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Mary L Bouxsein - One of the best experts on this subject based on the ideXlab platform.

  • effects of combination denosumab and high dose teriparatide administration on Bone Microarchitecture and estimated strength the data hd hr pqct study
    Journal of Bone and Mineral Research, 2021
    Co-Authors: Benjamin Z Leder, Hang Lee, Mary L Bouxsein, Sabashini K Ramchand, Natalie L David, Michael Bruce, Joy N Tsai
    Abstract:

    In postmenopausal women at high risk of fracture, we previously reported that combined denosumab and high-dose (HD; 40 μg) teriparatide increased spine and hip Bone mineral density (BMD) more than combination with standard-dose teriparatide (SD; 20 μg). To assess the effects of these combinations on Bone Microarchitecture and estimated Bone strength, we performed high-resolution peripheral quantitative computed tomography (HR-pQCT) at the distal radius and distal tibia in these women, who were randomized to receive either teriparatide 20 μg (n = 39) or 40 μg (n = 37) during months 0 to 9 overlapped with denosumab 60 mg s.c. given at months 3 and 9, for a 15-month study duration. The 69 women who completed at least one study visit after baseline are included in this analysis. Over 15 months, increases in total BMD were higher in the HD-group than the SD-group at the distal tibia (5.3% versus 3.4%, p = 0.01) with a similar trend at the distal radius (2.6% versus 1.0%, p = 0.06). At 15 months, cortical porosity remained similar to baseline, with absolute differences of -0.1% and -0.7% at the distal tibia and -0.4% and -0.1% at the distal radius in the HD-group and SD-group, respectively; p = NS for all comparisons. Tibial cortical tissue mineral density increased similarly in both treatment groups (1.3% [p < 0.0001 versus baseline] and 1.5% [p < 0.0001 versus baseline] in the HD-group and SD-group, respectively; p = 0.75 for overall group difference). Improvements in trabecular Microarchitecture at the distal tibia and estimated strength by micro-finite element analysis at both sites were numerically greater in the HD-group compared with SD-group but not significantly so. Together, these findings suggest that short-term treatment combining denosumab with either high- or standard-dose teriparatide improves HR-pQCT measures of Bone density, microstructure, and estimated strength, with greater gains in total Bone density observed in the HD-group, which may be of benefit in postmenopausal women with severe osteoporosis. © 2020 American Society for Bone and Mineral Research (ASBMR).

  • effects of combination denosumab and high dose teriparatide administration on Bone Microarchitecture and estimated strength the data hd hr pqct study
    Journal of Bone and Mineral Research, 2020
    Co-Authors: Benjamin Z Leder, Mary L Bouxsein, Sabashini K Ramchand, Natalie L David, Michael Bruce, Joy N Tsai
    Abstract:

    In postmenopausal women at high risk of fracture, we previously reported that combined denosumab and high-dose (HD, 40-μg) teriparatide increased spine and hip Bone mineral density (BMD) more than combination with standard-dose teriparatide (SD, 20-μg). To assess the effects of these combinations on Bone Microarchitecture and estimated Bone strength, we performed high-resolution peripheral quantitative computed tomography (HR-pQCT) at the distal radius and distal tibia in these women, who were randomized to receive either teriparatide 20-ug (n=39) or 40-μg (n=37) during months 0-9 overlapped with denosumab 60-mg s.c. given at month 3 and 9, for a 15-month study duration. The 69 women who completed at least one study visit after baseline are included in this analysis. Over 15 months, increases in total BMD were higher in the HD-group than the SD-group at the distal tibia (5.3% vs. 3.4%, P=0.01) with a similar trend at the distal radius (2.6% vs. 1.0%, P=0.06). At 15 months, cortical porosity remained similar to baseline, with absolute differences of -0.1% and -0.7% at the distal tibia and -0.4% and -0.1% at the distal radius, in the HD-group and SD-group, respectively, P=NS for all comparisons. Tibial cortical tissue mineral density increased similarly in both treatment groups (1.3% (P<0.0001 vs. baseline) and 1.5% (P<0.0001 vs. baseline) in the HD-group and SD-group, respectively, P=0.75 for overall group difference). Improvements in trabecular Microarchitecture at the distal tibia and estimated strength by micro-finite element analysis at both sites were numerically greater in the HD-group compared to SD-group, but not significantly so. Together, these findings suggest that short-term treatment combining denosumab with either high or standard-dose teriparatide improves HR-pQCT measures of Bone density, microstructure, and estimated strength, with greater gains in total Bone density observed in the HD-group, which may be of benefit in postmenopausal women with severe osteoporosis. This article is protected by copyright. All rights reserved.

  • red and white blood cell counts are associated with Bone marrow adipose tissue Bone mineral density and Bone Microarchitecture in premenopausal women
    Journal of Bone and Mineral Research, 2020
    Co-Authors: Sai Polineni, Mary L Bouxsein, Megi Resulaj, Alexander T Faje, Erinne Meenaghan, Miriam A Bredella, Ormond A Macdougald, Anne Klibanski, Pouneh K Fazeli
    Abstract:

    Bone marrow adipose tissue (BMAT) resides within the Bone marrow microenvironment where its function remains poorly understood. BMAT is elevated in anorexia nervosa, a disease model of chronic starvation, despite depletion of other fat depots. In addition to BMAT, the marrow microenvironment also consists of osteoblast and hematopoietic progenitors. BMAT is inversely associated with Bone mineral density (BMD) in multiple populations including women with anorexia nervosa, and regulates hematopoiesis in animal models. We hypothesized that BMAT would be associated with circulating populations of hematopoietic cells (red and white blood cells) in humans and performed a post hoc analysis of two studies-a cross-sectional study and a longitudinal study-to investigate this hypothesis. We studied 89 premenopausal women cross-sectionally (median age [interquartile range], 27 [24.5, 31.7] years), including 35 with anorexia nervosa. We investigated associations between red blood cell (RBC) and white blood cell (WBC) counts and BMAT assessed by 1 H-magnetic resonance spectroscopy, BMD assessed by DXA, and Bone Microarchitecture assessed by HR-pQCT. In addition, we analyzed longitudinal data in six premenopausal women with anorexia nervosa treated with transdermal estrogen for 6 months and measured changes in BMAT and blood cell counts during treatment. Cross-sectionally, BMAT was inversely associated with WBC and RBC counts. In contrast, BMD and parameters of Bone Microarchitecture were positively associated with WBC and RBC. In women with anorexia nervosa treated with transdermal estrogen for 6 months, decreases in BMAT were significantly associated with increases in both RBC and hematocrit (rho = -0.83, p = 0.04 for both). In conclusion, we show that BMAT is inversely associated with WBC and RBC in premenopausal women, and there is a potential association between longitudinal changes in BMAT and changes in RBC. These associations warrant further study and may provide further insight into the role and function of this understudied adipose depot. © 2020 American Society for Bone and Mineral Research.

  • effects of estrogen replacement on Bone geometry and Microarchitecture in adolescent and young adult oligoamenorrheic athletes a randomized trial
    Journal of Bone and Mineral Research, 2020
    Co-Authors: Mary L Bouxsein, Anne Klibanski, Kathryn E Ackerman, Vibha Singhal, Meghan Slattery, Kamryn T Eddy, Madhusmita Misra
    Abstract:

    : Oligoamenorrheic athletes (OAs) have lower Bone mineral density (BMD) and greater impairment of Bone Microarchitecture, and therefore higher fracture rates compared to eumenorrheic athletes. Although improvements in areal BMD (aBMD; measured by dual-energy X-ray absorptiometry) in OAs have been demonstrated with transdermal estrogen treatment, effects of such treatment on Bone Microarchitecture are unknown. Here we explore effects of transdermal versus oral estrogen versus no estrogen on Bone Microarchitecture in OA. Seventy-five OAs (ages 14 to 25 years) were randomized to (i) a 100-μg 17β-estradiol transdermal patch (PATCH) administered continuously with 200 mg cyclic oral micronized progesterone; (ii) a combined 30 μg ethinyl estradiol and 0.15 mg desogestrel pill (PILL); or (iii) no estrogen/progesterone (NONE) and were followed for 12 months. Calcium (≥1200 mg) and vitamin D (800 IU) supplements were provided to all. Bone Microarchitecture was assessed using high-resolution peripheral quantitative CT at the distal tibia and radius at baseline and 1 year. At baseline, randomization groups did not differ by age, body mass index, percent body fat, duration of amenorrhea, vitamin D levels, BMD, or Bone Microarchitecture measurements. After 1 year of treatment, at the distal tibia there were significantly greater increases in total and trabecular volumetric BMD (vBMD), cortical area and thickness, and trabecular number in the PATCH versus PILL groups. Trabecular area decreased significantly in the PATCH group versus the PILL and NONE groups. Less robust differences between groups were seen at the distal radius, where percent change in cortical area and thickness was significantly greater in the PATCH versus PILL and NONE groups, and changes in cortical vBMD were significantly greater in the PATCH versus PILL groups. In conclusion, in young OAs, Bone structural parameters show greater improvement after 1 year of treatment with transdermal 17β-estradiol versus ethinyl estradiol-containing pills, particularly at the tibia. © 2019 American Society for Bone and Mineral Research.

  • skeletal loading score is associated with Bone Microarchitecture in young adults
    Bone, 2019
    Co-Authors: Mary L Bouxsein, Kristin L Popp, Victoria Turkington, Julie M Hughes, Chun Xu, Ginu Unnikrishnan, Jaques Reifman
    Abstract:

    Abstract Physical activity that involves high strain magnitudes and high rates of loading is reported to be most effective in eliciting an osteogenic Bone response. Whether a history of participation in osteogenic activities during youth, as well as current participation in osteogenic activities, contributes to young adult Bone Microarchitecture and strength is unknown. PURPOSE: We determined the association between a new skeletal loading (SkL) score reflecting physical activity from age 11 to adulthood, the Bone specific physical activity questionnaire (BPAQ) and Bone Microarchitecture in young Black and White men and women. Methods We conducted a cross-sectional study of young ([mean ± SD] 23.7 ± 3.3 years) Black (n = 51 women, n = 31 men) and White (n = 50 women, n = 49 men) adults. Microarchitecture and estimated Bone strength (by micro-finite element analysis) were assessed at the ultradistal tibia using high-resolution peripheral quantitative computed tomography (HR-pQCT). Physical activity questionnaires were administered and a SkL score was derived based on ground reaction force, rate of loading, frequency, duration, and life period of participation per activity from age 11 onwards. BPAQ score was also calculated. We used multiple linear regression to determine associations between both SkL score and BPAQ score and Bone outcomes, adjusting for age, height, weight, sex, and race. Results We found that SkL score, which accounts for current and historical physical activity, was significantly associated with most cortical Bone parameters at the tibia including area, area fraction, porosity, thickness, and tissue mineral density (R2 = 0.27–0.55, all p  Conclusion These findings suggest that among young adults, greater amounts of osteogenic physical activity, as assessed by the SkL score and BPAQ are associated with improved Bone Microarchitecture and strength. With the potential to predict Bone parameters in young adults, these scores may ultimately serve to identify those most vulnerable to fracture.

Joy N Tsai - One of the best experts on this subject based on the ideXlab platform.

  • effects of combination denosumab and high dose teriparatide administration on Bone Microarchitecture and estimated strength the data hd hr pqct study
    Journal of Bone and Mineral Research, 2021
    Co-Authors: Benjamin Z Leder, Hang Lee, Mary L Bouxsein, Sabashini K Ramchand, Natalie L David, Michael Bruce, Joy N Tsai
    Abstract:

    In postmenopausal women at high risk of fracture, we previously reported that combined denosumab and high-dose (HD; 40 μg) teriparatide increased spine and hip Bone mineral density (BMD) more than combination with standard-dose teriparatide (SD; 20 μg). To assess the effects of these combinations on Bone Microarchitecture and estimated Bone strength, we performed high-resolution peripheral quantitative computed tomography (HR-pQCT) at the distal radius and distal tibia in these women, who were randomized to receive either teriparatide 20 μg (n = 39) or 40 μg (n = 37) during months 0 to 9 overlapped with denosumab 60 mg s.c. given at months 3 and 9, for a 15-month study duration. The 69 women who completed at least one study visit after baseline are included in this analysis. Over 15 months, increases in total BMD were higher in the HD-group than the SD-group at the distal tibia (5.3% versus 3.4%, p = 0.01) with a similar trend at the distal radius (2.6% versus 1.0%, p = 0.06). At 15 months, cortical porosity remained similar to baseline, with absolute differences of -0.1% and -0.7% at the distal tibia and -0.4% and -0.1% at the distal radius in the HD-group and SD-group, respectively; p = NS for all comparisons. Tibial cortical tissue mineral density increased similarly in both treatment groups (1.3% [p < 0.0001 versus baseline] and 1.5% [p < 0.0001 versus baseline] in the HD-group and SD-group, respectively; p = 0.75 for overall group difference). Improvements in trabecular Microarchitecture at the distal tibia and estimated strength by micro-finite element analysis at both sites were numerically greater in the HD-group compared with SD-group but not significantly so. Together, these findings suggest that short-term treatment combining denosumab with either high- or standard-dose teriparatide improves HR-pQCT measures of Bone density, microstructure, and estimated strength, with greater gains in total Bone density observed in the HD-group, which may be of benefit in postmenopausal women with severe osteoporosis. © 2020 American Society for Bone and Mineral Research (ASBMR).

  • effects of combination denosumab and high dose teriparatide administration on Bone Microarchitecture and estimated strength the data hd hr pqct study
    Journal of Bone and Mineral Research, 2020
    Co-Authors: Benjamin Z Leder, Mary L Bouxsein, Sabashini K Ramchand, Natalie L David, Michael Bruce, Joy N Tsai
    Abstract:

    In postmenopausal women at high risk of fracture, we previously reported that combined denosumab and high-dose (HD, 40-μg) teriparatide increased spine and hip Bone mineral density (BMD) more than combination with standard-dose teriparatide (SD, 20-μg). To assess the effects of these combinations on Bone Microarchitecture and estimated Bone strength, we performed high-resolution peripheral quantitative computed tomography (HR-pQCT) at the distal radius and distal tibia in these women, who were randomized to receive either teriparatide 20-ug (n=39) or 40-μg (n=37) during months 0-9 overlapped with denosumab 60-mg s.c. given at month 3 and 9, for a 15-month study duration. The 69 women who completed at least one study visit after baseline are included in this analysis. Over 15 months, increases in total BMD were higher in the HD-group than the SD-group at the distal tibia (5.3% vs. 3.4%, P=0.01) with a similar trend at the distal radius (2.6% vs. 1.0%, P=0.06). At 15 months, cortical porosity remained similar to baseline, with absolute differences of -0.1% and -0.7% at the distal tibia and -0.4% and -0.1% at the distal radius, in the HD-group and SD-group, respectively, P=NS for all comparisons. Tibial cortical tissue mineral density increased similarly in both treatment groups (1.3% (P<0.0001 vs. baseline) and 1.5% (P<0.0001 vs. baseline) in the HD-group and SD-group, respectively, P=0.75 for overall group difference). Improvements in trabecular Microarchitecture at the distal tibia and estimated strength by micro-finite element analysis at both sites were numerically greater in the HD-group compared to SD-group, but not significantly so. Together, these findings suggest that short-term treatment combining denosumab with either high or standard-dose teriparatide improves HR-pQCT measures of Bone density, microstructure, and estimated strength, with greater gains in total Bone density observed in the HD-group, which may be of benefit in postmenopausal women with severe osteoporosis. This article is protected by copyright. All rights reserved.

  • effects of denosumab and teriparatide transitions on Bone Microarchitecture and estimated strength the data switch hr pqct study
    Journal of Bone and Mineral Research, 2017
    Co-Authors: Joy N Tsai, Hang Lee, Kyle K Nishiyama, David Lin, Amy Yuan, Mary L Bouxsein, Benjamin Z Leder
    Abstract:

    In postmenopausal osteoporosis, switching from teriparatide to denosumab results in continued Bone mineral density (BMD) gains whereas switching from denosumab to teriparatide results in BMD loss. To assess the effects of these transitions on Bone Microarchitecture and strength, we performed high-resolution peripheral QCT (HR-pQCT) at the distal tibia and radius in postmenopausal osteoporotic women who received 24-months of teriparatide 20-mcg daily followed by 24-months of denosumab 60-mg every 6 months, 24-months of denosumab followed by 24-months of teriparatide, or 24-months of both medications followed by 24-months of denosumab. This article is protected by copyright. All rights reserved

  • effects of two years of teriparatide denosumab or both on Bone Microarchitecture and strength data hrpqct study
    The Journal of Clinical Endocrinology and Metabolism, 2016
    Co-Authors: Joy N Tsai, Hang Lee, Mary L Bouxsein, Nicholas P Derrico, Alexander V Uihlein, Sherriann M Burnettbowie, Robert M Neer, Benjamin Z Leder
    Abstract:

    Context: In postmenopausal osteoporosis, combining denosumab and teriparatide increases hip and spine Bone mineral density more than either monotherapy. Objective: The objective of the study was to determine the effects of 2 years of combination therapy on Bone Microarchitecture and estimated strength. Design: This was an open-label, randomized controlled trial. Participants and Methods: We performed high-resolution peripheral quantitative computed tomography at the distal tibia and radius in 94 postmenopausal osteoporotic women randomized to 2 years of teriparatide 20 μg sc daily, denosumab 60 mg sc every 6 months, or both. Results: Total volumetric Bone mineral density (vBMD) at the radius and tibia, trabecular vBMD at the radius, and cortical vBMD at the tibia all increased more in the combination group than both monotherapy groups (P < .002 for all comparisons with combination). Cortical thickness at the tibia also increased more in the combination group (8.1% ± 4.3%) than both other groups (P < .001)...

  • Effects of Antiresorptive Therapy on Bone Microarchitecture
    The Duration and Safety of Osteoporosis Treatment, 2016
    Co-Authors: Joy N Tsai, Mary L Bouxsein
    Abstract:

    Dual-energy X-ray absorptiometry (DXA) is widely used to measure Bone mineral density (BMD) for both clinical and research use. While DXA is well validated as a predictor of fracture, density is only one determinant of Bone quality. Other potential major contributors to fracture risk reduction include Bone morphology, Bone Microarchitecture, and the intrinsic physical properties of Bone tissue. This chapter focuses on the effect of antiresorptive therapy on Bone Microarchitecture as assessed by (1) traditional two-dimensional histomorphometry of iliac crest Bone biopsies and three-dimensional ex vivo micro-CT of biopsies and (2) imaging methods including high-resolution peripheral quantitative CT (HR-pQCT) that assess Bone Microarchitecture in vivo. Studies show that trabecular Microarchitecture is generally preserved or improved with antiresorptive treatment as assessed by histomorphometry and micro-CT of iliac crest biopsies. However, trabecular microarchitectural changes as assessed by HR-pQCT are generally not detected, possibly due to limited imaging resolution and modest reproducibility for trabecular Microarchitecture measurements. Cortical Microarchitecture is generally preserved or improved as assessed by both iliac crest Bone biopsy histomorphometry with micro-CT and by HR-pQCT of the distal radius and distal tibia. These studies highlight the important positive effects of antiresorptive treatment on trabecular and cortical Microarchitecture at axial and peripheral sites.

Didier Hans - One of the best experts on this subject based on the ideXlab platform.

  • effect of concomitant vitamin d deficiency or insufficiency on lumbar spine volumetric Bone mineral density and trabecular Bone score in primary hyperparathyroidism
    Osteoporosis International, 2016
    Co-Authors: Marcella D Walker, Didier Hans, Thomas Lang, Isra Saeed, James A Lee, Chiyuan A Zhang, Shonni J Silverberg
    Abstract:

    Summary Lower vitamin D and higher parathyroid hormone (PTH) levels are associated with higher volumetric BMD and Bone strength at the lumbar spine as measured by central quantitative computed tomography in primary hyperparathyroidism (PHPT), but there are no differences in Bone Microarchitecture as measured by trabecular Bone score (TBS).

  • Bone Microarchitecture assessed by tbs predicts osteoporotic fractures independent of Bone density the manitoba study
    Journal of Bone and Mineral Research, 2011
    Co-Authors: Didier Hans, Marc-antoine Krieg, Andrew L Goertzen, William D Leslie
    Abstract:

    The measurement of BMD by dual-energy X-ray absorptiometry (DXA) is the "gold standard" for diagnosing osteoporosis but does not directly reflect deterioration in Bone Microarchitecture. The trabecular Bone score (TBS), a novel gray-level texture measurement that can be extracted from DXA images, correlates with 3D parameters of Bone Microarchitecture. Our aim was to evaluate the ability of lumbar spine TBS to predict future clinical osteoporotic fractures. A total of 29,407 women 50 years of age or older at the time of baseline hip and spine DXA were identified from a database containing all clinical results for the Province of Manitoba, Canada. Health service records were assessed for the incidence of nontraumatic osteoporotic fracture codes subsequent to BMD testing (mean follow-up 4.7 years). Lumbar spine TBS was derived for each spine DXA examination blinded to clinical parameters and outcomes. Osteoporotic fractures were identified in 1668 (5.7%) women, including 439 (1.5%) spine and 293 (1.0%) hip fractures. Significantly lower spine TBS and BMD were identified in women with major osteoporotic, spine, and hip fractures (all p < 0.0001). Spine TBS and BMD predicted fractures equally well, and the combination was superior to either measurement alone (p < 0.001). Spine TBS predicts osteoporotic fractures and provides information that is independent of spine and hip BMD. Combining the TBS trabecular texture index with BMD incrementally improves fracture prediction in postmenopausal women.

  • Bone Microarchitecture assessed by tbs predicts osteoporotic fractures independent of Bone density the manitoba study
    Journal of Bone and Mineral Research, 2011
    Co-Authors: Didier Hans, Andrew L Goertzen, M A Krieg, William D Leslie
    Abstract:

    The measurement of BMD by dual-energy X-ray absorptiometry (DXA) is the “gold standard” for diagnosing osteoporosis but does not directly reflect deterioration in Bone Microarchitecture. The trabecular Bone score (TBS), a novel gray-level texture measurement that can be extracted from DXA images, correlates with 3D parameters of Bone Microarchitecture. Our aim was to evaluate the ability of lumbar spine TBS to predict future clinical osteoporotic fractures. A total of 29,407 women 50 years of age or older at the time of baseline hip and spine DXA were identified from a database containing all clinical results for the Province of Manitoba, Canada. Health service records were assessed for the incidence of nontraumatic osteoporotic fracture codes subsequent to BMD testing (mean follow-up 4.7 years). Lumbar spine TBS was derived for each spine DXA examination blinded to clinical parameters and outcomes. Osteoporotic fractures were identified in 1668 (5.7%) women, including 439 (1.5%) spine and 293 (1.0%) hip fractures. Significantly lower spine TBS and BMD were identified in women with major osteoporotic, spine, and hip fractures (all p < 0.0001). Spine TBS and BMD predicted fractures equally well, and the combination was superior to either measurement alone (p < 0.001). Spine TBS predicts osteoporotic fractures and provides information that is independent of spine and hip BMD. Combining the TBS trabecular texture index with BMD incrementally improves fracture prediction in postmenopausal women. © 2011 American Society for Bone and Mineral Research

  • correlations between trabecular Bone score measured using anteroposterior dual energy x ray absorptiometry acquisition and 3 dimensional parameters of Bone Microarchitecture an experimental study on human cadaver vertebrae
    Journal of Clinical Densitometry, 2011
    Co-Authors: Didier Hans, Renaud Winzenrieth, Nicole Barthe, Stéphanie Boutroy, Laurent Pothuaud, Marc-antoine Krieg
    Abstract:

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

  • correlations between grey level variations in 2d projection images tbs and 3d Microarchitecture applications in the study of human trabecular Bone Microarchitecture
    Bone, 2008
    Co-Authors: Laurent Pothuaud, Pascal Carceller, Didier Hans
    Abstract:

    X-ray imaging remains a very cost-effective technique, with many applications in both medical and material science. However, the physical process of X-ray imaging transforms (e.g. projects) the 3-dimensional (3D) Microarchitecture of the object or tissue being studied into a complex 2D grey-level texture. The 3D/2D projection process continues to be a difficult mathematical problem, and neither demonstrations nor well-established correlations have positioned 2D texture analysis-based measurement as a valid indirect evaluation of 3D Microarchitecture. The trabecular Bone score (TBS) is a new grey-level texture measurement which utilizes experimental variograms of 2D projection images. The aim of the present study was to determine the level of correlation between the 3D characteristics of trabecular Bone Microarchitecture, as evaluated using muCT reconstruction, and TBS, as evaluated using 2D projection images derived directly from 3D muCT reconstruction. Analyses were performed using sets of human cadaver Bone samples from different anatomical sites (lumbar spine, femoral neck, and distal radius). Significant correlations were established via standard multiple regression analysis, and via the use of a generic mathematical 3D/2D relationship. In both instances, the correlations established a significant relationship between TBS and two 3D characteristics of Bone Microarchitecture: Bone volume fraction and mean Bone thickness. In particular, it appears that TBS permits to accurately differentiate between two 3D Microarchitectures that exhibit the same amount of Bone, but different trabecular characteristics. These results demonstrate the existence of a robust and generic relationship, taking into consideration a simplified model of a 2D projection image. Ultimately, this may lead to using TBS measurements directly on DXA images obtained in routine clinical practice.

Sabashini K Ramchand - One of the best experts on this subject based on the ideXlab platform.

  • effects of combination denosumab and high dose teriparatide administration on Bone Microarchitecture and estimated strength the data hd hr pqct study
    Journal of Bone and Mineral Research, 2021
    Co-Authors: Benjamin Z Leder, Hang Lee, Mary L Bouxsein, Sabashini K Ramchand, Natalie L David, Michael Bruce, Joy N Tsai
    Abstract:

    In postmenopausal women at high risk of fracture, we previously reported that combined denosumab and high-dose (HD; 40 μg) teriparatide increased spine and hip Bone mineral density (BMD) more than combination with standard-dose teriparatide (SD; 20 μg). To assess the effects of these combinations on Bone Microarchitecture and estimated Bone strength, we performed high-resolution peripheral quantitative computed tomography (HR-pQCT) at the distal radius and distal tibia in these women, who were randomized to receive either teriparatide 20 μg (n = 39) or 40 μg (n = 37) during months 0 to 9 overlapped with denosumab 60 mg s.c. given at months 3 and 9, for a 15-month study duration. The 69 women who completed at least one study visit after baseline are included in this analysis. Over 15 months, increases in total BMD were higher in the HD-group than the SD-group at the distal tibia (5.3% versus 3.4%, p = 0.01) with a similar trend at the distal radius (2.6% versus 1.0%, p = 0.06). At 15 months, cortical porosity remained similar to baseline, with absolute differences of -0.1% and -0.7% at the distal tibia and -0.4% and -0.1% at the distal radius in the HD-group and SD-group, respectively; p = NS for all comparisons. Tibial cortical tissue mineral density increased similarly in both treatment groups (1.3% [p < 0.0001 versus baseline] and 1.5% [p < 0.0001 versus baseline] in the HD-group and SD-group, respectively; p = 0.75 for overall group difference). Improvements in trabecular Microarchitecture at the distal tibia and estimated strength by micro-finite element analysis at both sites were numerically greater in the HD-group compared with SD-group but not significantly so. Together, these findings suggest that short-term treatment combining denosumab with either high- or standard-dose teriparatide improves HR-pQCT measures of Bone density, microstructure, and estimated strength, with greater gains in total Bone density observed in the HD-group, which may be of benefit in postmenopausal women with severe osteoporosis. © 2020 American Society for Bone and Mineral Research (ASBMR).

  • effects of combination denosumab and high dose teriparatide administration on Bone Microarchitecture and estimated strength the data hd hr pqct study
    Journal of Bone and Mineral Research, 2020
    Co-Authors: Benjamin Z Leder, Mary L Bouxsein, Sabashini K Ramchand, Natalie L David, Michael Bruce, Joy N Tsai
    Abstract:

    In postmenopausal women at high risk of fracture, we previously reported that combined denosumab and high-dose (HD, 40-μg) teriparatide increased spine and hip Bone mineral density (BMD) more than combination with standard-dose teriparatide (SD, 20-μg). To assess the effects of these combinations on Bone Microarchitecture and estimated Bone strength, we performed high-resolution peripheral quantitative computed tomography (HR-pQCT) at the distal radius and distal tibia in these women, who were randomized to receive either teriparatide 20-ug (n=39) or 40-μg (n=37) during months 0-9 overlapped with denosumab 60-mg s.c. given at month 3 and 9, for a 15-month study duration. The 69 women who completed at least one study visit after baseline are included in this analysis. Over 15 months, increases in total BMD were higher in the HD-group than the SD-group at the distal tibia (5.3% vs. 3.4%, P=0.01) with a similar trend at the distal radius (2.6% vs. 1.0%, P=0.06). At 15 months, cortical porosity remained similar to baseline, with absolute differences of -0.1% and -0.7% at the distal tibia and -0.4% and -0.1% at the distal radius, in the HD-group and SD-group, respectively, P=NS for all comparisons. Tibial cortical tissue mineral density increased similarly in both treatment groups (1.3% (P<0.0001 vs. baseline) and 1.5% (P<0.0001 vs. baseline) in the HD-group and SD-group, respectively, P=0.75 for overall group difference). Improvements in trabecular Microarchitecture at the distal tibia and estimated strength by micro-finite element analysis at both sites were numerically greater in the HD-group compared to SD-group, but not significantly so. Together, these findings suggest that short-term treatment combining denosumab with either high or standard-dose teriparatide improves HR-pQCT measures of Bone density, microstructure, and estimated strength, with greater gains in total Bone density observed in the HD-group, which may be of benefit in postmenopausal women with severe osteoporosis. This article is protected by copyright. All rights reserved.

Steven K Boyd - One of the best experts on this subject based on the ideXlab platform.

  • visceral adipose tissue is associated with Bone Microarchitecture in the framingham osteoporosis study
    Journal of Bone and Mineral Research, 2017
    Co-Authors: Chingti Liu, Steven K Boyd, Yanhua Zhou, Kerry E Broe, Adrienne L Cupples, Marian T Hannan, Elise Lim, Robert R Mclean, Elizabeth J Samelson, Mary L Bouxsein
    Abstract:

    Obesity has been traditionally considered to protect the skeleton against osteoporosis and fracture. Recently, body fat, specifically visceral adipose tissue (VAT), has been associated with lower Bone mineral density (BMD) and increased risk for some types of fractures. We studied VAT and Bone Microarchitecture in 710 participants (58% women, age 61.3 ± 7.7 years) from the Framingham Offspring cohort to determine whether cortical and trabecular BMD and Microarchitecture differ according to the amount of VAT. VAT was measured from CT imaging of the abdomen. Cortical and trabecular BMD and Microarchitecture were measured at the distal tibia and radius using high-resolution peripheral quantitative computed tomography (HR-pQCT). We focused on 10 Bone parameters: cortical BMD (Ct.BMD), cortical tissue mineral density (Ct.TMD), cortical porosity (Ct.Po), cortical thickness (Ct.Th), cortical Bone area fraction (Ct.A/Tt.A), trabecular density (Tb.BMD), trabecular number (Tb.N), trabecular thickness (Tb.Th), total area (Tt.Ar), and failure load (FL) from micro-finite element analysis. We assessed the association between sex-specific quartiles of VAT and BMD, Microarchitecture, and strength in all participants and stratified by sex. All analyses were adjusted for age, sex, and in women, menopausal status, then repeated adjusting for body mass index (BMI) or weight. At the radius and tibia, Ct.Th, Ct.A/Tt.A, Tb.BMD, Tb.N, and FL were positively associated with VAT (all p-trend <0.05), but no other associations were statistically significant except for higher levels of cortical porosity with higher VAT in the radius. Most of these associations were only observed in women, and were no longer significant when adjusting for BMI or weight. Higher amounts of VAT are associated with greater BMD and better microstructure of the peripheral skeleton despite some suggestions of significant deleterious changes in cortical measures in the non-weight bearing radius. Associations were no longer significant after adjustment for BMI or weight, suggesting that the effects of VAT may not have a substantial effect on the skeleton independent of BMI or weight. © 2016 American Society for Bone and Mineral Research.

  • human trabecular Bone Microarchitecture can be assessed independently of density with second generation hr pqct
    Bone, 2015
    Co-Authors: Sarah L Manske, Ying Zhu, Clara Sandino, Steven K Boyd
    Abstract:

    The second generation HR-pQCT scanner (XtremeCTII, Scanco Medical) can assess human Bone Microarchitecture of peripheral limbs with a 61 μm nominal isotropic voxel size. This is a marked improvement from the first generation HR-pQCT that had a nominal isotropic voxel size of 82 μm, which is at the limit to accurately determine the thickness of individual human trabeculae. We sought to determine the accuracy of a direct morphometric approach to measure trabecular Bone Microarchitecture with three-dimensional morphological techniques using second generation HR-pQCT, and to compare this with the approach currently applied by the first generation HR-pQCT scanner based on derived indices using ex vivo scans of human cadaveric radii. We also compared images acquired and resampled to mimic the first generation HR-pQCT with those obtained directly from the first generation HR-pQCT. We evaluated 20 human cadaveric radii and a micro-CT performance phantom using the first (XtremeCT, Scanco Medical) and second generation HR-pQCT scanner (XtremeCTII) and compared a patient evaluation (XCTII, 61 μm) with a high resolution ex vivo protocol (HR, 30μm). We generated 82 μm scans of the same specimens to mimic a first-generation HR-pQCT evaluation (XCTIM, 82 μm) and compared these with a first-generation patient evaluation (XCTI, 82 μm). A standard structural extraction approach was applied to both XCTII and HR evaluations for assessment of Bone volume fraction (BV/TV), and a distance transform was used to assess trabecular number (Tb.N), trabecular thickness (Tb.Th) and trabecular separation (Tb.Sp). For XCTI and XCTIM evaluations we followed the manufacturer's standard procedure and assessed Bone mineral density (BMD), Tb.N with a distance transform, and then derived Bone volume ratio (BV/TV(d)), trabecular thickness (Tb.Th(d)) and separation (Tb.Sp(d)). The spatial resolution (10% MTF) was 142.2 μm for XCTI, 108.9 μm for XCTIM, 95.2μm for XCTII, and 55.9 μm for HR. XCTI and XCTIM provided strongly associated measurements of BMD and microarchitectural outcomes (R(2)>0.97), however there were systematic differences in all outcomes. The Tb.N was highly associated with HR by both XCTII (R(2)=0.93, mean error=-0.12 mm(-1)) and XCTIM (R(2)=0.98, mean error=0.25 mm(-1)). Also, both XCTII (R(2)=0.99, mean error=0.20mm) and XCTIM (R(2)=0.99, mean error=-0.18 mm) had Tb.Sp that were strongly related to HR. For Tb.Th, the XCTII was more closely related to HR (R(2)=0.94, mean error=0.04 mm) than the relatively weak XCTIM (R(2)=0.16, mean error=- 0.076 mm). We found that trabecular Microarchitecture assessment following the XCTII direct morphometric approach accurately represented the HR data. In particular, the measure of Tb.Th was markedly improved for XCTII compared with the derived approach of XCTIM. These data support the application of analysis techniques in HR-pQCT that are analogous to those traditionally used for micro-CT to assess trabecular Microarchitecture. The decreased dependence of structural outcomes on density provides a new, important opportunity to monitor human in vivo Bone Microarchitecture.

  • women with previous fragility fractures can be classified based on Bone Microarchitecture and finite element analysis measured with hr pqct
    Osteoporosis International, 2013
    Co-Authors: Kyle K Nishiyama, Heather M Macdonald, David A Hanley, Steven K Boyd
    Abstract:

    High-resolution peripheral quantitative computed tomography (HR-pQCT) measurements of distal radius and tibia Bone Microarchitecture and finite element (FE) estimates of Bone strength performed well at classifying postmenopausal women with and without previous fracture. The HR-pQCT measurements outperformed dual energy x-ray absorptiometry (DXA) at classifying forearm fractures and fractures at other skeletal sites. Areal Bone mineral density (aBMD) is the primary measurement used to assess osteoporosis and fracture risk; however, it does not take into account Bone Microarchitecture, which also contributes to Bone strength. Thus, our objective was to determine if Bone Microarchitecture measured with HR-pQCT and FE estimates of Bone strength could classify women with and without low-trauma fractures. We used HR-pQCT to assess Bone Microarchitecture at the distal radius and tibia in 44 postmenopausal women with a history of low-trauma fracture and 88 age-matched controls from the Calgary cohort of the Canadian Multicentre Osteoporosis Study (CaMos) study. We estimated Bone strength using FE analysis and simulated distal radius aBMD from the HR-pQCT scans. Femoral neck (FN) and lumbar spine (LS) aBMD were measured with DXA. We used support vector machines (SVM) and a tenfold cross-validation to classify the fracture cases and controls and to determine accuracy. The combination of HR-pQCT measures of Microarchitecture and FE estimates of Bone strength had the highest area under the receiver operating characteristic (ROC) curve of 0.82 when classifying forearm fractures compared to an area under the curve (AUC) of 0.71 from DXA-derived aBMD of the forearm and 0.63 from FN and spine DXA. For all fracture types, FE estimates of Bone strength at the forearm alone resulted in an AUC of 0.69. Models based on HR-pQCT measurements of Bone Microarchitecture and estimates of Bone strength performed better than DXA-derived aBMD at classifying women with and without prior fracture. In future, these models may improve prediction of individuals at risk of low-trauma fracture.

  • changes in trabecular and cortical Bone Microarchitecture at peripheral sites associated with 18 months of teriparatide therapy in postmenopausal women with osteoporosis
    Osteoporosis International, 2011
    Co-Authors: Heather M Macdonald, Kyle K Nishiyama, David A Hanley, Steven K Boyd
    Abstract:

    Summary We used high-resolution peripheral quantitative computed tomography (HR-pQCT) to monitor changes in Bone Microarchitecture and strength at the distal radius and tibia associated with 18 months of teriparatide therapy in postmenopausal women with osteoporosis. Despite treatment-associated declines in total and cortical BMD, trabecular thinning and reduced trabecular Bone volume, Bone strength did not change significantly from baseline.