DXA椎体骨折评价在骨质疏松诊断中的意义

目的比较双能X线骨密度仪的椎体骨折评价(vertebral fracture assessment,VFA)中Genant半定量法和6点定量法对椎体压缩诊断的差异,探讨联合应用VFA在骨质疏松诊断中的意义。方法对85名主诉有腰背痛或身高变矮的患者行骨密度检查(男12例,女73例),平均年龄68.1±10.4岁;女性绝经年龄49.4±3.4岁。同时应用VFA软件分析椎体是否存在压缩,分别采用Genant半定量法和6点定量法进行分析。结果骨密度采用世界卫生组织(WHO)诊断标准,诊断骨质疏松66人,低骨量14人,5人骨量正常,骨质疏松诊断率为77.65%。采用Genant半定量法判断椎体Ⅰ~Ⅲ度压缩76人,6点定量法判断椎体压缩64人,两种方法的椎体压缩诊断率有差异(P0.01),两种方法的Ⅱ、Ⅲ度椎体压缩的诊断率无差异(P0.05)。6例通过骨密度T值诊断的非骨质疏松患者用VFA分析诊断有椎体骨折(压缩Ⅱ~Ⅲ度),应用T值联合VFA椎体压缩Ⅱ~Ⅲ度诊断的骨质疏松率为84.71%,与单独使用T值相比诊断率有差异(P0.05)。结论使用双能X线骨密度仪进行椎体骨折评价时,Genant半定量法和6点定量法对椎体压缩程度为Ⅱ、Ⅲ度的诊断率无差异、一致性好。骨密度检查时联合行VFA可增加骨质疏松的诊断率。     

乳腺癌患者骨质疏松性椎体骨折相关因素分析

目的探索乳腺癌患者治疗前后的骨质疏松性椎体骨折率及相关影响因素。方法收集478例乳腺癌患者作为病例组与500例无乳腺癌病史的妇女作为对照组,采用Genant半定量方法对治疗前后的病例组和对照组胸部X线侧位片上的胸椎T4至腰椎L1进行评估,比较病例组与对照组椎体骨折率的差异,以及病例组治疗前后椎体骨折率的变化;按年龄、体质指数(BMI)、乳腺癌分子亚型(Luminal A、Luminal B、Triple-Negative及HER2+)、治疗时间、治疗方式进行分组,对影响椎体骨折的相关因素进行单因素分析及多因素Logistic回归分析。结果病例组治疗前的椎体骨折率为12.34%,治疗后的椎体骨折率为19.46%,对照组的椎体骨折率为14.40%;病例组治疗前的椎体骨折率与对照组以及病例治疗后组差异存在统计学意义(P<0.05);多因素Logistic回归分析显示年龄、治疗时间是椎体骨折的主要影响因素(P<0.05)。结论乳腺癌治疗的诸多因素都能增加骨质疏松性椎体骨折的风险,乳腺癌患者治疗后的椎体骨折率高于治疗前。     

中国人群定量CT（QCT）脊柱骨密度正常参考值的建立和骨质疏松症QCT诊断标准的验证

目的本研究的目的是建立中国人群定量CT腰椎骨密度正常参考值和验证国际定量CT脊柱骨密度骨质疏松症诊断标准是否适合中国人群。方法本研究采用了3个人群:①全国多中心20～40岁正常青年人群1584例;②年龄40～83岁,总共3420例社区健康人群;③因骨质疏松性脊柱骨折而就诊的432例骨折人群。腰椎骨密度采用美国Mindways的定量CT系统,测量腰椎第1～2椎体骨密度(如果有骨折椎体则测量临近的一个椎体),取平均值。采用国际定量CT腰椎骨密度骨质疏松症诊断标准,即腰椎骨密度120 mg/cm~3为正常,80～120 mg/cm~3为低骨量,80 mg/cm~3为骨质疏松症。社区健康人群采用脊柱侧位定位像,由有经验的骨放射医师根据Genant椎体骨折半定量分析法对胸4～腰4每个椎体分别判断为正常(0),轻度(1),中度(2)和重度(3)骨折。每个个体只要有一个椎体≥1,判断为骨折,每个个体椎体骨折的最高值作为该个体的骨折严重程度。脊柱骨折人群均有X线,CT和/或MR检查至少有一个椎体明确骨折。采用SPSS 19.0进行统计分析。计量数据进行正态分布检验,如果符合正态分布,以均数标准差表示。结果 20～40岁正常青年人的腰椎骨密度男性为(163.26±28.82)mg/cm~3,比女性(174.45±29.24)mg/cm~3低,P0.001。50岁开始,一直到80岁,女性骨密度比男性低(P0.05)。40～83岁正常社区人群以国际骨质疏松症定量CT诊断标准,人群33.2%为骨密度正常(120 mg/cm~3),38.3%为低骨量(80～120 mg/cm~3),28.5%为骨质疏松(80 mg/cm~3)。其椎体骨折的患病率分别为7.14%,14.6%和30.63%,呈倍比关系。432例确诊的脊柱骨折患者,86%脊柱定量CT骨密度低于80 mg/cm~3,其余14%骨密度在低骨量范围。结论建立了中国人群定量CT腰椎骨密度正常参考值,为定量CT的临床应用提供依据;研究结果表明国际定量CT腰椎骨质疏松症诊断标准适合中国人群,可以用于中国人群的定量CT诊断。     

绝经后医务人员骨密度与椎体骨折的横向研究

目的通过横向研究探讨绝经后医务人员骨密度与椎体骨折的相互关系。方法从单中心医务人员中,随机抽取216名绝经后女性,通过双能X线吸光测定仪检测其骨密度,运用Genant半定量法评估椎体骨折,分析骨密度与骨质疏松性骨折、椎体骨折的畸形程度以及EQ-5D评分的关系。结果绝经后医务人员椎体骨密度的正常组、骨量减少组及骨质疏松组分别占27%、35%、38%;随着骨密度T值的降低,正常组(T≥-1. 0)、骨量减少组(-2. 5T-1. 0)和骨质疏松组(T≤-2. 5)的椎体骨质疏松性骨折患病率明显升高(P0. 05),分别为28%、42%和53%;椎体骨折组(无论有/无临床症状)的骨密度明显低于无骨折组(P0. 01);椎体骨折畸形程度越重,其骨密度越低(P0. 01),躯体伸展程度、日常活动、疼痛或舒适度的EQ-5D评分亦越低(P0. 05)。结论绝经后医务人员随着骨密度的降低,骨质疏松和椎体骨折的患病率增加,生活质量亦降低。     

骨质疏松症与脊柱骨折

骨折为骨质疏松最为严重的并发症，骨质疏松性脊柱骨折既是发生再骨折的高危因素，又是预测再次骨折发生的最重要指标。脊柱骨折作为再次骨折的高危因素，它反映了患者骨结构的退变和骨强度(BMD)的下降。预测再次骨折发生的危险性时，结合骨密度降低和有无脊柱骨折，将更有价值。通过X线片可以对脊柱骨折进行评估和分级，Genant半定量法对脊椎骨折进行评估，不需测量椎体高度，较为简便、实用。在药物疗效的评估上，只有将BMD和脊柱骨折结合起来，结果才更为客观、准确。既能增加骨密度又能减少脊椎骨折发生的药物是最为理想的药物。     

QCT联合MRI脂肪定量技术对骨质疏松性骨折患者PVP疗效的评估

目的 探讨定量CT（QCT）联合磁共振成像（MRI）脂肪定量技术对骨质疏松性椎体压缩性骨折（OVCF）患者经皮椎体成形术（PVP）疗效的评估价值。方法 选取2019年4月至2021年4月医院行PVP治疗的165例OVCF患者作为研究对象，所有患者均行QCT联合MRI脂肪定量技术检查并获取相关参数[骨密度（BMD）、脂肪分数（FF）]；术后3个月应用Oswestry功能障碍指数（ODI）评价OVCF患者胸腰椎功能恢复状况，术后随访1年，以再发骨折作为随访终点事件，观察患者随访期间骨折再发情况；分析QCT联合MRI脂肪定量技术对OVCF患者PVP近期及远期疗效的评估价值。结果 术后3个月，ODI指数评估显示，165例OVCF患者中轻度障碍125例、中度障碍22例，重度障碍18例。术后随访1年，165例OVCF患者骨折再发率为16.36 %。不同近期及远期疗效OVCF患者BMD、FF参数比较，差异有统计学意义（P＜0.05）。绘制受试者工作特征（ROC）曲线，结果显示BMD、FF单独及联合评估OVCF患者PVP术后轻中度、中重度及轻重度胸腰椎功能障碍的曲线下面积（AUC）均＞0.7，具有中等评估价值，且联合评估价值最佳；BMD、FF单独及联合评估OVCF患者PVP术后再发骨折的AUC均＞0.7，且联合评估价值最佳。结论 QCT联合MRI脂肪定量技术对OVCF患者PVP近期及远期疗效均具有较高的评估价值，可准确反映胸腰椎功能恢复状况和骨折再发情况。     

运用定量形态学测量法检定原发性脊椎骨折

为比较半定量评定法(Visual Semiquantitative Assessment，SQ)与定量形态学测量法(Quantitative Morphometric Assessment，QM)对脊椎骨折的检测结果，随机抽样400名用DXA测量有骨量减少的绝经后妇女。她们的侧位标准胸腰椎平片均由三位经培训的放射科医师评阅(使用同一骨折判定标准)。并由一位放射科医师运用“六点法”测量每一椎体的前、中、后高度(T4-L4)。QM法的骨折阈值分别定为低于正常人椎体高度比例的平均值的2．0，2．5，3．0．3．5和4．0个标准差(即2．0s，2．5s，3．0s，3.5s，4．0s)，分析两种方法所检出的骨折椎体．再由第4位放射科医师将由两种诊断方法存在差异的椎体重新分析以确定此椎体是否有骨折，此结果作为“诊断标准”(CR)。各放射科医师间的Kappa值为0.80～0．81，各放射科医师与CR间的Kappa值为0．84～0．87，敏感性为85．17～91．75%，特异性为97.19～98．06%。QM法的各骨折阈值与CR间的Kappa值为0.54～0.75．其中以2．5s阈值与CR结果最为符合。其Kappa值为0．75．敏感性为70．23％．特异性为98．76%。实验结果表明，放射科压师间的SQ法结果符合率最好，且优于SQ与QM间的符合率。选用2．5s作为QM法筛选骨折阈值，可获得与CR较好的符合率。     

椎体后凸成形术后再发骨折的相关危险因素分析

[目的]探讨椎体后凸成形术治疗骨质疏松性椎体压缩骨折后不同类型再发骨折的特点和相关危险因素。[方法]回顾性研究2006年4月~2012年4月间,458例行椎体后凸成形术治疗的骨质疏松性椎体压缩骨折患者资料,根据术后再发椎体骨折情况分为原位再发骨折组36例,相邻椎体再骨折组33例,间隔椎体再骨折组35例,对照无再骨折组354例,对临床资料、影像学资料以及手术相关因素进行观察评估并分析。[结果](1)104例患者(22.71%)PKP术后发生再发骨折,66.7%的原位组和54.5%的相邻组椎体再发骨折发生在术后半年内;(2)体重指数低、基础陈旧椎体骨折数目多、骨密度t值低是三种类型再发骨折共同的危险因素;(3)椎体内骨水泥的形态学分布是原位组和相邻组再骨折的影响因素,原位组下终板骨水泥越局限骨小梁水平,原位再骨折的风险越大(OR值,0.311;P=0.016);相邻组上终板骨水泥越接近终板和椎间盘分布,相邻椎体再骨折的风险越大(OR值,4.831;P=0.018);(4)术后支具佩戴时间短是相邻椎体再骨折和间隔椎体再骨折的危险因素。[结论]椎体后凸成形术后三种类型的再发骨折均与严重骨质疏松有关,椎体内骨水泥的形态学分布特点是引起术后再骨折的重要因素,规范佩戴支具和抗骨质疏松治疗能降低再骨折风险。     

椎体骨质疏松性骨折评价方法和设备的临床应用现状

椎体骨质疏松性骨折是中老年人的常见病,无典型临床症状和体征,仅能依靠影像学检查确定。评价椎体骨折的影像学方法分为定性、半定量及定量形态学测量法,而检查设备有X线平片、双能X线吸收测量仪、CT定位像及MR检查等。本文针对以上方法及设备诊断椎体骨质疏松性骨折的价值予以综述。     

DXA影像评估绝经后女性椎体骨折

目的：做骨密度检测时,应用椎体骨折评估软件发现椎体骨折,提高椎体骨折诊断率。方法连续对217例≥50岁绝经后女性做股骨近端骨密度检测时,行胸腰椎侧位扫描,应用椎体骨折评估软件发现椎体骨折。根据骨密度T值分为T＞－2．5组和T≤－2．5组,年龄分为50～59岁组、60～69岁组和≥70岁组,绝经年限分为0～9年组、10～19年组和≥20年组,分析骨密度、年龄和绝经年限对椎体骨折率的影响,为了了解VFA对椎体骨折的评估的一致性,由同一位研究人员间隔2个月后再次对影像进行评估,采用Kappp统计方法行重复性检验。结果骨密度T＞－2．5患者椎体骨折率为21．6％,T≤－2．5患者椎体骨折率34．8％;各年龄组椎体骨折率：50－59岁为12．5％,60－69岁为25．6％,≥70岁为44．8％;绝经年限长的女性椎体骨折率显著升高。重复性检验提示一致性强度极强。结论对绝经后女性做骨密度检测时,同时进行椎体骨折评估有利于提高椎体骨折和骨质疏松诊断率。     

Agreement between semi-automatic radiographic morphometry and Genant semi-quantitative method in the assessment of vertebral fractures

Summary

Semi-automatic morphometry is highly reproducible and not time intensive; however, no study has evaluated agreement between semi-automated morphometric methods and the Genant semi-quantitative method performed as a rule by radiologists. Our study shows substantial agreement between both methods; however, semi-automatic morphometry upgrades mild deformities and overestimates the prevalence of fractures.

Introduction

The aim of this study was to evaluate the agreement between radiologists using the Genant semi-quantitative (SQ) method and semi-automated morphometry in the diagnosis of vertebral fractures in post-menopausal women.

Methods

Cross-sectional study was conducted in 2006–2007 in an age-stratified population-based sample of 824 post-menopausal women over the age of 50. From this population two sets of 95 and 50 X-ray were randomly extracted to test inter-rater agreement and agreement between SQ and semi-automated morphometry, and vertebral fractures were classified according to both methods. The Genant method was used to homogenise the diagnosis of fractures. Agreement was evaluated with weighted kappa. We evaluated each vertebral body independently and also the whole vertebral column (T4–L4) classifying women into the worst grade of fracture. For the qualitative interpretation of the agreement, we used the criteria described by Landis and Koch (Biometrics 33:159–174, 1977).

Results

The radiologists' agreement was 98.4% (Kappa, 0.75; 95% CI, 0.42–0.89). Agreement between semi-automated morphometry and SQ reached 97.6% and Kappa was 0.86 (95% CI, 0.66–0.94). In the whole evaluation of the spine semi-automated morphometry overestimates, the prevalence of fractures compared with the radiologists were 15.8% of women with fractures and 7.4% of women with moderate–severe fractures by semi-automated morphometry vs. 8.4% and 3.2% by the SQ method. The negative predictive value for MorphoXpress was 99% while the positive was 40%.

Conclusions

Semi-automated morphometry shows high reliability and a substantial agreement with the SQ approach but overestimates the prevalence of fractures. Its role in routine clinical practice is limited because positive results should be reassessed by qualitative or semi-quantitative methods.     

Radiographic methods for evaluating osteoporotic vertebral fractures

Reproducible methods for the radiological assessment of osteoporotic vertebral fractures, defined based on accurate criteria, are needed in everyday practice and in therapeutic trials and epidemiological studies.ObjectivesTo describe and to evaluate methods for osteoporotic vertebral fracture assessment based on standard radiographs or dual-energy X-ray absorptiometry (DXA) and to determine the role for each method in clinical practice, therapeutic trials, and epidemiological studies.MethodsA review written by a rheumatologist based on his clinical experience and on a literature review was submitted to four experts. Studies in English or French published between 1975 and February 2008 were retrieved from Medline using the keywords vertebral fracture, osteoporosis, vertebral deformity, and vertebral fracture assessment.ResultsOne hundred forty-nine articles were selected and read in their full-text version. There was no consensus regarding the definition of osteoporotic vertebral fractures. The following methods were evaluated: visual assessment, Genant's semi-quantitative assessment, Jiang's algorithm-based qualitative method, morphometric radiography, and DXA of the spine. In everyday practice, Genant's semi-quantitative assessment on standard radiographs may provide useful information on the severity and prognosis of osteoporosis. DXA done for bone mineral density measurement may detect vertebral fractures in asymptomatic patients. Assessment of standard radiographs remains the reference standard for diagnosing vertebral fractures in patients with suggestive symptoms (e.g., pain in the thoracic or lumbar spine, height loss, or thoracic kyphosis). For therapeutic trials and epidemiological studies, Genant's semi-quantitative assessment used by a trained and experienced observer is the preferred method, based on its good reproducibility and ability to differentiate fractures from other deformities. However, thousands of radiographs may be needed, making routine interpretation by an expert impractical. A visual semi-quantitative method may be used to separate normal radiographs from radiographs showing possible or obvious fractures, which can then be read by an expert. Alternatively, radiomorphometric indices can be determined on digitized radiographs in combination with a semi-quantitative assessment, with discordant cases being reviewed by an expert. We do not recommend Jiang's method at present, as it is still undergoing validation.     

Vertebral dimensions as risk factor of vertebral fracture in osteoporotic patients: a systematic literature review

Summary This systematic literature review studied the potential association between vertebral fracture risk and vertebral dimensions. Analysis showed that patients with vertebral fractures have smaller non-fractured vertebrae than patients without fractures. Vertebral size is an independent risk factor of vertebral fractures. Introduction Biomechanical factors such as vertebral dimensions may be a risk factor for vertebral fractures beside bone mineral density (BMD). The objective of this study was to evaluate potential association of vertebral size and shape with osteoporotic fracture risk through a systematic literature review. Methods Systematic analysis of published reports comparing vertebral dimensions of patients with and without osteoporotic fractures was performed. Data sources were electronic databases. Data extraction included methods, site, reproducibility and results of vertebral measurement, study population characteristics. It was noted if populations were matched or data were adjusted for age, height, weight and BMD. Results Of 634 reports identified by the literature search, the final review included 13 reports studying 4,428 women and 508 men; median age 64.2 years [range 51.7%–73.0%]. Measurements were performed with computed tomography scan, X-ray, or dual energy X-ray absorptiometry. Vertebral body height, width, depth, area, cross-sectional area (CSA), and volume were 5.5% to 9.5% smaller in fractured group than control group. After adjustment for confounding factors, area, CSA and volume were, respectively, 10.2% [range 7.1%–13.3%], 7.7% [range 1.2%–14.2%] and 9.5% [8.5%–10.5%] smaller in fractured group. Conclusions Vertebral size should be considered as a potential independent vertebral fracture risk factor.     

Enhanced prediction of fracture risk combining vertebral fracture status and BMD

Summary Prevalent vertebral fractures are associated with increased fracture risk, but the magnitude of this effect across a range of BMD T-scores has not been quantified. In this analysis, for any given BMD T-score, incident fracture risk varied up to twelve fold when information regarding prevalent radiographic vertebral fracture status was considered. Background Clinical fracture risk evaluation of older women usually includes assessment of bone mineral density (BMD) but often not vertebral fracture status. In this analysis, we quantified the impact of vertebral fracture burden on two year fracture risk across a range of BMD T-scores. Methods Data were from 2,651 postmenopausal women who were assigned to the placebo groups of the Fracture Prevention Trial (median observation 21 months) and the Multiple Outcomes of Raloxifene Evaluation Trial (MORE; observation 2 years). Using the Genant visual semiquantitative criteria, we defined prevalent vertebral fracture status as: a) presence or absence of fracture; b) fracture number; c) maximum semi-quantitative (SQ) score (normal=0, mild fracture=1, moderate fracture=2, severe fracture=3); and d) spinal deformity index (SDI) score (sum of SQ scores of T4 to L4 vertebrae). Incident fractures over two years were identified via lateral spine radiographs and outside the spine by questioning of patients and review of radiographs or radiographic reports. Results Femoral neck BMD T-score provided significant information regarding fracture risk. Across the range of T-scores, vertebral fracture status provided additional prognostic information. The risk increased with increasing number and severity of prevalent vertebral fractures and SDI, a summary measure of spine fracture burden. Across a range of BMD values, prevalent spine fracture burden as assessed by SDI increased the risk of incident vertebral fractures by up to 12-fold, nonvertebral fractures by about twofold, and any fractures by up to sevenfold. Conclusions These findings indicate that at any given BMD T-score, the risk of incident vertebral, non-vertebral, and any fracture depended heavily on prevalent radiographic vertebral fracture status. Assessment of vertebral fracture status, in addition to BMD, provides practical and relevant clinical information to aid in predicting fracture risk in postmenopausal women. This study was supported by Eli Lilly and Company.     

An evaluation of densitometric vertebral fracture assessment in men

Summary The utility of, and potential indications for, densitometric vertebral fracture assessment were evaluated in 1,168 men. A bimodal fracture distribution was observed, identifying fractures in 17% of men with no fracture history. Osteopenia or height loss of ≥ 2.5″ may be indications for VFA in men. Introduction Densitometric vertebral fracture assessment (VFA) is an excellent means to detect unappreciated vertebral fractures in women. However, little evaluation of VFA in men has been performed. This study evaluated VFA utility and explored potential VFA indications in men. Methods The study cohort consists of a population of 1,168 men (mean age, weight and BMI of 69.1 years, 188.8 pounds and 28.1 kg/m², respectively) referred for clinically indicated bone mineral density (BMD) measurement at the Wm. S. Middleton VAMC. Lateral VFA images and scans of the lumbar spine, proximal femur and non-dominant radius, were obtained by two technologists using a GE Healthcare Lunar Prodigy densitometer. Vertebral fractures were defined using the Genant visual semi-quantitative approach. Results Seventy-eight percent of vertebrae from T4–L5 and 93% from T8–L5 were adequately visualized on VFA. Vertebral fractures were detected in 32% (374/1,168) of these men. A bimodal distribution was observed with fractures being most common in the mid-thoracic spine and at the thoraco-lumbar junction. As would be expected, the prevalence of VFA-detected fractures increased with age and as BMD declined. Fracture prevalence did not increase until a historical height loss of ≥ 6.4 cm (2.5 inches) was reported. VFA-identified fractures were present in 17% of men who had no history of fracture. Furthermore, in men with densitometric osteopenia, no historical fracture and absence of glucocorticoid use (n = 158), vertebral fractures were detected in 18%. Conclusion VFA allows evaluation of the majority of vertebral bodies in men and identifies a substantial number of individuals with previously unappreciated fracture. Additionally, a more stringent height loss requirement, perhaps 2.5 inches or more, or densitometric osteopenia (low bone mineral density by DXA), may be appropriate as indications for performance of VFA in men.     

Reporting of vertebral fractures on spine X-rays

Vertebral fractures are the hallmark of osteoporosis, responsible for increased morbidity and mortality in post-menopausal women. However, two-thirds of vertebral fractures do not come to clinical attention. The aim of this study was to compare the identification of vertebral fractures on spine X-rays among rheumatologists. Study subjects were women aged 60–80 years having potential signs of vertebral fracture and visiting a rheumatologist. X-rays were performed according to standardized procedures. In 629 patients (among 824 included) at least one vertebral fracture was diagnosed, and the X-rays were then sent to a central facility where a semi-quantitative assessment of vertebral fracture was performed by a single rheumatologist trained for this evaluation. According to the vertebral level, kappa scores were between 0.20 to 0.77, i.e., below 0.6 from T4 to T7, and between 0.6 and 0.77 from T8 to L4. The false-negative fractures rate was 25.8% (and 15.7% of them were related to a numbering discrepancy). The rate of false positive fractures was 6.3%. At the patient level 6.8% had actually no fracture. This study shows that 25% of overall vertebral fractures are not diagnosed among patients considered as having at least one fracture. As a consequence, patients who require treatment to reduce fracture risk are not being properly identified.     

Visual identification of vertebral fractures in osteoporosis using morphometric X-ray absorptiometry.

Visual identification of vertebral fractures from spinal radiographs (visual XR) makes use of the reader's expertise in ruling out non-fracture deformities or normal variants. Scan images of the spine acquired by DXA may be analyzed quantitatively (morphometric X-ray absorptiometry [quantitative MXA]) or visually (visual MXA). The aims of this study were to compare visual and quantitative MXA with visual XR for the identification of vertebral fractures. Spinal radiographs and MXA scans were acquired at baseline and 1 year in 70 women referred with osteoporosis. These were assessed visually by two expert readers (observer A, a radiologist; observer B, a physician with expertise in osteoporosis) for evidence of prevalent and incident vertebral fractures. Observer C (a radiographer with expertise in vertebral morphometry) performed visual and quantitative assessments of the MXA scans. Visual assessment of spinal radiographs by observer A was used as the gold standard for comparison of methods. Sensitivity for the identification of prevalent fractures by MXA was best for visual MXA by observer A (92%), whereas quantitative MXA had the lowest sensitivity (82%). Specificity was >90% for both visual and quantitative MXA. Kappa scores for agreement for identification of prevalent fractures between visual XR (observer A) and visual MXA (all three observers), and between visual XR and visual MXA performed by reader B were similar (kappa = 0.85-0.87). Agreement with visual XR performed by observer A was slightly lower for quantitative MXA (kappa = 0.77). Interobserver agreement between the two expert readers (observers A and B) was the same for both visual XR and visual MXA (kappa = 0.86). Seven incident vertebral fractures were identified in four patients at follow-up. All four patients were identified by visual MXA, and three patients were identified by quantitative MXA. Observers A and B identified all seven incident fractures by visual MXA, and observer C missed one fracture that was also missed by quantitative MXA. An incident fracture of vertebra T6 was excluded from analysis by quantitative MXA because of poor image quality. We conclude that visual identification of vertebral fractures from MXA scans is superior to quantitative assessment. Used as a screening tool for conventional radiography, this approach could help reduce the radiation dose to the patient in the diagnosis and monitoring of osteoporosis.     

Comparison of Four Morphometric Definitions and a Semiquantitative Consensus Reading for Assessing Prevalent Vertebral Fractures

The assessment of vertebral fracture in patients with osteoporosis by conventional radiography has been improved over the past 10 years using either the semiquantitative (SQ) method devised by Genant et al. or quantitative morphometry. However, there is still no internationally agreed definition for vertebral fracture and there have been few comparative studies between these different approaches. Our study assessed the reproducibility of the SQ method and of four commonly used morphometric algorithms (Melton’s, Eastell’s, Minne’s and McCloskey’s methods) for assessing prevalent vertebral fractures, and examined the agreement of each morphometric algorithm with a SQ consensus reading performed by three experts. With this consensus reading in place of a gold standard, we determined relative measures of sensitivity, specificity and optimal cutoff threshold for each morphometric algorithm. The study was conducted in 39 postmenopausal women who had at least one osteoporotic vertebral fracture. Normal values were derived from 84 healthy postmenopausal women with apparently normal vertebral bodies. Our results indicate that the concordance of SQ method was excellent (intraobserver agreement on serial radiographs = 96.4%, κ= 0.91; agreement between individual readings and the consensus reading = 98%, κ= 0.95). Three morphometric approaches demonstrated good intra- and interobserver concordance (Melton: intraobserver agreement on serial radiographs = 92.7%, κ= 0.82, interobserver agreement = 91.1%, κ= 0.79; Eastell: intraobserver agreement on serial radiographs = 87.6%, κ= 0.66, interobserver agreement = 88.6%, κ= 0.68; McCloskey: intraobserver agreement on serial radiographs = 91.5%, κ= 0.72, interobserver agreement = 93.9%, κ= 0.78). Except for McCloskey’s method, the optimal cutoff thresholds defined in our study by highest κ score or Youden index in comparison with the SQ consensus reading were near the cutoff thresholds that were arbitrarily fixed. The four morphometric algorithms provided a good agreement with the results of the SQ consensus reading, but the more complex algorithm did not provide better results and even if we adjusted the cutoff threshold, no morphometric algorithm agreed perfectly with the SQ consensus reading. We conclude that morphometric approaches currently used should not be employed alone to detect prevalent vertebral fractures in studies on osteoporosis, but should rather be used in combination with a visual assessment. The SQ approach that allows differential diagnosis of vertebral deformities and has demonstrated a better reproducibility can be employed alone when it is performed by experienced and well-trained readers. Received: 3 July 2000 / Accepted: 26 March 2001