A comparison of spinal quantitative computed tomography with dual energy X-ray absorptiometry in European women with vertebral and nonvertebral fractures

Quantitative computed tomography (QCT) was compared to dual X-ray absorptiometry (DXA) measured in the lumbar spine of 508 European women defined as normal without fracture (NoF), or osteoporotic (OP), with either vertebral fracture (VF), or peripheral fracture (PF). The correlations between QCT and DXA BMD measurements were significantly different in normal and in osteoporotic patients, indicating that the two exams do not measure the same bone aspects. According to ROC curves results, QCT Z-scores separate OP from NoF with better sensitivity than all other measurements. A threshold to differentiate OP from NoF was chosen at Z-score=−1 for DXA-BMD and −1.5 for QCT-BMD. VF patients showed a highly significant decrease in BMD by DXA or QCT. PF patients revealed measurements lower than those of normal subjects but greater than those of VF, calling into question the idea of a diffuse osteoporosis causing nonvertebral fractures that is measurable by spinal DXA or QCT. DXA is weakly dependent upon age, and T-score or Z-score are equivalent for evaluating osteoporosis. QCT depends greatly upon age, and Z-score appears to be more efficient.     

Spinal bone mineral assessment in postmenopausal women: A comparison between dual X-ray absorptiometry and quantitative computed tomography

We compared quantitative computed tomography (QCT) and dual X-ray absorptiometry (DXA) with respect to their ability to discriminate subjects with and without prevalent vertebral fractures. In 240 post-menopausal women (mean age 63.7±6.9 years) lateral spine radiographs (T4-L4) were reviewed for the presence of vertebral fracture. Using a semiquantitative technique to grade the severity of vertebral deformities, we classified fractures as mild, moderate or severe (grade 1 to 3, respectively). Postero-anterior DXA (PA-DXA) and lateral DXA (L-DXA) measurements (L2–4) as well as QCT measurements of the lumbar spine (T12-L3 or L1–14) were obtained in all women. Seventy-two women were diagnosed with at least one fracture, and of these 40 were graded as mild. Comparing normal women with fractured women, we found the area under the receiver operating characteristics (ROC) curves to be greatest for QCT (0.81), followed by L-DXA (0.72) and PA-DXA (0.65). The differences among all three techniques were significant. Comparing the normal women with women having only mild fractures, the areas under the ROC curves were 0.79, 0.73 and 0.63 for QCT, L-DXA and PA-DXA, respectively. Significant differences existed between QCT and PA-DXA as well as between L-DXA and PA-DXA. Logistic regression analysis also revealed the highest age-adjusted odds ratios for QCT (3.67; 2.25–5.97) while L-DXA and PA-DXA showed substantially lower odds ratios (2.00; 1.39–2.87, and 1.54; 1.11–2.15, respectively). We conclude that low bone density as measured by QCT, PA-DXA or L-DXA is significantly associated with the prevalence of vertebral fractures. Of the methods studied, QCT of trabecular bone offered the best discriminatory capability. L-DXA proved to be superior to PA-DXA in its diagnostic sensitivity, particularly in women with mild fracture. Mild vertebral fractures are associated with decreased spinal bone density and may be regarded as osteoporotic deformities.     

Volumetric bone mineral density using peripheral quantitative computed tomography in Japanese women

The present study evaluated a commercial device for peripheral quantitative computed tomography (pQCT) and examined the age-related changes in normal Japanese women. The volumetric bone mineral density (vBMD) of the distal radius [integral bone mineral density (BMD_I), trabecular bone mineral density (BMD_T) and cortical with subcortical bone mineral density (BMD_SC)] was measured using pQCT (Norland-Stratec XCT960) in 617 healthy women aged 20–79 years and 75 subjects with osteoporosis aged 60–89 years who exhibited at least one vertebral fracture. The short-term precision errors in vivo (CV, %) were 1.1% for BMD_I 1.1% for BMD_T and 1.2% for BMD_SC. The correlations between pQCT and dual-energy X-ray absorptiometry measurements (Lunar DPX) of the lumbar spine werer0.8 (BMD_I, BMD_T and BMD_SC). The maximal mean vBMD values were observed between 20 and 49 years; BMD_I BMD_T and BMD_SC all showed a linear postmenopausal decline averaging 1.1% per year. The overall decreases in vBMD from the peak values in those 70–79 years were 34%, 32% and 33% in BMD_I, BMD_T and BMD_SC, respectively. The diagnostic sensitivity of osteoporosis was expressed as aT-score.T-scores using pQCT were –3.0 (BMD_I), –2.4 (BMD_T) and –2.9 (BMD_SC). Bone mineral measurement of the distal radius may be useful in the evaluation of age-related bone loss and for the diagnosis of osteoporosis.     

Bone measures in HIV-1 infected children and adolescents: disparity between quantitative computed tomography and dual-energy X-ray absorptiometry measurements

Investigators have found that dual-energy X-ray absorptiometry (DXA) of areal bone mineral density (BMD) values in HIV-1 infected children and adolescents are reduced. Volumetric bone density (BD) measured by quantitative computed tomography (CT) in this population has not been studied. This study was designed to evaluate bone measurements in HIV-1 infected children and adolescents using DXA and CT. Fifty-eight children and adolescents (32 females and 26 males with a mean age ± SD of 12.0±3.9 years, age range 5.0–19.4 years) with perinatally acquired HIV-1 infection underwent simultaneous bone area and density evaluation by DXA and CT. Height and weight measurements as well as pubertal assessment were performed on the same day. All but four subjects were receiving highly active antiretroviral therapy (HAART). Subjects were matched with healthy children and adolescents for age, gender, and ethnicity. HIV-1 infected children were significantly shorter ( P <0.001), lighter ( P <0.005), and had delayed puberty ( P <0.001) compared to controls. Using DXA, HIV-1 infected subjects had significantly less bone area ( P <0.001), bone mineral content (BMC) ( P <0.005), and BMD ( P <0.05) at the vertebral level compared to controls. In addition, bone area ( P <0.001), BMC ( P <0.001), and BMD ( P <0.005) of the whole body were also reduced relative to controls. In contrast, using CT, HIV-1 infected subjects had similar vertebral BD compared to controls, but smaller vertebral height and cross-sectional area (CSA) ( P =0.01 and P <0.005, respectively). DXA Z-scores provided values significantly lower than CT Z-scores in the HIV-1 infected population ( P <0.01). After accounting for weight and vertebral height, stepwise multiple regression demonstrated that the prediction of CT BD values of L1 to L3 from DXA values of these vertebrae was significantly improved. HIV-1 infected children and adolescents have lower vertebral and whole body BMC and BMD DXA measures. In contrast, vertebral BD measurements by CT are normal. The lower bone measurements were primarily due to the decreased bone and body size of the HIV-1 subjects.This work was presented in part at the Pediatric Academic Society Annual Meeting, San Francisco, California, 1–4 May 2004.     

Dual-energy X-ray absorptiometry of the calcaneus: Comparison with vertebral dual-energy X-ray absorptiometry and quantitative computed tomography

The purpose of this study was to determine the efficacy of using bone mineral measurements of the calcaneus to evaluate osteoporosis. Dual energy X-ray absorptiometry (DXA) of the calcaneus was compared with posteroanterior lumbar absorptiometry (DXA) and vertebral quantitative computed tomography (QCT) measurements in 171 white women (78 normal and 93 osteoporotic). DXA measurement of os calcis mineralization decreased significantly in osteoporosis, but to a lesser extent than in vertebral sites. In normal subjects, good correlations were observed between calcaneal and lumbar DXA (0.69) and QCT (0.56). In subjects with vertebral fractures, there was also good correlation between calcaneal DXA and QCT (0.59–0.69). This suggests that trabecular bone in calcaneus and vertebrae have related involution in cases of vertebral osteoporosis. However, the extent of bone loss is less marked in the calcaneus than in the vertebrae and is not sufficient to be accurately measured over time. We conclude, therefore, that although the global densitometric measurement at this site is not sufficiently sensitive for general use, it can be useful as a epidemiological research tool.     

Vertebral bone mineral measurement: A comparative study between quantitative computed tomography and dual X-ray absorptiometry

We examined vertebral bone mineral density (BMD) by quantitative computed tomography (QCT) and dual X-ray absorptiometry (DXA) in the same patients with osteoporosis or with suspected possible osteoporosis to compare the results obtained by both methods with special interest in the relationship between the values the assessed and occurrence of vertebral fracture. Spinal X-ray photographs were taken to decide the vertebral fracture and often deformities. Sites of severe osteoarthritis or compression fracture were excluded from the analysis. There was a significant overlap in bone mineral density of the third lumbar spine (or the second lumber swine) between patients with vertebral fracture and those without. Although both QCT and DXA discriminated those patients well, our results show that DXA did it, slightly better than QCT to discriminate those patients. This might be attributable the already too low trabecular BMD as assessed by QCT to be sensitive for the detection of further fall. Thus, considering disadvantages of QCT such as relatively high radiation dose, cumbersome technique and necessity of strict quality assurance, DXA would be the choice for assessment of bone density in the aged people rather than QCT.     

Volumetric quantitative computed tomography of the proximal femur: relationships linking geometric and densitometric variables to bone strength. Role for compact bone

Introduction In assessing cervical fractures of the proximal femur, this in vitro quantitative computed tomography (QCT) study had three objectives: to compare QCT to dual-energy X-ray absorptiometry (DXA) for predicting the failure load of the proximal femur, to compare the contributions of density and geometry to bone failure load, and to compare the contributions of cortical and trabecular bone to bone failure load. A novel three-dimensional (3D) analysis tool [medical image analysis framework (MIAF-Femur)] was used to analyze QCT scans. Methods The proximal ends of 28 excised femurs were studied (1) using QCT to separately measure bone mineral density (BMD) and geometric variables of trabecular and cortical bone, (2) using mechanical tests to failure in a stance configuration, and (3) using DXA to measure BMD. The variables were described with mean, standard deviation, and range. Correlation matrix and multivariate linear models were computed. Results Among correlations, cortical thicknesses of the femoral neck were significantly correlated with femoral failure load, especially of the inferoanterior quadrant (r ²=0.41; p<0.001), as was cortical volume at the “extended neck“ (r ²=0.41; p<0.001). Femoral failure load variance was best explained by a combination of QCT variables. Combining densitometric and geometric variables measured by QCT explained 76% of femoral failure load variance compared with 69% with the DXA model. Geometric variables (measured by QCT) explained 43% of femoral failure load variance compared with 72% for densitometric variables (measured by QCT). A model including only trabecular variables explained 52% of femoral failure load variance compared with 59% for a model including only cortical variables. Conclusion The QCT-MIAF reported here provides analysis of both geometric and densitometric variables characterizing cortical and trabecular bone. Confirmation of our results in an independent sample would suggest that QCT may better explain failure load variance for cervical fracture than the gold standard DXA-provided BMD. This work was supported in part by grants from EU, contract number: QLK6-CT-2002-02440-3DQCT     

Vertebral bone density in icelandic women using quantitative computed tomography without an external reference phantom

Vertebral trabecular bone mineral density (BMD) was measured in 187 healthy Icelandic women, age 35–64 years, by quantitative computed tomography (QCT) with the use of internal references (muscle and subcutaneous fat) instead of the traditional external references (phantoms). We found a mean 2.4 mg/cm³ (1.8%) bone loss per year in the age range 35–64 years. There was an accelerated phase (exponential) after menopause, with 4% loss per year for the first 1–5 years after menopause or 5-fold trabecular bone loss compared with the subsequent 11–15 years after menopause. Reproducibility was found to be 1.9%. This method thus compares with traditional QCT measurements and is highly reproducible. We find QCT using internal references a promising method for assessing fracture risk in perimenopausal women and for follow-up in osteoporotic patients.     

Correlations of dual-energy X-ray absorptiometry,quantitative computed tomography,and single photon absorptiometry with spinal and non-spinal fractures

Controversy continues as to which method of measuring bone mineral density (BMD) best detects osteoporosis and best correlates with fractures of the spine, hip and elsewhere. To answer these questions the prevalence of fractures was carefully determined among 90 subjects (70 with osteoporosis, 6 with mild primary hyperparathyroidism, 1 with osteomalacia and 13 normals) and simultaneous measurements were made using spinal computed tomography (QCT), spinal anteroposterior (AP) and supine lateral dual X-ray absorptiometry (DXA), femoral neck and total hip DXA, and distal third radial DXA and single photon absorptiometry (SPA). The DXA measurements which had the greatest sensitivity in detecting osteoporosis (defined as a BMD lower than –2.5 SD of peak bone mass at age 30 years) were the supine lateral spine DXA (84%) and femoral neck DXA (75%); less sensitive were the DXA measurements of the distal third of the radius (61%) and AP spine (51%). DXA measurements of the femoral neck and distal third of the radius were more useful than spinal measurements in detecting the osteopenia of mild primary hyperparathyroidism. Vertebral compression fractures (VCF) correlated well with spinal QCT (r=–0.38) and lateral spine DXA (r=–0.41), but poorly with AP spine DXA (r=–0.17) and distal third radial DXA (r=–0.02). Non-spinal fractures correlated best with the distal third radial DXA (r=–0.42). In conclusion, spinal QCT, supine lateral spine DXA and femoral neck DXA are the best BMD methods to screen for osteoporosis, whereas AP spine DXA is a poor screening method in women over 60 years of age. Spinal QCT and lateral spine DXA correlate well with VCFs, whereas correlations of VCFs with AP spine DXA, femoral neck DXA and distal third radial DXA are poor.     

A population-based comparison of quantitative dual-energy X-ray absorptiometry with dual-photon absorptiometry of the spine and hip

Summary Dual photon absorptiometry (DPA) is currently the most widely used method for noninvasive bone mineral density (BMD) measurement of the axial skeleton. Dual energy X-ray absorptimetry (DEXA) is a recently developed technique that uses an X-ray tube as a photon source; it has demonstrated several significant advantages over DPA in preliminary studies. We report here a quantitative comparison of the DEXA and DPA technologies using a Hologic DEXA (Hologic QDR model 1000, Waltham, MA) scanner and a Lunar DPA (Lunar Radiation DP3, gandolineum-153 source) scanner at both the proximal femur and lumbar spine sites using bone density measurements from a populationbased sample of older white men and women who had complete DEXA and DPA measurements of the hip (n=217) or the spine (n=176). To examine the relationship of BMD measured by the DPA scanner to BMD measured on the DEXA scanner, normal least squares linear regression was used to regress the DPA BMD on the DEXA BMD for each site. DEXA values were consistently lower than DPA values, with an average difference of 16%. The squared multiple correlation (R²) values were at or above 0.95 for almost all sites, with Ward's triangle having the lowest value (0.89). The slope for all sites was similar, ranging from 0.94 to 1.1. Research and clinical centers that wish to change to DEXA technology because of its shorter examination time and greater precision can therefore compare DEXA with DPA values using representative convesion factors.     

定量超声和双能X线骨密度测定诊断骨质疏松的比较

目的通过对同一个人的跟骨超声强度（STI）测量与双能X线吸收法（DEXA）测量腰2-4、股骨近端骨密度（BMD）的临床对比,评价定量超声骨质测量仪（QUS）跟骨STI的测量,对诊断骨质疏松（OP）的敏感性和与DEXA测量BMD的相关性.方法对3266名20～89岁健康人群同时采用DEXA测量L2-4、右股骨近端（Neck、Ward、Troch）BMD和QUS测量右跟骨STI值进行相关分析.结果峰值骨量男性STI与BMD均出现在20～29岁,女性STI出现在20～29岁,BMD则出现在30～39岁;随年龄的增加腰椎、股骨近端BMD及超声强度均下降,女性在50岁后,男性在70岁后有个显著下降过程;OP检出率两种仪器无明显差异.在健康人中BMD与STI的相关系数（R=0.21-0.26）,骨质疏松患者BMD与STI的相关系数（R=0.14-0.24）.结论DEXA测量的BMD与QUS测量的STI无相关关系.这表明QUS主要测量骨的结构,而DEXA则是测量骨量的变化,两者相辅相承,共同测量能更好地监测骨质疏松、预测OP性骨折的发生.     

The usefulness of dual energy X-ray and laser absorptiometry of the calcaneus versus dual energy X-ray absorptiometry of hip and spine in diagnosing manifest osteoporosis

Introduction  Osteoporosis is a major health problem. Dual energy X-ray absorptiometry (DXA) of the hip and spine is the worldwide standard in diagnosing osteoporosis. Measurement of bone mineral density (BMD) with dual energy X-ray and laser absorptiometry of the calcaneus (Calscan) might be a good alternative. Advantages of the Calscan are that it is quick, widely available and manageable. In this study we compared BMD expressed in T-scores measured by DXA and Calscan. The aim of this study was to define threshold T-scores on the Calscan that could exclude or predict osteoporosis correctly in comparison with DXA. Materials and methods  Patients ≥50 years attending our emergency department with a fracture were offered osteoporosis screening at our fracture and osteoporosis outpatient clinic (FO-Clinic) and enrolled in this study. BMD was measured at the hip and spine using DXA and at the calcaneus using Calscan. A T-score measured by DXA ≤−2 standard deviations (SD) below the reference population was defined as manifest osteoporosis and was the treatment threshold. Results  During a 10-month study period, 182 patients were screened with both devices. The mean DXA-T-score was −1.63 SD (range −4.9 to 2.1) and Calscan T-score −1.91 SD (range −5.3 to 1.4). There was a significant correlation between both devices (r = 0.47, P < 0.01). Using an upper threshold for the Calscan T-score of −1.3 SD, 47 patients could be classified as non-osteoporotic with 89.3% sensitivity (95% CI 80.0–95.3%). Using a lower threshold for the Calscan T-score of −2.9 SD, 34 patients could be classified by the Calscan as osteoporotic with 90.7% specificity (95% CI 83.5–95.4). The remaining 101 patients could only be correctly classified by DXA-T-scores. Conclusion  Although DXA is the established modality worldwide in measuring BMD it is restricted to specialized centres. Peripheral bone densitometers like the Calscan are widely available. When BMD measurements with DXA were compared to Calscan measurements it was possible to correctly classify 81 of 182 patients based on the Calscan T-score. Of these 81 patients 34 could be classified as manifest osteoporotic and 47 as non-osteoporotic. Therefore the Calscan seems to be a promising technique which might be used as a screening device at a FO-Clinic, especially when DXA is not easily available.     

Body composition in children with renal disease: use of dual energy X-ray absorptiometry

Dual energy X-ray absorptiometry (DEXA) is a non-invasive accurate method which estimates bone mineral content and density (BMD), as well as fat (FM) and lean (LM) body mass. This method was used in control children in order to establish normal values for BMD of lumbar spine and whole body composition {logistic curves, general equation E=k+K/[1+exp(-A)]}. In children with chronic renal failure (CRF), LM correlated with the urinary excretion of creatinine (r=0.97,P=0.0001) independently from glomerular filtration rate. However, the assessment of LM by DEXA must take into account the hydration level, since there is a positive correlation between fluid loss and reduction in LM in children on hemodialysis (r=0.98,P=0.0001). After renal transplantation, a significant loss of BMD (median –9.2%), was observed at 6 months which returned to 95% of pretransplant values by the end of the 1 st year. Maximal changes in LM and FM occurred during the first 3 months (–7.8% and +7.2%, respectively) and may be due to steroids; these should be influenced by physical activity since FM correlated inversely with maximal oxygen consumption (r=0.69P=0.0001). Recombinant growth hormone treatment could also increase LM and decrease FM, as shown in 9 patients. DEXA appears therefore to be a reliable method for evaluating therapeutic interventions affecting nutritional status in children with CRF.     

A comparison of quantitative dual-energy radiographic absorptiometry and dual photon absorptiometry of the lumbar spine in postmenopausal women

Summary Noninvasive bone densitometry is an important aspect in the detection and management of osteoporosis and other forms of metabolic disease of calcified tissue. A system using quantitative dual-energy digital projection radiography (QDR) of the lumbar spine was systematically tested against dual-photon absorptiometry (DPA) of the lumbar spine in 131 women over 55 years of age and free from major risk factors for osteoporosis. All subjects were scanned by both QDR and DPA under the same conditions. Measurements for a given subject were made within 15 minutes of each other. Bone mineral densities (BMD) were determined for four individual levels in the lumbar spine (L1-L4). Regression equations for BMD vs. age, height, and weight were calculated. The results of this investigation indicate that DPA- and QDR-derived BMD values are comparable. BMD values derived by QDR were consistently lower than those obtained by DPA (DPA=1.115 QDR+0.137, r=0.942). The L2 lumbar region was the most strongly correlated determination.     

Lumbar vertebral body compressive strength evaluated by dual-energy X-ray absorptiometry, quantitative computed tomography, and ashing

Bone densitometry with DXA (dual energy X-ray absorptiometry) and QCT (quantitative computed tomography) techniques are used for in vivo assessment of bone strength and thereby prediction of fracture risk. However, only few in vitro studies have investigated and compared these techniques’ ability to determine vertebral compressive strength. The aim of the present study was to (1) assess the predictive value of DXA, QCT, and pQCT (peripheral QCT) for vertebral bone compressive strength assessed by mechanical testing; (2) describe both linear and power relationship between density and strength; and (3) evaluate whether gender-related differences in the above relations were present. The material comprised human lumbar vertebrae L3 from 51 women and 50 men (age range: 18 to 96 years). The study showed that both DXA and CT techniques (QCT and pQCT) have a high predictive value for vertebral strength. The DXA BMD had a high correlation with maximum compressive load (r² = 0.86). The QCT and pQCT had high correlations with maximum compressive stress (r² = 0.75 and r² = 0.86, respectively). The correlation between ash density of the biomechanically tested specimen and maximum compressive stress was r² = 0.88. There were no differences between linear and power fit in the degree of determination between density and strength. There was no gender-related difference in the relationship between volumetric density and maximum compressive stress. In conclusion, it was demonstrated that DXA, QCT, and pQCT are ex situ equally capable of predicting vertebral compressive strength with a degree of determination (r²) between 75% and 86%. No differences were found between linear and power analysis of the relationship between density and strength, and no difference was found in the density strength relationship between women and men.     

定量CT椎体骨密度测定诊断骨质疏松症

[目的]探讨定量CT（QCT）椎体骨密度（BMD）测定在诊断骨质疏松症中的临床价值和诊断标准。[方法]对53例健康无症状中老年人和68例临床拟诊骨质疏松患者进行L1-4。椎体BMD测定。[结果]健康中老年人BMD随年龄增长而明显降低，有显著性差异。以BMD≤x-2．0 SD为诊断骨质量疏松症标准有68例，且各年龄段的BMD值均明显低于骨量截断值；如以BMD≤x-2．5 SD为诊断标准则有60例。[结论]QCT诊断骨质疏松症敏感、准确、重复性强，易于推广应用。以BMD≤x-2．0SD为诊断标准，更符合临床实际病例，并能减少漏诊。     

定量CT骨密度测定在中老年男性中的应用研究

目的探讨定量CT(quantitative computed tomography,QCT)骨密度测定在中老年男性中的应用价值。方法收集常规查体、年龄50岁以上的男性138例。每例患者均进行血清学指标检测、QCT和双能X线吸收检测法(DXA)骨密度测定。结果随年龄增加,QCT骨密度及DXA的股骨颈骨密度均呈下降趋势(P<0.05)。QCT方法检出低骨量69例(50.0%),骨质疏松27例(19.6%),而DXA方法检出骨量减少43例(31.2%),骨质疏松4例(2.9%),两种方法的检出率差异具有明显统计学意义(P<0.01)。在不同年龄组,QCT均比DXA对骨量减少的检出率高,且随年龄增加检出率逐渐升高(P<0.01)。结论中老年男性QCT较DXA骨密度测定的骨量减少检出率更高,随年龄增加检出率增加,QCT的方法可能更适于中老年男性骨质疏松防治过程中的检测。     

Dual-energy X-ray absorptiometry versus single photon absorptiometry of the radius

Summary Radial diaphyseal bone mineral density (BMD) was measured at the standard one-third site by dual-energy X-ray absorptiometry (DEXA) and by¹²⁵I single photon absorptiometry (SPA) in 70 consecutive subjects, aged 12–86 years, with metabolic disorders of the skeleton. Each patient was measured once by the DEXA (Hologic QDR-1000) instrument and four times by the SPA (Norland 2780) instrument on the same day by one or the other of 2 technicians. The DEXA and SPA measurements were linearly related and highly correlated (r=0.975,P<0.0001) over a range from severe osteopenia to high normal BMD. Ninety-five percent of the variation in the BMD determined by SPA was accounted for by DEXA, so that the BMD_SPA=1.035±0.027 (SEM)×BMD_DEXA−0.007±0.019 (SEM). This permits continued use of previously accumulated SPA databases. The coefficient of variation for repeat measurements by DEXA was 1.2% and by SPA 1.6%. Examination time by DEXA was 6–7 minutes, about 45% shorter than the corresponding SPA determinations. DEXA is the superior method for evaluation of the radius, as it provides faster and more precise measurements in clinical practice.     

定量CT研究成年女性腰部椎后肌群体质成分与腰椎骨密度的相关性

目的探讨成年女性腰部椎后肌群体质成分与腰椎骨密度的相关关系。方法将518名21~81岁的成年女性按年龄分为青中年组(≤50岁)和老年组(50岁),使用定量CT(QCT)测量L2~L4椎体骨密度(BMD)及L3椎体中部层面椎后肌群的脂肪面积、肌肉面积、脂肪肌肉比。使用独立样本T检验比较两组间差异,使用偏相关及多元线性回归分析研究BMD与年龄、BMI及椎后肌群体质成分的相关关系。结果青中年组BMI、椎后肌群脂肪面积及脂肪肌肉比低于老年组,而BMD及椎后肌群肌肉面积高于老年组,差异有统计学意义(P0.01)。控制年龄、BMI因素偏相关分析结果显示,青中年组及老年组BMD与椎后肌群脂肪面积呈负相关(r=-0.178、-0.200,P0.05),与脂肪肌肉比呈负相关(r=-0.138、-0.177,P0.05),而与肌肉面积无显著相关性(r=-0.050、0.066,P0.05)。回归分析显示,椎后肌群脂肪面积、年龄、BMI是BMD的主要影响因素。结论成年女性腰部椎后肌群脂肪浸润程度与腰椎骨密度存在相关性,且相关性随年龄而增加。