BMC and BMD linearity of response. Measured X-ray skin surface exposures for the Hologic and the Norland systems were 3.11 and 3.02 mR, respectively. In vivo spinal measurements (n=65) on the systems were highly correlated (BMC: r=0.993, SEE=1.770 g; area: r=0.984, SEE=1.713 cm²; BMD: r=0.990, SEE=0.028 g/cm²). In conclusion, both systems are comparable in terms of precision, accuracy, linearity of response, and exposure efficiency.     

定量超声和双能X线骨密度测定诊断骨质疏松的比较

目的通过对同一个人的跟骨超声强度（STI）测量与双能X线吸收法（DEXA）测量腰2-4、股骨近端骨密度（BMD）的临床对比,评价定量超声骨质测量仪（QUS）跟骨STI的测量,对诊断骨质疏松（OP）的敏感性和与DEXA测量BMD的相关性.方法对3266名20～89岁健康人群同时采用DEXA测量L2-4、右股骨近端（Neck、Ward、Troch）BMD和QUS测量右跟骨STI值进行相关分析.结果峰值骨量男性STI与BMD均出现在20～29岁,女性STI出现在20～29岁,BMD则出现在30～39岁;随年龄的增加腰椎、股骨近端BMD及超声强度均下降,女性在50岁后,男性在70岁后有个显著下降过程;OP检出率两种仪器无明显差异.在健康人中BMD与STI的相关系数（R=0.21-0.26）,骨质疏松患者BMD与STI的相关系数（R=0.14-0.24）.结论DEXA测量的BMD与QUS测量的STI无相关关系.这表明QUS主要测量骨的结构,而DEXA则是测量骨量的变化,两者相辅相承,共同测量能更好地监测骨质疏松、预测OP性骨折的发生.     

阿伦膦酸盐对绝经后骨质疏松妇女骨密度的影响

为了解阿伦膦酸盐对骨密度的影响及其安全性和耐受性,对２０名绝经后骨质疏松的妇女中进行阿伦膦酸盐（ａｌｅｎｄｒｏｎａｔｅ）１０ｍｇ／天和安慰剂的随机、双盲、前瞻性研究,为期一年。结果显示,１年后阿伦膦酸盐组与安慰剂组相比,骨密度平均增长率：椎骨分别为４．８７％与－０．２３％;股骨颈分别为６．８９％与－１．８４％,（Ｐ＜０．０５）。副反应仅为轻微胃肠道反应。结论：阿伦膦酸盐能有效增加骨密度,且药物安全,耐受性好     

Dual-energy X-ray absorptiometry of the calcaneus: Comparison with vertebral dual-energy X-ray absorptiometry and quantitative computed tomography

The purpose of this study was to determine the efficacy of using bone mineral measurements of the calcaneus to evaluate osteoporosis. Dual energy X-ray absorptiometry (DXA) of the calcaneus was compared with posteroanterior lumbar absorptiometry (DXA) and vertebral quantitative computed tomography (QCT) measurements in 171 white women (78 normal and 93 osteoporotic). DXA measurement of os calcis mineralization decreased significantly in osteoporosis, but to a lesser extent than in vertebral sites. In normal subjects, good correlations were observed between calcaneal and lumbar DXA (0.69) and QCT (0.56). In subjects with vertebral fractures, there was also good correlation between calcaneal DXA and QCT (0.59–0.69). This suggests that trabecular bone in calcaneus and vertebrae have related involution in cases of vertebral osteoporosis. However, the extent of bone loss is less marked in the calcaneus than in the vertebrae and is not sufficient to be accurately measured over time. We conclude, therefore, that although the global densitometric measurement at this site is not sufficiently sensitive for general use, it can be useful as a epidemiological research tool.