Standard Dual-energy X-ray Absorptiometry Research Articles

New point-of-care calcaneal ultrasound densitometer (Osteosys BeeTLE) compared to standard dual-energy X-ray absorptiometry (DXA)

Dual-energy X-ray absorptiometry (DXA) represents the gold standard for measuring bone mineral density (BMD). However, its size and bulkiness limit its use in mass screening. Portable and easily accessible instruments are more suitable for this purpose. We conducted a study to assess the repeatability, sensitivity, accuracy, and validation of a new ultrasound densitometer for the calcaneus (OsteoSys BeeTLe) compared to standard DXA. BMD (g/cm2) was measured at the femoral and lumbar spine levels using DXA (Discovery Acclaim (Hologic, Waltham, MA, USA) or Lunar Prodigy (GE Healthcare, Madison, WI, USA) devices). Bone Quality Index (BQI, a dimensionless measure of bone quality derived from measures of SOS [Speed Of Sound] and BUA [broadband ultrasound attenuation]) was measured with OsteoSys BeeTLe. The Bland–Altman test and simple linear regression were used to evaluate the association between values measured with the two instruments. Additionally, the ability of the T-score calculated with BeeTLe to identify patients with previous osteoporotic fractures was tested using ROC curves. A total of 201 patients (94.5% females) with a mean age of 62.1 ± 10.2 were included in the study. The BeeTLe instrument showed a coefficient of variation (CV, in 75 repeated measurements) of 1.21%, which was not statistically different from the CV of DXA (1.20%). We found a significant association between BQI and BMD at the femoral neck (r2 = 0.500, p < 0.0001), total femur (r2 = 0.545, p < 0.0001), and lumbar spine (r2 = 0.455, p < 0.0001). T-scores bias were 0.215 (SD 0.876), 0.021 (SD 0.889) and 0.523 (SD 0.092), for femoral neck, total hip and lumbar spine respectively. AUC for discriminating fracture and non-fractured patients were not significantly different with OsteoSys BeeTLe and standard DXA. In this preliminary study, BeeTLe, a new point-of-care ultrasound densitometer, demonstrated good repeatability and performance similar to DXA. Therefore, its use can be proposed in screening for osteoporosis.

Trabecular Bone Score Improves Early After Successful Kidney Transplantation Irrespective of Antiresorptive Therapy and Changes in Bone Mineral Density.

Trabecular bone score (TBS) is a new tool to assess trabecular bone microarchitecture based on standard dual-energy x-ray absorptiometry (DXA) of lumbar spine images. TBS may be important to assess bone quality and fracture susceptibility in kidney transplant recipients (KTRs). This study aimed to investigate the effect of different bone therapies on TBS in KTRs. We reanalyzed DXA scans to assess TBS in 121 de novo KTRs at baseline, 10 wk, and 1 y. This cohort, between 2007 and 2009, participated in a randomized, placebo-controlled trial evaluating the effect of ibandronate versus placebo in addition to vitamin D and calcium. Although bone mineral density (BMD) Z scores showed a subtle decrease in the first weeks, TBS Z scores increased from baseline to 10 wk for both treatment groups, followed by a slight decline at 12 mo. When comparing treatment groups and adjusting for baseline TBS, there were no differences found in TBS at 12 mo (P = 0.419). Correlation between TBS and BMD at baseline was weak (Spearman's ρ = 0.234, P = 0.010), and change in TBS was not correlated with changes in lumbar spine BMD in either of the groups (ρ = 0.003, P = 0.973). Treatment with ibandronate or vitamin D and calcium did not affect bone quality as measured by TBS in de novo KTRs, but TBS increased early, irrespective of intervention. Changes in TBS and BMD during the study period were not correlated, indicating that these measurements reflect different aspects of bone integrity. TBS may complement BMD assessment in identifying KTRs with a high fracture risk.

Plain radiographic indices are reliable indicators for quantitative bone mineral density in male and female patients before total hip arthroplasty

Osteoporosis is underdiagnosed in patients undergoing total hip arthroplasty (THA). Bone mineral density measurement by dual-energy X-ray absorptiometry (DXA) is the gold standard, but indices on plain hip radiographs also seemed to be reliable screening tools in female or Asian ethnicities in previous studies. Given the lack of knowledge about male patients and Caucasian ethnicities, this study was conducted to evaluate plane hip radiographic indices as a screening tool for osteopenia and osteoporosis in Caucasian female and also male patients before undergoing THA. A retrospective analysis of 216 elderly patients with pre-existing DXA before hip arthroplasty was performed and four indices were calculated on plain hip radiographs: Canal-Flare-Index (CFI), Canal-Calcar-Ratio (CCR), Canal-Bone-Ratio (CBR) 7 and 10 cm below the lesser trochanter. They were correlated with femoral neck DXA T-scores by Pearson’s correlation and intraclass correlation coefficient, and a ROC analysis was performed. A total of 216 patients (49.5% male) were included. CBR-7 and -10 were highly correlated (p < 0.001) with femoral neck T-score in males (Pearson’s correlation CBR-7 r = − 0.60, CBR-10 r = − 0.55) and females (r = − 0.74, r = − 0.77). CBR-7 and -10 also showed good diagnostic accuracy for osteoporosis in the ROC analysis in males (CBR-7: AUC = 0.75, threshold = 0.51; CBR-10: 0.63; 0.50) and females (CBR-7: AUC = 0.87, threshold = 0.55; CBR-10: 0.90; 0.54). Indices such as the Canal Bone Ratio (CBR) 7 or 10 cm below the lesser trochanter on plain hip radiographs are a good screening tool for osteopenia and osteoporosis on plain hip radiographs and can be used to initiate further diagnostics like the gold standard DXA. They differ between male and female patients.

Fragility spinal fractures among cirrhotic liver transplant candidates in Croatia

IntroductionExisting data on fragility spinal fractures prevalence in liver transplant candidates are scarce and inconsistent. This may be due to other comorbidities, besides hepatic osteodystrophy (HO), that contribute to bone loss and fragility fracture prevalence in chronic liver disease (CLD). ObjectivesThe aim of this study was to investigate the prevalence of spinal thoracic and lumbar fragility fractures among cirrhotic, non-chronic kidney disease (CKD), non-diabetic liver transplant candidates and to explore their relationship with clinical characteristics, laboratory markers and dual-energy x-ray absorptiometry (DXA) results. Material and methodsThis cross-sectional observational study was conducted at Merkur University Hospital, Croatia, between February 2019 and May 2023. Adult patients with liver cirrhosis referred for liver transplantation were included. Patients with acute infection, CKD, diabetes mellitus, malignancies, inflammatory bone diseases and those on corticosteroid or antiresorptive therapy were excluded. Clinical, laboratory and radiological assessment was carried out and patients were accordingly allocated into non-fractured and fractured group for the purpose of statistical analysis. ResultsA total of 90 patients were included in the study. There was 123 fractures, 87 (70.7 %) in the thoracic and 36 (29.3 %) in the lumbar region. Eighty-nine (72.4 %) fractures were grade 1, 31 (25.2 %) were grade 2 and 3 (2.4 %) were grade 3. Patients in the fractured group were significantly older (p < 0.001). No significant differences between fractured and non-fractured group according to laboratory and DXA parameters were noted. Subgroup with lumbar fractures had significantly lower bone mineral density values at L1-L4 region. Statistically significant negative correlation between bone specific alkaline phosphatase (BALP) and hip total BMD (rho = -0.414, p < 0.001) and spine total BMD (rho = -0.258, p = 0.014) values was found. ConclusionPresent study confirmed detrimental impact of CLD and HO on bone strength. DXA measurement correlated with the presence of lumbar fragility fractures. A combination of standard X-ray imaging and DXA is needed for adequate bone evaluation in pretransplant period and BALP could be useful for detecting HO in CLD. Searching for other risk factors and implementing bone turnover markers and additional imaging techniques for bone loss evaluation in liver transplant candidates is needed.

Comparison between calcaneus quantitative ultrasound and the gold standard DXA in the ability to detect osteoporosis in chronic obstructive pulmonary disease patients

BackgroundOsteoporosis is a prevalent comorbidity in patients with COPD that is usually underrecognized and hence, undertreated. Compared to the gold standard dual-energy X-ray absorptiometry (DXA), calcaneus quantitative ultrasound (QUS) is less expensive, more portable, and more accessible, especially in less developed countries. The aim of this study was to investigate the ability of calcaneus QUS to screen and prescreen for osteoporosis in patients with COPD.MethodsThis cross-sectional study enrolled 67 males older than 50 years with clinically stable COPD. DXA scans of the lumbar spine (L2–4) and femoral neck were performed. QUS of the right calcaneus (AOS-100) was used to assess the broadband ultrasound attenuation (BUA), speed of sound (SOS), osteo sono-assessment index (OSI), and T-score. When the T-score was ≤ − 2.5, osteoporosis was diagnosed by both DXA and QUS.ResultsForty-eight patients (71.6%) had DXA T-scores ≤ − 2.5 at either the lumbar spine or femoral neck. All QUS parameters (BUA, SOS, OSI, and T-score) could discriminate DXA-determined osteoporosis (the area under the curve varied from 0.64 to 0.83). The QUS T-score was significantly moderately correlated with the DXA T-score at both the femoral neck (r = 0.55) and lumbar spine (r = 0.52). The sensitivity and specificity of QUS in identifying osteoporosis were 10.4% and 94.7%, respectively. The positive and negative predictive values were 83.3% and 29.5%, respectively. When a QUS T-score of 0.09 was used as the cutoff, the sensitivity exceeded 90%, and 15% of the DXA scans were not warranted.ConclusionsThe sensitivity and specificity of calcaneus QUS were not sufficient for QUS to be used as an alternative to DXA for osteoporosis screening. However, QUS may be useful for prescreening before DXA to identify COPD patients who have either a high or low likelihood of osteoporosis. Consequently, QUS reduces the need for DXA referral.

The Vitamin D Metabolite Ratio Is Associated With Volumetric Bone Density in Older Men.

Serum 25-hydroxyvitamin D (25(OH)D) is the current marker of vitamin D adequacy, but its relationship with bone health has been inconsistent. The ratio of 24,25-dihydroxyvitamin D3 to 25(OH)D3 (vitamin D metabolite ratio or VMR) is a marker of vitamin D that has been associated with longitudinal changes in bone mineral density (BMD) and fracture risk. High-resolution peripheral quantitative computed tomography (HR-pQCT) provides information on bone health beyond standard dual-energy x-ray absorptiometry, in that it measures volumetric BMD (vBMD) as well bone strength. The relationship of the VMR with vBMD and bone strength remains unknown. We evaluated the associations of the VMR and 25(OH)D3 with vBMD and bone strength in the distal radius and tibia, assessed by HR-pQCT in 545 older men participating in the Osteoporotic Fractures in Men (MrOS) Study. Primary outcomes were vBMD and estimated failure load (EFL, a marker of bone strength) at the distal radius and tibia. The mean age was 84 ± 4 years, 88.3% were White, and 32% had an estimated glomerular filtration rate <60 mL/min/1.73 m2. In adjusted models, each twofold higher VMR was associated with a 9% (3%, 16%) higher total vBMD and a 13% (5%, 21%) higher EFL at the distal radius. Results were similar at the distal tibia. 25(OH)D3 concentrations were not associated with any of the studied outcomes. Among older men, a higher VMR was associated with greater vBMD and bone strength while 25(OH)D3 was not. The VMR may serve as a valuable marker of skeletal health in older men.

#3641 DOES IBANDRONATE OR CALCIUM AND VITAMIN D MAINTAIN OR IMPROVE BONE MICROARCHITECTURE IN THE FIRST YEAR AFTER KIDNEY TRANSPLANTATION?

Abstract Background and Aims Modern immunosuppressive protocols are associated with less loss of bone mass immediately after kidney transplantation, as compared with previous eras. Even so, bone microarchitecture may still be disturbed due to long-standing uremia, leading to bone fragility and fracture susceptibility. Trabecular bone score (TBS) is a new tool to assess trabecular bone microarchitecture based on standard dual energy X-ray absorptiometry (DXA) of lumbar spine images. TBS reflects bone quality rather than quantity. Studies on the effect of common anti-fracture strategies on TBS in kidney transplant recipients (KTR) are scarce. Our aim was to investigate different treatments on bone microarchitecture by TBS in KTR. Method We analyzed TBS changes and potential treatment effects in 179 de novo KTR, 118 of whom had participated in a randomized controlled trial[1] evaluating the effect of ibandronate (active/placebo) on top of calcium and vitamin D in the first year after kidney transplantation. Trial participants were compared to 61 patients transplanted in the same time-period, meeting the same study inclusion criteria, but receiving no specific bone-directed treatment. Correlations between changes in TBS and lumbar spine BMD were investigated. We used ANOVA and ANCOVA with adjustment for baseline TBS values to evaluate the potential effects of calcium and vitamin D with/without concomitant ibandronate on TBS 12 months after transplantation, as compared to no treatment. Results Mean TBS increased in all groups from baseline to 12 months after transplantation (2.1% for ibandronate/calcium/vitamin D, 2.7% for calcium/vitamin D, and 3.4% for no treatment). Adjusting for baseline TBS, there were no significant differences in TBS at 12 months, neither with overall comparison (p = 0.377) nor when comparing the groups pairwise. The correlation between TBS and BMD was weak (r = 0.170, p = 0.02) at baseline, and change in TBS was not significantly correlated with change in lumbar spine BMD in any of the groups. Conclusion In a group of de novo KTR with reasonably well-preserved bone mass, it does not appear that one year of treatment with ibandronate or calcium and vitamin D significantly affects bone quality as measured by TBS. We found surprisingly weak correlation between changes in TBS and BMD over the study period, indicating that these measurements reflect different aspects of bone integrity and metabolism. This study strengthens the view that focus should be on identifying KTR at high risk of fracture at time of transplantation, as these patients could benefit from anti-resorptive therapy.

Measurement of body composition by DXA, BIA, Leg-to-leg BIA and near-infrared spectroscopy in breast cancer patients – comparison of the four methods

Body composition plays a crucial role in therapy adherence and the prognosis of cancer patients. The aim of this work was to compare four measurement methods for determining body composition regarding their validity, reliability and practicability in order to be able to draft a practical recommendation as to which method is most suitable as a standard measurement method in oncology. Fat mass (FM) and fat-free mass (FFM) was estimated for 100 breast cancer patients with ages of 18-70 years during a defined 20-week inpatient and outpatient rehabilitation process after primary therapy or follow-up rehabilitation. The four methods used were dual energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA), leg-to-leg BIA and near-infrared spectroscopy (NIRS). At baseline (t0) and after 20 weeks (t20) the agreement between the four body composition analysis methods was quantified by pairwise method comparisons using Bland-Altman bias and limits of agreement estimates, t-tests and Lin's concordance correlation coefficients (CCCs). CCCs and Bland-Altman plots indicated that DXA and BIA, DXA and NIRS as well as BIA and NIRS showed an excellent agreement concerning FM estimation at both time points (CCC>0.9). In contrast, no methods agreed with a CCC higher than 0.9 with respect to FFM estimation. However, most estimates were also significantly different between two methods, except for BIA and NIRS which yielded comparable FFM and FM estimates at both time points, albeit with large 95% limits of agreement intervals. The agreement between DXA and BIA was best in the lowest BMI tertile and worsened as BMI increased. Significant differences were also found for FFM changes measured with DXA versus BIA (mean difference-0.4kg, p=0.0049), DXA versus to Leg-to-leg BIA (-0.6kg, p=0.00073) and for FM changes measured with DXA versus Leg-to-leg BIA (0.5kg, p=0.0011). For accurate and valid body composition estimates, Leg-to-leg BIA cannot be recommended due to its significant underestimation of FM or significant overestimation of FFM, respectively. BIA and NIRS results showed good agreement with the gold standard DXA. Therefore both measurement methods appear to be very well suitable to assess body composition of oncological patients and should be used more frequently on a routine basis to monitor the body composition of breast cancer patients.

Lumbar Bone Mineral Density Estimation From Chest X-Ray Images: Anatomy-Aware Attentive Multi-ROI Modeling.

Osteoporosis is a common chronic metabolic bone disease often under-diagnosed and under-treated due to the limited access to bone mineral density (BMD) examinations, e.g., via Dual-energy X-ray Absorptiometry (DXA). This paper proposes a method to predict BMD from Chest X-ray (CXR), one of the most commonly accessible and low-cost medical imaging examinations. The proposed method first automatically detects Regions of Interest (ROIs) of local CXR bone structures. Then a multi-ROI deep model with transformer encoder is developed to exploit both local and global information in the chest X-ray image for accurate BMD estimation. The proposed method is evaluated on 13719 CXR patient cases with ground truth BMD measured by the gold standard DXA. The model predicted BMD has a strong correlation with the ground truth (Pearson correlation coefficient 0.894 on lumbar 1). When applied in osteoporosis screening, it achieves a high classification performance (average AUC of 0.968). As the first effort of using CXR scans to predict the BMD, the proposed algorithm holds strong potential to promote early osteoporosis screening and public health.

Improvement of Patient Classification Using Feature Selection Applied to Bidirectional Axial Transmission.

Osteoporosis is still a worldwide problem, particularly due to associated fragility fractures. Patients at risk of fracture are currently detected using the X-Ray gold standard dual-energy X-ray absorptiometry (DXA), based on a calibrated 2-D image. Different alternatives, such as 3-D X-rays, magnetic resonance imaging (MRI) or ultrasound, have been proposed, the latter having advantages of being portable and sensitive to mechanical and geometrical properties. Bidirectional axial transmission (BDAT) has been used to classify between patients with or without nontraumatic fractures using "classical" ultrasonic parameters, such as velocities, as well as cortical thickness and porosity, obtained from an inverse problems. Recently, complementary parameters acquired with structural and textural analysis of guided wave spectrum images (GWSIs) have been introduced. These parameters are not limited by solution ambiguities, as for inverse problem. The aim of the study is to improve the patient classification using a feature selection strategy for all available ultrasound features completed by clinical parameters. To this end, three classical feature ranking methods were considered: analysis of variance (ANOVA), recursive feature elimination (RFE), and extreme gradient boosting importance feature (XGBI). In order to evaluate the performance of the feature selection techniques, three classical classification methods were used: logistic regression (LR), support vector machine (SVM), and extreme gradient boosting (XGB). The database was obtained from a previous clinical study [Minonzio et al., 2019]. Results indicate that the best accuracy of 71 [66-76]% was achieved by using RFE and SVM with 22 (out of 43) ultrasonic and clinical features. This value outperformed the accuracy of 68 [64-73]% reached with 2 (out of 6) DXA and clinical features. These values open promising perspectives toward improved and generalizable classification of patients at risk of fracture.

Precision of the GE Lunar Total Body-Less Head Scan for the Measurement of Three-Compartment Body Composition in Athletes

Introduction:Dual energy X-ray absorptiometry (DXA) is widely used for the assessment of lean mass (LM), fat mass (FM) and bone mineral content (BMC). When observing standardised protocols, DXA has a high level of precision for the assessment of total body composition, including the head region. However, including the head region may have limited relevance in athletes and can be problematic when positioning taller athletes who exceed scan boundaries. This study investigated the precision of a new total-body-less-head (TBLH) DXA scan for three-compartment body composition measurement in athletes, with outcomes compared to the standard total-body DXA scan. Methods: Precision errors were calculated from two consecutive scans with re-positioning (Lunar iDXA, GE Healthcare, Madison, WI), in male and female athletes from a range of sports. TBLH precision was determined from repeat scans in 95 athletes (male n = 55; female n = 40; age: 26.0 ± 8.5 y; body mass: 81.2 ± 20.5 kg; stature: 1.77 ± 0.11 m), and standard total-body scan precision was derived from a sub-sample of 58 athletes (male n = 19; female n = 39; age: 27.6 ± 9.9 y; body mass: 69.6 ± 14.8 kg; stature: 1.72 ± 0.94 m). Data from the sub-sample were also used to compare precision error and 3-compartment body composition outcomes between the standard total-body scan and the TBLH scan. Results:: TBLH precision errors [root mean squared-standard deviation, RMS-SD (coefficient of variation, %CV)] were bone mineral content (BMC): 15.6 g (0.5%), lean mass (LM): 254.3 g (0.4%) and fat mass (FM): 199.4 g (1.3%). These outcomes compared favourably to the precision errors derived from the standard total-body scan [BMC: 12.4 g (0.4%), LM: 202.2 g (0.4%), and FM: 160.8 g (1.1%)]. The TBLH scan resulted in lower BMC (-19.5%), LM (-6.6%), and FM (-4.5%) compared to the total-body scan (BMC: 2,308 vs. 2,865 g; LM: 46,954 vs. 50,276 g; FM: 15,183 vs. 15,888 g, all p<0.005). ConclusionThe TBLH scan demonstrates high in-vivo precision comparable to that of the standard total-body scan in a heterogeneous cohort of athletes. Given the impact of head exclusion on total body composition outcomes, TBLH scans should not be used interchangeably with the standard total-body scan.

Humeral BMD can be Measured With DXA and Is Lower in the Surgical Arm After Total Shoulder Arthroplasty

Background: As arthroplasty leads to bone loss, we hypothesized that humeral bone mineral density (BMD) is lower after total shoulder arthroplasty (TSA) in the operative versus non-operative arm. However, there is no clinical approach to measure humeral BMD with dual-energy x-ray absorptiometry (DXA). The purposes of this pilot study were to develop DXA methodology to measure humerus BMD, propose humerus regions of interest (ROIs), compare TSA BMD to the non-operative arm, correlate humeral BMD with standard sites, and evaluate measurement reproducibility. Methodology: Thirty-eight adults 1-5 years post-TSA had standard clinical DXA scans plus full humerus scans using the atypical femur fracture feature; precision was assessed in a subset (n = 32). Six custom ROIs were used to measure BMD throughout the humerus. Radius and humeral BMD were compared between arms by paired t-test and correlated ipsilaterally using Pearson's Correlation. Custom ROI BMD precision was assessed using the International Society for Clinical Densitometry (ISCD) advanced precision calculator. Results: Study included 38 subjects (24M/14F), with mean (SD) age and time post-surgery of 69.6 (7.7) years and 2.5 (1.3) years respectively. BMD was lower (p < 0.01) at all custom humerus sites (3.8% to 8.2%) on the surgical side but not different at radius sites. Humeral BMD correlated positively with ipsilateral ultra-distal and 1/3 radius (r = 0.54 to 0.86; p < 0.05). Custom BMD precision (%CV) ranged from 6.0-16.0%. Conclusions: Humerus BMD can be measured using DXA and is lower in the TSA arm. Radius BMD correlated with humeral BMD but was not lower in the surgical arm. BMD precision was worse than usual clinical sites; use of software optimized for the femur is a notable limitation and likely contributes to suboptimal precision. Further study to assess the clinical utility of humeral BMD is needed. Automation and optimization of these measurements should improve precision.

Evaluation of the association between osteoporosis and periodontitis in postmenopausal women: A clinical and radiographic study

This study aimed to assess the relationship between the osteoporotic condition and periodontitis in postmenopausal women. Ninety-four women aged 50-80 years were studied in this cross-sectional study. Bone mineral density (BMD) of lumbar vertebra BMD (LBMD), total hip BMD (HBMD), and neck of femur BMD (NBMD) was assessed using standardized dual-energy X-ray absorptiometry (DXA) (normal: T-score ≥-1, osteopenic: -2.5 ≤ t-score <-1, osteoporotic: T-score <-2.5). Bleeding point index (BI), O'Leary plaque index (PI), and clinical attachment loss (CAL) were recorded. Cementoenamel junction, alveolar-crest distance (CEJ-AC) was measured from cone-beam computed tomography images. Periodontitis severity was represented by CAL and CEJ-AC distance. One-way analysis of variance followed by Post hoc Tukey was performed for examining differences among the groups for different variables. Pearson correlation coefficient® and backward regression analysis were used to investigate the effect of confounding variables on CEJ-AC as the dependent variable. Significance was considered at P < 0.05. Mean CEJ-AC was significantly higher in the osteoporotic and osteopenic groups compared to the normal group (P = 0.001). There was a significant positive correlation between CEJ-AC and NBMD and LBMD (P < 0.001). The associations between LBMD and CEJ-AC existed even after adjusting for confounding factors (P = 0.002). The differences in BI, PI, and CAL were not statistically different between the groups (P > 0.05). Although osteoporosis is not the main cause of periodontitis, it can indirectly affect periodontal status by increasing CEJ-AC. Early diagnosis of osteoporosis followed by early referral to a dentist for the treatment of potential existing periodontal diseases is important to avoid complications among postmenopausal women.

Accuracy of Opportunistic Bone Mineral Density Assessment on Staging Computed Tomography for Gynaecological Cancers.

Background and Objectives: Women with gynecological cancers constitute a high-risk cohort for loss of bone density. International guidance stipulates women undergoing cancer treatments associated with bone loss should have a quantitative assessment of bone density. Access to Dual-energy X-ray Absorptiometry (DXA) is limited. This study aimed to assess the accuracy of opportunistic bone density measurement on staging computed tomography (CT) scans for gynaecological malignancies, in comparison to the gold standard DXA. Materials and Methods: Women with a staging CT scan of the abdomen and pelvis for a new diagnosis of gynecological cancer were recruited. DXA was performed within 6 weeks of treatment for gynaecological cancer. Lumbar bone density was measured by CT attenuation values, in Hounsfield units (HU), of the anterior trabecular region. Correlations between CT and DXA parameters were analysed. Receiver Operating Characteristic(ROC) curves for diagnosis of low bone density and osteoporosis were analysed. Results: Final cohort included 48 of 50 women recruited. There was good diagnostic accuracy for abnormal bone density and osteoporosis, with areas under the ROC curve at L1 of 0.77 (p = 0.002) and 0.80 (p = 0.020) respectively. CT-HU of 170–190 yielded sensitivities of 87–90%, positive predictive values of 75–84% and negative predictive values of 71–75% for the diagnosis of low bone mineral density. CT-HU of 90–110 yielded specificities of 85–93% for the diagnosis of osteoporosis. Moderate correlations were found between CT-HU and both DXA T-scores and diagnostic categories. Conclusions: This is the first study to assess the opportunistic application of CT in the assessment of bone health in women with gynaecological cancer, a cohort at high-risk of osteoporosis. The correlation between bone density assessment in CT-HU and DXA, and strong AUC values for the diagnosis of low bone density (0.77) and osteoporosis (0.80) support this pragmatic solution in resolving the care-gap in cancer treatment-induced bone loss, often associated with poor access to DXA.

Comparison of Dual-Energy X-ray Absorptiometry and Bioelectrical Impedance Analysis in the Assessment of Body Composition in Women with Anorexia Nervosa upon Admission and Discharge from an Inpatient Specialist Unit.

Assessment of body composition is fundamental in diagnosis and treatment of anorexia nervosa (AN). The gold standard dual-energy X-ray absorptiometry (DXA) is expensive and not universally available. Bioelectrical impedance analysis (BIA) is a non-invasive, inexpensive method relative to DXA. We compared DXA and BIA in the assessment of fat-free mass (FFM), fat mass (FM), and body fat percentage (BF%) in women with AN upon admission (ANT1) and discharge (ANT2) from an inpatient specialist unit with a referent healthy control (HC) group. The study population consisted of 31 ANT1, 25 ANT2, and 52 HC women with median age of 21 years. Body composition was measured by DXA and Tanita foot-to-foot BIA. Comparison between the two methods was done using Bland–Altman analysis, Pearson’s correlation coefficient, Lin’s concordance correlation coefficient, and linear regression. The mean difference (bias) in FM and BF% values obtained by DXA and BIA in ANT1 (FM: +1.01 kg, BF%: +2.26%) and ANT2 (FM: +1.49 kg, BF%: +1.66%) were comparable to HC (FM: −1.32 kg, BF%: −2.29%) although in opposite directions. Less bias was observed in FFM values in ANT1 (−0.46 kg) and ANT2 (−0.86 kg) than in HC (+2.03 kg); however, the limits of agreement between the two methods were wider in ANT1 and ANT2 than in HC for all measurements. No association was observed between age, percentage of total body water, and the time spent on the inpatient specialist unit with the difference in estimates of body composition between DXA and BIA. Comparison of DXA and BIA suggests that DXA should remain the gold standard for measuring body composition; the development of more specific BIA equations is required to improve validity and precision of BIA in patients with AN. Despite ease and cost in both BIA access and operation, the suitability of BIA in a low bodyweight eating disorders population remains questionable.

Trabecular and cortical bone involvement in rheumatoid arthritis by DXA and DXA-based 3D modelling.

To evaluate cortical and trabecular bone involvement of the hip in RA patients by dual-energy X-ray absorptiometry (DXA) and 3D analysis. The secondary end-point was to evaluate bone involvement in patients treated with classic (c-DMARD) or biological (b-DMARD) disease-modifying antirheumatic drug therapies and the effect of the duration of the disease and corticosteroid therapy on 3D parameters. A cross-sectional study of 105 RA patients and 100 subjects as a control group (CG) matched by age, sex, and BMI was carried out. BMD was measured by DXA of the bilateral femoral neck (FN) and total hip (TH). The 3D analyses including trabecular and cortical BMD were performed on hip scans with the 3D-Shaper software. FN and TH BMD and trabecular and cortical vBMD were significantly lower in RA patients. The c-DMARD (n = 75) group showed significantly lower trabecular and cortical vBMD than the CG. Despite the lower values, the b-DMARD group (n = 30) showed no significant differences in most parameters compared with the CG. The trabecular and cortical 3D parameters were significantly lower in the group with an RA disease duration of 1 to 5years than in the CG, and the trabecular vBMD was significantly lower in the group with a duration of corticosteroid therapy of 1 to 5years than in the CG, while no significant differences were found by standard DXA in the same period. RA patients had a higher risk of developing low BMD or osteoporosis than controls. RA patients receiving c-DMARD therapy showed significantly lower BMD than controls, while no significant differences in most parameters were found between RA patients receiving b-DMARDs and controls. 3D-DXA allowed us to find changes in trabecular and cortical bone compartments in RA patients.

Spectrum of microarchitectural bone disease in inborn errors of metabolism: a cross-sectional, observational study

BackgroundPatients diagnosed with inborn errors of metabolism (IBEM) often present with compromised bone health leading to low bone density, bone pain, fractures, and short stature. Dual-energy X-ray absorptiometry (DXA) is the current gold standard for clinical assessment of bone in the general population and has been adopted for monitoring bone density in IBEM patients. However, IBEM patients are at greater risk for scoliosis, short stature and often have orthopedic hardware at standard DXA scan sites, limiting its use in these patients. Furthermore, DXA is limited to measuring areal bone mineral density (BMD), and does not provide information on microarchitecture.MethodsIn this study, microarchitecture was investigated in IBEM patients (n = 101) using a new three-dimensional imaging technology high-resolution peripheral quantitative computed tomography (HR-pQCT) which scans at the distal radius and distal tibia. Volumetric BMD and bone microarchitecture were computed and compared amongst the different IBEMs. For IBEM patients over 16 years-old (n = 67), HR-pQCT reference data was available and Z-scores were calculated.ResultsCortical bone density was significantly lower in IBEMs associated with decreased bone mass when compared to lysosomal storage disorders (LSD) with no primary skeletal pathology at both the radius and tibia. Cortical thickness was also significantly lower in these disorders when compared to LSD with no primary skeletal pathology at the radius. Cortical porosity was significantly greater in hypophosphatasia when compared to all other IBEM subtypes.ConclusionWe demonstrated compromised bone microarchitecture in IBEMs where there is primary involvement of the skeleton, as well as IBEMs where skeletal complications are a secondary outcome. In conclusion, our findings suggest HR-pQCT may serve as a valuable tool to monitor skeletal disease in the IBEM population, and provides insight to the greatly varying bone phenotype for this cohort that can be used for clinical monitoring and the assessment of response to therapeutic interventions.

207. Postmenopausal women presenting for spinal fusion surgery have abnormal microarchitecture despite normal DXA

BACKGROUND CONTEXT More than 400,000 spinal fusion surgeries are performed annually in the US, with related health care costs exceeding $287 billion. As spinal fusion involves extensive instrumentation of the vertebrae, patients with skeletal abnormalities may be at increased risk for complications. However, preoperative identification of high-risk patients remains a challenge. Due to skeletal effects of aging and estrogen deficiency, postmenopausal (PM) women may be at particular risk. Dual energy x-ray absorptiometry (DXA) measurements of areal BMD are subject to artifact in patients with spinal pathology, and may be limited as screening tests. PURPOSE This prospective study investigated skeletal health in postmenopausal women having lumbar spine fusion and matched controls using DXA and high resolution peripheral QCT (HRpQCT) measurements of volumetric BMD (vBMD) and microarchitecture. We aimed to determine if HRpQCT would reveal additional abnormalities in vBMD and microarchitecture in fusion patients compared to DXA. STUDY DESIGN/SETTING Prospective, single center study. PATIENT SAMPLE A total of 60 patients were included in this study. PM women undergoing lumbar fusion were prospectively enrolled and compared to PM controls. OUTCOME MEASURES HRpQCT measurements of cortical and trabecular vBMD and microarchitecture, DXA, age and BMI. METHODS PM women undergoing lumbar fusion (n=20) were matched 1:2 by age with PM controls (n=40) who had no history of spine surgery or secondary osteoporosis. Subjects had assessments by standard DXA and high resolution peripheral QCT (HRpQCT) to measure cortical (Ct) and trabecular (Tb) vBMD and microarchitecture of the distal radius and tibia. RESULTS Mean age of subjects was 66+/-6 years, BMI (28+/-6 kg/m2) without any significant differences between groups. By DXA, T-scores in fusion patients were normal at the lumbar spine (mean 0.0) and osteopenic at the total hip (-1.2), femoral neck (-1.5) and 1/3 radius (-1.5). T- Scores did not differ significantly from controls at any site. In contrast, HRpQCT revealed low vBMD (total, Ct, Tb) in fusion patients compared to controls at both radius and tibia, with total vBMD 21-30% lower, Ct density ∼7% and Tb density ∼25% lower. Fusion patients had microarchitectural abnormalities, significantly fewer, thinner and more widely spaced trabeculae. Specifically, Tb number was 9% lower, Tb thickness 6% lower, and Tb separation 23% greater at the radius with similar differences at the tibia. CONCLUSIONS In summary, PM women presenting for spine fusion surgery had low volumetric BMD and abnormal trabecular microarchitecture, despite DXA values that were normal or slightly low. Our results suggest that additional techniques may be necessary for detection of bone quality deficits in patients presenting for spinal fusion. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Osteoporosis in Parkinson's Disease: Relevance of Distal Radius Dual-Energy X-Ray Absorptiometry (DXA) and Sarcopenia

Osteoporotic fractures are common in Parkinson's disease (PD). Standard dual-energy X-ray absorptiometry (DXA) measuring bone mineral density (BMD) at the femoral neck and lumbar spine (central sites) has suboptimal sensitivity in predicting fracture risk in the general population. An association between sarcopenia and osteoporosis in PD has not been studied. We compared BMD and osteoporosis prevalence in PD patients vs controls; determined the osteoporosis detection rates using central alone vs central plus distal radius DXA; and analyzed factors (in particular, sarcopenia) associated with osteoporosis. One hundred and fifty-six subjects (102 patients with PD, 54 spousal/sibling controls) underwent femoral neck-lumbar spine-distal radius DXA. Seventy-three patients and 46 controls were assessed for sarcopenia using whole-body DXA and handgrip strength. Patients underwent clinical and serum biochemical evaluations. PD patients had significantly lower body mass index compared to controls. After adjustment for possible confounders, distal radius BMD and T-scores were significantly lower in PD patients compared to controls, but not at the femoral neck/lumbar spine. With distal radius DXA, an additional 11.0% of patients were diagnosed with osteoporosis (32.0% to 43.0%), vs 3.7% in controls (33.3% to 37.0%) additionally diagnosed; this increase was largely driven by the markedly higher detection rate in female PD patients. Female gender (adjusted odds ratio [ORadjusted] = 11.3, 95% confidence interval [CI]: 2.6–48.6) and sarcopenia (ORadjusted = 8.4, 95% CI: 1.1–64.9) were independent predictors for osteoporosis in PD. Distal radius DXA increased osteoporosis detection, especially in female PD patients, suggesting that diagnostic protocols for osteoporosis in PD could be optimized. A close association between osteoporosis and sarcopenia was documented for the first time in PD, which has important implications for clinical management and future research.

P1621VITAMIN D SUPPLEMENTATION: CHANGES IN BONE MINERAL DENSITY IN KIDNEY TRANSPLANT PATIENTS WITH LONG TERM DURATION OF THE GRAFT

Abstract Background and Aims In the medical literature, several studies have linked bone mineral density (BMD) with vitamin D deficiency in kidney transplant patients (KTRs). However, in spite of the fact that ergocalciferol, cholecalciferol and calcifediol reduce parathyroid hormone (PTH) and improves calcium levels, their effects on the bone mineral density (BMD) in KTRs remain undefined. In consideration of the lack of data available, we aim at investigating the effect of inactive form of vitamin D supplementation on the BMD over a follow-up period up to 2 year, in a real-life cohort of long-term kidney transplant(KT). Method This study was carried out in KTRs who were followed up in a Nephrology Unit. Exclusion criteria were parathyroidectomy, therapy with bisphosphonate, previous history of bone fractures. Demographic, clinical and immunosuppressive agents were collected. Based on 25-OH-D levels, KTRs were classified as suffering from deficiency (&amp;lt; 30 ng/mL). BMD was evaluated at lumbar vertebral bodies (LV) and right femoral hip (FH) by a single operator, using a standard dual energy X-ray absorptiometry. According to WHO criteria, results were expressed as T-score (standard deviation [SD] relative to young healthy adults), and Z-score (SD relative to age-matched controls). Osteoporosis and osteopenia were defined as T score ≤ −2.5 SD and T score &amp;lt; −1 and &amp;gt; −2.5 SD, respectively. Laboratory data, 25-OH-D, and BMD were measured at baseline and after 24 months of supplementation therapy. Vitamin D deficiency was corrected using standard treatment strategy recommended for general population. Continuous variables were expressed as mean ± SD whereas categorical variables as percentage. The Student’s t test and chi-square test were used to compare to compare continuous and categorical variables, respectively. For before and after comparisons of continuous variables, the paired t-test or one-sample Wilcoxon signed rank test were used based on variable’s distribution. Results Data pertaining to 111 out of 133 consecutive outpatients were collected, of whom most were males (69.4%), no-smokers (89.1%) and treated with glucocorticoids (84%). The mean age was 53.9±11.6 years and months after transplant was 161.6±128.3. No statistical differences were found among patients with normal BMD, osteopenia or osteoporosis at LV and FH in terms of age at transplant, gender distribution, time on dialysis, BMI and eGFR, serum calcium, serum phosphate, 25-OH-D and iPTH. At baseline, 25-OH-D was 13.9±7.2 ng/ml and the prevalence of osteopenia/osteoporosis was 40.9% (T-Score -1.69±0.37; Z-score -1.16±1.09) and 21.8 % (T-Score -3.15±0.50; Z-score -2.27±0.58) at LV; 55.3 % (T-Score -1.8±0.46; Z-score -0.84±0.633) and 14 % (T-Score -2.83±0.39; Z-score -1.65±0.49) at FH. After 27.6±3.7 months of therapy with cholecalciferol at mean dose of 13.396±7.537 UI at week, 25-OH-D values increased to 29.4±9.4 ng/ml (p&amp;lt;0.0001) while no statistically significant changes were found in Z-score and T-score at both sites, except for a mild improvement in lumbar vertebral Z-score, reaching −0.82± 0.7 (p = 0.06) in KTRs with osteopenia Conclusion Our study showed BMD remained stable after up to 2 years of inactive vitamin D therapy in long-term kidney transplant with vitamin D deficiency. A mild increase in Z-score was observed in the L-spine. Further designated studies should be conducted to demonstrate the effect of vitamin D on BMD.