Economic comparison of diagnostic approaches for evaluating osteoporosis in older women

Of the technologies available, dual-energy X-ray absorptiometry of the hip or femoral neck (DXA-FN) is the best predictor of hip fractures. Diagnostic approaches utilizing measures of peripheral sites with office-based technology, such as calcaneal quantitative ultrasound (QUS), may reduce costs although clinical and economic outcomes have not been evaluated. The objective was to compare three approaches for diagnosing osteoporosis in older women. The design was a decision-analytic model using diagnostic measures and clinical and economic outcomes from the Study of Osteoporotic Fractures, a prospective cohort of older white women that measured BMD and QUS and assessed fracture outcomes. The setting and patients were a hypothetical cohort of older white women presenting for diagnosis of osteoporosis. For the diagnostic and treatment alternatives, three diagnostic approaches—DXA-FN alone, QUS alone and a sequential approach (first QUS, then DXA-FN for those with low values for QUS)—were compared to no diagnosis. The outcome measures were the number of women identified for treatment, number of hip fractures prevented following diagnosis and subsequent treatment, number of women needed to treat to prevent one hip fracture and total direct medical costs. The sequential approach identified fewer women to treat, prevented more hip fractures and incurred lower total costs than using DXA alone. Diagnosis with QUS alone identified more women to treat and incurred higher total costs than DXA alone under most conditions. Compared to other approaches for diagnosing osteoporosis, sequential use of QUS followed by DXA resulted in fewer women treated and lower total costs.This study was conducted by the Oregon Health and Sciences University Evidence-based Practice Center under contract to the Agency for Healthcare Research and Quality, contract no. 290-97-0018, task order no. 4, Rockville, Md. AHRQ Disclaimer: The authors of this report are responsible for its content. No statements in this report should be construed as the official position of the Agency for Healthcare Research and Quality or the US Department of Health and Human Services.     

Dual-energy X-ray absorptiometry of the spine in anteroposterior and lateral projections

Dual-energy X-ray absorptiometry (DXA) of the lumbar spine provides an estimation of the bone mineral content (BMC) corrected by the projected area of the spine and expressed in g/cm². This two-dimensional estimate of the bone mineral density (BMD) is influenced by the skeletal size, assessed by the subject's height. In order to obtain an estimate of the volumetric BMD, we measured BMC with a new DXA device (Sophos L-XRA) equipped with 24 detectors and a rotating arm, thus allowing scanning of the lumbar spine in both an anteroposterior (AP) projection and a lateral (LAT) projection with the patient in a supine position. Comparison between the results obtained on the third (L3) and fourth (L4) lumbar vertebrae with automatic or manual analysis showed that the best precision was obtained with the lateral measurement of L3 alone with an automatic soft tissue baseline determination. Results were expressed in g/cm² and in g/cm³ (by dividing the g/cm² value by the width (AP area divided by the height of the vertebra) of L3), and were compared with those obtained by conventional AP scanning of L2–4 (g/cm²). The in vivo precision error evaluated by triplicate measurements on 10 controls was 17 mg/cm² (1.96%) and 5.2 mg/cm³ (2.31%) for LAT L3 as compared with 13 mg/cm² (1.15%) for AP L2–4. Volumetric BMD (g/cm³) measurement, assessed in vitro on a calibrated hydroxyapatite phantom, and the absolute values obtained in normal women were similar to those obtained by quantitative computed tomography (QCT). In 39 healthy adults (27±4 years) BMD expressed in g/cm² was correlated with height (r=0.36 for AP L2–4 andr=0.39 for LAT L3;p<0.05 for both) but not with LAT L3 BMD expressed in g/cm³ (r=0.02; NS). The age-related bone loss between 30 and 80 years of age, derived from the normal values for 101 healthy women (age range 19–73 years) was 36% for AP L2–4, 52% for LAT L3 (g/cm²) and 60% for LAT L3 (g/cm³). In a group of 22 women with untreated postmenopausal vertebral osteoporosis (one or more non-traumatic vertebral crush fractures) the mean decrease in BMD, expressed as a percentage of the age-adjusted normal value, was more pronounced (p<0.001) for LAT L3 BMD (–21% in g/cm²,Z-score –1.08; –22% in g/cm³,Z-score –0.94) than for AP L2–4 BMD (–9%,Z-score –0.66). We conclude that: 1) BMD measurement restricted to the vertebral body of L3 can be achieved with a low precision error with this new DXA device; 2) it allows an estimate of the volumetric density (g/cm³) which does not seem to be influenced by skeletal size; 3) lateral BMD appears to be more sensitive than conventional AP scanning for assessing age-related bone loss and should be useful in the investigation of trabecular osteoporosis.     

1 G和模拟微重力下前列腺癌细胞PC-3对小鼠成骨样细胞MC3T3-E1增殖和活性的影响

目的　探讨1 G和模拟微重力条件下前列腺癌细胞分泌物对成骨细胞增殖和活性的影响,以期今后用于对抗微重力导致的骨质丢失以及常人的骨质疏松。　方法　1 G条件下,将小鼠成骨样细胞MC3T3 E1与人前列腺癌细胞PC 3分别接种在混合培养板的外室和内室中培养48 h, 用MTT法检测MC3T3 E1的增殖、用PNPP法检测MC3T3 E1 的碱性磷酸酶(ALP)活性。回转器模拟微重力条件下,将培养过PC 3的培养液加入到培养24 h的MC3T3 E1培养瓶中,培养瓶固定于回转器,转速20 r/min 下继续培养48 h 后,用MTT 法检测MC3T3 E1 的增殖、用PNPP 法检测MC3T3 E1的ALP活性。　结果　1 G条件下,与PC 3混合培养后,MC3T3 E1的增殖和ALP活性均较对照组有显著增加(P<0 05)。回转模拟微重力条件下MC3T3 E1 的增殖和ALP活性比静止对照组有显著下降(P<0 05),与微重力可导致骨质丢失的现象相一致。回转培养、加PC 3 培养液的MC3T3 E1的增殖和ALP活性比回转对照组有增加趋势,但不具统计学意义(P>0 05)。　结论　前列腺癌细胞确实分泌了某种因子可刺激成骨细胞的增殖和活性,模拟微重力条件的实验结果没有1 G条件的显著,这可能是实验方法不同所导致,有待进一步深入研究。     

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％。     

Alterations in hippocampal non-phosphorylated MAP2 protein expression in schizophrenia

Microtubule-associated proteins (MAPs) are central to the development of normal neuronal cytoarchitecture and have been suggested in previous studies to be altered in schizophrenia. We investigated hippocampal phosphorylated and non-phosphorylated MAP2 expression in schizophrenia in relation to neuronal orientation and interneuronal distance. One paraffin embedded mid-hippocampal block was obtained from each of 8 schizophrenic and 11 control postmortem brains and immunohistochemistry for the phosphorylated and non-phosphorylated forms of MAP2 performed. Within the corona ammonis (CA) subregions and the subiculum, we assessed densitometry readings for non-phosphorylated MAP2-positive neurones (MAP2-NP), and counted the number of neurones immunopositive for phosphorylated MAP2 (MAP2-P). Using image analysis computer software we measured interneuronal distances and neuronal orientation. While there were no overall alterations in densitometric density of MAP2-NP neurones in any hippocampal subregions, we found a left-sided increase in densitometric density of MAP2-NP neurones within the subiculum (F=8.740, P<0.021), and the CA1 (F=7.044, P<0.033) of schizophrenic subjects which were unrelated to age, postmortem interval or neuroleptic exposure. There was no accompanying alteration of interneuronal distances, neuronal orientation. The findings support previous work demonstrating altered subicular MAP2 expression in schizophrenia and indicate that the finding may be lateralised. However, in contrast to previous investigations, we have demonstrated this alteration in MAP2 expression is due to an increase in the non-phosphorylated form of MAP2, rather than a decrease in total MAP2 expression. These findings suggest that cytoskeletal assembly is abnormal in schizophrenia and generate testable hypotheses regarding the developmental basis of the disorder.     

阅片室内环境照度的检测与分析

目的参照DIN(多伊奇工业标准)6856等有关国际标准,对影响影像诊断质量因素之一的阅片室内环境(IRR)进行检测与分析。方法采用工业光度学测定方法,用风光牌ZF-2型照度计对山东省的省、地(市)、县三级医院共44个阅片室内的IRR进行检测,并进行统计学处理。结果(1)各级医院IRR普遍偏高,不合格率(按超过100LX计)45.45%;最严重者竟高达520lx,超过允许最大值(100lx)5倍多;(2)各级医院间IRR不合格率比较,无显著差异(X2=4.0813,P<0.05),即IRR的状况不因医院的升高而有所改善。(3)影像科室与非影像科室相比较,具有显著性差异(X2=4.0813,P<0.05),即非影像科室的IRR尤其不符合医学影像的诊断阅片要求。结论本检测结果表示:各级医院的IRR不合格率偏高,尤以影像科室为重,不符合现代医学影像的诊断阅片要求,难以保证诊断质量,亟待解决。     

Evaluation of Bone Mineral Density Using Three-Dimensional Solid State Phosphorus-31 NMR Projection Imaging

A solid state magnetic resonance imaging technique is used to measure true three-dimensional mineral density of synthetic hydroxyapatite phantoms and specimens of bone ex vivo. The phosphorus-31 free induction decay at 2.0 T magnetic field strength is sampled following application of a short, hard radiofrequency excitation pulse in the presence of a fixed amplitude magnetic field gradient. Multiple gradient directions covering the unit sphere are used in an efficient spherical polar to Cartesian interpolation and Fourier transform projection reconstruction scheme to image the three-dimensional distribution of phosphorus within the specimen. Using 3–6 Gauss/cm magnetic field gradients, a spatial resolution of 0.2 cm over a field of view of 10 cm is achieved in an imaging time of 20–35 minutes. Comparison of solid state magnetic resonance imaging with dual energy X-ray absorptiometry (DXA), gravimetric analysis, and chemical analysis of calcium and phosphorus demonstrates good quantitative accuracy. Direct measurement of bone mineral by solid state magnetic resonance opens up the possibility of imaging variations in mineral composition as well as density. Advantages of the solid state magnetic resonance technique include avoidance of ionizing radiation; direct measurement of a constituent of the mineral without reliance on assumptions about, or models of, tissue composition; the absence of shielding, beam hardening, or multiple scattering artifacts; and its three-dimensional character. Disadvantages include longer measurement times and lower spatial resolution than DXA and computed tomography, and the inability to scan large areas of the body in a single measurement, although spatial resolution is sufficient to resolve cortical from trabecular bone for the purpose of measuring bone mineral density. Received: 13 March 1997 / Accepted: 4 November 1997     

Performance of four clinical screening tools to select peri- and early postmenopausal women for dual X-ray absorptiometry

Several methods to select postmenopausal women for dual X-ray absorptiometry (DXA) have been proposed. We decided to compare the performance of three clinical decision rules (SCORE, ORAI, OST) with the usual case-finding strategy based on the presence of a major risk factor for future fracture (CFMRF). The study subjects were 2009 healthy, white, peri- or early postmenopausal women participating in the Danish Osteoporosis Prevention Study (DOPS). DXA results expressed as T-scores and scores on SCORE, ORAI, OST and CFMRF were extracted from the DOPS database. First, we evaluated the screening tools as originally described by the developers. The resulting sensitivities and specificities ranged from 18% to 92% and from 66% to 85%, respectively. Only OST achieved a high sensitivity (92%) with respect to femoral neck T-score –2.5; however, the sensitivity with respect to lumbar spine T-score –2.5 was only 51%. Next, the performance of the screening tools was evaluated against T-score –2.0 (and T-score –2.5) in at least one of the regions: femoral neck, total hip or lumbar spine. Using ROC curve analysis, we determined cut-offs yielding sensitivities as close as possible to 90%. The CFMRF and the ORAI tool were too coarse to yield 90% sensitivity. The performances of OST and SCORE were equal from a clinical perspective in that the sensitivities and the specificities varied from 89% to 94% and from 23% to 28%, respectively. The performance of CFMRF was no better than could be expected by chance, yielding a sensitivity of 19% and a specificity of 85%. Applying SCORE or OST 75% of the women would have to be referred for densitometry to identify 90% of the women with T-score –2.0 (or T-score –2.5) in at least one region. In conclusion, our results question the utility of all the evaluated tools for screening peri- and early postmenopausal women for low BMD. However, if a decision on referral has to be made, it may be based on the simple OST rule, which performed as well as or better than any of the other tools.     

Evaluation of changes in central airway dimensions,lung area and mean lung density at paired inspiratory/expiratory high-resolution computed tomography

The aim of this study was to improve the understanding of interdependencies of dynamic changes in central airway dimensions, lung area and lung density on HRCT. The HRCT scans of 156 patients obtained at full inspiratory and expiratory position were evaluated retrospectively. Patients were divided into four groups according to lung function tests: normal subjects (n=47); obstructive (n=74); restrictive (n=19); or mixed ventilatory impairment (n=16). Mean lung density (MLD) was correlated with cross-sectional area of the lung (CSA_L), cross-sectional area of the trachea (CSA_T) and diameter of main-stem bronchi (D_B). The CSA_L was correlated with CSA_T and D_B. MLD correlated with CSA_L in normal subjects (r=–0.66, p<0.0001) and patients with obstructive (r=–0.62, p<0.0001), restrictive (r=–0.83, p<0.0001) and mixed ventilatory impairment (r=–0.86, p<0.0001). The MLD correlated with CSA_T in the control group (r=–0.50, p<0.0001) and in patients with obstructive lung impairment (r–0.27, p<0.05). In patients with normal lung function a correlation between MLD and D_B was found (r=–0.52, p<0.0001). CSA_L and CSA_T correlated in the control group (r=0.67, p<0.0001) and in patients with obstructive lung disease (r=0.51, p<0.0001). The CSA_L and D_B correlated in the control group (r=0.42, p<0.0001) and in patients with obstructive lung disease (r=0.24, p<0.05). Correlations for patients with restrictive and mixed lung disease were constantly lower. Dependencies between central and peripheral airway dimensions and lung parenchyma are demonstrated by HRCT. Best correlations are observed in normal subjects and patients with obstructive lung disease. Based on these findings we postulate that the dependencies are the result of air-flow and pressure patterns.     

股骨双能X线骨密度仪测量及患病情况分析

目的 :了解江门市区正常人群股骨密度的变化特点 ,提高临床医生对骨质疏松症诊断的可预测性和可靠性。材料和方法 :采用法国产双能 X线骨密度仪测量 ,正常人群 72 9例中 ,男 376例 ,女 35 3例。分别作髋骨中股骨颈、沃氏三角区、大转子的测量。年龄范围为 10～ 89岁 ,每 10岁为一个年龄组进行统计分析。结果 :男、女股骨上端峰值骨量为2 0～ 2 9岁。各组骨密度值随年龄增长而下降。结论 :提供了江门市区正常人各年龄组股骨上端骨密度的正常数据及变化特点