Assessment of the bone mineral density in the lumbar vertebrae of newborns by quantitative computed tomography

 Objective. To assess the true mineral density (BMD, in g/cm³) of the lumbar spine in newborns. Design and patients. A post-mortem analysis of five infants with gestational ages ranging from 35 to 40 weeks, and birth weights from 2765 to 3200 g, was conducted using dual-energy quantitative computed tomography (QCT; Siemens Somatom DR). A 2 or 4 mm thick slice was obtained for each lumbar vertebra from L1 to L4. The density measured in these vertebrae was corrected by reference to a solid phantom (Osteo-CT) measured simultaneously. A three-dimensional image of the spine (Elscint CT Twin), as well as a photomicrograph of histological preparation from L2 vertebra, were also obtained in another term baby for comparison with the CT results. Results and conclusions. In the range of values studied, the vertebral densities were not dependent on birth weight. BMD values measured in L2, L3 and L4 were not significantly different, but were 10% lower than in L1 in four of five infants. The spatial resolution of the QCT protocol used (0.4 mm) did not permit the differentiation of trabecular and cortical bone, and the vertebral bodies appeared very homogeneous and dense, with a mean density value of 210±30 mg Ca/cm³, which is 2.5 times higher than the mean maximum value found in young normal adults. These preliminary results highlight the potential of QCT in neonatology. Special protocols will, however, need to be developed for in vivo measurements in this particular paediatric field.     

Anteroposterior versus lateral bone mineral density of spine assessed by dual X-ray absorptiometry

Recently, it has been suggested that lateral (LAT) spine bone mass measurements by absorptiometry may be more sensitive for detecting bone loss than the standard anteroposterior (AP) projection. The aim of this study was to evaluate the precision of LAT spine dual-energy X-ray absorptiometry (DEXA) and its diagnostic sensitivity. A group of 1554 subjects with no risk factors that might affect bone metabolism and 185 osteoporotic patients with vertebral fractures were studied. Bone mineral density (BMD) was measured in the lumbar spine (standard AP and LAT projections) and proximal femur with a DEXA absorptiometer. The precision of the measurements was assessed in 15 volunteers. Diagnostic sensitivity was evaluated by the Z-score method. Comparing young people and the elderly, spine bone loss in the latter was similar for AP and LAT projections, when it was evaluated in absolute values (glcm²). However, when it was evaluated in percentage terms, bone loss was about twice as high in the LAT projection. LAT spine BMD correlated significantly with all the other areas assessed. The best correlation was found with the standard AP projection (r=0.67,P<0.0001). The precision in the LAT projection was found to be within an acceptable range (1.6% in normal subjects, 2% in osteoporotic patients), even though it was about twice that obtained in the AP projection. Diagnostic sensitivity was also better with the AP projection. It is concluded that LAT spine BMD measurements can be assessed with acceptable precision although it is about twice as high as for AP spine measurements. The percentage decrease in BMD in the elderly is greater for measurements made in the LAT projection than for measurements made in the AP projection. However, there is no enhancement of diagnostic sensitivity in osteoporosis. BMD measurements in the LAT projection are not as good as in the AP projection but they may offer complementary information of the regional evolution of spine bone mass.     

Alcoholism-associated spinal and femoral bone loss in abstinent male alcoholics,as measured by dual X-ray absorptiometry

Although alcoholism is a known risk factor for osteoporosis, there are few published reports on alcoholism-associated bone loss. To study alcoholism-associated bone loss, this study used a dual X-ray absorptiometry (DXA) densitometer to measure lumbar and femoral bone mineral density (BMD) in a previously little-studied population: 32 relatively healthy, nonhospitalized, Caucasian, alcoholic men with a period of abstinence longer than that previously studied (median abstinence 4.0 months, range 3 days–36 months). DXA is a new, highly precise densitometric method with many advantages over the methods used in previous studies. The subjects had statistically significant bone loss at three sites: lumbar spine, femoral neck, and Ward's triangle (multiple correction adjusted two-tailed P < 0.008). Compared to the mean BMD of sex-, age-, and race-matched norms, the subjects' average femoral neck, Ward's triangle, and lumbar BMDs were, respectively, 0.56, 0.69, and 0.57 standard deviations (SDs) below the normative values.This study was partially funded by a National Institutes of Health Short Term Research Training Grant (PHSHL 07491) to K.C.     

Accuracy of single-energy quantitative computed tomography in the assessment of bone mineral density of cervical vertebrae

Earlier studies have shown that single-energy quantitative computed tomography (SEQCT) is a reliable method for bone mineral density (BMD) measurements in thoracic and lumbar vertebrae. Moreover, SEQCT has proved to be a useful parameter in the selection of appropriate implants in cervical spondylodesis. The aim of this study was to determine the accuracy of SEQCT in cervical vertebrae BMD measurement. BMD with reference to calcium hydroxyapatite (Ca₁₀[PO₄]₆[OH]₂) was assessed by SEQCT in 100 human vertebral bodies of the cervical spine. Bone cylinders were then cut from the appropriate region of interest. The cylinder volume was determined by the liquid displacement technique. The density of the mineral component was measured following incineration at 1100 °C for 24 h. The calculated BMD was correlated with the SEQCT values, resulting in a coefficient of r = 0.79 (P < 0.01). Mean SEQCT values were significantly lower than those determined by direct density assessment (t-test for coupled sampling, P < 0.02). This result was in agreement with studies on thoracic and lumbar vertebrae. These data suggest that SEQCT can reliably measure BMD in the cervical spine. Received 12 July 1996; Revision received 17 January 1997; Accepted 10 March 1997     

Assessment of bone mineral density in the jaws and its relationship to radiomorphometric indices

Objectives

The aim of this study was to evaluate maxillary, mandibular and femoral neck bone mineral density using dual energy X-ray absorptiometry (DXA) and to determine any correlation between the bone mineral density of the jaws and panoramic radiomorphometric indices.

Methods

49 edentulous patients (18 males and 31 females) aged between 41 and 78 years (mean age 60.2 ± 11.04) were examined by panoramic radiography. Bone mineral density (BMD) of the jaws and femoral neck was measured with a DXA; bone mineral density was calculated at the anterior, premolar and molar regions of the maxilla and mandible.

Results

The mean maxillary molar BMD (0.45 g cm⁻²) was significantly greater than the maxillary anterior and premolar BMD (0.31 g cm⁻², P < 0.05). Furthermore, the mean mandibular anterior and premolar BMD (1.39 g cm⁻² and 1.28 g cm⁻², respectively) was significantly greater than the mean mandibular molar BMD (1.09 g cm⁻², P < 0.01). Although BMD in the maxillary anterior and premolar regions were correlated, BMD in all the mandibular regions were highly correlated. Maxillary and mandibular BMD were not correlated with femoral BMD. In addition, mandibular cortical index (MCI) classification, mental index (MI) or panoramic mandibular index (PMI) values were not significantly correlated with the maxillary and mandibular BMDs (P > 0.05).

Conclusions

The BMD in this study was highest in the mandibular anterior region and lowest in the maxillary anterior and premolar regions. The BMD of the jaws was not correlated with either femoral BMD or panoramic radiomorphometric indices.     

绝经后妇女腰椎骨密度容积性定量CT测量研究

目的 应用容积性定量CT(vQCT)技术和双能X线吸收测量(DXA)仪测量绝经后妇女腰椎容积性骨密度(BMD),评价2种检查方法区分骨质疏松伴椎体骨折与骨质疏松不伴骨折的差异.方法 选取绝经后妇女118名[平均年龄(62.1±7.0)岁],按照所行胸腰椎X线平片检查结果及腰椎DXA测量的参数[前后位BMD(AP-SPINE)]值分组,>均值-1个标准差(x-1s)为正常组、x-1s～x-2s为骨量减少组、0.05).在骨质疏松组和骨质疏松伴骨折组AP-SPINE仅与3D-CORT间有相关性(R2=0.189,P<0.01);App60 BV/TV%、App80 BV/TV%、App100 BV/TV%、App120 BV/TV%与3D-TRAB或2D-TRAB之有相关性(3D法:R2值分别为0.955、0.951、0.941、0.912;2D法:R2值分别为0.912、0.910、0.878、0.821;P值均<0.01).容积性BMD的测量精确度为0.70%～2.25%.结论 vQCT技术可区分骨质疏松及伴骨质疏松性骨折绝经后妇女骨量,能力高于DXA,其中整体骨BMD诊断严重骨质疏松的效果最好;App BV/TV%可反映骨质疏松者骨小梁丢失程度,预测骨折风险.     

Bone mineral density reference values in the normal female and male population of Izmir,Turkey

In this study we aimed to establish the dual-energy X-ray absorptiometry (DXA) bone mineral density (BMD) reference values of healthy Turkish women and men residing in Izmir, western Turkey. We examined 347 women and 119 men (age range 20-80 years) who did not have any known risk factor that might affect bone mass. The BMD measurements were performed by Hologic QDR 4500 W Elite DXA instrument from the lumbar spine (L1-L4) and non-dominant hip. In women the mean BMD (g/cm(2))+/-standard deviation (SD) of the normal reference group between 20 and 39 years of age was 0.963+/-0.121 g/cm(2) in the lumbar spine and 0.891+/-0.119 g/cm(2) in total femoral region. The percentages of annual and total BMD losses in women between 30 and 80 years of age were 0.74 and 29% at spinal level and 0.65 and 26% in femoral region, respectively. The average BMD of the normal men's group between 20 and 39 years of age was 0.996+/-0.111 g/cm(2) in the lumbar spine and 1.025+/-0.110 g/cm(2) in femoral region. The percentages of annual and total BMD losses were 0.33 and 13% at spinal level and 0.50 and 20% in femoral region, respectively. In conclusion, like the values reported from mid-Anatolian region of Turkey, the BMD values of Turkish women and men residing in Izmir, western Anatolia, are also lower than in most European countries with regard to US and preinstalled Hologic values.     

Bone mineral density reference values in the normal female and male population of İzmir, Turkey

In this study we aimed to establish the dual-energy X-ray absorptiometry (DXA) bone mineral density (BMD) reference values of healthy Turkish women and men residing in İzmir, western Turkey. We examined 347 women and 119 men (age range 20–80 years) who did not have any known risk factor that might affect bone mass. The BMD measurements were performed by Hologic QDR 4500 W Elite DXA instrument from the lumbar spine (L1–L4) and non-dominant hip. In women the mean BMD (g/cm²)±standard deviation (SD) of the normal reference group between 20 and 39 years of age was 0.963±0.121 g/cm² in the lumbar spine and 0.891±0.119 g/cm² in total femoral region. The percentages of annual and total BMD losses in women between 30 and 80 years of age were 0.74 and 29% at spinal level and 0.65 and 26% in femoral region, respectively. The average BMD of the normal men's group between 20 and 39 years of age was 0.996±0.111 g/cm² in the lumbar spine and 1.025±0.110 g/cm² in femoral region. The percentages of annual and total BMD losses were 0.33 and 13% at spinal level and 0.50 and 20% in femoral region, respectively. In conclusion, like the values reported from mid-Anatolian region of Turkey, the BMD values of Turkish women and men residing in İzmir, western Anatolia, are also lower than in most European countries with regard to US and preinstalled Hologic values. Electronic Publication     

Physical bone changes in carragheenin-induced arthritis evaluated by quantitative computed tomography

Repeated non-invasive measurements were performed in dogs of trabecular bone density (TBD), low density bone area (LDBA), and high density bone area (HDBA) in chronic arthritis using quantitative computed tomography (QCT). Unilateral chronic arthritis of the knee had been induced by weekly instillation of 2 ml carragheenin into the right knee joint for 12 weeks with the left knee serving as a control. CT scanning of the distal femoral condyles was performed in 12 mature dogs with chronic arthritis. Another 6 dogs underwent a longitudinal CT study starting immediately prior to induction of arthritis. During induction of arthritis TBD decreased (P<0.01), LDBA increased (P<0.05) and HDBA decreased (P<0.01) in the arthritic bone. Opposite changes were found on the control side, i.e. TBD increased (P<0.01), LDBA decreased (P<0.01) and HDBA increased (P<0.01). The chronic arthropathic bone showed 20% lower TBD (P< 0.0001), greater LDBA (P<0.0001) and lower HDBA (P<0.0001) as compared with the control bone. Reproducibility tests of TBD showed a coefficient of variation of 0.8%. Indentation tests and histomorphometric analyses confirmed the bone density changes as measured by CT.     

比较桡尺骨皮质分层指数与单光子吸收法骨矿定量法诊断骨质疏松症的价值

 目的比较桡尺骨皮质分层指数与SPA骨矿定量法诊断骨质疏松症的价值.方法将桡尺骨X线表现按皮质分层情况分为4级,利用SPA骨矿密度测定仪测量桡尺骨骨密度,比较4级桡尺骨皮质分层指数的骨密度值.结果Ⅰ级与Ⅱ级间骨密度无显著差异,Ⅱ级与Ⅲ级与Ⅳ间均有显著差异,但相邻2级间骨矿密度值交叉重叠较大.结论SPA较桡尺骨皮质分层指数敏感,但缺乏特异性,更适用于动态监测骨矿含量变化情况.     

DXA椎体骨折评估联合腰椎侧位骨密度诊断老年性骨质疏松的临床研究

目的研究双能X线吸收检测法（DXA）椎体骨折评估（VFA）联合腰椎侧位骨密度诊断老年性骨质疏松的效能。方法选取我院DXA同时检测髋部、腰椎前后位、腰椎侧位骨密度及VFA的老年受检者86例,根据DXA骨密度低下或VFA有脆性骨折诊断骨质疏松。比较腰椎侧位骨密度联合VFA与常规DXA检测髋部及腰椎前后位骨密度诊断骨质疏松的检出率。检出率的比较采用χ2检验。结果所有受检者中,常规DXA检测髋部及腰椎前后位诊断出骨质疏松患者58例（58/76,76.3%）,侧位骨密度联合VFA诊断出骨质疏松患者76例（76/76,100%）,二者检出率差异有统计学意义（χ2=10.617,P < 0.001）。其中,股骨颈骨密度诊断骨质疏松疏检出率（55.3%）高于髋部整体（34.2%）,二者差异有统计学意义（χ2=6.812,P < 0.05）;髋部骨密度、腰椎前后位骨密度、腰椎侧位骨密度和VFA诊断骨质疏松症检出率分别为60.5%、47.4%、84.2%和78.9%,腰椎侧位骨密度与VFA的骨质疏松检出率比较,差异无统计学意义（χ2=0.700,P>0.05）,但二者均高于髋部骨密度的骨质疏松检出率（χ2=10.66、6.110,均P < 0.05）。结论DXA检测腰椎侧位骨密度联合VFA对老年性骨质疏松的诊断具有重要价值,能够避免骨质疏松的漏诊。     

髋关节表面置换术后股骨近端及髋臼骨密度初步研究

目的 评价髋关节表面置换术（RSAH）对股骨近端及髋臼侧骨量的影响.方法 选择符合入组标准的单侧RSAH病人26例,于术后1年行髋关节手术侧及健侧的股骨近端和髋臼的骨密度检查,参考Taylor及Wilkinson方法分别将术后股骨近端及髋臼分为6个（1～6区）和3个（A1～A3）兴趣区,测量各兴趣区骨密度,用t检验对各区手术侧与健侧骨密度值进行比较.结果 手术侧的股骨近端5、6区的骨密度值大于健侧的,两者差异有统计学意义（P＜0.05）;1、2、3、4区的骨密度值在手术侧与健侧间的差异无统计学意义（P＞0.05）.髋臼侧全部区域中髋臼头侧（A1区）密度值,手术侧小于健侧,两者差异有统计学意义（P＜0.05）;手术侧与健侧的髋臼内侧及尾侧（A2、A3区）的骨密度比较,其差异无统计学意义（P＞0.05）.结论 关节表面置换术后股骨近端骨量可以得到有效保存和恢复,而髋臼侧骨质有丢失可能.     

Digital X-ray radiogrammetry better identifies osteoarthritis patients with a low bone mineral density than quantitative ultrasound

This study assessed the ability of quantitative ultrasound (QUS) and digital X-ray radiogrammetry (DXR) to identify osteopenia and osteoporosis in patients with knee osteoarthritis (OA). One hundred and sixty-one patients with painful knee OA (81 men, 80 women; age 62.6±9.2 years, range 40–82 years) were included in this cross-sectional study and underwent dual-energy X-ray absorptiometry (DXA) of both hips and the lumbar spine, QUS of the phalanges and calcanei of both hands and heels, and DXR using radiographs of both hands. Unpaired t-test, Mann-Whitney U test, ROC analysis and Spearman’s rank correlation were used for comparisons and correlation of methods. Using DXA as the reference standard, we defined a low bone mineral density (BMD) as a T-score ≤−1.0 at the lumbar spine or proximal femur. In contrast to phalangeal or calcaneal QUS, DXR was able to discriminate patients with a low BMD at the lumbar spine (p<0.0001) or hips (p<0.0001). ROC analysis showed that DXR had an acceptable predictive power in identifying OA patients a low hip BMD (sensitivity 70%, specificity 71%). Therefore, DXR used as a screening tool could help in identifying patients with knee OA for DXA.     

Measurements of bone mineral density of the proximal femur by two commercially available dual energy X-ray absorptiometric systems

Two dual energy X-ray absorptiometric (DXA) instruments have recently become commercially available for local bone densitometry: the QDR-1000 (Hologic Inc.) and the DPX (Lunar Radiation Corp.). We report the precision, influence of femoral rotation, correlation and agreement of bone mineral measurements of the proximal femur by these two instruments. In vitro (femur phantom) short-term precision was 1.1%–3.5%, and the long-term precision was 1.2%–3.8%. In vivo (groups of 10 premenopausal and 10 postmenopausal women) short-term precision of duplicate measurements was 1.6%–4.7%, and long-term precision was 1.9%–5.5%. Overall, the precision for Ward's triangle was over 3% and that for the femoral neck and trochanter, 2%–3%. Rotation of a femur phantom produced a statistically significant change in the bone mineral density (BMD) of the femoral neck. Within a clinically relevant range of femoral rotation (20° inward rotation ±5°) the coefficient of variation (CV%) increased by a mean factor of 1.1–1.4. Although the correlation (r < 0.9) between BMD measurements of the proximal femur by the DPX and QDR-1000 in 30 postmenopausal women was high, there was lack of agreement between the two instruments. We found no statistically significant differences between the right and left femur in 30 postmenopausal women. A bilateral femur scan took a mean total time of about 22 min. We conclude that with the introduction of DXA instruments, the precision of bone mineral measurements of the proximal femur has improved. However, for comparability between commercially available DXA instruments, it might be advantageous if units were standardized. Offprint requests to: O.L. Svendsen     

Spinal bone mineral density by quantitative CT in a normal Italian population

The purpose of this study was to describe the normal cross-sectional pattern of spinal bone loss associated with aging in an Italian population and to compare these values to the American normative database. A group of 472 healthy subjects (382 females and 90 males) were recruited for bone mineral density (BMD) assessment by quantitative computed tomography (QCT). To eliminate technique-related differences in a comparison of Italian and American normal values obtained with two different scanners we performed a cross-calibration analysis scanning the same computerized imaging reference system (CIRS) phantom at both centers. The results of the cross-calibration study using the CIRS phantom were used to compare regression slopes of BMD with age and age-adjusted mean BMD of American men and women vs cross-calibrated Italian men and women. American men and women decrease more rapidly vs Italian men and women, and Italian men have significantly lower age-adjusted mean BMD than American men. For these reasons we recommend normal values to be locally obtained for an Italian population. Correspondence to: G. Guglielmi     

Comparison of bone mineral density in the jaws of patients with and without chronic periodontitis

Objectives

Although several studies have addressed the relationship between systemic bone mineral status and the severity of periodontitis, there is little knowledge of the relationship between periodontal disease and locally detected bone mineral density. The aim of this study was to compare the mandibular bone mineral density of patients with chronic periodontitis with that of periodontally healthy subjects.

Methods

48 systemically healthy subjects were included in the study and underwent a periodontal examination to determine their status. 24 subjects were periodontally healthy and the other 24 had moderate or severe chronic periodontitis. The mandibular bone mineral density of the subjects was determined by dual energy X-ray absorptiometry. The region of interest on the body of the mandible was independently determined on the dual energy absorptiometry radiographs, and a computer calculated the bone mineral density of these regions.

Results

The mandibular bone mineral density of the subjects with periodontitis was significantly lower than that of the periodontally healthy subjects (p < 0.01). There were significant negative correlations between the mandibular bone mineral density values and parameters related to the amount of periodontal destruction.

Conclusions

Low bone mineral density in the jaw may be associated with chronic periodontitis.     

Dual-energy X-ray absorptiometry applied to the assessment of tibial subchondral bone mineral density in osteoarthritis of the knee

Objective Plain X-ray is an imprecise tool for monitoring the subchondral bony changes associated with the development of knee osteoarthritis (OA). Our objective was to develop and validate a technique for assessing tibial subchondral bone density (BMD) in knee OA using dual energy X-ray absorptiometry (DXA).Design Patients with OA of at least one knee underwent DXA scanning of both knees. Regions of interest (ROI) were placed in the lateral and medial compartments of tibial subchondral bone. Weight-bearing plain X-rays and Te ^99m scintiscans of both knees were obtained and scored.Results One hundred and twelve patients (223 knees) underwent DXA and radiography. Intra-observer CV% was 2.4% and 1.0% for the medial and lateral ROI respectively. Definite OA (Kellgren and Lawrence Grade 2, 3 or 4) was correlated with age-related preservation of subchondral BMD compared to radiographically normal knees. Raised BMD was also associated with subchondral sclerosis, and positive scintigraphy.Conclusion DXA may provide a safe, rapid and reliable means of assessing knee OA. Cross-sectional age-related subchondral tibial BMD loss is attenuated by knee OA.Work completed at Bristol Royal Infirmary, Bristol, BS2 8HW, UK     

多发性骨髓瘤患者骨密度的改变

目的 探讨多发性骨髓瘤（MM）患者骨密度改变的特点,评价双能X线骨密度仪（DXA）对MM患者骨密度（BMD）测量的价值。方法 采用Hologic QDR-2000型双能X线骨密度仪,测量34例MM患者及24例正常人全身、L2－4椎体正侧位及左股骨近端骨密度,动态监测免疫球蛋白G（IgG)型和未定型MM患者化疗前后的BMD;测定血清免疫蛋白、蛋白电泳、血钙和血磷。结果 （1）MM患者全身、腰椎、左股骨近端BMD明显低于正常人（P＜0．05）;（2）IgG型Ⅲ期患者BMD明显低于Ⅱ期（P＜0．05）;（3）IgG型腰椎BMD与IgG的变化呈负相关,而与全身、左股骨近端BMD无相关性;（4）MM常规化疗有效患者,腰椎BMD明显上升（P＜0．05）,全身及左股骨折近端的BMD反而下降。结论 DXA是定量监测MM患者BMD变化和评价疗效和敏感方法。MM患者BMD降低经有效治疗是可逆转的,但腰椎与股骨近端骨损害及骨修复是不均一的。     

Variation between femurs as measured by dual energy X-ray absorptiometry (DEXA)

It is commonly assumed that there is minimal variation between the hips in an individual, but is densitometry of one femur representative of the other? We performed bone mineral density (BMD) measurements of both hips using a Hologic QDR 1000 densitometer. There were 110 patients, all of whom were right handed, and three main groups of subjects: (1) normal volunteers (n = 36); (2) subjects with known hip pathology (n = 36); (3) subjects with medical conditions not affecting the hip (n = 38). The mean age of the subjects was 46 (21–87) years and a standard analysis protocol was followed in all patients. The coefficient of variation (COV) for femurs was 0.9–3%, depending upon the region studied and the BMD. The left femur had a greater BMD 48% of the time and there were variable differences between femurs in each group studied. While the greatest differences were found in people with unilateral hip pathology, all groups had mean differences greater than the COV It may be acceptable to study only one hip, but the large variation between femurs in individuals should be borne in mind when interpreting data.