腰椎定量CT骨密度测定与双能X线骨密度测量在老年男性骨质疏松症中的应用效果对比

目的对比分析腰椎定量CT(QCT)骨密度(BMD)测定与双能X线(DXA) BMD测量在老年骨质疏松症中的应用效果。方法对84例老年男性患者行腰椎QCT BMD测定和腰椎正位及髋关节DXA BMD测量,两项检查的时间间隔≤20 d。对比分析QCT测定BMD与DXA测量BMD对老年骨质疏松的检出率。结果DXA诊断84例老年男性腰椎、髋关节及腰椎或髋关节骨质疏松的检出率分别为5. 95%、9. 52%、13. 10%;腰椎QCT测定椎体松质骨骨质疏松的检出率为35. 71%,差异有统计学意义(P 0. 05)。结论腰椎QCT和DXA均可检测BMD,但腰椎QCT测定BMD的敏感性较腰椎正位及髋关节DXA测量BMD更好,更能准确反映出骨质代谢的变化。     

腰椎定量CT与双能X线骨密度测量对老年男性骨质疏松的诊断效能比较

目的评估腰椎定量悦栽与双能X线骨密度测量诊断老年男性骨质疏松的效能。方法 连续选取2012年2月至2012年8月期间于北京积水潭医院干部科住院的老年男性患者,共59例,年 龄54耀92岁。本组病例均行腰椎正位和髋关节DXA及腰椎QCT检查,且两项检查间隔时间不超过 1个月。结果采用世界卫生组织（WHO )DXA -2. 5SD和国际临床骨密度学会（ISCD )腰椎QCT < 80 mg/cm3的骨质疏松诊断标准,DXA诊断本组病例腰椎、髋关节及腰椎或髋关节任一部位骨质疏松 的检出率分别为0%_、. 5豫和8. 5豫。腰椎QCT诊断本组病例骨质疏松的检出率为35. 6豫。其中腰 椎QCT诊断为骨质疏松而腰椎正位DXA未诊断者21例,占35. 6豫,其中3例CT显示有骨质疏松性 椎体骨折;腰椎QCT诊断为骨质疏松而髋关节DXA或任一部位DXA未诊断者均为16例,占 27. 1豫。结论 腰椎QCT比髋关节DXA及腰椎正位DXA对老年男性骨质疏松的诊断更敏感。腰 椎QCT骨密度测量对老年男性的骨质疏松诊断具有较高的临床价值。     

绝经妇女腰椎及髋关节定量cT骨密度测量诊断骨质疏松的初步研究

目的比较绝经后妇女L2-L4椎体及髋关节两个部位的定量CT骨密度（BMD )测量诊断骨 质疏松的效能。方法175例绝经妇女,年龄48-96岁,平均年龄为69 ±9岁。同时QCT测量L2-L4椎体的平均体积骨密度及髋关节类DXA的面积骨密度,右股骨颈和全髋二个感兴趣区（ROI )。 采用国际临床骨密度学会（ISCD )QCT骨质疏松诊断标准（<80 mg/cm3 )和WHO髋关节DXA骨密 度诊断标准即股骨颈或全髋感兴趣区的T值（-2.5 SD )进行骨质疏松诊断。比较二者诊断骨质疏 松的效能。结果175绝经后妇女中,QCT骨密度测量腰椎部位骨密度值骨质疏松的检出率是44%( 77/175 )。如果采用髋部检查股骨颈部位为11%.( 19/175 ),全髋部位为14%.( 24/175 ),或二者任一 部位为18%_( 31/175 )。如果只做腰椎,不做髋关节,有7人漏诊,而如果只做髋关节,不做腰椎会漏 诊44人。结论采用QCT骨密度测量,绝经妇女腰椎检查骨质疏松检出率为44%_,而髋部检查检出 率为18%_。采用QCT骨密度测量,测量腰椎一个部位就可以诊断骨质疏松。     

髋部定量CT（QCT）骨质疏松防治管理临床应用：2015 ISCD共识--部分Ⅰ摘录

国际临床骨密度测量学会(ISCD)发布了髋部定量CT(QCT)临床应用的最新共识。ISCD致力于汇总归纳定量CT的临床应用证据并在2015年ISCD指南修订会议上发布共识指南报告,讨论并一致通过了关于支持医学应用的证据、依据和矛盾,以及未来研究建议的共识。     

美国放射学院（ACR)关于定量CT( QCT)骨密度测量 操作指南

随着螺旋CT技术的进步和定量CT( QCT)分析技术的发展,定量CT( QCT)骨密度测量的临床应用越来越引起大家的 重视。美国放射学院(ACR)组织专家起草,并于2008年颁布了 ACR定量CT( QCT)骨密度测量操作指南。该指南的目的在 于制定临床工作中QCT检查实施和诊断的参考标准,包括其设备要求、质量控制、适用人群、临床适应症和禁忌症,医生和技 术员资质要求,以及QCT测量规范和报告规范。该指南提出了对绝经后妇女和50岁及以上男性的QCT诊断参考标准。建议 脊柱QCT采用BMD绝对值诊断,即BMD >120 mg/cm3诊断为骨量正常,BMD 120 mg/cm3 -80 mg/cm3诊断为低骨量,BMD < 80 mg/cm3诊断为骨质疏松。QCT髋关节测量的T值可以根据WHO DXA标准来诊断骨质疏松。该指南对我国的QCT临 床应用具有指导意义。     

中国人骨质疏松症诊断标准专家共识（第三稿• 2014版）

中国老年学学会骨质疏松委员会组织专家在2000年第二稿的基础上,复习了近年来国际国内在骨质疏松症诊断方面的研究进展,结合中国人群特点和中国骨质疏松症防治实际情况,制定本共识为各级医疗机构开展骨质疏松症诊疗工作提供参考。骨密度测量在骨质疏松症诊断中有重要作用,可以参照WHO-2.5 SD的标准,也可以根据中国人群的实际情况采用中国老年学学会骨质疏松委员会(OCCGS)建议的-2.0SD或者骨量下降25%作为诊断标准。并提出了在使用DXA骨密度诊断时需要注意DXA的局限性,避免漏诊。根据近年来定量CT研究的成果,首次在共识中建议采用国际临床骨密度学会(ISCD)和美国放射学院(ACR)推荐的腰椎QCT骨密度低于80 mg/cm3作为骨质疏松的诊断标准。首次建议在骨质疏松诊断中的FRAX应用。脆性骨折作为骨质疏松症诊断标准的重要性,并推荐综合影像检查诊断脆性骨折和鉴别诊断。强调了骨生化检查的作用。     

非骨密度DXA测量对骨折风险的预测——骨小梁评分（TBS）：ISCD 2015官方共识（第四部分）

DXA测量骨密度(BMD)是诊断和治疗骨质疏松症的金标准,但是BMD只能解释60%～80%的骨强度,除BMD外还有众多其他骨骼特征与骨强度和骨折风险相关。且可以通过先进的影像技术获得这些骨骼特征。但是与传统的DXA相比较,这些技术的费用较高且获取不易。因此,在标准DXA测量基础和临床风险因素上,发展能够提升骨折预测的非侵入性检查技术来满足临床实践要求是一个重要的挑战。为此,骨小梁评分(trabecular bone score),一个从腰椎DXA图像衍生而来的灰阶结构指数被研究出来。ISCD专题工作组的目的是复习相关证据并提出如何在临床工作中使用TBS的建议。在临床中应用TBS来进行骨折风险评估、指导治疗、治疗监测和使用,以及在关于更高骨折风险的情况下如何使用TBS被一一列出。我们通过专家组对工作组的建议和证据进行了仔细的评审后推出了此官方立场。     

基于髋部和脊柱定量CT有限元分析在成人骨质疏松症诊治中的临床应用 2015年国际临床骨密度学会(ISCD)官方共识（第二部分）

国际临床骨密度学会（ISCD）已经形成了新的基于定量CT（QCT）的脊柱及髋部有限元分析（FEA）的临床应用官方建议。ISCD定量CT工作组回顾了QCT临床应用证据,并在2015临床骨密度测量发展大会提出了新的报告建议。在这里,我们对支持ISCD官方建议的医学证据、理论基础、争议和进一步研究的建议进行探讨。第一部分和第三部分论述了髋关节QCT的临床应用,并讨论了利用以其它疾病诊断为目的的CT扫描（如结肠成像）,从而进行骨质疏松症随机筛查的临床可行性。     

定量CT骨密度测量(QCT)在骨质疏松症诊治中的临床应用2007国际临床骨密度学会(ISCD)共识摘录

<正>译者注国际临床骨密度学会(ISCD)在2007年根据Engelke等十一位国际著名专家组意见,形成了QCT和外周定量CT(pQCT)骨密度测量在骨质疏松诊疗的临床应用共识,全文发表在Journal of ClinicalDensitometry,2008,11:123-162上。鉴于pQCT在国内尚未开展,省略该共识中关于pQCT的相关内容。本文作者通过仔细阅读和翻译该共识文章,摘录如下。     

定量CT骨密度测量（QCT )在骨质疏松症诊治中的临床应用2007国际临床骨密度学会（ISO))共识摘录

国际临床骨密度学会（ISCD )在2007年根据 Engelke等十一位国际著名专家组意见,形成了 QCT 和外周定量CT( pQCT)骨密度测量在骨质疏松诊疗 的临床应用共识,全文发表在Journal of Clinical Densitometry,2008, 11 : 123-162 上。鉴于 pQCT 在 国内尚未开展,省略该共识中关于pQCT的相关内 容。本文作者通过仔细阅读和翻译该共识文章,摘 录如下。     

Clinical use of quantitative computed tomography and peripheral quantitative computed tomography in the management of osteoporosis in adults: the 2007 ISCD Official Positions.

The International Society for Clinical Densitometry (ISCD) has developed Official Positions for the clinical use of dual-energy X-ray absorptiometry (DXA) and non-DXA technologies. While only DXA can be used for diagnostic classification according to criteria established by the World Health Organization, DXA and some other technologies may predict fracture risk and be used to monitor skeletal changes over time. ISCD task forces reviewed the evidence for clinical applications of non-DXA techniques and presented reports with recommendations at the 2007 ISCD Position Development Conference. Here we present the ISCD Official Positions for quantitative computed tomography (QCT) and peripheral QCT (pQCT), with supporting medical evidence, rationale, controversy, and suggestions for further study. QCT is available for bone mineral density measurements at the spine, hip, forearm, and tibia. The ISCD Official Positions presented here focus on QCT of the spine and pQCT of the forearm. Measurements at the hip may have clinical relevance, as this is an important fracture site; however, due to limited medical evidence, definitive advice on its use in clinical practice cannot be provided until more data emerge.     

Densitometry in Glucocorticoid-Induced Osteoporosis

Bone density measurement is a critical tool in the management of glucocorticoid-induced osteoporosis (GIOP). This review addresses the utility of various measurement devices (dual-energy X-ray absorptiometry [DXA], quantitative ultrasound [QUS], quantitative CAT scanning [QCT]), their role in monitoring changes in bone mineral density (BMD), and the relationship of BMD and fracture risk in GIOP. A higher BMD threshold should be utilized for estimating fracture risk in patients on glucocorticoids.     

基于体素的股骨近端骨密度和骨皮质厚度的测量及可重复性研究

目的研究基于定量CT(quantitative computed tomography,QCT)的股骨近段骨密度和骨皮质厚度体素化测量的可重复性,为髋部骨折研究提供技术支持。方法选择28例短时间内QCT扫描两次的髋部骨折患者,其中男性6例,女性22例。从QCT影像中手动分割出股骨近段结构。借助体素形态学分析(voxel-based morphometry,VBM)思想,选择一个形状和结构适中的股骨近段结构作为标准模板,通过三维弹性配准算法将其他股骨近段映射到标准模板上。采用最小二乘和列文伯格-马夸尔特(Levenberg-Marquardt)方法将CT值转化成体素化的骨密度和骨皮质厚度值。最后,使用统计参数图(statistical parametric mapping,SPM)方法对28例患者短时间内两次QCT扫描数据的股骨近段骨密度和骨皮质厚度进行统计分析,获取三维统计参数图。结果所选28例骨折患者短时间内两次QCT扫描数据的股骨近段骨密度和骨皮质厚度的测量结果差异无统计学意义(P0.05),一致性均较好,说明测量结果较为准确。结论股骨近段骨密度和骨皮质厚度的测量方法具有较好的可重复性,为髋部骨折风险评估提供有效手段。     

Repeating Measurement of Bone Mineral Density when Monitoring with Dual-energy X-ray Absorptiometry: 2019 ISCD Official Position

Bone mineral density (BMD) can be measured at multiple skeletal sites using various technologies to aid clinical decision-making in bone and mineral disorders. BMD by dual-energy X-ray absorptiometry (DXA) has a critical role in predicting risk of fracture, diagnosis of osteoporosis, and monitoring patients. In clinical practice, DXA remains the most available and best validated tool for monitoring patients. A quality baseline DXA scan is essential for comparison with all subsequent scans. Monitoring patients with serial measurements requires technical expertise and knowledge of the least significant change in order to determine when follow-up scans should be repeated. Prior ISCD Official Positions have clarified how and when repeat DXA is useful as well as the interpretation of results. The 2019 ISCD Official Positions considered new evidence and clarifies if and when BMD should be repeated. There is good evidence showing that repeat BMD measurement can identify people who experience bone loss, which is an independent predictor of fracture risk. There is good evidence showing that the reduction in spine and hip fractures with osteoporosis medication is proportional to the change in BMD with treatment. There is evidence that measuring BMD is useful following discontinuation of osteoporosis treatment. There is less documentation addressing the effectiveness of monitoring BMD to improve medication adherence, whether monitoring of BMD reduces the risk of fracture, or effectively discriminates patients who should and should not recommence treatment following an interruption of medication. Further research is needed in all of these areas.     

Bone Density Reduction in Various Measurement Sites in Men and Women with Osteoporotic Fractures of Spine and Hip: The European Quantitation of Osteoporosis Study

We have measured bone mineral density (BMD) using dual X-ray absorptiometry (DXA) of the spine and hip, spinal quantitative computed tomography (QCTspi), and peripheral radial quantitative computed tomography (pQCTrad) in 334 spine and 51 hip fracture patients. The standardized hip and spine BMD for each patient was calculated and compared with the combined reference ranges published previously, each densitometer having been cross-calibrated with the prototype European Spine Phantom (ESPp) or the European Forearm Phantom (EFP). Male and female fracture cases had similar BMD values after adjusting for body size, where appropriate. This suggests that the relationship between bone density (mass per unit volume) and fracture risk is similar between men and women. However, compared with age-matched controls, mean decreases in BMD ranged from 0.78 SD units (women with hip fracture, DXAspi) to 2.57 SD units (men with spine fractures, QCTspi). The proportion of spine and hip fracture patients falling below the cutoff for osteoporosis (T-score <−2.5 SD) proposed by the World Health Organization (WHO) study group varied according to different BMD measurement procedures (range 18–94%). This finding suggests that the WHO definition requires different thresholds when used with non-DXA BMD measurement techniques. Receiver operator characteristic (ROC) analysis was used to compare measurement techniques for their ability to discriminate between cases and controls. Among DXA sites, the proximal femur was preferred when evaluating generalized bone loss, particularly in elderly people. An additional spinal BMD measurement may add clinical value if spine fracture risk assessment has a high priority. Both axial and peripheral QCT techniques performed comparably to DXA in spinal osteoporosis, so investigators and clinicians may use any of the three technologies with similar degrees of confidence for the diagnosis of generalized or site-specific bone loss providing straightforward clinical guidelines are followed. Received: 21 May 1997 / Accepted: 24 June 1998     

Executive Summary of the 2013 International Society for Clinical Densitometry Position Development Conference on Bone Densitometry

The International Society for Clinical Densitometry (ISCD) convenes a Position Development Conference (PDC) every 2–3 yr to make recommendations for guidelines and standards in the field of musculoskeletal measurement and assessment. The recommendations pertain to clinically relevant issues regarding the acquisition, quality control, interpretation, and reporting of various aspects of musculoskeletal health metrics. Topics for consideration are developed by the ISCD Board of Directors and the Scientific Advisory Committee. For the 2013 PDC, body composition analysis was a central topic area for the first time and considered timely because of the scientific advances in measurement of fat and lean body mass by dual-energy X-ray absorptiometry (DXA). Indications for DXA and vertebral fracture assessment and use of reference data to calculate bone mineral density T-scores were also updated. Task Forces for each of these areas were assigned questions of relevance to a clinical audience and asked to conduct comprehensive literature reviews. Reports with proposed Position Statements were then presented to an international panel of experts. The Expert Panel included representatives of the International Osteoporosis Foundation, the American Society for Bone and Mineral Research, the National Osteoporosis Foundation, Osteoporosis Canada, and the North American Menopause Society. The PDC was held in Tampa, FL, contemporaneously with the Annual Meeting of the ISCD, March 21 through March 23, 2013. This report describes the methodology of the 2013 ISCD PDC and summarizes the results of the 2013 ISCD PDC for vertebral fracture assessment/DXA and National Health and Nutrition Survey (NHANES) Reference Database Task Forces. A separate article in this issue will summarize the results of the Body Composition Analysis Task Forces.     

Proximal Femoral Structure and the Prediction of Hip Fracture in Men: A Large Prospective Study Using QCT

The structure of the femoral neck contributes to hip strength, but the relationship of specific structural features of the hip to hip fracture risk is unclear. The objective of this study is to determine the contribution of structural features and volumetric density of both trabecular and cortical bone in the proximal femur to the prediction of hip fracture in older men. Baseline QCT scans of the hip were obtained in 3347 men ≥65 yr of age enrolled in the Osteoporotic Fractures in Men Study (MrOS). All men were followed prospectively for an average of 5.5 yr. Areal BMD (aBMD) by DXA was also assessed. We determined the associations between QCT‐derived measures of femoral neck structure, volumetric bone density, and hip fracture risk. Forty‐two men sustained incident hip fractures during follow‐up: an overall rate of 2.3/1000 person‐years. Multivariable analyses showed that, among the QCT‐derived measures, lower percent cortical volume (hazard ratio [HR] per SD decrease: 3.2; 95% CI: 2.2–4.6), smaller minimal cross‐sectional area (HR: 1.6; 95% CI: 1.2–2.1), and lower trabecular BMD (HR: 1.7; 95% CI: 1.2–2.4) were independently related to increased hip fracture risk. Femoral neck areal BMD was also strongly related to hip fracture risk (HR: 4.1; 95% CI: 2.7–6.4). In multivariable models, percent cortical volume and minimum cross‐sectional area remained significant predictors of hip fracture risk after adjustment for areal BMD, but overall prediction was not improved by adding QCT parameters to DXA. Specific structural features of the proximal femur were related to an increased risk of hip fracture. Whereas overall hip fracture prediction was not improved relative to aBMD, by adding QCT parameters, these results yield useful information concerning the causation of hip fracture, the evaluation of hip fracture risk, and potential targets for therapeutic intervention.     

Comparison of T-scores from different skeletal sites in differentiating postmenopausal women with and without prevalent vertebral fractures.

It is not clear how bone mineral density (BMD) measurements from several regions of lumbar spine and proximal femur should be utilized in assessing fracture risk. We examined how well the newest ISCD recommendations differentiate subjects with and without prevalent vertebral fractures in 187 postmenopausal women presenting for routine bone densitometry. The association between T-scores from proximal femur and lumbar spine sites and the probability of having a vertebral fracture was modeled via logistic regression with adjustment for age. The lowest T-score of any hip or spine sites (the current ISCD recommendation) and the proximal femur measurements, particularly the femoral neck and total hip, displayed the strongest association with the probability of vertebral fractures.Subjects with a T-score < -2.5 at multiple hip sites had a higher probability of having a vertebral fracture. The sensitivity and specificity associated with particular T-score cutoff values varied greatly depending on the site of measurement.Consequently, T-score values from different sites that had comparable sensitivity/specificity for detecting the presence of vertebral fractures differed by as much as 1.5 T-score units. This finding implies that a single cutoff value, such as -2.5, might not be clinically acceptable when applied to T-scores from different sites.     

Discordance in patient classification using T-scores.

In their original study report, "Assessment of Fracture Risk and Its Application to Screening for Postmenopausal Osteoporosis," the World Health Organization (WHO) explicitly stated that any T-score criterion for osteoporosis is sensitive to bone mineral density (BMD) measurement site and technique, as well as the young adult reference population. Yet, the T = -2.5 criterion introduced by WHO is used for many different BMD techniques, despite the fact that it was based primarily on the relationship between forearm measurements and prevalent hip fracture in postmenopausal Caucasian females. It is reasonable to expect that a T-score threshold of -2.5 may be inappropriate for different skeletal sites and measurement techniques. This may explain the large variation in osteoporosis prevalence observed when different skeletal sites are measured. In this study, we compared the prevalence of osteoporosis (based on the T = -2.5 criterion) at different skeletal sites using the manufacturer's normative data. We determined the expected mean T-score for a 60-yr-old Caucasian female at the heel (ultrasound), hip (dual X-ray absorptiometry [DXA]), spine (PA DXA, lateral DXA, and quantitative computed tomography [QCT]), and forearm (DXA). Assuming a normal distribution of T-scores at a fixed age, we computed the expected percentage of 60-yr-old Caucasian women that would be classified as osteoporotic using the -2.5 standard deviation criterion for each technique. At age 60 yr, the expected mean T-score ranged from -2.5 (spine QCT) to -0.7 (heel). Prevalence estimates ranged from 3% at the heel to 50% for spinal QCT. It was also noted that the sites with the strongest relationship to hip fracture risk (the hip and heel) showed the least age-related T-score decline and lowest estimated prevalence. We conclude that a single T-score criterion cannot be universally applied to all BMD measurements. The discrepancies in the prevalence of osteoporosis are the result of several factors, including differences in age-related bone loss at different skeletal sites, differences in the young adult reference populations used by the various bone densitometry devices, and technology-related differences. Using estimated BMD by heel ultrasound, few patients will have T-scores below -2.5, whereas most postmenopausal women will fall below this level for spine bone density measurements performed by lateral DXA or QCT. Based on these data, it may be necessary to provide a T-score criterion specific to the type of densitometric evaluation performed.