A comparison of quantitative dual-energy radiographic absorptiometry and dual photon absorptiometry of the lumbar spine in postmenopausal women

Summary Noninvasive bone densitometry is an important aspect in the detection and management of osteoporosis and other forms of metabolic disease of calcified tissue. A system using quantitative dual-energy digital projection radiography (QDR) of the lumbar spine was systematically tested against dual-photon absorptiometry (DPA) of the lumbar spine in 131 women over 55 years of age and free from major risk factors for osteoporosis. All subjects were scanned by both QDR and DPA under the same conditions. Measurements for a given subject were made within 15 minutes of each other. Bone mineral densities (BMD) were determined for four individual levels in the lumbar spine (L1-L4). Regression equations for BMD vs. age, height, and weight were calculated. The results of this investigation indicate that DPA- and QDR-derived BMD values are comparable. BMD values derived by QDR were consistently lower than those obtained by DPA (DPA=1.115 QDR+0.137, r=0.942). The L2 lumbar region was the most strongly correlated determination.     

应用双能CT与定量CT对椎体骨密度测量的对照研究

目的应用双能CT(DECT)及定量CT(QCT)测量腰椎骨密度,评价利用双能CT测量骨密度(BMD)的可行性。方法对56名志愿者采用DECT检查,获得钙值图,测量骨钙CT值及骨髓CT值,同时应用QCT测量骨密度(BMD),分析骨钙CT值及骨髓CT值与BMD值的相关性。结果腰椎椎体骨钙CT值与BMD值呈显著正相关(L1-5椎体Pearson相关系数分别为:r=0.715,0.692,0.739,0.673,0.686,P0.01);骨髓CT值与BMD值呈正相关(L1-5椎体Pearson相关系数分别为r=0.343、0.315、0.439、0.440、0.456,L5椎体P0.05,其余椎体P0.01)。结论 DECT所测量腰椎骨钙CT值及骨髓CT值与QCT所测BMD值密切相关,可定量反映腰椎BMD变化。     

Normative values of lumbar spine mineral density and fracture threshold in Japanese measured by dual photon absorptiometry based on scinticamera methods (Dualomex HC-1)

Using a dual photon absorptiometer Dualomex HC-1 based on the scinticamera system utilizing¹⁵³Gd, bone density of the lumbar vertebrae was measured to set up normative values for each group in both sexes along with fracture threshold. Bone density of the lumbar spine was measured in 712 male and female subjects ranging in age between 16 and 96 years at 11 medical instructions all over Japan, to establish normative values for each age and sex group. The peak bone mass of 0.75 g/cm² was reached in the 30s in males and that of 0.76 g/cm² in the 40s in females. The lumbar spine density obtained by this method showed good parallelism with the Singh index and degree of lumbar spine bone loss according to Jikei University method. A high correlation was also found between the bone density obtained by this method and that obtained by Lunar DP-4 (r=0.902, n=28). Spinal compression fracture was found in about 2/3 of the subjects with L2 – L4 bone density measured in the anterior-posterior direction of less than 0.58 g/cm² and 3/4 of those with the corresponding value less than 0.49 g/cm². Bone density less than 0.49 g/cm² was therefore tentatively called the range predicting fracture (dangerous range) and that between 0.49 and 0.58 as the range warning fracture (warning range).     

Vertebral and total body bone mineral content by dual photon absorptiometry

Conclusions Techniques have been developed using dual-photon absorptiometry for precise and accurate measurement of bone mineral content in the lower spine and in the total body. A spinal measurement requires only 20 min and a total body scan about 60 min. The dose from these measurements is very low allowing them to be repeated at frequent intervals. We feel these improved techniques will prove of great value both for examining the skeleton in normal populations and for evaluation of osteoporosis and other skeletal abnormalities.     

Lumbar spine bone measurements in infants: whole-body vs lumbar spine dual X-ray absorptiometry scans.

Availability of software delineation of the lumbar spine region from infant whole-body (IWB) dual energy X-ray absorptiometry scan offers an opportunity to gain additional information at the lumbar spine without a separate scan, although the validity of this technique has never been tested. Lumbar spine measurements derived from IWB scans using software-delineated first to fourth lumbar vertebrae, and from specific infant spine (IS) scans, were determined in 111 infants using two pencil-beam densitometers. Intraoperator repeatability determined by reanalysis of 10 pairs of IWB and IS scans from each densitometer. Lumbar spine area, bone mineral content, and bone mineral density from IWB and IS scans were significantly correlated r = 0.68-0.95, p < 0.001 for all comparisons) but show poor agreement (Bland-Altman method) with one SD of the differences equal to 26-55% of the mean. Intraoperator reanalysis shows good agreement with one SD of the differences from IWB scans at <7% of the mean, and <2.9% from IS scans. Findings were the same for both densitometers. We conclude that lumbar spine bone measurements from IWB or IS scans are highly reproducible and significantly correlated but data from IWB scans cannot substitute for data from IS scans.     

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。     

Total and regional bone mineral density by dual photon absorptiometry in patients on maintenance hemodialysis.

To evaluate bone loss in renal osteodystrophy, we measured total and regional (head, trunk, pelvis, leg and arm) bone mineral density (BMD) by dual photon absorptiometry in 72 patients on maintenance hemodialysis (HD). We also examined the validity of serum carboxy-terminal parathyroid hormone (C-PTH) and intact-PTH as an indicator of secondary hyperparathyroidism. Total BMD correlated inversely with age in female patients (r = -0.57, p less than 0.01), but not in male patients. Female patients older than 50 years were omitted from analysis to exclude the effect of menopause on bone. Among clinical and biochemical parameters, only trunk BMD correlated inversely with the duration of HD (r = -0.26, p less than 0.05). Head, trunk and total BMD correlated inversely with serum alkaline phosphatase, C-PTH and intact-PTH, while pelvis BMD did not. Leg and arm BMD also correlated inversely with serum intact-PTH, but not with serum C-PTH. The serum level of C-PTH correlated positively with the duration of HD (r = 0.40, p less than 0.005), while intact-PTH did not. As compared with 18 control male volunteers aged 25-42 years, trunk, pelvis, leg, arm and total BMD were significantly lower in male patients on HD aged 22-49 years, whereas head BMD did not differ significantly between the two groups. The percent decrease of BMD was most prominent in the trunk (-19.6%, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Bone mineral content by photon absorptiometry of the mandible compared with that of the forearm and the lumbar spine

Summary A new method for measuring the bone mineral content (BMC) of the mandible by dualphoton absorptiometry (DPA) has recently been introduced. The purpose of the present investigation therefore was to examine the long-term precision for 32 monthsin vitro andin vivo for assessment of BMC in the mandible and to examine the relationshipin vivo among BMC of the mandible, the forearms, and the lumbar spine as measured by DPA and/or single-photon absorptiometry (SPA). For comparison, the relationship between forearm BMC as measured by DPA and SPA was studied. The long-term precision of the mandibular BMC was 0.8%in vitro, independent of age and change of radioactive source, and 2.1% by assessmentin vivo. A significant relationship (P<0.01) was found between BMC of the lumbar spine and the forearms and between the two sets of forearm BMC measured by DPA and SPA. Thus, relative BMC changes of the forearms can be compared without respect to type of forearm bone scanner used. The BMC changes of the mandible can only be evaluated by scanning of the mandible itself. The present DPA bone scanner is suitable for follow-up analyses of the BMC changes of the mandible and the forearms.     

双能X线和单光子吸收法及定量超声诊断骨质疏松症的比较

了解三种方法诊断骨质疏松症（ＯＰ）之间的关系。方法应用双能Ｘ线吸收法（ＤＸＡ）和单光子吸收法（ＳＰＡ）及定量超声（ＱＵＳ），同时随机测量２９４例受试者腰椎后前位和侧位、左侧髓部和前臂骨矿密度（ＢＭＤ）及右侧胫骨超声速度（ＳＯＳ）。结果ＤＸＡ和ＳＰＡ测量桡骨ＯＰ的检出率分别为２５．９％和２１．４％，ＤＸＡ测量腰椎后前位、侧位、侧位兴趣区、Ｗａｒｄ’ｓ区和股骨颈ＯＰ检出率分别为１６．０％、２２．８％、２６．２％、１９．４％和４．４２％，ＱＵＳ的ＯＰ检出率为１７．７％。三种方法及不同部位之间的测量结果呈显著相关（ｒ＝０．４９４～０．９６７，Ｐ＜０．０１）。ＤＸＡ测量前臂１／３处ＢＭＤ显著高于ＳＰＡ。诊断ＯＰ的齐同率ＤＸＡ各部位相互之间平均为４０．１％±１５．５％，ＤＸＡ与ＳＰＡ平均为４８．４％±１９．０％，ＱＵＳ与ＤＸＡ和ＳＰＡ平均为３８．８％±１０．２％，各平均值之间无显著差异。结论ＯＰ的检出率取决于受检部位，腰椎侧位兴趣区和挠骨是检出率最高的部位，股骨颈和尺骨是最低的部位。ＳＰＡ与ＤＸＡ测量前臂ＢＭＤ高度相关，诊断结果无显著性差别。     

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。     

Comparative study of a biochemical index for the estimation of bone demineralization and dual photon absorptiometry

Multivariate classification methods were used to create an early detection technique for determining bone density. This biochemical index (QuiOs) is clinically useful as a potential adjunct in identifying the presence of biochemical deficiencies known to cause osteopenia and the devastating effects of osteoporosis. The test uses the following serum concentrations of a predetermined set of blood constituents: calcium, phosphorus, alkaline phosphatase (ALP), two alkaline phosphatase isoenzymes (liver and intestine), estradiol, and progesterone. Using the results of these six biochemical and hormonal tests, a correlation equation was developed that demonstrates a nonlinear relationship between QuiOs and Ward's triangle of DPA. A sensitivity of 86% and a specificity of 80% was demonstrated for this biochemical index against DPA in this clinical trial.     

Comparative assessment of bone mineral density of the forearm using single photon and dual X-ray absorptiometry

Summary Forearm bone mineral density (BMD) was measured at proximal and distal sites by ¹²⁵I single photon absorptiometry (SPA) and by dual energy X-ray absorptiometry (DXA) in 67 consecutive subjects, aged 18–75 years. Correlations and regression equations between these two techniques were determined. All forearm measurements were significantly correlated with each other (r=0.599–0.926; P0.0001). Although SPA and DXA correct for fat in different ways, we found similar correlation and regression equations in women with body mass index measurements above and below the mean. In addition, forearm measurements by both techniques were moderately correlated with vertebral spine and hip BMD. We conclude that overall, SPA forearm measurements in a population can be calibrated to DXA measurements if necessary, and that DXA forearm measurements are as predictive of the remainder of the skeleton as SPA measurements.     

Effect of calcitonin on total body bone mineral contents of experimental osteoporotic rats determined by dual photon absorptiometry

Summary Total body bone mineral (TBBM) content in rats was measured by dual photon absorptiometry (DPA). TBBM showed significant increases over 4 weeks in control groups with significant bone loss over the same time in prednisolone-injected rats on low calcium feed. Daily injections of calcitonin significantly reduced loss of bone mass. Both prednisolone- and prednisolone-calcitonin-injected groups showed significantly elevated serum alkaline phosphatase with the prednisolone-calcitonin group also exhibiting elevated serum calcium and phosphate levels, confirming the impact of the experimental protocol. TBBM measured by DPA in all groups correlated well (r=0.928,P<0.001 n=20) with the total ash weight suggesting that the method reflects total skeletal mineral content in the small animal. TBBM measurement by DPA proves well-suited to monitoring bone mineral in a small animal experimental setting.     

Stone fragility--measurement of stone mineral content by dual photon absorptiometry.

We measured the mineral content of urinary tract stones by dual photon absorptiometry, which is widely used for the analysis of bone mineral content, and compared the values of the stones by dual photon absorptiometry (DPA values) with the results of an in vitro fracture study as well as those of an in vivo extracorporeal shock wave lithotripsy treatment study. The results of a preliminary experiment showed that the DPA values of 20 urinary tract stones reflected actual stone mineral content. As a result of the in vitro fracture study, the DPA value calculated by volume of a struvite stone, which was the most easily disintegrated, was the lowest (0.53 g/cm3). The DPA values of calcium oxalate monohydrate and apatite stones, which poorly disintegrated, were the highest (0.98, 1.01 g/cm3). The DPA value of calcium oxalate dihydrate, which moderately disintegrated, was 0.86 g/cm3. By the in vivo extracorporeal shock wave lithotripsy treatment study, the total DPA values of stones measured before extracorporeal shock wave lithotripsy treatment in 12 patients were 0.73 +/- 0.34 g in successful cases and 1.92 +/- 0.43 g in unsuccessful cases with a significant difference between the two (p less than 0.05). These results showed that the measurement of stone mineral content by dual photon absorptiometry was useful in predicting the fragility of stones against shock waves before performing extracorporeal shock wave lithotripsy treatment for patients with urinary tract stones.     

Evaluation of lumbar spine bone mineral density in the anteroposterior and lateral projections by dual-energy X-ray absorptiometry.

Dual-energy x-ray absorptiometry (DXA) is an established method for estimating bone mineral density (BMD) of the lumbar spine. In a prospective study, the sensitivity of BMD measurements between anteroposterior and lateral projections were evaluated in 204 postmenopausal women based on their DXA analysis. Patients were divided into two groups according to the absence or presence of lumbar scoliosis. Lateral projection DXA measurements were more sensitive than AP projection measurements for early detection of bone loss in postmenopausal women. Lateral projection DXA analysis is not recommended in spines with lumbar scoliosis.     

Relationships between bone structure in the iliac crest and bone structure and strength in the lumbar spine

The purpose of this study was to examine the relationship between histomorphometric variables of cancellous bone structure and ultimate compressive strength (UCS) in the second lumbar vertebra (L2) and to determine whether structural variables in the iliac crest are predictive of the same variables and of UCS in L2. At autopsy, 7.5 mm diameter cores were removed from the iliac crest and from L2 of 29 subjects who had died suddenly without bone disease. Cancellous bone volume (BV/TV, %) was significantly lower in L2 than in iliac crest due to lower trabecular number (Tb.N, per mm) and thickness (Tb.Th, µm). There were significant correlations between iliac crest and L2 for BV/TV, Tb.N and trabecular separation (Tb.Sp, µm), but not for Tb.Th. BV/TV was negatively correlated, and Tb.Sp was positively correlated with age at both sites. Tb.Th was not significantly correlated with age in the iliac crest, but a significant negative correlation was observed in L2. The UCS of vertebral cores was negatively correlated with age. BV/TV and Tb.Th in L2 were positively correlated with UCS in L2. Cortical width and BV/TV in iliac crest were positively correlated with UCS in L2. We conclude that: (1) cancellous bone volume in the iliac crest is higher than in the lumbar spine due to thicker, more closely spaced trabecular plates, (2) the changes in structural variables with age are generally similar in the iliac crest and lumbar vertebra, but trabecular thinning with age is more evident in the spine than in the ilium, and (3) the compressive strength of cancellous bone in the lumbar spine is correlated with histomorphometric variables of bone structure, as measured both in the lumbar spine and in the iliac crest.     

单能与双能X线吸收法测量骨密度的比较

应用单能Ｘ线测量（ＳＸＡ）及双能Ｘ线测量（ＤＥＸＡ）法测量北京地区正常妇女骨密度，对两种方法进行比较，以选择反映骨丢失敏感的部位。共测量３００名，年龄为２０～７９岁，每岁５名，测量部位分别为ＳＸＡ法的非优势前臂远端（８ｍｍ－Ｄ）、１／４远端（１／４－Ｄ）、超远端（Ｕｌｔｒａ－Ｄ），ＤＥＸＡ法的腰椎正位（Ｌ２－４）、右股骨颈（Ｎｅｃｋ）、Ｗａｒｄ＇ｓ三角（Ｗａｒｄ）及粗隆区（Ｔｒｏｃｈ），两种方法各有１０名妇女进行了仪器重复性检验。Ｎｅｃｋ、Ｗａｒｄ骨密度峰值分布在２０～２９岁，Ｕｌｔｒａ－Ｄ、Ｌ２－４ＢＭＤ分布在３０～３９岁，８ｍｍ－Ｄ、１／４－Ｄ、Ｔｒｏｃｈ分布于４０～４９岁年龄组。所有部位ＢＭＤ在峰值后随年龄增长逐渐降低，８ｍｍ－Ｄ年下降率最高（１．１６％）。两种方法测得７个部位ＢＭＤ值之间均有显著相关。与绝经前相比，绝经后妇女各部位ＢＭＤ值下降迅速，尤以绝经后１１～１５年内显著，其中Ｗａｒｄ三角下降率最高为４２．９％。     

Intersample variation in bone histomorphometry: Comparison between parameter values measured on two contiguous transiliac bone biopsies

Summary In order to evaluate the intersample variations for bone histomorphometric parameters in various metabolic bone diseases, either for a group or for one single patient, two complete contiguous transiliac bone biopsies were taken in 55 subjects. The diagnoses were osteoporosis (OP), renal osteodystrophy (ROD), osteomalacia (OM), primary hyperparathyroidism (HPT), metastatic bone disease, fluorosis, thyrotoxic bone, and “normal” bone. The following histomorphometric parameters were measured: trabecular bone volume (TBV), trabecular osteoid surfaces (TOS) and volume (TOV), trabecular resorption surfaces (TRS), and calcification rate (CR). The thickness index of osteoid seams (TIOS) was calculated. The measurements were performed with both manual and computerized methods which give similar results according to our previous study. The differences between parameters values measured on both cores were expressed by the difference in percent of the mean and by the intrapair coefficient of variation. Moreover, for each parameter, the confidence interval for one subject was calculated from the residual mean square of a two-way analysis of variance. For each parameter, the intersample variation differs according to the diagnosis. Confidence interval (risk=5%) for one single subject reaches 29% for TBV in OP; 16% for TOS; 26% for TOV and TIOS in OM; 25% for TRS in ROD, and 69% in HPT, but is much lower for groups of 10 and 20 patients. These variations must be taken into account when successive biopsies are performed in one individual or in groups of patients to follow the course of a disease or evaluate the effects of a therapy.     

Factors influencing short-term precision of dual X-ray bone absorptiometry (DXA) of spine and femur

In this study we analyzed the effect of variations in bone area size, baseline soft tissue composition represented by the R-value, and bone region of interest positioning on the precision in vivo of bone mineral density (BMD) and content (BMC) as measured by dual X-ray absorptiometry (DXA). The posterior-anterior (PA) spine, decubitus latcral, and femur modes were evaluated. Eleven (PA-spine), 9 (dec-lat), and 14 (femur) postmenopausal women were scanned twice on a Norland XR-26 with repositioning to determine short-term precision of BMD, BMC, AREA, and the R-value. Phantom precisions (CV[%] of 10 consecutive scans) for BMD (BMC) were PA spine: 0.66% (0.57%), neck: 1.1% (1.2%), and trochanter: 0.55% (1.0%). Precisions in vivo (CV[%]; two consecutive scans averaged over all patients) were PA spine: 0.9% (1.0%), dec-lat: 7.1% (18%), neck: 1.3% (1.9%), and trochanter: 2.5% (4.9%). BMD precision could be fully explained by BMC and AREA variations. However, BMC alone was a particularly poor predictor of BMD in the dec-lat (r²=0.05) and in the neck (r²=0.13) modes. AREA was a strong predictor for BMC precision explaining between 41% and 88% of the BMC changes. Changes in soft tissue composition contributed significantly in explaining the BMC changes in the dec-lat projection. A higher dependence of BMC changes on AREA changes resulted in a larger difference between BMC and BMD precision. Thus, particularly in the femur and in the decubitus lateral modes, the use of BMD is advantageous compared with BMC.