Texture Analysis Using CT and Chemical Shift Encoding-Based Water-Fat MRI Can Improve Differentiation Between Patients With and Without Osteoporotic Vertebral Fractures

PurposeOsteoporosis is a highly prevalent skeletal disease that frequently entails vertebral fractures. Areal bone mineral density (BMD) derived from dual-energy X-ray absorptiometry (DXA) is the reference standard, but has well-known limitations. Texture analysis can provide surrogate markers of tissue microstructure based on computed tomography (CT) or magnetic resonance imaging (MRI) data of the spine, thus potentially improving fracture risk estimation beyond areal BMD. However, it is largely unknown whether MRI-derived texture analysis can predict volumetric BMD (vBMD), or whether a model incorporating texture analysis based on CT and MRI may be capable of differentiating between patients with and without osteoporotic vertebral fractures.Materials and MethodsTwenty-six patients (15 females, median age: 73 years, 11 patients showing at least one osteoporotic vertebral fracture) who had CT and 3-Tesla chemical shift encoding-based water-fat MRI (CSE-MRI) available were analyzed. In total, 171 vertebral bodies of the thoracolumbar spine were segmented using an automatic convolutional neural network (CNN)-based framework, followed by extraction of integral and trabecular vBMD using CT data. For CSE-MRI, manual segmentation of vertebral bodies and consecutive extraction of the mean proton density fat fraction (PDFF) and T2* was performed. First-order, second-order, and higher-order texture features were derived from texture analysis using CT and CSE-MRI data. Stepwise multivariate linear regression models were computed using integral vBMD and fracture status as dependent variables.ResultsPatients with osteoporotic vertebral fractures showed significantly lower integral and trabecular vBMD when compared to patients without fractures (p<0.001). For the model with integral vBMD as the dependent variable, T2* combined with three PDFF-based texture features explained 40% of the variance (adjusted R2[Ra2] = 0.40; p<0.001). Furthermore, regarding the differentiation between patients with and without osteoporotic vertebral fractures, a model including texture features from CT and CSE-MRI data showed better performance than a model based on integral vBMD and PDFF only (Ra2 = 0.47 vs. Ra2 = 0.81; included texture features in the final model: integral vBMD, CT_Short-run_emphasis, CT_Varianceglobal, and PDFF_Variance).ConclusionUsing texture analysis for spine CT and CSE-MRI can facilitate the differentiation between patients with and without osteoporotic vertebral fractures, implicating that future fracture prediction in osteoporosis may be improved.

Tibial nerve stimulation increases vaginal blood perfusion and bone mineral density and yield load in ovariectomized rats

ABSTRACTHuman menopause transition and post-menopausal syndrome, driven by reduced ovarian activity and estrogen levels, are associated with an increased risk for symptoms including but not limited to sexual dysfunction, metabolic disease, and osteoporosis. Current treatments (both hormonal and non-hormonal) are limited in efficacy and may have adverse consequences, so investigation for additional treatment options is necessary. Previous studies have demonstrated that tibial nerve stimulation or electro-acupuncture near the tibial nerve are minimally invasive treatments that increase vaginal blood perfusion or serum estrogen in the rat model. In this study we examined the effects of twice weekly tibial nerve stimulation (0.2 ms pulse width, 20 Hz, 2x motor threshold) under ketamine-xylazine anesthesia in ovariectomized (OVX) female Sprague Dawley rats on menopause-associated physiological parameters. Rats were split into three groups (n = 10 per group): 1) intact control (no stimulation), 2) OVX control (no stimulation), and 3) OVX stimulation (treatment group). Tibial nerve stimulation did not increase serum estradiol levels, but transiently increased vaginal blood perfusion during stimulation for up to 5 weeks after OVX and increased areal bone mineral density and yield load of the right femur (side of stimulation) compared to the unstimulated OVX control. Additional studies to elucidate the full potential of tibial nerve stimulation on menopause-associated symptoms under different experimental conditions are warranted.SummaryPercutaneous tibial nerve stimulation increases vaginal blood perfusion, areal bone mineral density, and femur yield load in an ovariectomized rat model of menopause.

Dairy Food Intake Is Not Associated with Measures of Bone Microarchitecture in Men and Women: The Framingham Osteoporosis Study

Previous studies reported that dairy foods are associated with higher areal bone mineral density (BMD) in older adults. However, data on bone strength and bone microarchitecture are lacking. We determined the association of dairy food intake (milk, yogurt, cheese, milk + yogurt, and milk + yogurt + cheese, servings/week) with high resolution peripheral quantitative computed tomography (HR-pQCT) measures of bone (failure load, cortical BMD, cortical thickness, trabecular BMD, and trabecular number). This cross-sectional study included participants with diet from a food frequency questionnaire (in 2005–2008 and/or 1998–2001) and measurements of cortical and trabecular BMD and microarchitecture at the distal tibia and radius (from HR-pQCT in 2012–2015). Sex-specific multivariable linear regression estimated the association of dairy food intake (energy adjusted) with each bone measure adjusting for covariates. Mean age was 64 (SD 8) years and total milk + yogurt + cheese intake was 10.0 (SD 6.6) and 10.6 (6.4) servings/week in men and women, respectively. No significant associations were observed for any of the dairy foods and bone microarchitecture measures except for cheese intake, which was inversely associated with cortical BMD at the radius (p = 0.001) and tibia (p = 0.002) in women alone. In this cohort of primarily healthy older men and women, dairy intake was not associated with bone microarchitecture. The findings related to cheese intake and bone microarchitecture in women warrant further investigation.

The influence of snuff and smoking on bone accretion in late adolescence. The Tromsø study, Fit Futures

Summary Areal bone mineral density (aBMD) predicts future fracture risk. This study explores associations between use of tobacco and bone accretion in Norwegian adolescents. Our results indicate that use of snuff is negatively associated with accretion of aBMD in adolescence and may be a signal of increased future fracture risk. Purpose Bone mineral accrual in childhood and adolescence is a long-term primary preventive strategy of osteoporosis. Areal bone mineral density (aBMD) is a surrogate measure of bone strength and a predictor of fracture risk. The aim of this population-based 2-year follow-up cohort study was to explore associations between use of snuff and smoking and changes (∆) in aBMD in Norwegian girls and boys aged 15–17 years at baseline. Methods The first wave of the Tromsø study, Fit Futures was conducted from 2010 to 2011. Femoral neck (FN), total hip (TH), and total body (TB) bone mineral content (BMC) and aBMD were measured by dual-energy X-ray absorptiometry. Information on use of snuff, smoking habits, and other lifestyle related variables were collected through self-administered questionnaires. Two years later, during 2012–2013, the measurements were repeated in the second wave. The present study included 349 girls and 281 boys and compared “non-users” (n = 243 girls, 184 boys) with “users” (n = 105 girls, 96 boys) of snuff and “non-smokers” (n = 327 girls, 249 boys) with “smokers” (n = 21 girls, 31 boys) using linear regression adjusted for age, baseline height and weight, change in height and weight, pubertal maturation, physical activity, ethnicity, alcohol consumption, diagnosis known to affect bone, and medication known to affect bone. The influence of “double use” on bone accretion was also explored. Results In girls, no associations between use of snuff and ∆aBMD were found. In boys, use of snuff was associated with reduced bone accretion in all ∆aBMD models. Sensitivity analysis with exclusion of “sometimes” users of snuff strengthened associations at femoral sites in girls and attenuated all associations in boys. In girls, no associations between smoking and ∆aBMD were found. In boys, only the association with TB ∆aBMD was significant in the fully adjusted models. In girls, “double users” analyses showed similar association to smoking. In boys, nearly all models showed statistically significant associations with a difference of ~ 1–2% in ∆aBMD between “non-users” and “double users” during 2 years of follow-up. Conclusions Our results indicate that tobacco use in late adolescence could be detrimental to bone accretion and may be a signal of increased fracture risk in adult life.

Diet Quality and Bone Density in Youth with Healthy Weight, Obesity, and Type 2 Diabetes

Purpose: To assess relationships between diet quality and areal bone mineral density (aBMD) in youth with healthy weight, obesity, and type 2 diabetes (T2D). Methods: We performed a secondary analysis of cross-sectional data from youth (55% African American, 70% female) ages 10–23 years with T2D (n = 90), obesity (BMI > 95th; n = 128), or healthy weight (BMI < 85th; n = 197). Whole body (less head) areal bone mineral density (aBMD) was assessed by dual-energy X-ray absorptiometry (DXA). aBMD was expressed as age-, sex-, and ancestry-specific standard deviation scores (Z-scores). Whole body aBMD Z-scores were adjusted for height-for-age Z-score. Diet was assessed via three-day diaries, and the Healthy Eating Index (HEI) was computed. Total HEI score and HEI subcomponent scores were compared across groups, and associations with aBMD Z-scores were assessed via linear regression adjusted for group, age, sex, and ancestry. Results: Mean HEI was similar between the healthy weight, obesity, and T2D groups. Several HEI sub-components differed between groups, including meats and beans, total vegetables, milk, saturated fat, sodium, oils, and empty calories. The obesity and T2D group had significantly greater aBMD Z-scores compared to the healthy weight group. Multiple linear regression analyses revealed a significant positive association between HEI and aBMD Z-score (p < 0.05). The HEI sub-components for whole grains (p = 0.052) and empty calories (p < 0.05) were positively associated with aBMD Z-score. Conclusions: Individuals that followed a dietary pattern more closely aligned with the Dietary Guidelines for Americans had greater bone density. Since few studies have investigated the role of diet on bone in youth with obesity-related conditions, additional research is required among these populations.

Performance of HR-pQCT, DXA, and FRAX in the discrimination of asymptomatic vertebral fracture in postmenopausal Chinese women

Summary Volumetric bone density (vBMD) and trabecular microarchitecture measured by high-resolution peripheral quantitative computed tomography (HR-pQCT) can discriminate the patients with high risk of asymptomatic vertebral fracture (VF) in postmenopausal Chinese women. These findings suggested that HR-pQCT could provide additional information on bone quality of the patients with asymptomatic VF. Introduction Although there were several studies using HR-pQCT to investigate asymptomatic VF, it remains uncertain if HR-pQCT parameters can discriminate asymptomatic VF patients, especially in Chinese population. The purpose of this study was to investigate whether bone quality measured by HR-pQCT could discriminate asymptomatic VF independent of hip areal bone mineral density (aBMD) measured by dual-energy x-ray absorptiometry (DXA) and fracture risks evaluated using built-in Fracture Risk Assessment Tool (FRAXBMD). Methods This is a nested case–control study. One hundred seventy-five ambulatory Chinese postmenopausal women aged 60–79 years were retrieved from Normative Reference Standards (NRS) cohort in Hong Kong. DXA was used to identify VF from lateral spine images (VFA) using Genant’s semi-quantitative method. Major osteoporotic fracture risk was calculated using FRAX tool. HR-pQCT was used to assess vBMD, microarchitecture, and estimated strength at both distal radius and tibia. Comparison of HR-pQCT parameters between asymptomatic VF and control was performed using covariance analysis. Logistic regression analysis was performed for calculating the adjusted odds ratio (OR) with 95% confidence intervals (CI) of fracture status as per SD decrease in HR-pQCT parameters. Results Women with asymptomatic VF were older than those of the control in our NRS cohort. Nevertheless, after adjusted for covariance, asymptomatic VF showed significantly lower trabecular vBMD (Tb.vBMD) at radius but higher SMI at tibia as compared with those of the control. Tb.vBMD at radius yielded the highest value of area under the curve (AUC) as compared with total hip aBMD and FRAXBMD. However, no significant difference was found among each other. Conclusion Tb.vBMD at the radius and SMI at the tibia provided by HR-pQCT can discriminate asymptomatic VF independent of hip aBMD and FRAXBMD by DXA in postmenopausal women.

Bone Microarchitecture Decline And Risk Of Fall And Fracture In Men With Poor Physical Performance – The Strambo Study

Context High fracture risk in subjects with low muscle strength is attributed to high risk of fall. Objective To study the association of muscle mass and physical performance with bone microarchitecture decline and risk of fall and nonvertebral fracture in men. Design Prospective 8-year follow-up of a cohort. Setting General population. Participants 821 volunteer men aged ≥60. Interventions Hip areal bone mineral density (aBMD) and appendicular lean mass (ALM) were assessed at baseline by DXA. Lower limb relative ALM (RALM-LL) is ALM-LL/(leg length) 2. The physical performance score reflects ability to perform chair stands and static and dynamic balance. Bone microarchitecture was assessed by high resolution peripheral QCT (HR-pQCT) at baseline, after 4 and 8 years. Statistical analyses were adjusted for shared risk factors. Outcomes Rate of change in the HR-pQCT indices, incident falls and fractures. Results Cortical bone loss and estimated bone strength decline were faster in men with low vs. normal RALM-LL (failure load: -0.74±0.09 vs. -0.43±0.10%/year; p&lt;0.005). Differences were similar between men with poor and those with normal physical performance (failure load: -1.12 ±0.09 vs. -0.40±0.05%/year; p&lt;0.001). Differences were similar between men having poor performance and low RALM-LL and men having normal RALM-LL and performance (failure load: -1.40±0.17 vs. -0.47±0.03%/year; p&lt;0.001). Men with poor physical performance had higher risk of fall (HR=3.52, 95%CI: 1.57–7.90, p&lt;0.05) and fracture (HR=2.68, 95%CI: 1.08–6.66, p&lt;0.05). Conclusion Rapid decline of bone microarchitecture and estimated strength in men with poor physical performance and low RALM-LL may contribute to higher fracture risk.