Dual-energy X-ray Absorptiometry Machines Research Articles

Significance of non-motor symptoms and development of a screening tool for osteoporosis in Parkinson's disease

Background and purposeParkinson's disease (PD) patients have a higher likelihood of having osteoporosis compared to controls, therefore deserving special attention. This study was to 1) investigate the association of non-motor symptoms with osteoporosis amongst PD patients, and 2) develop screening tools for osteoporosis. Materials and methodsPD Patients were included (n = 109). The factors/variables were obtained from clinical records due to the retrospective nature of this study. The bone mineral density (BMD) of the lumbar spine and femoral neck was examined using a dual-energy X-ray absorptiometry machine, according to which they were categorized as either having (T-score ≤ -2.5) or not having osteoporosis (T-score>-2.5) at the two sites. The non-motor symptoms were assessed using clinical scales, including non-motor experiences of daily living, depression, anxiety, cognitive function, and autonomic function. The potential covariates included demographic and clinical factors/variables, such as age and sex. Logistic regression was used to investigate the associations and establish the screening tools. ResultsPatients with autonomic dysfunction had significantly (p = 0.011) higher odds of having femoral neck osteoporosis compared to those with no/minimal dysfunction after adjusting for sex, disease duration, and body mass index, demonstrating a strong association (odds ratio=12.81). Based on the four factors/variables, a screening tool with a good accuracy was established (C-statistic = 0.85). ConclusionPD patients with autonomic dysfunction had greater odds of having femoral neck osteoporosis compared to those with no/minimal dysfunction. The screening tool may lay a foundation for developing screening models with higher accuracy to identify which PD patients may require a BMD test.

BODY COMPOSITION USING DXA VERSUS BIA IN A MIXED COHORT OF COLLEGE STUDENTS

BACKGROUND Body composition assessment is an important clinical and research tool. Dual energy x-ray absorptiometry (DXA) is the ‘gold standard’ and useful in the research environment, however, it is expensive, reliant on a trained technician, requires a large space, and is immoveable. Bioelectrical impedance (BIA) measurements have improved with the application of 8-electrode multifrequency units and could offer faster, cheaper, and portable alternative if measurements are comparable. The purpose of this study was to determine how well bone mineral content (BMC), lean body mass (LBM), and fat mass measurements made with BIA compared to those made with DXA. METHODS 46 (36 female) college students [avg 21.2 yr, 167.2 cm, 67.2 kg, 28.9% fat; 6 Asian, 4 Hispanic, 3 Black] had their BIA and DXA whole body composition measured within minutes of each other. Three compartments were compared BIA vs DXA: BMC, fat mass, and LBM. Pearson’s correlation coefficients were determined. RESULTS Absolute fat mass (r=0.95), lean mass (r=0.98), and BMC (r=0.91) were highly correlated between the assessment methods. CONCLUSIONS A quadripolar multifrequency BIA device can be a valid body composition surrogate in research environments using college students when a DXA machine is impractical to use.w

A Study on Intelligent Optical Bone Densitometry.

Osteoporosis is a prevalent chronic disease worldwide, particularly affecting the aging population. The gold standard diagnostic tool for osteoporosis is Dual-energy X-ray Absorptiometry (DXA). However, the expensive cost of the DXA machine and the need for skilled professionals to operate it restrict its accessibility to the general public. This paper builds upon previous research and proposes a novel approach for rapidly screening bone density. The method involves utilizing near-infrared light to capture local body information within the human body. Deep learning techniques are employed to analyze the obtained data and extract meaningful insights related to bone density. Our initial prediction, utilizing multi-linear regression, demonstrated a strong correlation (r = 0.98, p-value = 0.003**) with the measured Bone Mineral Density (BMD) obtained from Dual-energy X-ray Absorptiometry (DXA). This indicates a highly significant relationship between the predicted values and the actual BMD measurements. A deep learning-based algorithm is applied to analyze the underlying information further to predict bone density at the wrist, hip, and spine. The prediction of bone densities in the hip and spine holds significant importance due to their status as gold-standard sites for assessing an individual's bone density. Our prediction rate had an error margin below 10% for the wrist and below 20% for the hip and spine bone density.

Decreasing Radiation Exposure in the Treatment of Pediatric Long Bone Fractures Using a DXA Scan: A Proof of Concept

Background: Fractures are typically evaluated and monitored using plain radiographs, but in the pediatric population the goal is always to reduce radiation exposure when possible. Dual-energy X-ray absorptiometry (DXA) is an imaging modality that uses less radiation. The evaluation of upper and lower extremity fractures in the pediatric population using DXA imaging has not yet been studied.Method: Radiographs of 19 patients treated for forearm or tibia fractures were compared to images taken with a DXA machine. The angulation and translation of the fractures were measured twice each by two independent observers. Correlation of these values between plain radiographs and DXA scans along with intra- and inter-observer reliability was calculated.Results: A total of 19 patients with a forearm or tibia fracture were enrolled in the study. Correlation with conventional radiographs for angulation was r=0.77, p<0.001, while for translation was r=0.76, p<0.001. The mean difference between the methods was 0.5 degrees (range of -6.7 to 7.7) for angulation and 4% (range of -28% to 37%) for translation. For plain radiographs the inter-rater reliability was 0.90 (95% confidence interval of 0.84-0.93) for angulation and 0.89 (0.68-0.95) for translation. The inter-rater reliability for DXA imaging was 0.77 (0.69-0.83) for angulation and 0.76 (0.41-0.88) for translation.Conclusion: Our study showed that DXA imaging correlates well with plain radiographs when measuring angulation and translation of forearm and tibia fractures in the pediatric population. This study is a proof of concept that DXA, a low-dose radiation alternative to plain radiographs, may be useful in the management of pediatric fractures.Level of Evidence: Level III Key Concepts•Decreasing radiation exposure in the pediatric population is an ongoing goal in pediatric orthopaedics.•Fracture follow-up imaging in the pediatric population currently is mainly restricted to plain radiographs.•A lower dose imaging modality might be an alternative to plain radiographs to monitor long bone fracture alignment.

Protocol: Can coronary artery calcium score identified on thoracic planning CT scans be used and actioned to identify cancer survivors at high risk of cardiac events: A feasibility study in cancer survivors undergoing radiotherapy in Australia

IntroductionA coronary artery calcium (CAC) CT scan can identify calcified plaque and predict risk of future cardiac events. Cancer survivors undergoing thoracic radiotherapy routinely undergo a planning CT scan, which...

Cortical Thickness of Proximal Femur as a Preliminary Indicator of Bone Mineral Density

Background: Osteoporosis progresses with advancing age. Estimation of bone mineral density (BMD) using dual energy X-ray absorptiometry (DXA) is valuable in predicting fracture risk in the elderly. DXA machines however may not always be available in under-resourced developing countries. Aim: To find values of CTI and CFI in normal adult young and old, male and female population of Southern Punjab. Study design: Cross-sectional population study Methods: Measurements were recorded from 107 anteroposterior radiographs of proximal femur of normal adult male and female subjects divided in two groups: Young: 22 male and 26 females with mean age 28±3.4 and Old: 31 male and 28 females with mean age 61+5.2. Results: Statistical comparison between male and female subjects for CTI was not significant in the Y and O groups. Similar comparison for CFI while not significant in the Y-group was highly significant in the O-group. In overall comparison of Y and O groups the difference was very highly significant for CTI and CFI; both showing higher values in the Y-group. Conclusion; CTI and CFI measured from radiographs of proximal femur are reliable parameters and can be recommended for preliminary assessment of bone mineral density in developing countries. Keywords: Proximal femur, morphometry, cortical thickness index (CTI), canal flare index (CFI), bone mineral density

Вплив тестостерону на якість та мінеральну щільність кісткової тканини в чоловіків

Актуальність. Одним із чинників, що впливають на стан кісткової тканини в чоловіків, є андрогени. У чоловіків літнього віку концентрація загального тестостерону в сироватці крові поступово знижується паралельно зі зростанням глобуліну, який зв’язує статеві гормони, що призводить до більш швидкого зниження вільного тестостерону порівняно з загальним. Мета: оцінити вплив фракцій тестостерону на показники мінеральної щільності та якості кісткової тканини в чоловіків. Матеріали та методи. Обстежені 72 чоловіки віком 40–86 років, які були розподілені згідно з показниками мінеральної щільності кісткової тканини (МЩКТ) на дві групи: основна група — з низькою МЩКТ (n = 39); контрольна група — показник МЩКТ у межах вікової норми (n = 33). Показники МЩКТ, знежиреної та жирової маси визначали за допомогою двофотонної рентгенівської абсорбціометрії (Prodigy, GEНС Lunar, Мадісон, США). Якість трабекулярної кісткової тканини (Trabecular bone score, TBS) на рівні поперекового відділу хребта (L1-L4) оцінювали за допомогою методики TBS iNsight (Med-Imaps, Pessac, Франція). Рівень тестостерону та глобуліну, що зв’язує статеві гормони (ГЗСГ), визначали методом електрохемілюмінесцентного імуноаналізу. Результати. Встановлено, що чоловіки з низькою МЩКТ мають вірогідно нижчі показники індексу вільного тестостерону та біологічно доступного тестостерону, на той час як рівень ГЗСГ є вірогідно вищим. У чоловіків із низькою МЩКТ встановлений позитивний вірогідний зв’язок між індексом вільного тестостерону та МЩКТ на рівні поперекового відділу хребта (r = 0,31; p = 0,05) та шийки стегнової кістки (r = 0,32; p = 0,05). Доведено, що індекс вільного тестостерону впливає не лише на кортикальну кісткову тканину, а й на трабекулярну. Висновки. Вільний тестостерон є універсальним показником, що має доведений вплив не лише на кортикальну та трабекулярну кісткову тканини, а й на показники жирової та знежиреної маси.

Age-related changes in bone tissue in men

The purpose of the study was to establish age-related changes of male bone tissue. Materials and methods. The study was conducted by the Department of Clinical Physiology and Pathology of the Musculoskeletal System of the State Institution “D.F. Chebotarev Institute of Gerontology by the National Academy of Medical Sciences of Ukraine”. It involved 342 healthy men aged 20 to 89 years without osteoporosis and osteoporotic fractures or any pathology with a confirmed impact on bone tissue, as well as any somatic pathology in the sub- and decompensation. The following methods of examination were used: questionnaire, anthropometric measurements, clinical and instrumental examination. Bone mineral density (BMD) was measured by the dual-energy X-ray absorptiometry machine “Prodigy, GEНС Lunar” at the level of the entire skeleton, lumbar spine (L1-L4), proximal femur and femoral neck, distal and ultra-distal forearm bones. Results. We have detected a significant 14.8 % decrease of BMD at the level of femoral neck in the group of men aged 60–69 years, by 20 % in the group of men aged 70–79 years, and by 24.1% in the group of men aged 80–89 years compared to the men aged 20–29 years; at the same time, at the lumbar spine there was registered a decrease of this parameter by 1.6 % in men aged 60–69 years, by 1.9 % in men of 70–79 years and by 0.8 % in men of 80–89 years, respectively. Among the examined practically healthy men, the bone tissue remained at the normal level relative to age in 67.8%; osteopenia was detected in 27.8 %, and osteoporosis in 4.4%. Conclusions. An age-associated BMD reduction was registered at various skeletal sites in the practically healthy men without any clinically significant factors affecting bone tissue metabolism. The most pronounced BMD loss was observed at the level of femoral neck. At the same time, 4.4 % of examined had osteoporosis without any clinical signs.

Body composition reference ranges in community-dwelling adults using dual-energy X-ray absorptiometry: the Australian Body Composition (ABC) Study.

BackgroundReference ranges for lean mass (LM) and fat mass (FM) are essential in identifying soft tissue disorders; however, no such reference ranges exist for the most commonly used Hologic dual‐energy X‐ray absorptiometry (DXA) machine in Australia.MethodsCross‐sectional study of community‐dwelling adults (aged 18–88 years) who underwent a Hologic DXA scan at one of three commercialized densitometry centres in Australia. Age‐specific and sex‐specific percentile curves were generated for LM [LM, appendicular lean mass (ALM), ALM adjusted for height squared (ALM/h2), and ALM adjusted for body mass index (ALM/BMI)] and FM [FM, FM adjusted for height squared (FM/h2), appendicular fat mass, and android and gynoid fat] parameters using the LMS statistical method. Cutpoints equivalent to T‐scores of −1, −2, and −2.5 standard deviations below the young mean reference group (20–29 years) were also generated for LM parameters.ResultsA total of 15 479 community‐dwelling adults (54% men) with a median age of 33 years (interquartile range: 28, 42) were included. LM, ALM, and ALM/h2 remained stable until age 50, after which these parameters started to decline in both sexes. Compared with age 50, median percentiles of LM, ALM, and ALM/h2 declined by −5.9 kg, −3.7 kg, and −0.86 kg/m2 in men and by −2.5 kg, −1.8 kg, and −0.10 kg/m2 in women at age 70, respectively. Adjusting ALM for BMI (rather than height squared) resulted in different trends, with ALM/BMI decreasing from as early as age 20. Compared with age 20, median percentiles of ALM/BMI at age 40 declined by −0.10 kg/kg/m2 in men and by −0.06 kg/kg/m2 in women; and at age 70, ALM/BMI declined by −0.25 kg/kg/m2 in men and by −0.20 kg/kg/m2 in women. Cutpoints equivalent to T‐scores of −1, −2, and −2.5 standard deviations for ALM/BMI were 1.01, 0.86, and 0.77 kg/kg/m2 in men and 0.70, 0.59, and 0.53 kg/kg/m2 in women, respectively. All FM parameters progressively increased from age 20 and continued up until age 70.ConclusionsWe developed reference ranges for LM and FM parameters from Hologic DXA machines in a large cohort of Australian adults, which will assist researchers and clinicians in identifying soft tissue disorders such as obesity, sarcopenia, and cachexia.

Comparison of Differences in Bone Mineral Density Measurement With 3 Hologic Dual-Energy X-Ray Absorptiometry Scan Modes

Bone mineral density (BMD) measurement using dual-energy X-ray absorptiometry (DXA) is considered a diagnostic parameter for osteoporosis by the World Health Organization (WHO). DXA densitometers have different scanning modes for BMD measurements, although the specific scanning modes vary based upon the manufacturer. For DXA machines manufactured by Hologic, which are used globally, a range of scanning modes exist, including but not limited to (in order of decreasing spatial resolution) Array, Fast Array, and Express Array. Only a handful of prior studies have compared the reproducibility of BMD measurements across scan modes. The present study aimed to add to this body of literature by investigating the differences in BMD measured between 3 scanning modes in Hologic DXA machines at 19 different health centers. As part of cross-calibration activities for two multi-center studies in China measuring BMD, the European spine phantom (ESP, 1.000 g/cm2) was scanned on 19 different Hologic DXA machines. To measure differences in BMD between the 3 scan modes most commonly found on the Hologic models available (i.e., Array, Fast Array, Express Array), the ESP measurement was performed 10 times for each scan mode on each Hologic DXA machine. One-sample t test was used to compare the average difference between the measured ESP results of the 3 scanning modes at each hospital and reference ESP values. Single factor analysis of variance was performed to compare the average differences between the pairs of scanning modes using the reference ESP. Statistically significant differences between the measured ESP results with reference ESP values were found with each scanning mode at 19 hospitals (all p values <0.05). Consistent with this finding, differences in average BMD between the Array mode and Fast Array mode were invariably the smallest compared to differences seen between the other two pairs of scan modes. Significant differences were observed between average ESP BMD for the Array and Express Array scan modes (0.971 ± 0.013 vs 0.935 ± 0.027, p < 0.001), and between Fast Array and Express Array scan modes (0.972 ± 0.012 vs 0.935 ± 0.027, p < 0.001). However, no significant difference in average ESP BMD was observed between the Array and Fast Array scan modes (0.971 ± 0.013 vs 0.972 ± 0.012, p = 0.997). The selection of ideal scanning mode requires a balance of scanning time, radiation exposure, and measurement accuracy. In this ex vivo study, the Fast Array scanning mode appeared to be a reasonable choice compared with Array and Express Array for BMD measurements by Hologic DXA. Future in vivo studies can help guide the clinical application of these findings.

Machine Learning Can Improve Clinical Detection of Low BMD: The DXA-HIP Study

Background: Identification of those at high risk before a fracture occurs is an essential part of osteoporosis management. This topic remains a significant challenge for researchers in the field, and clinicians worldwide. Although many algorithms have been developed to either identify those with a diagnosis of osteoporosis or predict their risk of fracture, concern remains regarding their accuracy and application. Scientific advances including machine learning methods are rapidly gaining appreciation as alternative techniques to develop or enhance risk assessment and current practice. Recent evidence suggests that these methods could play an important role in the assessment of osteoporosis and fracture risk. Methods: Data used for this study included Dual-energy X-ray Absorptiometry (DXA) bone mineral density and T-scores, and multiple clinical variables drawn from a convenience cohort of adult patients scanned on one of 4 DXA machines across three hospitals in the West of Ireland between January 2000 and November 2018 (the DXA-Heath Informatics Prediction Cohort). The dataset was cleaned, validated and anonymized, and then split into an exploratory group (80%) and a development group (20%) using the stratified sampling method. We first established the validity of a simple tool, the Osteoporosis Self-assessment Tool Index (OSTi) to identify those classified as osteoporotic by the modified International Society for Clinical Densitometry DXA criteria. We then compared these results to seven machine learning techniques (MLTs): CatBoost, eXtreme Gradient Boosting, Neural network, Bagged flexible discriminant analysis, Random forest, Logistic regression and Support vector machine to enhance the discrimination of those classified as osteoporotic or not. The performance of each prediction model was measured by calculating the area under the curve (AUC) with 95% confidence interval (CI), and was compared against the OSTi. Results: A cohort of 13,577 adults aged ≥40 yr at the age of their first scan was identified including 11,594 women and 1983 men. 2102 (18.13%) females and 356 (17.95%) males were identified with osteoporosis based on their lowest T-score. The OSTi performed well in our cohort in both men (AUC 0.723, 95% CI 0.659–0.788) and women (AUC 0.810, 95% CI 0.787-0.833). Four MLTs improved discrimination in both men and women, though the incremental benefit was small. eXtreme Gradient Boosting showed the most promising results: +4.5% (AUC 0.768, 95% CI 0.706–0.829) for men and +2.3% (AUC 0.833, 95% CI 0.812–0.853) for women. Similarly MLTs outperformed OSTi in sensitivity analyses—which excluded those subjects taking osteoporosis medications—though the absolute improvements differed. Conclusion: The OSTi retains an important role in identifying older men and women most likely to have osteoporosis by bone mineral density classification. MLTs could improve DXA detection of osteoporosis classification in older men and women. Further exploration of MLTs is warranted in other populations, and with additional data.

Metabolic Score for Visceral Fat (METS-VF) Estimation - A Novel Cost-Effective Obesity Indicator for Visceral Adipose Tissue Estimation.

BackgroundVisceral adipose tissue (VAT) assessment is limited in clinical practice due to expensive, time consuming and limited availability of MRI and DXA machines. We explored the utility of a recently developed Metabolic Score for Visceral Fat (METS-VF) to assess VAT in south Asian individuals with morbid obesity.Patients and MethodsIndividuals with BMI ≥35 kg/m2 aged between 30 and 60 years were randomly selected from a database of individuals with morbid obesity, attending a multi-disciplinary bariatric clinic in a tertiary care teaching hospital in southern India. Body composition was assessed by using a Hologic Discovery A dual-energy X-ray absorptiometry (DXA) machine. METS-VF was used to estimate VAT by using a previously published algorithm.ResultsThe mean age and body mass index of the study subjects (N=350) were 38.2 years and 40.1 kg/m2. The MET-VF score performed satisfactorily (AUC of 0.78 (95% CI 0.72–0.85)) for predicting an increased visceral adipose tissue (VAT area ≥ 163 cm2) as detected by DXA. A METS-VF value of 7.3 was found to have a good sensitivity and reasonable specificity in predicting elevated VAT in this population.ConclusionThis is the first study to validate the utility of METS-VF as a surrogate measure of visceral adiposity in south Indian individuals with morbid obesity. Given the simplicity, easy availability, reliability and inexpensive nature of this obesity indicator, it may find its widespread use in lower middle-income countries.

Intermachine differences in DXA measurements vary by skeletal site, and impact the assessment of low bone density in children.

Bone mineral content (BMC) and areal-bone mineral density (aBMD) measurements of the lumbar spine (LS) and whole body less head (WBLH) by dual energy X-ray absorptiometry (DXA) are recommended for bone health assessment in children. Intermachine differences were not considered previously in formulating these recommendations. DXA measurements of the LS, WBLH, total hip, femoral neck and distal 1/3 radius from the Bone Mineral Density in Childhood Study were examined. Healthy children, ages 6 to 16years, from five clinical centers participated. The same spine, whole body, and femur phantoms were measured on each Center's DXA machine. Percentage of individuals with low BMC or aBMD (Z-score<-1.5) was determined. Clinical center differences were evaluated by analysis of covariance adjusting for height and BMI Z-score, calcium intake, physical activity, Tanner stage and bone age. Logistic regression assessed odds of low BMC or aBMD across clinical centers. Significant differences among Clinical Centers (p<0.05) were evident in adjusted mean BMC and aBMD Z-scores (n=1503) for all skeletal sites. WBLH BMC and aBMD Z-scores had the greatest range across centers (-0.13 to 0.24, and -0.17 to 0.56, respectively). The percentage of children with Z-scores less than -1.5 varied among Clinical Centers from 1.9 [95%CI 0.8, 4.5] to 8.1 [95%CI 5.7, 11.3] for WBLH BMC, 1.1 [95%CI 0.4, 3.5] to 6.3 [95%CI 3.8, 10.1] for WBLH aBMD, and from 4.4 [95%CI 2.8, 7.0] to 12.6 [95%CI 9.3, 16.9] for distal 1/3 radius aBMD. For each skeletal site except total hip aBMD and femoral neck BMC, at least one center had significantly lower odds of low bone density. By design, our reference ranges capture intermachine variability. Most clinical centers don't know where their machine falls within the range of intermachine variability, and this may affect diagnosis of children evaluated for conditions that threaten bone health. Total hip scans showed the least, and whole body scans showed the most intermachine variability. Pediatric bone health assessment recommendations should recognize intermachine differences and address this important issue.

How to Interpret Dual Energy X-Ray Absorptiometry for Clinicians

Introduction: Dual energy X-ray absorptiometry (DXA) is a clinically proven method for measuring bone mineral density (BMD) in the lumbar spine, hip, femoral neck, and forearm. It is used for management and to monitor response of therapy of metabolic bone disease. Vertebral fracture assessment (VFA) is additional software that can be added to most DXA machines for the sole purpose of evaluating of occult fractures. DXA has excellent reproducibility, and emits low radiation dose (effective dose 1–3 mSv), which is equivalent to day-to-day background radiation. International Society for Clinical Densitometry (ISCD) recommends obtaining BMD of the posterolateral L1–L4, total hip, femoral neck, and distal one-third forearm.1 It is important for clinicians managing patients for metabolic bone disease to be able to review their own DXA images and reports to ensure the accuracy of the technical performance and interpretation. This is because DXA errors are not uncommon. One particular study of 354 DXA images reviewed showed 90% contained technical errors and 80% interpretation errors were found.2 ISCD has established guidelines for the best practice in DXA performance.3 Periodic quality assurance of DXA equipments should be performed by each center. Although most centers are knowledgeable, there still remains a gap in knowledge that affects interpretation. The aim of this video is to give a short review for clinicians on how to interpret BMD on their own and recognize pitfalls that can result in error in clinical decision making. Methods: A concise review of DXA images and reports is discussed. Results: A four-step approach on how clinicians can interpret their own DXA scan images is described in the video. The first step is to evaluate for proper positioning, review of edges placement, exclude artifacts such as lesions and calcifications if present, and confirm appropriate region-of-interest placement. By applying these four steps, clinicians can reduce potential errors that can lead to errors in medical management. In addition, clinical examples are given on how to monitor BMD changes overtime. This will require each institution to establish its margin of technical error known as precision error to determine its least significant change of each site (spine, total hip, femoral neck, and distal forearm). This allows clinicians to determine whether the change noted is clinically significant. The indications and interpretation of VFA are discussed.4 This is a lateral spine imaging to evaluate for fractures. This nicely augments DXA readings in those patients who are candidates for this VFA based on ISCD guidelines, which is discussed in this video. Conclusion: There are several quality measures needed to produce quality DXA images and reports. As clinicians, we should be empowered to be able to review our own DXA images and make appropriate clinical decisions regarding treatment. No competing financial interests exist. Runtime of video: 12 mins 52 secs

Diagnosis of Osteoporosis using modified U-net architecture with attention unit in DEXA and X-ray images.

Osteoporosis, a silent killing disease of fracture risk, is normally determined based on the bone mineral density (BMD) and T-score values measured in bone. However, development of standard algorithms for accurate segmentation and BMD measurement from X-ray images is a challenge in the medical field. The purpose of this work is to more accurately measure BMD from X-ray images, which can overcome the limitations of the current standard technique to measure BMD using Dual Energy X-ray Absorptiometry (DEXA) such as non-availability and inaccessibility of DEXA machines in developing countries. In addition, this work also attempts to analyze the DEXA scan images for better segmentation and measurement of BMD. This work employs a modified U-Net with Attention unit for accurate segmentation of bone region from X-Ray and DEXA images. A linear regression model is developed to compute BMD and T-score. Based on the value of T-score, the images are then classified as normal, osteopenia or osteoporosis. The proposed network is experimented with the two internally collected datasets namely, DEXSIT and XSITRAY, comprised of DEXA and X-ray images, respectively. The proposed method achieved an accuracy of 88% on both datasets. The Dice score on DEXSIT and XSITRAY is 0.94 and 0.92, respectively. Our modified U-Net with attention unit achieves significantly higher results in terms of Dice score and classification accuracy. The computed BMD and T-score values of the proposed method are also compared with the respective clinical reports for validation. Hence, using the digitized X-Ray images can be used to detect osteoporosis efficiently and accurately.

Metabolomics profiling reveals Echinops latifolius Tausch improves the trabecular micro-architecture of ovariectomized rats mainly via intervening amino acids and glycerophospholipids metabolism

Echinops latifolius Tausch (ELT) is traditional Mongolian medicine in China, and often used to against osteoporosis, strengthen tendons and bones, clear bones heat. To study efficacy of ELT on ovariectomized (OVX) rats and underly metabolic pathways related to trabecular micro-architecture changing of OVX. Three-month-old female Wistar rats were randomly divided into 4 groups (n=6) including normal group (without surgery), sham group (bilateral laparotomy), OVX group (bilateral ovariectomy), and ELT-treated groups (ELT-treated after bilateral ovariectomy). The effects of ELT on trabecular micro-architecture and biochemical markers of OVX rat were investigated by dual-energy X-ray absorptiometry machine and Enzyme-linked immunosorbent assay (ELISA), respectively. Untargeted metabolomics strategy was applied to discover the potential biomarkers and related metabolic pathways involving the progression of OVX-induced osteoporosis. The trabecular micro-architecture and biochemical markers of OVX rats were improved by ELT. We found 36 potential biomarkers and 21 related metabolic pathways were involved in progression of OVX-induced osteoporosis. Amino acids metabolism and glycerophospholipids metabolism were mainly intervened in ELT treatment on ovariectomized rats. The disordered amino acids and glycerophospholipids metabolism closely related to the imbalance between bone resorption and formation were reversed by administration of ELT, indicating that the influences of ELT on OVX rats' trabecular micro-architecture may possible be associated with intervening amino acids and glycerophospholipids metabolism. This approach may provide the metabolomic perspective to link metabolic alterations and anti-osteoporosis action of ELT, to further explain how ELT works in postmenopausal patients with bone loss.

A trans-ethnic two-stage polygenetic scoring analysis detects genetic correlation between osteoporosis and schizophrenia

BackgroundsTo explore the genetic correlation between schizophrenia (SCZ) and osteoporosis (OP).Design, setting, participants, measurementsWe conducted a trans-ethnic two-stage genetic correlation analysis of OP and SCZ, totally invoking 2286 Caucasia subjects in discovery stage and 4124 Chinese subjects in replication stage. The bone mineral density (BMD) and bone area values of ulna & radius, hip and spine were measured using Hologic 4500W dual energy X-ray absorptiometry machine. SCZ was diagnosed according to DSM-IV criteria. For the genome-wide association study (GWAS) of Caucasian OP, Chinese OP and Chinese SCZ, SNP genotyping was performed using Affymetrix SNP 6.0 array. For the GWAS of Caucasian SCZ, SNP genotyping was conducted using the Affymetrix 5.0 array, Affymetrix 6.0 array and Illumina 550 K array. Polygenetic risk scoring (PRS) analysis was conducted by PRSice software. Also, Linkage disequilibrium score regression (LD Score regression) analysis was performed to evaluate the genetic correlation between OP and SCZ. Multi-trait analysis of GWAS (MTAG) was performed to detect novel candidate genes for osteoporosis and SCZ.ResultsIn the Caucasia discovery samples, significant genetic correlations were observed for ulna & radius BMD vs. SCZ (P value = 0.010), ulna & radius area vs. SCZ (P value = 0.031). In the Chinese replication samples, we observed significant correlation for ulna & radius area vs. SCZ (P value = 0.019). In addition, LD Score regression also identified significant genetic correlations between SCZ and bone phenotypes in Caucasian and Chinese sample respectively. MTAG analysis identified several novel candidate genes, such as CTNNA2 (MTAG P value = 2.24 × 10−6) for SCZ and FADS2 (MTAG P value = 2.66 × 10−7) for osteoporosis.ConclusionsOur study results support the overlapped genetic basis for osteoporosis and SCZ, and provide novel clues for elucidating the biological mechanism of increased osteoporosis risk in SCZ patients.

Short Sleep Is Associated With Low Bone Mineral Density and Osteoporosis in the Women's Health Initiative.

Short sleep duration, recognized as a public health epidemic, is associated with adverse health conditions, yet little is known about the association between sleep and bone health. We tested the associations of usual sleep behavior and bone mineral density (BMD) and osteoporosis. In a sample of 11,084 postmenopausal women from the Women's Health Initiative (WHI; mean age 63.3 years, SD = 7.4), we performed a cross-sectional study of the association of self-reported usual hours of sleep and sleep quality (WHI Insomnia Rating Score) with whole body, total hip, femoral neck, and spine BMD using linear regression models. We also studied the association of sleep duration and quality with dual-energy X-ray absorptiometry (DXA)-defined low bone mass (T-score < -2.5 to <-1) and osteoporosis (T-score ≤ -2.5) using multinomial regression models. We adjusted for age, DXA machine, race, menopausal symptoms, education, smoking, physical activity, body mass index, alcohol use, physical function, and sleep medication use. In adjusted linear regression models, women who reported sleeping 5 hours or less per night had on average 0.012 to 0.018 g/cm2 significantly lower BMD at all four sites compared with women who reported sleeping 7 hours per night (reference). In adjusted multinomial models, women reporting 5 hours or less per night had higher odds of low bone mass and osteoporosis of the hip (odds ratio [OR] = 1.22; 95% confidence interval [CI] 1.03-1.45, and 1.63; 1.15-2.31, respectively). We observed a similar pattern for spine BMD, where women with 5 hours or less per night had higher odds of osteoporosis (adjusted OR = 1.28; 95% CI 1.02-1.60). Associations of sleep quality and DXA BMD failed to reach statistical significance. Short sleep duration was associated with lower BMD and higher risk of osteoporosis. Longitudinal studies are needed to confirm the cross-sectional effects of sleep duration on bone health and explore associated mechanisms. © 2019 American Society for Bone and Mineral Research.

Geographical differences in osteoporosis, obesity, and sarcopenia related traits in white American cohorts

It has been reported that geographical variation influences bone mineral density (BMD), obesity, and sarcopenia related traits in other countries. However, there is lack of similar studies in the US population. In this study, we compared data from three US study cohorts to evaluate geographical variations of BMD and body composition. BMD, fat mass and lean mass were collected from Dual-energy X-ray absorptiometry machine. ANCOVA and Chi-square tests were used to compare the differences between BMDs, obesity and sarcopenia related traits from different regional sites (Omaha, Kansas City and Baton Rouge/New Orleans). Eta-squared was used to measure the effect sizes of these differences. A total of 11,315 Caucasians from our previous three study cohorts were compared. There was no significant geographical difference in BMD for males or females under the criteria of p-values < 0.05 and effect size η2 > 0.01. There were significant geographical differences with medium effect size (p-value < 0.001, 0.01 < η2 < 0.14) for whole body fat mass percentage and index of low muscle mass. For Caucasians in the United States, there is no significant geographical effect found on BMD. The obesity and sarcopenia related traits are significantly different between the three study cohorts.

A Cross-Calibration Study of GE Lunar iDXA and GE Lunar DPX Pro for Body Composition Measurements in Children and Adults

Objective: To cross-calibrate dual energy X-ray absorptiometry machines when replacing GE Lunar DPX-Pro with GE Lunar iDXA. Methods: A cross-sectional study was conducted in 126 children (3–19 years) and 135 adults (20–66 years). Phantom cross calibration was carried out using aluminum phantom provided with each of the machines on both machines. Total body less head (TBLH), lumbar spine (L2–L4) and left femoral neck bone mineral density (BMD), bone mineral content (BMC), and bone area were assessed for each patient on both machines. TBLH lean and fat mass were also measured. Bland-Altman analysis, linear regressions, and independent sample t test were performed to evaluate consistency of measurements and to establish cross-calibration equations. Results: iDXA measured 0.33% lower BMD and 0.64% lower BMC with iDXA phantom as compared to DPX-Pro phantom (p < 0.001). In children, TBLH-BMC, femoral BMC and area were measured 10%–14% lesser, TBLH area was higher by 1%–2% and L2–L4 area by 10%–14% by iDXA as compared to DPX-Pro. iDXA measured higher TBLH fat [15% (girls), 31% (boys)] than DPX-Pro. In adults, TBLH-BMD (1.7%–3.4%), BMC (6.0%–10.9%) and area (4.2%–7.6%) were measured lesser by iDXA than DPX-Pro. L2–L4 BMD was higher [2.7% (men), 1.8% (women)] by iDXA than DPX-Pro. Femoral BMC was 2.11% higher in men and 4.1% lower in women by iDXA as compared to DPX-Pro. In children, R2 of cross-calibration equations, ranged from 0.91 to 0.96; in adults, it ranged from 0.93 to 0.99 (p < 0.01). After the regression equations were applied, differences in BMD values between both machines were negligible. Conclusion: A strong agreement for bone mass and body composition was established between both machines. Cross-calibration equations need to be applied to transform DPX-Pro measurements into iDXA measurements to avoid errors in assessment. This study documents a need for use of cross-calibration equations to transform DPX-Pro body composition data into iDXA values for clinical diagnosis.