Measurement of lumbar spine bone mineral: a comparison of dual photon absorptiometry and computed tomography

A comparison of computed tomography (CT) and dual photon absorptiometry (DPA) in the measurement of spinal bone mineral was made in 44 subjects of whom 26 had vertebral crush fractures. Although CT measures only trabecular bone within the vertebral body whilst DPA measures the whole vertebral segment, a good correlation was observed (r = 0.80) when these quantities were expressed in dimensionally similar units. Trabecular bone in the distal radius measured by CT correlated less well with vertebral CT (r = 0.65). Cortical bone in the radius correlated poorly with the spinal DPA measurement (r = 0.38).     

Comparisons between X-ray photodensitometric and gamma-ray absorptiometric findings of bone mineral measurements, and the evidence of their convertibility.

Fifty-two bone mineral measurements were made in chronic renal failure patients using two different radiologic techniques concurrently: gamma-ray absorptiometry; and x-ray photodensitometry. Although the sites of measurements of the cortical bone mineral mass in radius were different (distal vs. proximal) and different parameters were determined (in units of gm/cm vs. gm/cm2), a moderately good correlation was found between measurements by the two techniques (r = 0.61, p less than 0.001). Using external bone width, it was possible to calculate from photodensitometric measurements the bone mass per unit length (gm/cm). This conversion improved the correlation with absorptiometry values considerably (r = 0.78, p less than 0.001). A similar correlation was found between the trabecular bone mass in the distal radius, measured by absorptiometry, and the cortical bone mass in the proximal radius, determined by photodensitometry (r = 0.79, p less than 0.001), the correlation between the cortical and trabecular bone masses by absorptiometry being only slightly higher (r = 0.84, p less than 0.001). The residual variations not explained by the correlations between the absorptiometric and photodensitometric techniques may be largely due to the real differences of bone mineral masses at the two measuring sites and by the inherent methodological errors.     

~1H-MRS与DWI在骨质疏松症中的初步应用

目的 探讨绝经后女性腰椎骨髓脂肪分数(fat fraction,FF)、表观扩散系数(apparent diffusion coefficient,ADC)值与骨密度(bone mineral densities,BMD)的关系.资料与方法 将行腰椎双能量X线吸收测定(dual X-rayabsorptionmetry,DXA)的60例绝经后女性根据T值分为3组:骨质正常组(T>-1.0)20例,骨质减少组(T=-1.0～-2.5)20例,骨质疏松组(T<-2.5)20例.所有研究对象均行氢质子磁共振波谱分析(~1H MR spectroscopy,~1H-MRS)、MR扩散加权成像(diffusion weighted imaging,DWI),分别测定L_3椎体FF和ADC值.采用组间t检验对不同骨质组间FF、ADC值差异进行统计学分析.采用Pearson相关分析3组间FF、ADC值与BMD的相关性. 结果骨质疏松组脂肪含量[(59.1±8.8)%,P=0.003]与骨质减少组脂肪含量[(54±7.6)%,P=0.039]均比骨质正常组[(49±9.1)%]高.骨质疏松组比骨质减少组椎体脂肪含量高(P=0.045).椎体骨髓ADC值与T值无相关性.所有绝经后女性患者FF值与T值呈负相关(r=-0.46,P<0.01),与ADC值间呈轻度负相关(r=-0.25,P<0.05),但骨质疏松组中FF值与ADC值间呈较明显负相关(r=-0.72,P<0.01).ADC值与T值无相关性(r=0.315,P>0.05).结论 绝经女性椎体骨髓脂肪含量随着BMD的减小而增大.MRS可作为BMD检查的辅助手段.MRS与DWI可以无创性了解骨质疏松症患者骨髓的生理、病理变化,单纯DWI并不能反映BMD的改变.     

Assessment of bone mass by image analysis of metacarpal bone roentgenograms: a quantitative digital image processing (DIP) method

a digital processing (DIP) method for assessing bone mass was developed on the basis of image analysis of roentgenograms. Linearity between DIP values and the actual calcium carbonate content was scarcely affected even if roentgenograms were made with bone phantoms placed in different depths of water or by altering the voltage of X-ray generation. In clinical studies, coefficients of variation (CV) for various measurements were lower than 2.4%. When the correlations between the DIP values and the bone mineral densities in the distal one-third of the radius, and the 2nd to 4th lumbar vertebrae were investigated in 340 females, there were good positive correlations of r = 0.799, and r = 0.611, respectively (p less than 0.001). The DIP value was significantly lower in patients showing a low Singh index and in those with vertebral fractures than in other subjects. These results suggest that the DIP method provides an index with which to assess the efficacy of treatment and which can be used as a criterion in screening for osteoporosis.     

Bone mineral content in early-postmenopausal and postmenopausal osteoporotic women: comparison of measurement methods

To investigate associations among methods for noninvasive measurement of skeletal bone mass, we studied 40 healthy early postmenopausal women and 68 older postmenopausal women with osteoporosis. Methods included single- and dual-energy quantitative computed tomography (QCT) and dual-photon absorptiometry (DPA) of the lumbar spine, single-photon absorptiometry (SPA) of the distal third of the radius, and combined cortical thickness (CCT) of the second metacarpal shaft. Lateral thoracolumbar radiography was performed, and a spinal fracture index was calculated. There was good correlation between QCT and DPA methods in early postmenopausal women and modest correlation in postmenopausal osteoporotic women. Correlations between spinal measurements (QCT or DPA) and appendicular cortical measurements (SPA or CCT) were modest in healthy women and poor in osteoporotic women. Measurements resulting from one method are not predictive of those by another method for the individual patient. The strongest correlation with severity of vertebral fracture is provided by QCT; the weakest, by SPA. There was a high correlation between single- and dual-energy QCT results, indicating that errors due to vertebral fat are not substantial in these postmenopausal women. Single-energy QCT may be adequate and perhaps preferable for assessing postmenopausal women. The measurement of spinal trabecular bone density by QCT discriminates between osteoporotic women and younger healthy women with more sensitivity than measurements of spinal integral bone by DPA or of appendicular cortical bone by SPA or CCT.     

骨质疏松与恶性骨质破坏致椎体压缩性骨折的CT磁共振成像影像特点及鉴别诊断

目的 探究采用CT、磁共振成像(MRI)鉴别诊断骨质疏松与恶性骨破坏导致的椎体压缩性骨折的临床疗效.方法 选择2019年12月至2020年12月经临床诊疗证实为骨质疏松及恶性骨质破坏致脊椎骨折的患者76例,分为2组:A组(骨质疏松改变并伴有压缩性骨折,36例),B组(恶性骨破坏致压缩性骨折,40例).对比2组患者椎体、...     

Percutaneous vertebroplasty for compression fracture: analysis of vertebral body volume by CT volumetry

PURPOSE: To evaluate the relationships between volume of vertebral bodies with compression fracture (measured by CT volumetry) before percutaneous vertebroplasty, the amount of bone cement injected, and the effect of treatment. MATERIAL AND METHODS: We examined 49 consecutive patients, with 104 vertebral body compression fractures, who underwent percutaneous injection of bone cement. Vertebral body volume was measured by CT volumetry. The patient's pain level was assessed using a visual analog scale (VAS) before and after the procedure. Improvement in VAS was defined as the decrease in VAS after the procedure. Relationships between vertebral body volume, the amount of bone cement, and the effect of treatment were evaluated using Pearson's correlation coefficient test. RESULTS: Average vertebral body volume was 26.3 +/- 8.1 cm3; average amount of bone cement was 3.2 +/- 1.1 ml; and average improvement in VAS was 4.9 +/- 2.7. The vertebral body volume was greater if a larger amount of bone cement was injected. There was a significant positive correlation between vertebral body volume and amount of bone cement (r = 0.44; P < 0.0001). However, there was no correlation between vertebral body volume and improvement in VAS, or between amount of bone cement and improvement in VAS. CONCLUSION: In percutaneous vertebroplasty for vertebral body compression fracture, there is a positive correlation between vertebral body volume and amount of bone cement, but improvement in VAS does not correlate with vertebral body volume or amount of bone cement.     

The spine deformity index in osteoporosis is not related to bone mineral and ultrasound measurements.

In 34 female patients suffering from osteoporotic vertebral compression fractures, the spine deformity index (SDIM) was determined, according to the method of Minne et al (1988), to reflect the radiological severity of established osteoporosis. Peripheral (single-photon absorptiometry (SPA) of the non-dominant distal forearm) and axial (quantitative computed tomography (QCT) of the lumbar spine) bone mineral measurements, as well as the broadband ultrasound attenuation of the os calcis, were performed in the osteoporotic patients and in a control group of 20 age-matched women. No correlation could be found between bone mineral measurements and radiological severity of osteoporosis, expressed as SDIM. All three densitometry methods showed clearly reduced values in patients with vertebral crush fractures. Correlations established in the control group between peripheral and axial bone mass (SPA versus QCT) could no longer be found in the osteoporotic group, thus indicating changes in bone mineral density of the spine after the occurrence of osteoporotic fractures. Our data show that SDIM is an additional parameter of osteoporotic change in the spine, independent from bone mass measurements. In the management of osteoporotic patients, quantitative radiological methods (i.e. SDIM) in addition to densitometry might be of value for grading and monitoring the progress of disease.     

双能CT能谱曲线及骨钙CT值对骨质疏松的诊断价值

目的探讨双能CT能谱曲线及骨钙CT值对腰椎骨质疏松的诊断价值。资料与方法纳入84例疑似骨质疏松患者行腰椎(L3、L4)双能CT扫描及双能骨密度检查,并经双能CT图像后处理获得能谱曲线斜率及骨钙CT值。根据双能X线骨密度仪(DXA)测量腰椎T值,并分为非骨质疏松组58例和骨质疏松组26例。比较两组能谱曲线斜率和骨钙CT值的差异,分析能谱曲线斜率和骨钙CT值与DXA参数间的相关性。结果骨质疏松组患者骨钙CT值小于非骨质疏松组,差异有统计学意义(P<0.01);两组患者椎体能谱曲线斜率差异有统计学意义(P<0.01)。L3能谱曲线斜率与DXA椎体T值、骨密度均呈显著正相关(r=0.59、0.59,P<0.01);L4能谱曲线斜率与DXA椎体T值、骨密度均呈显著正相关(r=0.62、0.63,P<0.01);L3骨钙CT值与DXA椎体T值、骨密度亦均呈显著正相关(r=0.61、0.61,P<0.01);L4骨钙CT值与DXA椎体T值、骨密度亦均呈显著正相关(r=0.57、0.57,P<0.01)。结论双能CT能谱曲线斜率及骨钙CT值可较好地反映腰椎骨密度情况,为骨质疏松的诊断及治疗效果评估提供参考。     

Medullar fat influences texture analysis of trabecular microarchitecture on X-ray radiographs

Alteration of trabecular architecture is a predictor of fracture risk in osteoporosis. Until now, microarchitecture analysis is difficult to evaluate in routine clinical practice for osteoporosis. Texture analysis on X-ray images has been advocated to be a suitable method to assess microarchitecture in bone diseases. The X-ray acquisition conditions have been often taken into consideration; however, the influence of anatomical conditions on texture parameters has received little interest. Because fat is a well-known problem with computed tomography and densitometry, we have designed a cadaver study to compare the influence of marrow lipids on numerous texture parameters. Twenty-one human distal radii were obtained, radiographed, and analyzed using a software that measures: heterogeneity, skeletonized parameters, run-lengths and fractal dimensions. Texture parameters were measured before, and after an extensive delipidation period lasting 3 weeks. Quality of the radiographs was improved after defatting. Delipidation had a very significant effect on measurements: afterwards defatting, the images were less blurred, and a better delineation of trabeculae and marrow cavities was obtained. This provoked an increase of parameters based on the grey level distribution but had no influence on parameters describing the reticulated honeycomb microarchitecture of the trabeculae (i.e., fractal dimension). Some parameters appeared anisotropy-sensitive, due to the different constitution and size of the trabeculae. The fat content of bone marrow induces noise that can modify some texture parameters. One should take into account the fat content of the marrow when using texture analysis to compare patients with osteoporosis due to various etiologies.     

磁共振波谱技术在腰椎原发性骨质疏松中的诊断价值

目的探讨磁共振(MR)波谱脂肪测量技术评估腰椎原发性骨质疏松的价值。方法利用1.5T MR波谱(MRS)及双能X线吸收法(DXA)对56例研究对象进行检查,收集腰椎L3椎体脂肪比(FF)及L1~4椎体骨密度(BMD)值,以T值-2.5为临界点分为2组,将T值>-2.5定为阴性组和T值≤-2.5定为阳性组,采用Pearson法对FF-MRS与BMD作相关性分析。结果阴性组与阳性组之间的FF及BMD差异均有统计学意义(P<0.01),FF与BMD平均值存在高度负相关关系(r=-0.806,P<0.01)。结论MR波谱因其在评估骨质量方面有较好的优势,可为原发性骨质疏松评估提供一个有效的辅助方法。     

Cross-sectional study of osteopenia with quantitative MR imaging and bone densitometry

PURPOSE: To evaluation the cancellous bone-induced intravoxel spin dephasing rate (R2') and its relationship to bone mineral density and marrow fat and to examine these parameters as predictors of vertebral fracture status. MATERIALS AND METHODS: R2' and R2, the rate constants for reversible and irreversible spin dephasing, and marrow fat fraction were measured in the lumbar vertebrae and proximal femur. One hundred thirty-nine subjects (mean age, 62.4 years +/- 11.4 [SD]; 33 men, 106 women) had spinal dual-energy x-ray absorptiometric bone mineral density (BMD) T scores ranging from +3 to -5. R2', BMD, and bone marrow composition as determinants of vertebral fracture status were examined. RESULTS: Strongest single predictors of fracture status for BMD and R2' were the Ward triangle (r(2) = 0.48) and trochanter (r(2) = 0.37), respectively. Combined, the two parameters and sites increased fracture prediction (r(2) = 0. 62), whereas the combination of multiple BMD sites did not. Multivariate regression involving marrow fat fraction further improved fracture status prediction. R2' was correlated with BMD at all sites, although slopes differed by a factor of up to 2.5, which reflected differences in trabecular orientation relative to the static field. R2, the true transverse relaxation rate, was negatively correlated with marrow fat fraction. A non-age-related increase in marrow fat fraction in osteoporosis parallels earlier findings in animal models. CONCLUSION: Cancellous bone marrow R2' measured in the proximal femur provides information, which, with BMD, improves prediction of vertebral fracture status.     

Correlation of MR lumbar spine bone marrow perfusion with bone mineral density in female subjects

PURPOSE: To prospectively assess lumbar spine bone marrow perfusion at dynamic magnetic resonance (MR) imaging and correlate perfusion with bone mineral density (BMD) in female subjects. MATERIALS AND METHODS: BMD measurement and dynamic MR imaging of the lumbar spine were performed in 69 female subjects (mean age +/- standard deviation, 57 years +/- 11). Subjects were stratified into premenopausal (n = 19) and postmenopausal (n = 50) groups, with the latter group including both women who were (n = 13) and women who were not (n = 37) receiving hormone replacement therapy. BMD (in grams per square centimeter) was measured with dual energy absorptiometry in the lumbar spine. Peak enhancement ratio, measured with time-signal intensity curves calculated from dynamic MR image data, represented bone marrow perfusion. Peak enhancement ratio was compared with age and BMD by using linear regression analysis and Pearson correlation. RESULTS: A significant positive correlation was found for BMD with peak enhancement ratio of lumbar vertebrae among all subjects (n = 69, r = 0.63, P <.001), all postmenopausal women (n = 50, r = 0.50, P <.001), and postmenopausal women without hormone replacement therapy (n = 37, r = 0.61, P <.001). However, the correlation between BMD and peak enhancement ratio was not significant (P >.05) in premenopausal women (n = 19) or postmenopausal women receiving hormone therapy (n = 13). Both BMD and peak enhancement ratio were inversely correlated with age (P <.001, Pearson correlation). Pearson partial correlation coefficient for peak enhancement ratio and mean in all subjects, with control for inverse correlation with age, was significant (r = 0.63, P <.001). CONCLUSION: Significant correlation was found between the peak enhancement ratio of vertebral bone marrow and BMD in postmenopausal female subjects. This result may suggest a vascular component in the pathogenesis of osteoporosis.     

Measurement of femoral bone density using dual photon absorptiometry. Values in osteoporosis]

X-ray absorptiometry allows measuring the density of bone in the upper end of the femur in 3 mains areas: the neck, Ward's triangle and the greater trochanter. Failin prospective data, it is not possible at present to know whether one of these areas has better performances than the others for the assessment of fracture risks. The interpretation of the measurement is based on the idea that bone demineralization is the main risk factor of osteoporotic fracture. It is carried out on the basis of reference normal values, which must be determined in the French population. More sophisticated predictive models of fracture risks are being developed. In young adults, the reproducibility of the measurements is lower than 2% for the neck and the trochanter, and around 2.5 to 3% for Ward's triangle. The density of femoral bone is not well correlated to that of the other bony sites (os calcis, ulna, vertebrae: r = 0.3 to 0.7). On the other hand, the correlation between the right and left femur is good, as well as that of the three femoral measurement areas between them. A fracture of the upper end of the femur is often associated with a decrease in femoral bone density (-12 to -15%, according to the site of measurement), while the measurement in the ulna or the spine is normal or just slightly lowered. Femoral bone rarefaction is also noted in vertebral osteoporosis. Dual photon absorptiometry allows, in most cases, an accurate and reproducible measurement of the femoral bone density. This measurement is indicated to assess the risk of osteoporosis on menopause and in elderly subjects and/or those with lumbar osteoarthritis.     

The differences in panoramic mandibular indices and fractal dimension between patients with and without spinal osteoporosis

OBJECTIVES: The aims of this study were to evaluate the relationship between osteoporosis, oral signs, body mass index and age; and to assess the possibility of using these parameters as an indicator of post-menopausal osteoporosis. The oral signs were panoramic-based mandibular indices, such as cortical width, cortical index, panoramic mandibular index and mandibular crest resorption degree; the number of teeth and fractal dimension analysis. METHODS: Forty-eight post-menopausal women between the ages of 40 years and 64 years were evaluated. Mandibular indices and the number of mandibular teeth were measured and evaluated from panoramic radiographs and fractal dimension was calculated from the direct digital periapical radiographs of the mandibular premolar-molar region in box-counting method. Weight, height, menopausal status and age of the patients were recorded by questionnaire. Bone mineral densities of the patients were measured with dual energy X-ray absorptiometry. RESULTS: In this study there were no statistically significant differences between the osteoporotic and non-osteoporotic patients for cortical width, panoramic mandibular index, alveolar crest resorption degree, fractal dimension and the number of mandibular teeth, but there was a difference for cortical index. Binary logistic regression analyses demonstrated that age (P = 0.015) was an important risk factor for osteoporosis. CONCLUSION: The results of this study demonstrated that osteoporotic patients were more likely to have altered inferior cortex morphology than non-osteoporotic patients and age is an important risk factor for osteoporosis.     

骨质疏松症~1H-MRS脂肪分数定量研究:Meta分析

目的采用Meta分析的方法综合评价1H-MRS相对定量指标脂肪分数与骨质疏松症骨密度的关系,探索脂肪分数能否如骨密度一样成为诊断骨质疏松症的可靠指标。方法检索Pubmed、Cochrane图书馆、Medline、中国知网(CNKI)等数据库中2000年1月—2014年12月公开发表的有关1H-MRS评价骨质疏松的中英文文献,提取文献中骨质疏松组与正常组的相对定量指标(脂肪分数),以及脂肪分数与骨密度的Pearson相关系数r值。采用review manager 5.0统计学软件对纳入文献的脂肪分数进行Meta分析,获得汇总加权均数差(WMD)及95%CI;并对脂肪分数与骨密度的Pearson相关系数r进行分析。结果纳入9篇文献(英文7篇,中文2篇),共499例病人(正常组210例,骨质疏松组289例)。Meta分析结果显示,骨质疏松组的脂肪分数高于正常组,汇总WMD为9.25(95%CI:6.95~11.56);通过合并Pearson相关系数r分析,脂肪分数与骨密度呈负相关(-0.59,95%CI:-0.76~-0.42)。结论 1H-MRS测量的脂肪分数在评价骨质疏松症中有一定的临床价值,可作为双能X线吸收法的补充检查。其能否像骨密度一样成为诊断骨质疏松症的可靠指标,可行性及准确性需要更多的研究。     

Trabecular bone structure of the distal radius, the calcaneus, and the spine: which site predicts fracture status of the spine best?

RATIONALE AND OBJECTIVES: To compare trabecular bone structure measures obtained in magnetic resonance images of the distal radius and the calcaneus as well as computed tomographic images of the spine versus bone mineral density (BMD) of the spine and the calcaneus in the prediction of osteoporotic spine fracture status. MATERIAL AND METHODS: High-resolution magnetic resonance images of the calcaneus and the distal radius and thin-section computed tomographic images of thoracic and lumbar vertebrae were obtained from 74 cadavers. Structure analysis was performed using parameters analogous to standard histomorphometry. BMD of the spine was determined by using quantitative computed tomography and of the calcaneus by using dual x-ray absorptiometry. Spine radiographs of these cadavers were assessed concerning vertebral deformities. RESULTS: The diagnostic performance in differentiating fracture and nonfracture subjects was highest for structure parameters in the spine and slightly lower for these parameters in the distal radius and for BMD of the spine. CONCLUSION: In this study structure parameters in the spine were best suited to predict the osteoporotic fracture status of the spine.     

Comparative bone density measurements in healthy women and women with osteoporosis

To compare methods of noninvasive measurement of bone mineral content, 40 healthy early postmenopausal women and 68 postmenopausal women with osteoporosis were studied. The methods included mono- and dual-energy quantitative computed tomography (QCT) and dual-photon absorptiometry (DPA) of the lumbar spine, single-photon absorptiometry (SPA) of the distal third of the radius, and combined cortical thickness (CCT) of the second metacarpal shaft. Lateral thoracolumbar radiographic studies were performed and the spinal fracture index calculated. There was good correlation between QCT and DPA methods in early postmenopausal women and moderate correlation in postmenopausal osteoporotic women. Correlations between spinal measurements (QCT or DPA) and appendicular cortical measurements (SPA or CCT) were moderate in healthy women and poor in osteoporotic women. Measurements resulting from one method were not predictive of measurements obtained by another method for individual patients. The strongest correlation with severity of vertebral fracture was provided by QCT and the weakest by SPA. There was good correlation between single- and dual-energy QCT results. Osteoporotic women and younger healthy women can be distinguished by the measurement of spinal trabecular bone density using QCT, and this method is more sensitive than the measurement of spinal integral bone by DPA or of appendicular cortical bone by SPA or CCT.     

Comparisons of bone mass measurements on various skeletal sites including quantitative ultrasonography of the calcaneus for assessing age-related losses, their correlations, and diagnostic agreement using the Japanese and WHO criteria for osteoporosis

Purpose The aim of this study was to compare age-related bone losses and correlations among several bone mass measurements and to evaluate diagnostic agreement among them using the Japanese and WHO criteria for osteoporosis. Materials and methods A total of 846 women (mean ± SD: age 54 ± 9 years) were evaluated. Bone mineral densities of the lumbar spine, femoral neck, and calcaneus were measured by dual X-ray absorptiometry and distal radius by peripheral computed tomography. Quantitative ultrasonography (QUS) parameters of the calcaneus were also measured. The age-related bone losses after 50 years of age and correlations among bone mass results were evaluated using linear regression analysis. Diagnostic agreement was evaluated by kappa statistics. Results The annual losses ranged from 1.0% to 1.6%. The correlation coefficients ranged from 0.54 to 0.78. The kappa scores ranged from 0.52 to 0.30 for all subjects using the Japanese criteria and from 0.38 to 0.15 using the WHO criteria. Conclusion Bone mass measurements including QUS on various skeletal sites documented age-related changes similarly, and their bone masses correlated moderately. The diagnostic agreements among them were fair to poor. To screen out women with a risk of osteoporosis, it is important to choose which technique to use and which skeletal site to measure.