Spine Dual-energy X-ray Absorptiometry Images Research Articles

Trabecular Bone Score as a More Sensitive Tool to Evaluate Bone Involvement in MEN1-related Primary Hyperparathyroidism.

The skeletal involvement of multiple endocrine neoplasia type 1-related primary hyperparathyroidism (MHPT) is not exactly the same as that of sporadic primary hyperparathyroidism (SHPT). Trabecular bone score (TBS) as a texture parameter has been reported to reflect trabecular bone damage. This study aimed to compare the clinical characteristics, especially the skeletal involvement, between patients with MHPT and SHPT. The clinical characteristics were retrospectively collected in 120 patients with MHPT and compared with 360 patients with SHPT in the same period. Dual-energy X-ray absorptiometry were conducted in some patients with MHPT, in whom bone mineral density (BMD) and calculated TBS derived from lumbar spine dual-energy X-ray absorptiometry images were compared with those of patients with SHPT. Although the duration of disease in the MHPT group was longer, the age at hospital visit was significantly lower than that in the SHPT group (43.5 [interquartile range, 31.5-52.0] vs 52.0 [interquartile range, 40.5-61.0], P < .001). The proportion of skeletal involvement in the MHPT group was significantly lower. However, in the subgroup of MHPT cases (n = 86) with data of BMD, there was no significant difference in skeletal involvement from SHPT cases matched for gender and age. Although the BMD and TBS in the lumbar spines of patients with MHPT were lower than those of patients with SHPT (BMD: 0.91 ± 0.18 g/cm2 vs 1.01 ± 0.17 g/cm2; TBS: 1.22 ± 0.14 vs 1.29 ± 0.11, P < .001). According to TBS, among 34 patients with MHPT with normal BMD, 15 patients had bone microstructure damage. The cancellous bone microarchitecture was more severely damaged in patients with MHPT according to TBS, which suggested that TBS could be a sensitive supplemental index in addition to BMD to identify bone-involvement risk in patients with MHPT.

What Role Does Trabecular Bone Score Play in Chronic Inflammatory Rheumatic Diseases?

Patients suffering from rheumatic inflammatory diseases, e.g., systemic sclerosis, rheumatoid arthritis, and ankylosing spondylitis, are at risk of low bone mass. Dual-energy X-ray Absorptiometry (DXA) is the traditional radiological measurement technique for bone mineral density (BMD). The recently developed trabecular bone score (TBS) enhances the skeletal information provided by standard BMD. It re-analyzes the spatial dynamics of pixel intensity changes in lumbar spine DXA images, defining a quantitative index, characterizing trabecular bone microarchitecture. It has been demonstrated that low TBS values are associated with an increased incidence of fractures in patients with rheumatic diseases. These methods used together for bone damage evaluation can be of value to identify individuals who will potentially fracture. The main scientific literature on the clinical aspects of osteoporosis, including the use of TBS in evaluating this pathology, are herein reported aimed at shedding light on the role trabecular bone score plays in chronic inflammatory rheumatic diseases.

Diagnostic performance of morphometric vertebral fracture analysis (MXA) in children using a 33-point software program.

There is significant inter and intraobserver variability in diagnosing vertebral fractures in children. We aimed to evaluate the diagnostic accuracy of morphometric vertebral fracture analysis (MXA) using a 33-point software program designed for adults, on dual-energy x-ray absorptiometry (DXA) images of children. Lateral spine DXA images of 420 children aged between 5 and 18years were retrospectively reviewed. Vertebral fracture assessment (VFA) by an expert pediatric radiologist using Genant's semiquantitative scoring system served as the gold standard. All 420 DXA scans were analyzed by a trained radiographer, using semi-automated software (33-point morphometry). VFA of a random sample of 100 DXA was performed by an experienced pediatric clinical scientist. MXA of a random sample of 30 DXA images were analyzed by three pediatric radiologists and the pediatric clinical scientist. Diagnostic accuracy and inter and intraobserver agreement (kappa statistics) were calculated. Overall sensitivity, specificity, false positive (FP) and false negative (FN) rates for the radiographer using the MXA software were 80%, 90%, 10%, and 20% respectively and for mild fractures alone were 46%, 92%, 8%, and 54% respectively. Overall sensitivity, specificity, FP, and FN rates for the four additional observers using MXA were 89%, 79%, 21%, and 11% respectively and for mild fractures alone were 36%, 86%, 14%, and 64% respectively. Agreement between two expert observers was fair to good for VFA and MXA [kappa=0·29 to 0·76 (95% CI: 0·17-0·88) and 0·29 to 0·69 (95% CI: 0·17-0·83)] respectively. MXA using a 33-point technique developed for adults is not a reliable method for the identification of mild vertebral fractures in children. A pediatric standard is required which not only incorporates specific vertebral body height ratios but also the age-related physiological changes in vertebral shape that occur throughout childhood.

Trabecular Bone Score-An Emerging Tool in the Management of Osteoporosis.

Areal bone mineral density (aBMD) is currently the gold standard for the diagnosis of osteoporosis, however, it has its own pitfalls. Trabecular bone score (TBS), a novel tool in the evaluation of osteoporosis is an indirect indicator of bone microarchitecture. It is a textural index that evaluates pixel gray-level variations in the lumbar spine DXA (dual energy X-ray absorptiometry) image. Both cross-sectional and longitudinal studies have demonstrated that TBS may independently predict fragility fractures. TBS can also be used to adjust FRAX probabilities of fracture, though data available till date doesn’t support any additional benefit. TBS also shows an improving trend with anti-osteoporotic treatment; however, the least significant change (LSC) is high that it takes more than 2 years for the change to manifest. TBS is also used in the evaluation of bone strength in cases of secondary osteoporosis. Though TBS predicts fracture risk independently in both genders, with the currently available data, it cannot be recommended as a standalone tool for decision regarding treatment of osteoporosis. TBS can be used as a tool to complement BMD in assessment of bone health. Additional studies are needed to assess its utility in clinical practice.

Reliability of TBS: experience from a network of tertiary care centres

Introduction Trabecular bone score (TBS), a textural estimate of bone microarchitecture, is increasingly used as part of fracture risk assessment. It is derived from lumbar spine dual-energy X-ray absorptiometry (DXA) scans and provides additional information for 10-year absolute fracture risk calculation using the FRAX tool. The precision of TBS measurements is important for determining if the change in TBS over time is significant enough to indicate a real biological change clinically. Objectives This study aims to calculate the precision, as expressed by the root-mean-square percent coefficient of variation (RMS-%CV), and the least significant change (LSC) of TBS across three academic hospitals in Toronto, Canada. Methods Participants were prospectively recruited from Toronto General Hospital (TGH), Toronto Western Hospital (TWH) and Princess Margaret Cancer Centre (PMCC), all part of the University Health Network (UHN) Centre of Excellence in Skeletal Health Assessment (CESHA). Four ISCD-certified technologists each performed DXA scans on 30 participants, using four Hologic DXA machines (one Horizon A and three Discovery As), according to standard protocol for precision testing. At each centre, the participants were scanned twice at the lumbar spine by the same operator on the same day. Both scans were performed within a few minutes of each other, with only time for the participant to get off the table and be repositioned. TBS was analyzed from each of the two lumbar spine DXA images using TBS iNsight version 3.0. As a result, two TBS values were generated per participant. This study was done as part of quality control and written informed consent was obtained prior to the scans. RMS-%CV and LSC were computed for test-retest TBS values at individual centres, and combined for participants across all centres. Results A total of 120 participants (35 men, 85 women) completed this precision study. Mean age was 54 (age range= 20-90), mean BMD at the lumbar spine and total hip were 0.954 (SD± 0.171) g/cm2 and 0.879 (SD±0.164) g/cm2, and mean T-scores were -0.9 (SD±1.5) and -0.5 (SD± 1.2), respectively. The RMS-%CV for lumbar spine and total hip BMD were 0.95% and 1.04%, respectively. The RMS-%CV and LSC for TBS are shown in table below: Conclusion In summary, TBS as determined from lumbar spine DXA images has a precision error of 2.85% compared to 0.95% for lumbar spine BMD. BMD laboratories should perform precision testing for TBS in addition to BMD. Clinicians should interpret changes in TBS values and the calculated fracture risk keeping this level of precision in mind.

Lumbar Vertebrae Morphological Analysis and an Additional Approach for Vertebrae Identification in Lumbar Spine DXA Images

Introduction: Bone mineral density measured by dual-energy X-ray absorptiometry (DXA) is the gold standard for diagnosis of osteoporosis. However, DXA interpretation can be influenced by analytic errors which can, in turn, interfere with diagnostic accuracy. One such source of potential error is the accurate identification of specific lumbar vertebrae on lumbar spine DXA images. Although the International Society for Clinical Densitometry has introduced several approaches to aid with this process, there remain individuals whose lumbar vertebrae cannot be labeled with certainty using these approaches. We designed the present study to systematically evaluate lumbar spine DXA images among a large cohort of Chinese patients and present an additional simple strategy for identifying L5 named the “em dash”-shaped L5 or “—”-shaped L5, based upon the two-dimensional relationship between the bilateral pedicles with the central spinous process on DXA images. Methodology: Lumbar spine posteroanterior DXA images from adult patients receiving care at a large tertiary hospital in Beijing, China from May to August 2016 were retrospectively reviewed. For each patient, data were collected regarding key anatomic features seen on DXA (positions of the most superior portions of the iliac crests, the lowest vertebra with ribs, and the longest transverse processes) and the proportion of patients presenting with “H”-shaped L4 and “—”-shaped L5. Chi-squared analyses were used to compare proportions across age strata. Results: DXA images from 1125 patients (79.6% female) were evaluated. The mean age of patients was 52.5 ± 14.8 yr (range: 19–90 yr). A horizontal line drawn across the superior-most portions of the iliac crests crossed the disk space between L4 and L5 among 78.3% of patients. The lowest ribs were most frequently (83.9%) observed at T12. Almost 80% of individuals had the longest transverse processes at L3. L4 was predominantly “H”-shaped (73.3%), however we found that the proportion of individuals with “H”-shaped L4 decreased steadily after 50 yr of age (p < 0.001). By contrast we observed that L5 was predominantly “—”-shaped (80.3%), with no significant differences in proportions across all age strata (p = 0.063). Conclusions: The “—”-shaped L5 can be incorporated as an additional reference tool for lumbar spine DXA image analysis and may be particularly helpful for lumbar vertebrae identification among patients over 50 yr of age.

Aortic vascular calcification is inversely associated with the trabecular bone score in patients receiving dialysis.

Progressive chronic kidney disease (CKD) confers a marked increase in risk for vascular calcification, cardiovascular disease, fracture and mortality, with likely contributing factors including dysregulated bone metabolism and mineral homeostasis. In general population studies, increased vascular calcification is directly related to mortality and inversely related to bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA). In patients with CKD, abnormalities in turnover, mineralization and bone volume reduce the ability of DXA to predict fracture. The trabecular bone score (TBS) obtained from lumbar spine DXA images, provides a surrogate measure of microarchitectural integrity not captured by BMD. This study aimed to examine the association of the TBS to prevalent abdominal aortic calcification (AAC) in patients with CKD receiving dialysis. We performed a cross-sectional study of dialysis patients awaiting transplantation. All patients underwent laboratory testing, lateral spinal radiographs including the abdominal aorta, DXA imaging and TBS assessment. AAC scores were determined using the Kauppila method. Correlations and linear regression models were used to determine predictors of AAC scores. 146 patients (60% male, mean age 48 ± 13 years) were included, of whom 49% had prevalent calcification with an AAC score ≥ 1. Of those with calcification, the mean AAC score was 7 ± 5.5 and 42 patients had scores ≥ 6, considered to indicate severe AAC. TBS values corresponding to intermediate or high risk for fracture (<1.31) were present in 35% of patients. TBS values correlated inversely to AAC scores (β = -0.206, p = 0.013) and remained significant in multivariable linear regression, adjusting for age, BMI and time on dialysis (-0.160, p = 0.031). There was no significant correlation of AAC scores to any BMD parameter. There is a high prevalence of AAC in relatively young dialysis patients awaiting transplantation and their AAC scores are inversely related to the TBS but not to DXA-derived BMD parameters. In patients with CKD on dialysis, TBS assessment reflects microarchitectural abnormalities of bone not captured by DXA. The inverse relationship of TBS to vascular calcification may provide insights into bone-vascular interactions in CKD.

The main autoimmune and nonautoimmune etiologies of endogenous hyperthyroidism do not seem to influence the increased prevalence of morphometric vertebral fractures and osteoporosis in Portuguese men

ObjectivesThe purpose of this study was to evaluate the effects of hyperthyroidism and their etiology on bone mineral density (BMD), on body soft tissue composition, on the prevalence of vertebral fractures detected by vertebral fracture assessment (VFA) and on the trabecular bone score (TBS). MethodsFrom an initial population of 119 Portuguese men (78 with hyperthyroidism [HT]+ 41 controls [CTs]) admitted to the Endocrinology Department we selected 41 men aged over 50 with clinical hyperthyroidism to participate; each one was matched by age and height with a control person. BMD (g/cm2) at the lumbar spine, hip, radius 33% and whole body and the total body masses (kg) were studied by dual-energy X-ray absorptiometry (DXA). VFA with Genant semiquantitative method was used to detect fractures. The TBS was obtained from lumbar spine DXA images. No patient had been treated previously for hyperthyroidism or osteoporosis. Adequate statistical tests were used. ResultsIn the hyperthyroidism group, total lean mass (CT 58.16 ± 7.7 vs. HT 52.3 ± 5.7, P = 0.03) and distal radius BMD (CT 0.769 ± 0.05 vs. HT 0.722 ± 0.08, P = 0.005) were lower; there was a significantly higher prevalence of osteoporosis (CT 9.7% vs. HT 29.3%, P = 0.015) and vertebral fractures (CT 2.4% vs. HT 24.4%, P = 0.007). TBS was similar in both groups (CT 1.328 ± 0.11 vs. HT 1.356 ± 0.11, P = not significant). Comparing patients with Graves' disease with patients with toxic goiter, there were no differences regarding BMD, BMD qualification, prevalence of fractures and TBS and just total lean mass was significantly lower in patients with Graves' disease. ConclusionsThese results suggest that in a group of hyperthyroid men aged over 50 there are significant decreases in cortical bone BMD and lean mass and a higher prevalence of osteoporosis and silent vertebral fractures, but the etiology of the hyperthyroidism does not seem to influence it. Besides the antithyroid drugs, some patients may benefit from bone-directed treatments.

Effects of Teriparatide, Denosumab, or Both on Spine Trabecular Microarchitecture in DATA-Switch: a Randomized Controlled Trial

In postmenopausal women, 2 yr of combined teriparatide and denosumab increases bone mineral density more than either drug alone, and switching from either combination or teriparatide to denosumab for an additional 2 yr further increases bone mineral density. Conversely, switching from denosumab to teriparatide results in transient bone loss. The effects of these interventions on spine microarchitecture are unknown. In the DATA and DATA-Switch studies, 94 postmenopausal osteoporotic women were randomized to receive 24 mo of teriparatide (20 µg daily), denosumab (60 mg every 6 mo), or both. Then, women originally assigned to 24 mo of teriparatide received 24 mo of denosumab, whereas subjects originally randomized to 24 mo of denosumab received 24 mo of teriparatide. Subjects who received both drugs received an additional 24 mo of denosumab alone. Spine trabecular bone score (TBS, a gray-level textural assessment of bone microarchitecture) was measured blinded from treatment groups using images from 2-dimensional dual-energy X-ray absorptiometry spine scans at 0, 12, 24, 30, 36, and 48 mo in 65 women who had posterior-anterior spine dual-energy X-ray absorptiometry images suitable for TBS analysis. After 24 mo, TBS increased by 2.7 ± 4.7% in the teriparatide group (p = 0.009 vs baseline), by 1.8 ± 5.0% in the denosumab group (p = 0.118 vs baseline), and by 4.5 ± 6.7% in the combination group (p = 0.017 vs baseline), with no significant between-group differences. In the 6 mo after the treatments were switched (months 24–30), TBS continued to increase in the combination-to-denosumab and teriparatide-to-denosumab groups but decreased by −1.1 ± 4.0% in the denosumab-to-teriparatide group (p < 0.05 vs other groups). After 48 mo, compared to month 0, TBS increased by 5.1 ± 5.8% in the teriparatide-to-denosumab group, by 3.6 ± 4.2% in the denosumab-to-teriparatide group, and by 6.1 ± 4.7% in the combination-to-denosumab group (p < 0.001 vs baseline for all groups, p = not significant for between-group differences). Switching from teriparatide to denosumab also increased spine TBS. Conversely, switching from denosumab to teriparatide transiently degraded spine trabecular microarchitecture, the clinical consequences of which require further study.

Clinical Application of Spine Trabecular Bone Score (TBS)

Trabecular bone score (TBS) is a software program recently approved by the US Food and Drug Administration for post-acquisition processing of lumbar spine dual-energy X-ray absorptiometry images that allows assessment of bone texture as a surrogate for bone microarchitecture. Low TBS values are associated with increased risk of major osteoporotic fracture risk in postmenopausal women and men aged 40 years and older independent of BMD. TBS data can be used to adjust FRAX probability of fracture. As such, TBS data can be useful in osteoporosis treatment initiation decisions. Following treatment initiation, TBS increases are smaller than seen with BMD; at present, there is insufficient evidence that TBS can be used to monitor treatment. TBS may be particularly helpful in fracture risk prediction for those with diabetes mellitus or receiving glucocorticoid therapy, but additional validation of existing observations is needed. In summary, TBS should not be used alone to guide treatment initiation, but can be used with FRAX to estimate fracture probability in postmenopausal women and older men, thereby facilitating treatment initiation decisions.

Trabecular bone score in kidney transplant recipients.

It is uncertain whether bone mineral density (BMD) can accurately predict fracture in kidney transplant recipients. Trabecular bone score (TBS) provides information independent of BMD. Kidney transplant recipients had abnormal bone texture as measured by lumbar spine TBS, and a lower TBS was associated with incident fractures in recipients. Trabecular bone score (TBS) is a texture measure derived from dual energy X-ray absorptiometry (DXA) lumbar spine images, providing information independent of bone mineral density. We assessed characteristics associated with TBS and fracture outcomes in kidney transplant recipients. We included 327 kidney transplant recipients from Manitoba, Canada, who received a post-transplant DXA (median 106 days post-transplant). We matched each kidney transplant recipient (mean age 45 years, 39% men) to three controls from the general population (matched on age, sex, and DXA date). Lumbar spine (L1-L4) DXA images were used to derive TBS. Non-traumatic incident fracture (excluding hand, foot, and craniofacial) (n = 31) was assessed during a mean follow-up of 6.6 years. We used multivariable linear regression models to test predictors of TBS, and multivariable Cox proportional hazard regression was used to estimate hazard ratios (HRs) per standard deviation decrease in TBS to express the gradient of risk. Compared to the general population, kidney transplant recipients had a significantly lower lumbar spine TBS (1.365 ± 0.129 versus 1.406 ± 0.125, P < 0.001). Multivariable linear regression revealed that receipt of a kidney transplant was associated with a significantly lower mean TBS compared to controls (-0.0369, 95% confidence interval [95% CI] -0.0537 to -0.0202). TBS was associated with fractures independent of the Fracture Risk Assessment score including BMD (adjusted HR per standard deviation decrease in TBS 1.64, 95% CI 1.15-2.36). Kidney transplant recipients had abnormal bone texture as assessed by TBS and a lower lumbar spine TBS was associated with fractures in recipients.

Fracture Risk Prediction by Non-BMD DXA Measures: the 2015 ISCD Official Positions Part 2: Trabecular Bone Score

Bone mineral density (BMD) as measured by dual-energy X-ray absorptiometry (DXA) is the gold standard for the diagnosis and management of osteoporosis. However, BMD explains only 60%–80% of bone strength, and a number of skeletal features other than BMD contribute to bone strength and fracture risk. Advanced imaging modalities can assess some of these skeletal features, but compared to standard DXA, these techniques have higher costs and limited accessibility. A major challenge, therefore, has been to incorporate in clinical practice a readily available, noninvasive technology that permits improvement in fracture-risk prediction beyond that provided by the combination of standard DXA measurements and clinical risk factors. To this end, trabecular bone score (TBS), a gray-level textural index derived from the lumbar spine DXA image, has been investigated. The purpose of this International Society for Clinical Densitometry task force was to review the evidence and develop recommendations on how to incorporate TBS in clinical practice. Clinical applications of TBS for fracture risk assessment, treatment initiation, monitoring of treatment, and use of TBS in special conditions related to greater fracture risk, were addressed. We present the official positions approved by an expert panel following careful review of the recommendations and evidence presented by the TBS task force.

Trabecular bone score as an indicator for skeletal deterioration in diabetes.

Trabecular bone score (TBS) is a novel texture index that evaluates the pixel gray-level variations in lumbar spine dual-energy X-ray absorptiometry images and is related to bone microarchitecture independent of bone mineral density (BMD). We investigated lumbar spine TBS as an indicator for skeletal deterioration in diabetes. Cross-sectional data were collected from subjects participating in an ongoing prospective, community-based, cohort study from 2009 to 2010. We included 1229 men and 1529 postmenopausal women older than 50 years in the Ansung cohort. Biochemical parameters, lumbar spine TBS, and BMD from dual-energy X-ray absorptiometry images were measured. Lumbar spine TBS was lower in men with diabetes than in nondiabetic men (1.287 ± 0.005 vs 1.316 ± 0.003, P < .001), whereas lumbar spine BMD was higher in men with diabetes (1.135 ± 0.010 vs 1.088 ± 0.006 g/cm(2)). Lumbar spine TBS was lower in women with diabetes than in nondiabetic women only in an unadjusted model (1.333 ± 0.004 vs 1.353 ± 0.003). However, women younger than 65 years (n = 707) with diabetes had a lower TBS than those without diabetes, even after adjusted for covariates (P < .001). Diabetes was not associated with BMD at femur sites in both genders. TBS was negatively correlated with glycated hemoglobin, fasting plasma glucose, fasting insulin, and homeostasis model assessment for insulin resistance but not with homeostasis model assessment for β-cell function in both genders. The inverse association between lumbar spine TBS and insulin resistance may make it an indicator for determining skeletal deterioration in diabetic patients who have high BMD.

Age-related normative values of trabecular bone score (TBS) for Japanese women: the Japanese Population-based Osteoporosis (JPOS) study.

Trabecular bone score (TBS), a surrogate measure of bone microarchitecture, represents fracture risk independently of bone density. We present normative TBS values from a representative population study of Japanese women. This database would enhance our understanding of trabecular bone microarchitecture and improve osteoporosis management. TBS is a texture parameter that quantifies local variation in gray level distribution within dual-energy X-ray absorptiometry (DXA) images of the lumbar spine. While TBS is associated with fracture risk independently of areal bone mineral density (aBMD), normative TBS values have only been reported for Caucasian women. This study provides age-specific normative values of TBS from a representative sample of Japanese women. We randomly selected 4,550 women aged 15-79 years from 7 areas throughout Japan. Women younger than 20 years and those with any medical history which might affect bone metabolism were excluded, and the remaining 3,069 with at least two assessable vertebrae from the first to the fourth vertebrae were subjected to analysis. TBS values were calculated from spine DXA images using TBS iNsight software (Med-Imaps, France). Age-related models of TBS were constructed using piecewise linear regression analysis. Participant age, body mass index (BMI), spine aBMD, and TBS (mean ± SD) were 48.7 ± 16.8 years, 22.9 ± 3.4, 0.888 ± 0.169 g/cm(2), and 1.187 ± 0.137, respectively. A three-piece linear regression model of TBS on age explained 70.7% of the total variance in TBS and comprised very small age-related changes in the youngest segment of the regression line, rapid loss in the middle segment, and small loss in the oldest segment. TBS was lower in Japanese women than in Caucasian women across all age ranges, with the difference increasing with age up through 65 years. The normative values of TBS for Japanese women presented here would enhance our understanding of trabecular bone microarchitecture and help improve the management of osteoporosis.

Spine Trabecular Bone Score Subsequent to Bone Mineral Density Improves Fracture Discrimination in Women

Bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) is used to diagnose osteoporosis and assess fracture risk. However, DXA cannot evaluate trabecular microarchitecture. This study used a novel software program (TBS iNsight; Med-Imaps, Geneva, Switzerland) to estimate bone texture (trabecular bone score [TBS]) from standard spine DXA images. We hypothesized that TBS assessment would differentiate women with low trauma fracture from those without. In this study, TBS was performed blinded to fracture status on existing research DXA lumbar spine (LS) images from 429 women. Mean participant age was 71.3 yr, and 158 had prior fractures. The correlation between LS BMD and TBS was low (r = 0.28), suggesting these parameters reflect different bone properties. Age- and body mass index–adjusted odds ratios (ORs) ranged from 1.36 to 1.63 for LS or hip BMD in discriminating women with low trauma nonvertebral and vertebral fractures. TBS demonstrated ORs from 2.46 to 2.49 for these respective fractures; these remained significant after lowest BMD T-score adjustment (OR = 2.38 and 2.44). Seventy-three percent of all fractures occurred in women without osteoporosis (BMD T-score > −2.5); 72% of these women had a TBS score below the median, thereby appropriately classified them as being at increased risk. In conclusion, TBS assessment enhances DXA by evaluating trabecular pattern and identifying individuals with vertebral or low trauma fracture. TBS identifies 66–70% of women with fracture who were not classified with osteoporosis by BMD alone.

SP0008 How to treat: Osteoporosis

Osteoporosis is an extraordinarily common disorder which is the main pathoegenetic factor associated with fractures which occur in approximately 50% of Caucasian women and 20% of Caucasian men over the...

Correlations Between Trabecular Bone Score, Measured Using Anteroposterior Dual-Energy X-Ray Absorptiometry Acquisition, and 3-Dimensional Parameters of Bone Microarchitecture: An Experimental Study on Human Cadaver Vertebrae

Developing a novel technique for the efficient, noninvasive clinical evaluation of bone microarchitecture remains both crucial and challenging. The trabecular bone score (TBS) is a new gray-level texture measurement that is applicable to dual-energy X-ray absorptiometry (DXA) images. Significant correlations between TBS and standard 3-dimensional (3D) parameters of bone microarchitecture have been obtained using a numerical simulation approach. The main objective of this study was to empirically evaluate such correlations in anteroposterior spine DXA images. Thirty dried human cadaver vertebrae were evaluated. Micro-computed tomography acquisitions of the bone pieces were obtained at an isotropic resolution of 93 μm. Standard parameters of bone microarchitecture were evaluated in a defined region within the vertebral body, excluding cortical bone. The bone pieces were measured on a Prodigy DXA system (GE Medical-Lunar, Madison, WI), using a custom-made positioning device and experimental setup. Significant correlations were detected between TBS and 3D parameters of bone microarchitecture, mostly independent of any correlation between TBS and bone mineral density (BMD). The greatest correlation was between TBS and connectivity density, with TBS explaining roughly 67.2% of the variance. Based on multivariate linear regression modeling, we have established a model to allow for the interpretation of the relationship between TBS and 3D bone microarchitecture parameters. This model indicates that TBS adds greater value and power of differentiation between samples with similar BMDs but different bone microarchitectures. It has been shown that it is possible to estimate bone microarchitecture status derived from DXA imaging using TBS.

Association of Coronary Aortic Calcium With Abdominal Aortic Calcium Detected on Lateral Dual Energy X-Ray Absorptiometry Spine Images

The association of abdominal aortic calcium (AAC) on lateral spine bone densitometry with coronary artery calcium (CAC) has not been reported. We studied 33 men and 73 women who had CAC scored with electron beam computed tomography at the eighth visit of the Rancho Bernardo study and lateral spine dual-energy x-ray absorptiometry images fully evaluable for AAC at the ninth study visit. The association between CAC level and AAC tertile was assessed by ordinal logistic regression analysis. The odds ratio of having a greater CAC score for those with an AAC score in the top tertile (24-point scale score > or =5) was 6.42 (95% confidence interval 2.28 to 18.1) and using the 8-point scale (score > or =3) was 3.38 (95% confidence interval 1.26 to 9.07) compared with those with AAC scores in the bottom tertiles, adjusted for age, gender, systolic blood pressure, total and high-density lipoprotein cholesterol, smoking status, and diabetes. A 24-point AAC score of > or =5 had a sensitivity of 65% and specificity of 70% to detect a high CAC score (> or =400 points). An 8-point AAC score of > or =3 had a sensitivity of 45% and specificity of 78%. In conclusion, a high level of AAC on lateral spine dual-energy x-ray absorptiometry was strongly associated with coronary artery disease and might be commonly encountered because bone densitometry is indicated for all women aged > or =65 years and all men aged > or =70 years. Its presence should be reported to the patient's physician to identify and manage modifiable risk factors.

An Atlas Improves Interobserver Agreement Regarding Application of the ISCD Vertebral Body Exclusion Criteria

Coexisting conditions such as osteoarthritis and compression fracture may spuriously elevate the dual-energy X-ray absorptiometry (DXA)-measured lumbar spine bone mass. To improve the diagnostic utility of lumbar spine DXA to diagnose osteoporosis, the International Society for Clinical Densitometry (ISCD) suggests excluding vertebrae affected by focal structural anomalies or unusual T-score discrepancies. However, we previously demonstrated only moderate agreement between physicians regarding vertebral body exclusion. We hypothesized that an atlas containing examples of vertebrae to exclude would improve interobserver agreement. Subsequently, we developed an interactive web-based atlas of lumbar spine DXA images with options to exclude vertebrae and compare one's answers to those derived by group consensus. Before and after review of the atlas, 5 ISCD-certified physicians applied the exclusion criteria to 90 DXA scans, recording the indications for vertebral exclusion on a standardized worksheet. After development and review of the atlas, interobserver agreement regarding vertebral body exclusion improved significantly ( p < 0.0001). We plotted the deviation of each physician's reported T-score vs the mean T-score for each of 90 scans, and demonstrated that the scatter from the mean is decreased after atlas review. Furthermore, correlations in T-score improved in 7 of 10 physician pairs after atlas review. We conclude that an interactive atlas promotes uniform lumbar spine DXA interpretation.

Clinical Utility of Spine Bone Density in Elderly Women

It is common clinical practice to obtain a bone density measurement at both the hip and spine to evaluate osteoporosis. With aging, degenerative changes in the lumbar spine may elevate the bone mineral density (BMD) results giving false assurances that the fracture risk at the spine is low. We examined the association of spine osteoarthritis and bone mineral density in 1082 community-dwelling ambulatory older women aged 50-96 years who participated in a 1992-1996 osteoporosis research clinic visit. The BMD was measured at the hip and posteroanterior (PA) and lateral lumbar spine using dual energy X-ray absorptiometry (DXA). Spine osteoarthritis was identified on the PA lumbar spine DXA images by a musculoskeletal radiologist. Forty percent of women had evidence of spine osteoarthritis (OA). Women with spine OA had a mean age of 77.4 yr (95% confidence interval [CI]: 76.5-78.2), were significantly older than women without spine OA (mean age, 66.8 yr; 95% CI: 65.9-67.7), and were more likely to have prevalent radiographic fractures (14.2% vs. 9.5%; p<0.05). Age-adjusted BMD at the femoral neck, total hip, PA spine, and lateral spine was significantly higher in women with spine OA. Women with spine OA were more likely to have osteoporosis by the World Health Organization classification at the femoral neck and total hip than those without spine OA, but less likely based on the PA spine (14.4% vs. 24.5%). Despite higher BMD levels, women with OA of the lumbar spine had higher prevalence of osteoporosis at the hip and more radiographic vertebral fractures. In elderly women 65 yr and older who are likely to have spine OA, the DXA measurement of the spine may not be useful in assessing fracture risk, and DXA of the hip is recommended for identification of osteoporosis.