QCT与DXA对老年类风湿关节炎患者骨质疏松症诊断价值的对比研究

目的 对比研究定量计算机断层扫描法(quantitative computed tomography,QCT)与双能X线吸收法(dual energy X-ray absorptiometry,DXA)在老年类风湿关节炎(rheumatoid arthritis,RA)患者骨质疏松症中的诊断价值.方法 选取老年RA患者...     

DXA骨密度检测在骨质疏松症诊断、预防、治疗中的指导作用

目的笔者通过对国际临床骨密度学会共识文件(ISCD,2005年版)[1]观点的理解及解读,结合近10年操作DXA检测2万多例患者的经验,总结我国著名学者近10年来发表的文章观点,希望能够帮助解决临床医生存在的:(1)T/Z值使用混淆;(2)诊治目标人群应选取什么样的患者需要接受骨质疏松治疗指征不明确;(3)治疗方案不系统、检测部位不合理等问题。方法根据ISCD(2005年版)提出的诊断骨质疏松症有效部位的选择、T/Z值的诊断人群及使用,我国著名学者近10年发表的文章观点、DXA骨密度检测对骨质疏松症治疗的指导应用,以及笔者总结多年临床经验对DXA其他功能在临床的应用及解读,结合DXA在不同年龄段、不同部位所出现的BMD状况,提出相应防治措施。结果通过DXA正确应用、监测患者所可能出现的骨质疏松状况,从而做出有效的风险评估和骨质疏松程度的提示,为临床治疗提供数据支持。结论双能X线骨密度仪(DXA)是目前被公认用于判断骨量最好的检测工具,ISCD(2005年版)的观点为我们在诊断和治疗骨质疏松症方面提供了有效的依据。     

QCT和DXA对腰椎骨质疏松症检出率的Meta分析

目的 通过对定量CT（quantitative computed tomography,QCT）和双能X线吸收测量仪(dual-energy X-ray absorptiometry,DXA）腰椎骨质疏松症(osteoporosis ,OP)检出率研究数据进行Meta分析,了解QCT和DXA对腰椎OP的诊断价值。方法 检索 PubMed、Web of Science、Cochrane Library、万方、维普及中国知网中自建库以来至2022年1月1日的相关文献,提取目标数据。采用Stata 11.0软件进行数据分析,根据异质性检验结果选择固定效应模型或随机效应模型对数据进行汇总分析。结果 共纳入24篇研究,总样本量为4 008例,其中男性2 265例,女性1743例。24项研究间异质性显著,按随机效应模型分别汇总QCT和DXA对腰椎OP检出率为0.44(95 %CI：0.37~0.52)和0.17(95 %CI：0.14~0.21)。QCT对男、女性腰椎OP检出率分别为0.32(95 %CI：0.22~0.43)和0.45(95 %CI：0.33~0.58),DXA则分别为0.14(95 %CI：0.08~0.20)和0.24(95 %CI：0.17~0.30)。QCT在45~、60~岁和75岁及以上的人群中腰椎OP检出率分别为0.41(95 %CI：0.21~0.61)、0.43(95 %CI：0.33~0.54)和0.48(95 %CI：0.41~0.54),DXA则分别为0.30(95 %CI：0.12~0.49)、0.16(95 %CI：0.11~0.20)和0.15(95 %CI：0.10~0.21)。QCT和DXA对国内人群腰椎OP检出率分别为0.40(95 %CI：0.33~0.47)和0.15(95 %CI：0.12~0.19),对国外人群分别为0.68(95 %CI：0.43~0.93)和0.28(95 %CI：0.18~0.39)。QCT与DXA对腰椎OP检出率的差值(率差)定量合并结果为0.25(95 %CI：0.20~0.31),在男性为0.26(95 %CI：0.18~0.34),在女性为0.28(95 %CI：0.17~0.39),在45~、60~岁和75岁及以上人群中分别为0.10(95 %CI：0.06~0.14)、0.26(95 %CI：0.19~0.33)和0.30(95 %CI：0.18~0.41),及在国内外人群分别为0.23(95 %CI：0.17~0.29)和0.38(95 %CI：0.13~0.64)。结论 QCT比DXA对腰椎OP的检出率高,且QCT对男、女性和各年龄段及不同地区间人群的腰椎OP检出率均高于DXA,率差值随年龄的增加而增大,提示QCT对高年龄组腰椎OP的早期发现可能具有更高的价值。     

骨质疏松症影像学检查的进展

骨质疏松症是以骨量减少、骨组织微细结构被破坏、骨强度下降、骨脆性增加、极易发生骨折为特征的全身性骨骼疾病.随着老龄人口的增加,骨质疏松成为了一个严峻的公共健康问题.二维双能X线骨密度仪(DXA)是目前临床上检查骨质疏松症的主要手段.近年来,影像学技术进展迅速,特别是三维定量计算机断层扫描(QCT)为进一步检测松质骨及皮质骨骨密度、骨微结构、骨几何特性与其他生物力学参数,探索骨质疏松症的病理生理过程,敏感地进行临床诊断、监控病程变化与疗效提供了技术支持.放射影像学技术与生物力学有限元模型相结合,有利于评价骨强度和骨的力学性能.     

DXA测量活体大鼠骨的精密性及骨丢失的检测

目的 了解QDR－4500A型双能X射线吸收法（DXA）测量活体大鼠的精密性和探测去卵巢后大鼠骨丢失的能力。方法 测量15只体重为202－311g的SD大鼠全身、股骨及腰椎的骨密度（BMD）,每只大鼠测量3次,可得变异系数（CV）,15只大鼠CV的平均值为该指标的批内CV。结果 ①全身、股骨、腰椎BMD的批内CV分别为0．71％、2．02％和2．44％。全身BMD的批内CV显著低于股骨和腰椎（P＜0．05）;②全身BMD的批间CV为0．99％,股骨整体为2．81％,腰椎总体（L3－L6）为3．42％;③术后4周去卵巢组全身、股骨、腰椎BMD与假手术组比较无显著性变化,而股骨远侧干骺端BMD低于假手术组（P＜0．05）;④去卵巢后14周腰椎总体（L4－L6）的BMD低于假手术组（P＜0．05）。结论 QDR－4500A型DXA测量大鼠全身、股骨和腰椎BMD有较好的精密性,全身优于局部骨骼;其精密性能满足检出去卵巢后骨丢失。     

DXA诊断椎体压缩性骨折的应用进展

椎体压缩性骨折不仅是骨质疏松的主要临床表现之一,而且在预测骨折风险中具有重要意义,双能X线骨密度吸收仪(DXA)从最初的一种定量测量仪器发展到可以进行成像,目前已经可以用椎体侧位DXA成像来诊断椎体骨折并进行椎体骨折评估,可以更好的了解骨骼状态,而且放射暴露比普通X片低得多,本文就DXA在椎体压缩性骨折诊断方面的进展综述如下.     

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。     

DXA在糖耐量低减的老年男性脂肪含量测量中的应用

目的 探讨应用双能X线吸收法(DXA)进行人体脂肪含量测量的可行性,并研究糖耐量低减的老年男性患者中脂肪含量与骨密度的相关性.方法 选取171例糖耐量低减的老年男性行腰椎、股骨及全身的DXA检查,收集测量的骨密度、脂肪含量百分比、组织厚度及体重指数(BMI)等数据进行相关性统计分析.结果 腰椎骨密度与腹部脂肪含量(fat%腹部)呈正相关,相关系数r=0.263(P<0.001);股骨颈骨密度与臀部脂肪含量(fat%臀部)呈负相关,r=-0.284(P<0.001).fat%腹部、fat%臀部与BMI高度相关,r=0.561,0.377(P<0.001);腹部、臀部组织厚度与BMI高度相关,r分别为0.854,0.850(P<0.001).结论 DXA测量所得的脂肪含量百分比及组织厚度可作为肥胖检测的定量指标,更多应用于临床;脂肪成分对骨密度具有双重影响,其机制尚待进一步研究.     

定量超声检测对绝经后骨质疏松症的应用价值

目的评价定量超声检测技术(QUS)对绝经后骨质疏松症的临床应用价值。方法 88例绝经后女性分别使用QUS测量左跟骨T值、双能X线吸收法(DXA)测量L1-4及髋部骨密度、T值,采用Spearman分析两种检测方法相关性。以DXA法诊断骨质疏松症(OP)为金标准,分析QUS诊断OP的ROC曲线下面积、cutoff、灵敏度、特异度、符合率、Youden指数。结果相关分析显示,QUS测量左跟骨与DXA测量L1、L2、L3、股骨颈、大转子、全髋T值相关系数分别为0.244、0.252、0.371、0.485、0.539、0.506(P0.05或P0.01);ROC曲线下面积0.669,以QUS测量T值-2.35为cutoff,QUS诊断OP的灵敏度、特异度、符合率、Youden指数分别为69.1%、65.0%、64.77%、0.341。结论 QUS与DXA检测骨密度存在相关性,可作为OP的筛查工具,但诊断效能一般,不可替代DXA检查。     

双能X线吸收法及定量CT法诊断骨质疏松症的比较研究

本研究比较了双能Ｘ线吸法（ＤＸＡ）与定量ＣＴ（ＱＣＴ）在骨质疏松症诊断中的应用。对５６例健康妇女（Ｈ组）及４８例骨折后骨质疏松妇女（ＯＰ组）进行了ＤＸＡ及ＱＣＴ测量。ＤＸＡ与ＱＣＴ在Ｈ、ＯＰ组均显著相关（ｒ＝０．７５，Ｐ＜０．０００１，ｒ＝０．５８，Ｐ＜０．０００１）。Ｈ组及ＯＰ组，随年龄增长的骨减少率，ＱＣＴ较ＤＸＡ法为高。而两组中骨密度的差别，ＱＣＴ较ＤＸＡ法更大（Ｐ＜０．０５）。结论；由于ＱＣＴ可以选择性测量椎体松质骨，故可较ＤＸＡ更能很好地区分健康人与骨质疏松病人。     

DXA、QCT和SPA方法测量47例绝经后妇女骨质疏松症的比较

以骨密度测量应用最广的３种方法（ＤＸＡ─双能ｘ线吸收法，ＱＣＴ─定量ＣＴ法和ＳＰＡ─单光子吸收法）测量绝经后妇女的骨矿密度，比较其测量值、诊断结果和相关关系。首先用ＳＰＡ法测量绝经后妇女１８１例，诊断骨质疏松（ＯＰ）４７例。三种方法测量骨矿密度的均值分别低于峰值骨量的Ｍ─２ｓ的９％、２１．４％和２１％，且ＤＸＡ和ＱＣＴ两种方法测量的均值都在骨折阈值范围内。ＤＸＡ和ＱＣＴ诊断４７例ＯＰ之间无显著性差异，当排除椎骨骨质增生后的ｘ２＝０．２３７，且ＤＸＡ和ＱＣＴ测量值之间为正相关，ｒ＝０．７９９，而ＤＸＡ、ＱＣＴ和ＳＰＡ之间的相关系数，ｒ＝０．１８５和０．２８５，ＤＸＡ诊断ＯＰ的敏感性为８６．６％，特异性为７０％。     

Singh指数法的临床应用探讨

目的 探讨Singh指数法在骨质疏松症诊断及预测骨折风险方面的临床意义。方法 取260例绝经后妇女的前后位骨盆X线片,根据有无椎体压缩变形分成两组：非椎体压缩组（209例,46－80岁）和椎体压缩组（51例）按Singh指数法的分度标准,将股骨近段骨质丢失的情况由低到 高分成连续性的Ⅶ度。结果 非椎体压缩组有96．6％的对象Singh指数异常,Ⅴ度至Ⅵ度84．1％,Ⅳ度及Ⅳ度以下12．5％;椎体压缩组,所有病例的Singh指数均显示异常,Ⅴ度3．9％,Ⅳ度9．8％,Ⅲ度及Ⅲ度以下86．3％。两组病例的Singh指数与年龄呈负相关（非椎体压缩组r＝－0．637,椎体压缩组r＝－0．654,P＜0．01）;两组病例在SinghⅣ度显示最大的交汇,并以Ⅳ度为界,非椎体压缩组的Singh指数主要分布在Ⅳ度以上区域,而椎体压缩组则主要分布在Ⅳ度以下区域。结论 Singh指数法是一种经济、方便和有效的骨密度测定方法,结合临床和有关生化检查,可用于骨质疏松症的诊断和骨折风险的预测,应作为诊断临床骨质疏松症最基本的手段之一。     

Apparent bone mineral density estimated from DXA in healthy men and women

The aim of this study was to measure bone mineral density (BMD) in healthy people and examine the influence of age, anthropometry, and postmenopause on calculated bone mineral apparent density (BMAD). The study included 541 healthy subjects (249 men and 292 women), aged 20 to 79 years. Anthropometric measurements included height, weight, and body mass index (BMI). Bone mineral content (BMC) and areal BMD were measured at the lumbar spine and proximal femur, using dual-energy X-ray absorptiometry (DXA). The calculation of volumetric density relied on the formula BMAD=BMD/BA (where BA = bone area). Association between densitometric parameters and age, height, weight, and postmenopause was analyzed with multiple regression. BMC and BMD decreased with age, especially in postmenopausal women. The average annual bone loss in spine was 0.2% in both sexes, whereas femur loss was 0.5% in men and 0.3% in women. Bone area slightly increased with age in both sexes, and BMD loss after the age of 50 could be attributed to bone area increase. To minimize the effect of bone size on bone density, volumetric density and areal density were regressed to age, anthropometry, and postmenopause. Age and postmenopause were significantly associated with BMD and BMAD in the spine and femur. Furthermore, BMD showed a stronger association with height and weight than BMAD, in both regions. Weaker association of body height and weight with BMAD than with BMD suggests that BMD depends on the bone size and body size and that the different BMDs could be the consequence of the difference in those parameters.     

广东省女性绝经后原发性骨质疏松症调查分析

目的探讨广东省女性绝经后骨密度的变化规律及其影响因素相关分析。方法本研究通过对广东省50～87岁的1772名中老年人完成骨质疏松症问卷调查和进行双能X-ray骨密度测量。筛选绝经后原发性骨质疏松症患者274例,以5岁为1个年龄段,将其分成7个组。分析腰椎和髋部BMD值的变化规律。体重指数、脂肪含量与骨密度的关系。结果广东省不同城市女性原发性骨质疏松症患病率为11.1%～19.2%,总体患病率为15.5%。体重指数与髋部neck、Total骨密度相关系数(r=0.282,r=0.272,P<0.05),脂肪含量与腰椎正位Total骨密度相关系数(r=0.086,P<0.05)。结论广东省女性骨质疏松症患者腰椎骨密度在55～65岁和70～79岁两个年龄段丢失明显,髋部骨密度丢失在65岁以后下降速率加快。体重指数与髋部骨密度值有一定相关性,脂肪含量和腰椎骨密度值有较小相关性。     

胶东半岛老年性骨质疏松症骨代谢生化指标 与骨密度相关性研究

目的 研究胶东半岛老年性骨质疏松症(OP)患者骨代谢生化指标与骨密度(BMD)的相关关系,探讨骨代谢生化指标对早期诊断OP的临床意义.方法 采用双能X线骨密度仪(DEXA)对胶东半岛沿海地区多中心多阶段整群抽样297名40～89岁居民进行腰椎(L2-4)BMD测量.采用酶联免疫法(ELISA)分别测定血抗酒石酸酸性磷酸酶(TRAP-5b)、I型胶原C端肽(CTX)、骨特异性碱性磷酸酶 (BALP)、骨钙素(BGP)、降钙素(CT)、25-羟基维生素D[25(OH)D]以及血钙(Ca)和磷(P)并进行比较,应用SPSS13.0软件进行统计分析.结果 OP患者各部位BMD明显低于正常组(均P<0.01).老年男性BMD与骨形成和骨吸收指标呈现降低趋势.其中,OP组较对照组BGP、TRAP-5b和25(OH)D明显下降(P<0.05),而血CTX和BALP较对照组升高.老年女性血TRAP-5b、CTX、BALP和 BGP在OP组显著升高(均P<0.01),而CT和25(OH)D明显降低.各组研究对象骨代谢生化标志物均有统计学意义.结论 骨代谢生物指标作为OP的监测指标,比BMD更加灵敏、特异.能够早期反映患者骨代谢水平,对指导OP的早期预防及治疗有重要意义.     

Spine and femur BMD by DXA in patients with varying severity spinal osteoporosis

Summary Bone mineral density (BMD) at the lumbar spine, femoral neck, trochanteric region, and Ward's triangle was measured using dual-energy X-ray absorptiometry (DXA) in 118 women with osteoporotic vertebral collapse (average age 65 years), divided into four groups according to numbers and SD of vertebral deformation below norms: group 1:-3SD deformations only; group 2: one-4SD deformation; group 3: two-four-4SD deformations; and group 4: 5 or more-4SD deformations. There were no significant differences between the groups. Results were compared with those from 80 premenopausal (average age 32 years, range 20–40 years) and 109 postmenopausal normal women (average age 64, range 60–70 years). Mean BMD in osteoporotic group 1 was lower than premenopausal normal women by 32% at the lumbar spine, 31% femoral neck, 30% trochanteric region, and 44% at Ward's triangle, and postmenopausal controls by 17% lumbar spine, 16% femoral neck, 17% trochanter, and 14% Ward's triangle. There was a clear trend to reduction in mean BMD between osteoporotic groups 1 and 4 at all four measured sites with significant differences at the spine of 0.102 g/cm² (P<0.01) and Ward's triangle 0.059 g/cm² (P<0.01). When compared with premenopausal controls, there was a reduction in mean BMD between osteoporotic groups 1 and 4 of 10% at the lumbar spine, 7% femoral neck, 8% trochanteric region, and 13% Ward's triangle. Receiver operating characteristic analysis showed no significant differences in diagnostic sensitivities among the four measured sites for vertebral fractures. We conclude from this crosssectional data that the majority of bone loss in spinal osteoporosis occurs before the onset of fractures.     

骨质疏松症患者的牙周组织检查

骨质疏松症和牙周炎均为中老年人的多发病，并都有骨的吸收破坏，骨量减少。为了阐明两者的关系，本研究对２９例中重度骨质疏松症患者和２５例骨密度正常者的牙周状况进行了检查与对比。结果表明：骨质疏松症患者和骨密度正常者的牙周炎患病率无明显差别，表明骨质疏松症与牙周炎之间无明显的相关关系。根据本研究结果提示：骨质疏松症在牙周炎的发生上并不起主要作用，局部（菌斑诱导的非特异性炎症）因素比全身因素在牙周炎的发病机理中更为重要。     

Switching from DXA pencil-beam to fan-beam. I: Studies in vitro at four centers

The performance of the Hologic QDR-2000 DXA osteodensitometer was critically evaluated at four centers, using at all four centers one bone equivalent humanoid spine phantom supplied by the manufacturer. Results were compared with results from Hologic QDR-1000/W using that phantom tested at the same centers.

It appears that the concept of fan-beam scanning—as used in the QDR-2000: a fan-beam, a linear array detector above the phantom, and an x-ray tube located rather close to the spine below the phantom—creates problems due to the magnification effect of the fan beam. The effect of decreasing the distance between the “vertebrae” of the phantom and the couch are: bone mineral content (BMC) increases by 2.8% per cm, projected area (Area) by 2.8% per cm, and bone mineral density (BMD) is unchanged.

When QDR-1000/W is upgraded to QDR-2000, BMD is relatively constant, but there are shifts of BMC and Area which are partly due to the magnification effect of the fanbeam. Replacement of a QDR-1000/W with a QDR-2000 can invalidate longitudinal measurements, even for BMD, unless the proportionality factors of the QDR-2000 are checked and, if necessary, changed. This is true for switching from QDR-1000/W to pencil-beam mode of QDR-2000 or to fanbeam mode of QDR-2000.

Even with pencil-beam mode, the long-term precision error with phantoms is higher for QDR-2000 than for QDR-1000/W (for BMD, 0.47% versus 0.35%).     

Switching from DXA pencil-beam to fan-beam. II: Studies in vivo

Switching from the Hologic QDR-1000/W to the QDR-2000 DXA densitometer was critically evaluated with regard to cross-calibration and dosimetry. Studies with bone equivalent humanoid spine phantoms and patient studies were done. Fan-beam scanning with the QDR-2000 is problematic because of magnification.

Mean phantom bone mineral content (BMC) and bone mineral density (BMD) were moderately but significantly different. Biological variation disguised differences between the two devices in humans, but significant differences were revealed when individual data were analyzed. Longitudinal assessments of BMC and BMD, initiated with QDR-1000/W and continued with the QDR-2000, should employ singlebeam mode only and not fan-beam mode—but even if that is done, significant errors can be introduced.

The new QDR-2000 should be properly cross-calibrated with the original densitometer, and one should make sure that the same software, phantom, and type of collimator are used. The radiation dose is substantially higher with QDR2000 (fan-beam and high-resolution array mode) than with QDR-1000/W (pencil-beam mode) and QDR-2000 (pencilbeam mode), and higher than claimed by the manufacturer. The typical radiation dose given by the manufacturer was half the actual radiation dose measured (e.g., for fan-beam scan 62 μSv versus 33 μSv). High-resolution array mode does not improve precision, but augments the radiation dose to the patient.     

原发性骨质疏松发病的相关因素

阐明原发性骨质疏松发病与性别、年龄、饮食、体重、绝经年限和体内雌激素水平的关系。结果证明骨质疏松发生率女性比男性明显增高，并随年龄增长而增高；饮食中加食牛奶者比不食用牛奶者较低；超重和肥胖者比瘦者为低；绝经后骨质疏松随着年龄的增长而增高，并与雌二醇水平呈负相关。