Design of Time-Resolved Shifted Dual Transmission Grating Spectrometer for the X-Ray Spectrum Diagnostics

A new time-resolved shifted dual transmission grating spectrometer （SDTGS） is designed and fabricated in this work. This SDTGS uses a new shifted dual transmission grating （SDTG） as its dispersive component, which has two sub transmission gratings with different line densities, of 2000 lines/mm and 5000 lines/mm. The axes of the two sub transmission gratings in SDTG are horizontally and vertically shifted a certain distance to measure a broad range of 0.1-5 keV time-resolved X-ray spectra. The SDTG has been calibrated with a soft X-ray beam of the synchrotron radiation facility and its diffraction efficiency is also measured. The designed SDTGS can take full use of the space on a record panel and improve the precision for measuring spatial and temporal spectrum simultaneously. It will be a promising application for accurate diagnosis of the soft X-ray spectrum in inertial confinement fusion.

Prevalence and outcome of sarcopenia in non-alcoholic fatty liver disease

BACKGROUND Nonalcoholic fatty liver disease(NAFLD)includes a spectrum of conditions,progressing from mild steatosis to advanced fibrosis.Sarcopenia,characterized by decreased muscle strength and mass,shares common pathophysiological traits with NAFLD.An association exists between sarcopenia and increased NAFLD prevalence.However,data on the prevalence of sarcopenia in NAFLD and its impact on the outcomes of NAFLD remain inconsistent.AIM To analyze the prevalence and outcomes of sarcopenia in patients with NAFLD.METHODS We conducted a comprehensive search for relevant studies in MEDLINE,Embase,and Scopus from their inception to June 2023.We included studies that focused on patients with NAFLD,reported the prevalence of sarcopenia as the primary outcome,and examined secondary outcomes,such as liver fibrosis and other adverse events.We also used the Newcastle-Ottawa scale for quality assessment.RESULTS Of the 29 studies included,the prevalence of sarcopenia in NAFLD varied widely(1.6%to 63.0%),with 20 studies reporting a prevalence of more than 10.0%.Substantial heterogeneity was noted in the measurement modalities for sarcopenia.Sarcopenia was associated with a higher risk of advanced fibrosis(odd ratio:1.97,95%confidence interval:1.44-2.70).Increased odds were consistently observed in fibrosis assessment through biopsy,NAFLD fibrosis score/body mass index,aspartate aminotransferase to alanine aminotransferase ratio,diabetes(BARD)score,and transient elastography,whereas the fibrosis-4 score showed no such association.Sarcopenia in NAFLD was associated with a higher risk of steatohepatitis,insulin resistance,cardiovascular risks,and mortality.CONCLUSION This systematic review highlights the critical need for standardized diagnostic criteria and measurement methods for sarcopenia in NAFLD patients.The variability in study designs and assessment methods for sarcopenia and liver fibrosis may account for the inconsistent findings.This review demonstrates the multidimensional impact of sarcopenia on NAFLD,indicating its importance beyond liver-related events to include cardiovascular risks,mortality,and metabolic complications.

Evaluation of the dual vascular supply patterns in ground-glass nodules with a dynamic volume computed tomography

BACKGROUND In recent years,the detection rate of ground-glass nodules(GGNs)has been improved dramatically due to the popularization of low-dose computed tomography(CT)screening with high-resolution CT technique.This presents challenges for the characterization and management of the GGNs,which depends on a thorough investigation and sufficient diagnostic knowledge of the GGNs.In most diagnostic studies of the GGNs,morphological manifestations are used to differentiate benignancy and malignancy.In contrast,few studies are dedicated to the assessment of the hemodynamics,i.e.,perfusion parameters of the GGNs.AIM To assess the dual vascular supply patterns of GGNs on different histopathology and opacities.METHODS Forty-seven GGNs from 47 patients were prospectively included and underwent the dynamic volume CT.Histopathologic diagnoses were obtained within two weeks after the CT examination.Blood flow from the bronchial artery[bronchial flow(BF)]and pulmonary artery[pulmonary flow(PF)]as well as the perfusion index(PI)=[PF/(PF+BF)]were obtained using first-pass dual-input CT perfusion analysis and compared respectively between different histopathology and lesion types(pure or mixed GGNs)and correlated with the attenuation values of the lesions using one-way ANOVA,student’s t test and Pearson correlation analysis.RESULTS Of the 47 GGNs(mean diameter,8.17 mm;range,5.3-12.7 mm),30(64%)were carcinoma,6(13%)were atypical adenomatous hyperplasia and 11(23%)were organizing pneumonia.All perfusion parameters(BF,PF and PI)demonstrated no significant difference among the three conditions(all P>0.05).The PFs were higher than the BFs in all the three conditions(all P<0.001).Of the 30 GGN carcinomas,14 showed mixed GGNs and 16 pure GGNs with a higher PI in the latter(P<0.01).Of the 17 benign GGNs,4 showed mixed GGNs and 13 pure GGNs with no significant difference of the PI between the GGN types(P=0.21).A negative correlation(r=-0.76,P<0.001)was demonstrated between the CT attenuation values and the PIs in the 30 GGN carcinomas.CONCLUSION The GGNs are perfused dominantly by the PF regardless of its histopathology while the weight of the BF in the GGN carcinomas increases gradually during the progress of its opacification.

DXA仪测量骨密度的质量控制及效果评价

目的分析同一厂家生产的不同型号DXA仪及使用不同年限DXA仪测量骨密度(BMD)的质量控制和效果评价。方法 2008年和2012年分别对GE-Lunar制造的的DPX-L仪和Prodigy仪行准确度(accuracy)和精确度(precision)测验。准确度试验仅测试作者自行研制的腰椎体模,精确度试验分别对腰椎体模、女性腰椎和DXA仪自带质量控制体模进行分析。所有测试均按照测量技术要求由同一技师操作。准确度试验为1 d内连续扫描腰椎体模10次,计算BMD测量值与体模真值的百分比。精确度试验分别以腰椎体模、厂家质量控制体模和女性腰椎为对象,每日测量1次,连续25次,计算变异系数(CV)。精确度测试中3个测量对象CV值的计算和应用方法略有差异。结果以BMD为描述指标,2008年DPX-L仪与Prodigy仪BMD准确度误差分别为0.80%和3.80%,差异有统计学意义(P<0.001),Prodigy仪应用4年前后的准确度误差分别为3.80%和3.70%(P>0.05)。DPX-L仪应用15年(至2008年)与Prodigy仪开始应用时(2008年)腰椎体模的精确度误差分别为1.88%和0.33%,差异有统计学意义(P<0.001),DPX-L仪淘汰前精确度误差较Prodigy仪大5.6倍;女性腰椎精确度误差分析显示DPX-L仪的误差较Prodigy仪大4.9倍。结论不同DXA仪及不同使用年限其准确度和精确度均不同,应重点关注不能校正的精确度。短期精确度较长期精确度的干扰因素少,可比性较强。

271例3～11岁儿童骨密度分析

目的：探讨儿童时期全身及身体各部位骨密度的变化规律，方法：选择济南市区无任何内外科疾病、未出现第二性征的271例3—11岁儿童作为研究对象，采用美国LUNAR公司生产的DPX—NT型双能X线骨密度仪测量全身及各部位（包括头、上肢、下肢、躯干、肋骨、骨盆和脊柱）的骨密度。结果：儿童时期骨密度值随年龄增长而增加，身体各部位的骨密度存在显著的性别及年龄差异。尽管骨的发育因躯体部位、性别、年龄而异，但男、女童均在6～8岁年龄段增长较快，9～11岁时增长缓慢。结论：骨的发育因性别、年龄和部位不同而呈现不同规律，在评价骨密度时应予以考虑。

97例5～7岁儿童身体成分分析

目的：了解5～7岁儿童身体成分，比较正常儿童与肥胖儿童、男童与女童身体的脂肪组织、肌肉组织、骨密度、骨矿物质含量之间的差异。方法：对97例（男童49例，女童48例）5～7岁儿童，按照体重指数（BMI）分为正常组和脂肪超量／肥胖组，BMI≤18为正常，BMI〉18为超重／肥胖。采用双能X射线骨密度仪（DXA），测量全身骨密度、骨矿物质含量、肌肉组织含量、脂肪组织含量及其百分比、躯干脂肪含量及其与全身脂肪含量的比值，并对其结果进行比较。结果：①正常组女童全身的脂肪含量、脂肪百分含量、躯干脂肪含量均明显高于男童，男童肌肉组织含量明显高于女童，差异有显著性（P〈0．05）；②脂肪超量／肥胖组男童与女童脂肪含量及肌肉组织含量差异无显著性（P〉0．05）；③骨密度、骨矿物质含量男女比较差异无显著性。结论：正常发育的儿童脂肪组织含量及肌肉组织含量男女之间存在差异，骨密度差异无显著性，运动对减少脂肪含量、增加肌肉含量有益，应鼓励儿童特别是女童增加户外活动。

沈阳市5岁以上儿童骨密度分析研究

目的研究沈阳地区5岁以上儿童骨密度变化规律，了解该地区儿童骨密度的正常参考范围。方法选择2003～2007年在沈阳市儿童医院儿保门诊进行体检的5～15岁健康儿童及青少年为研究对象，利用美国LUNAR公司生产的DPX．NT型双能X线骨密度仪进行检测。结果各年龄纽儿童骨密度与其年龄（r=0.997，P〈0．001）、身高（r=0．983，P〈0．001）呈显著正相关，在青春期前（8～12岁）男女骨密度有显著性差异（P〈0．01）。结论骨密度受年龄、性别影响，可作为儿童期钙营养的判定指标。

双能X线吸收仪测定骨密度对骨质疏松症的诊断价值

目的:应用双能X线吸收仪(DEXA)测定腰椎L2～4前后位(anterior鄄post,A鄄P正位)和侧位的骨密度(BMD),以界定L2～4前后位和侧位男、女患者骨质疏松症(OP)的诊断临界值。方法:测定2115例患者L2～4的BMD,其中前后位1018例,侧位1097例。以T值≤-2.0s和≤-2.5s为诊断标准进行OP检出率分析。结果:按T值≤-2.0s、≤-2.5s计算,其中女性L2～4前后位的OP检出率分别为32.5%和14.5%,侧位分别为59.0%和33.4%;男性L2～4的前后位OP检出率分别为17.6%和6.4%,侧位分别为45.9%和17.8%。无论男女,以T值≤-2.0s为标准时,L2～4前后位与侧位的OP检出率差异显著(P<0.01)。L2～4前后位以T值≤-2.0s为标准的OP检出率和侧位以T值≤-2.5s为标准的OP检出率一致(P>0.05)。结论:男、女性L2～4前后位BMD测定可参考以T值≤-2.0s作为OP的诊断标准,侧位可参考以T值≤-2.5s作为诊断标准。

应用双能X线骨密度仪测定131名健康妇女骨密度变化

应用双能X线骨密度仪 (DEXA)测定 1 3 1名不同年龄和绝经年限妇女骨密度 (BMD)变化 ,并观察外周血液中雌二醇 (E2 )、卵泡刺激素 (FSH)、碱性磷酸酶 (AKP)、骨钙素 (BGP)、血钙、血磷等指标 ,探讨BMD和E2 、AKP、BGP、Ca、P的相互关系。结果表明 ,妇女随着年龄及绝经年限增加 ,BMD及E2 水平逐年下降 ,BMD和E2 呈正相关 ;绝经后各组BGP和AKP明显高于绝经前各组 ,BMD和AKP、BGP呈负相关 ;血钙水平于绝经早期有一过性增加 ,以后略有下降 ,并保持在一相对稳定水平 ;血磷各组变化不大。由此可见 ,DEXA是一种理想的骨密度测定仪。BMD测定和E2 、AKP、BGP等生化指标可以早期诊断绝经后骨质疏松症 。

昆明地区女性腰椎双能X线骨密度调查分析

目的 调查昆明成年女性腰椎骨密度变化及其相关因素。方法 采用双能X线骨吸收仪前后位测量腰椎骨密度 (BMD) ,受检女性 345名 ,年龄 2 0～ 90岁 ,排除影响骨代谢疾病。结果 BMD值L1 <L2 <L3 L4 ,各椎体骨峰值均在 2 0～ 2 9岁。BMD随增龄下降 ,5 0～ 5 9岁下降最快 ,年均失骨 1 31% ,是绝经前的 6倍 ;80岁后累积失骨 32 0 6 %。BMD与体重极显著正相关 (P <0 0 0 1) ,BMD与年龄、绝经年限、生育胎次极显著负相关P均 <0 0 0 1。腰椎压缩变形占 70岁以上妇女的 5 8 4 9% ,其中 1 4BMD呈假性增高。结论 女性腰椎骨密度在 30岁前上升 ,5 0岁后加速下降 ,终生失骨近 1 3,失骨的决定性因素是增龄和绝经。未发现高海拔对骨量积累产生负面影响。

颅骨牵张术中新骨骨密度的定量评价

目的:探讨颅骨牵张术修复骨缺损过程中新骨骨密度的评价方法。方法:成年健康山羊18只,颅顶区制备25mm×10mm全层颅骨缺损,随机分为实验组和对照组,实验组15只建立牵张术修复颅骨缺损的动物模型,于牵张结束后2,4,6周分别处死5只动物,对照组3只动物与实验组牵张后6周动物同期处死,QCT、DEXA两种方法测量新骨骨密度,比较两种测量方法骨密度值(BMD)及相关性。结果:实验组QCT测量牵张间隙各兴趣区BMD值较前一时段对应BMD值明显增加(P<0.05),同一牵张间隙内各固定时段两端(R2、R3)较中央(R1)BMD值明显高(P<0.05),R2、R3之间无明显差别(P>0.05);DEXA测量固定期4周,各兴趣区BMD值较固定2周对应BMD值明显增加(P<0.05),而固定期6周,仅牵张间隙中央(R1)较固定4周对应BMD值增加有统计学意义(P<0.05),同一牵张间隙内固定期2,4周两端(R2、R3)较中央(R1)BMD值明显高(P<0.05);两种检测方法测得平均骨密度值在各时段均存在正相关(P<0.005);对照组缺损区QCT、DEXA检测未显示有新骨形成。结论:两种检测方法均能反映牵张过程新骨骨密度变化,QCT不受解剖结构和牵张器形状的影响,更适于颅面骨牵张术新骨形成的监测评价。

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。

Validation of quantitative computed tomography-derived areal bone mineral density with dual energy X-ray absorptiometry in an elderly Chinese population

Background The performance of computed tomography X-ray absorptiometry （CTXA） against the dual energy X-ray absorptiometry （DXA） as standard has not been studied in Chinese population. The aim of this study was to evaluate the precision of this measurement and validate the value of quantitative computed tomography （QCT） by comparing CTXA results with DXA results in an elderly Chinese population. Methods One hundred and three females of 46 to 76 years old and 49 males of 52 to 76 years old were recruited from the Prospective Urban Rural Epidemiology study. All subjects underwent hip scans by both QCT and DXA on the same day. For precision determination, 30 subjects had duplicate DXA hip scans. The hip QCT data of a subset of 27 subjects were separately analyzed by two observers and reanalyzed by one observer at a different time. The inter- and intra-observer variations of CTXA measurement were assessed, and the difference and correlation between CTXA and DXA results were analyzed. Results The inter- and intra-observer variations of CTXA were 0.070 and 0.024 g/cm^2 in the femoral neck （FN）, and 0.030 and 0.012 g/cm2 in the total hip （TH）, which were comparable to the DXA inter-scan variations （0.013 g/cm2 for FN and 0.014 g/cm2 for TH）. The results of CTXA bone mineral density （BMD） were highly correlated with those of DXA （R2 = 0.810 for FN and R2 = 0.878 for TH）. The BMD values of CTXA in FN and TH were lower than those of DXA by 21.0% and 17.8% （P〈0.05）, respectively. However, after appropriate transformation, the difference was eliminated and a comparable T score could be obtained. Conclusions CTXA shows good agreement with DXA for the measurement of BMD in the proximal femur, which makes QCT suitable for the quantification of bone mineral content in the hip and helpful for the diagnosis of osteoporosis.

Hand bone mass in rheumatoid arthritis:A review of the literature

Rheumatoid arthritis(RA) is a common chronic inflammatory disease and periarticular osteoporosis or osteopenia of the inflamed hand joints is an early feature of RA Quantitative measurement of hand bone loss may be an outcome measure for the detection of joint destruction and disease progression in early RA. This systematic review examines the published literature reporting hand bone mass in patients with RA, particularly those using the dual X-ray absorptiometry(DXA) methods The majority of the studies reported that hand bone loss is associated with disease activity, functional statusand radiological progression in early RA. Quantitative measurement of hand bone mineral density by DXA may be a useful and practical outcome measure in RA and may be predictive for radiographic progression or functional status in patients with early RA.

Adipokines and C-reactive protein in relation to bone mineralization in pediatric nonalcoholic fatty liver disease

AIM: To investigate bone mineral density (BMD) in obese children with and without nonalcoholic fatty liver disease (NAFLD); and the association between BMD and serum adipokines, and high-sensitivity C-reactive protein (HSCRP). METHODS: A case-control study was performed. Cases were 44 obese children with NAFLD. The diagnosis of NAFLD was based on magnetic resonance imaging (MRI) with high hepatic fat fraction (≥ 5%). Other causes of chronic liver disease were ruled out. Controls were selected from obese children with normal levels of aminotransferases, and without MRI evidence of fatty liver as well as of other causes of chronic liver diseases. Controls were matched (1-to 1-basis) with thecases on age, gender, pubertal stage and as closely as possible on body mass index-SD score. All participants underwent clinical examination, laboratory tests, and whole body (WB) and lumbar spine (LS) BMD by dual energy X-ray absorptiometry. BMDZ-scores were calcu- lated using race and gender specific LMS curves. RESULTS: Obese children with NAFLD had a significantly lower LS BMDZ-score than those without NAFLD [mean, 0.55 (95%CI: 0.23-0.86) vs 1.29 (95%CI: 0.95-1.63); P < 0.01]. WB BMD Z-score was also decreased in obese children with NAFLD compared to obese children with no NAFLD, though borderline significance was observed [1.55 (95%CI: 1.23-1.87) vs 1.95 (95%CI: 1.67-2.10); P = 0.06]. Children with NAFLD had significantly higher HSCRP, lower adiponectin, but similar leptin levels. Thirty five of the 44 children with MRI-diagnosed NAFLD underwent liver biopsy. Among the children with biopsy-proven NAFLD, 20 (57%) had nonalcoholic steatohepatitis (NASH), while 15 (43%) no NASH. Compared to children without NASH, those with NASH had a significantly lower LS BMD Z-score [mean, 0.27 (95%CI: -0.17-0.71) vs 0.75 (95%CI: 0.13-1.39); P < 0.05] as well as a significantly lower WB BMD Z-score [1.38 (95%CI: 0.89-1.17) vs 1.93 (95%CI: 1.32-2.36); P < 0.05]. In multiple regression analysis, NASH (standardized β coefficient, -0.272; P < 0.01) and HSCRP (standardized β coefficient, -0.192; P < 0.05) were significantly and independently associated with LS BMD Z-score. Similar results were obtained when NAFLD (instead of NASH) was included in the model. WB BMD Z-scores were significantly and independently associated with NASH (standardized β coefficient, -0.248;P < 0.05) and fat mass (standardized β coefficient, -0.224;P < 0.05). CONCLUSION: This study reveals that NAFLD is associated with low BMD in obese children, and that systemic, low-grade inflammation may accelerate loss of bone mass in patients with NAFLD.

Green coffee bean extract improves obesity by decreasing body fat in high-fat diet-induced obese mice

Objective:To evaluate possible lipid catabolism and body fat regulation effects of 3-caffeoylquinic acid in Green coffee bean extract(GCBE) in high-fat diet(HFD)-induced obese mice.Methods:Obesity was induced in mice using a HFD for four weeks.Then,mice were fed only HFD or HFD with GCBE at 50,100,and 200 mg/kg.Fatty acid synthesis mechanism regulation of body fat was investigated through real-time PCR and Western blot assay.Body fat reduction was measured through dual-energy X-ray absorptiometry.Results:In HFD-induced obese mice,GCBE treatment significantly decreased body weight gain,liver weight and white adipose tissue weights with regulation of adipose tissue lipolysis hormones,like adiponectin and leptin.GCBE treatment decreased mR NA expression levels of adipogenesis and adipocyte metabolism related genes in adipose tissues and the liver,and decreased the corresponding protein expression.Dual energy X-ray absorptiometry measurements were used to compare body fat between mice on high-fat and those treated with GCBE.GCBE treated mice had a lower fat mass compared to HFD alone fed mice and relative body weight and fat mass were markedly decreased.Conclusions:GCBE has a potential anti-obesity effect with lowering body fat accumulation by regulating adipogenesis and lipid metabolism-related genes and proteins in WAT and liver.

Bone mass in axial spondyloarthritis:A literature review

AIM: To review the published literature reporting bone loss in patients with axial spondyloarthritis(SpA) particularly those studies using dual X-ray absorptiometry(DXA) methods. METHODS: This literature review examines the reported bone mass in patients with ax-SpA, particularly those using the DXA methods. The MEDLINE, Web of Science and Scopus databases were searched for relevant articles published between September 1992 and November 2013. Some of used search terms were ankylosing spondylitis(AS), SpA, spondyloarthropathy, bone loss, bone mass, osteopenia, bone mineraldensity, osteoporosis(OP), densitometry. Studies in which bone loss was investigated by using DXA in patients with Sp A were eligible. Each article was reviewed and the key elements were noted.RESULTS: There were 286 hits on MEDLINE, 200 on Web of Science and 476 on Scopus. After applying inclusion and exclusion criteria, we identified 55 articles in our systematic search. The sample size of the studies varied from 14 to 332 patients with SpA. The reported age range varied from 25 to 56 years in the reviewed studies. The symptom duration of patients with axS pA varied from 1.6 to 49 years. There were more males than females in these studies. Most of the recruited females were premenopausal women. Reported HLA-B27 positivity changed between 19% to 95%. The prevalence of OP and osteopenia in patients with Sp A varied from 3%-47% to 5%-88%, respectively, in the included studies. In particular, the prevalence of OP and osteopenia ranged from 2.0%-47.0% and 5.0%-78.3%, respectively, in patients with AS. There are conflicting results regarding the relationship among disease activity, acute phase response and bone mass. Some studies suggest good correlation of bone mass with disease activity and acute phase reactants.CONCLUSION: Bone loss may be determined in patients with ax Sp A at the lumbar spine or proximal femur even in the early phase of the disease and may be associated with inflammation(bone marrow edema) at the vertebral colon.

OSTC在2型糖尿病性骨质疏松症筛查中的作用

目的探讨中国大陆地区妇女骨质疏松筛查工具(OSTC)与双能X线吸收检测法(DXA)诊断2型糖尿病性骨质疏松症的一致性。方法收集404例2型糖尿病绝经后妇女的临床资料,应用双能X线骨密度仪测量腰椎(L1~4)和股骨颈骨密度,利用公式计算OSTC得分。将OSTC分值与DXA测定的不同部位骨密度进行比较。结果随年龄增长,受试者腰椎、股骨颈骨密度逐渐下降,各组间股骨颈骨密度差异有统计学意义(P <0.05)。应用DXA在腰椎(L1~4)、股骨颈的骨质疏松检出率分别为22.5%、21.8%。OSTC有危险组中达到骨质疏松诊断标准的比例为21.5%。以股骨颈为检测部位,OSTC识别骨质疏松症受试者工作特征曲线下面积为0.78(P=0.000)。OSTC诊断腰椎(L1~4)和股骨颈骨质疏松症的最佳截点均为-25.5,敏感度分别为63.7%、86.4%,特异度分别为48.9%、42.7%。结论 OSTC可用于早期筛查2型糖尿病性骨质疏松症,最佳截点是-25.5。

不同DEXA测量股骨头骨矿的比较

目的 评估不同双能X线吸收测量仪(DEXA)的准确性及不同扫描条件对测量值的影响。方法 取6个人体切除的股骨头作为实验标本。分别以Hologic QDR-2000及Aloka DCS-3000 DEXA,在不同的扫描条件下(分别在4cm的有机玻璃板上、水深5cm、10cm、15cm、20cm、25cm及30cm)对实验标本进行骨矿测量。最后将股骨头标本放入马福炉内,在700℃高温下焚化24 h。取出灰化的6个标本,分别称重。并与其DEXA测量值做比较性研究。结果 BMC值与灰重的相关关系显示,在无水条件下,Hologic及Aloka双能X线吸收测量仪BMC测量值与灰重都明显相关。Hologic QDR-2000机(r=0.965～0.996)优于Aloka DCS-3000(r=0.823～0.964),尤其是随水深增加,前者的优越性就更为突出。结论 两种不同厂家生产的DEXA都可为骨矿定量提供可靠的准确性。Hologic QDR-2000机测量股骨头BMC值与灰重明显相关,其优越性大于Aloka DCS-3000 DEXA。随水深增加,前者较后者测量的准确性就更为明显。

Risk assessment instruments for screening bone mineral density in a Mediterranean population

AIM To evaluate the power of six osteoporosis-screening instruments in women in a Mediterranean country.METHODS Data concerning several osteoporosis risk factors were prospectively collected from 1000 postmenopausal women aged 42-87 years who underwent dual-energy X-ray absorptiometry(DEXA) screening. Six osteoporosis risk factor screening tools were applied to this sample to evaluate their performance and choose the most appropriate tool for the study population.RESULTS The most important screening tool for osteoporosis status was the Simple Calculated Osteoporosis Risk Estimation, which had an area under the curve(AUC)of 0.678, a sensitivity of 72%, and a specificity of 72%, with a cut-off point of 20.75. The most important screening tool for osteoporosis risk was the Osteoporosis Self-assessment Tool, which had an AUC of 0.643, a sensitivity of 77%, and a specificity of 46%,with a cut-off point of-2.9.CONCLUSION Some commonly used clinical risk instruments demonstrate high sensitivity for distinguishing individuals with DEXA-ascertained osteoporosis or reduced bone mineral density.