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Klaus Engelke - One of the best experts on this subject based on the ideXlab platform.
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guidelines for the assessment of bone density and microarchitecture in vivo using high resolution peripheral Quantitative Computed Tomography
Osteoporosis International, 2020Co-Authors: Danielle E Whittier, Andrew J Burghardt, Steven K Boyd, Julien Paccou, Ali Ghasemzadeh, Roland Chapurlat, Klaus Engelke, Mary L BouxseinAbstract:The application of high-resolution peripheral Quantitative Computed Tomography (HR-pQCT) to assess bone microarchitecture has grown rapidly since its introduction in 2005. As the use of HR-pQCT for clinical research continues to grow, there is an urgent need to form a consensus on imaging and analysis methodologies so that studies can be appropriately compared. In addition, with the recent introduction of the second-generation HrpQCT, which differs from the first-generation HR-pQCT in scan region, resolution, and morphological measurement techniques, there is a need for guidelines on appropriate reporting of results and considerations as the field adopts newer systems. A joint working group between the International Osteoporosis Foundation, American Society of Bone and Mineral Research, and European Calcified Tissue Society convened in person and by teleconference over several years to produce the guidelines and recommendations presented in this document. An overview and discussion is provided for (1) standardized protocol for imaging distal radius and tibia sites using HR-pQCT, with the importance of quality control and operator training discussed; (2) standardized terminology and recommendations on reporting results; (3) factors influencing accuracy and precision error, with considerations for longitudinal and multi-center study designs; and finally (4) comparison between scanner generations and other high-resolution CT systems. This article addresses the need for standardization of HR-pQCT imaging techniques and terminology, provides guidance on interpretation and reporting of results, and discusses unresolved issues in the field.
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clinical use of Quantitative Computed Tomography qct of the hip in the management of osteoporosis in adults the 2015 iscd official positions part i
Journal of Clinical Densitometry, 2015Co-Authors: Thomas Lang, Sundeep Khosla, Ling Qin, Klaus Engelke, Philippe K Zysset, William D Leslie, John A Shepherd, John T SchousboeAbstract:The International Society for Clinical Densitometry (ISCD) has developed new official positions for the clinical use of Quantitative Computed Tomography of the hip. The ISCD task force for Quantitative Computed Tomography reviewed the evidence for clinical applications and presented a report with recommendations at the 2015 ISCD Position Development Conference. Here, we discuss the agreed on ISCD official positions with supporting medical evidence, rationale, controversy, and suggestions for further study. Parts II and III address the advanced techniques of finite element analysis applied to Computed Tomography scans and the clinical feasibility of existing techniques for opportunistic screening of osteoporosis using Computed Tomography scans obtained for other diagnosis such as colonography was addressed.
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clinical use of Quantitative Computed Tomography based finite element analysis of the hip and spine in the management of osteoporosis in adults the 2015 iscd official positions part ii
Journal of Clinical Densitometry, 2015Co-Authors: Philippe K Zysset, Thomas Lang, Sundeep Khosla, Ling Qin, Klaus Engelke, William D Leslie, John A Shepherd, John T SchousboeAbstract:The International Society for Clinical Densitometry (ISCD) has developed new official positions for the clinical use of Quantitative Computed Tomography (QCT)-based finite element analysis of the spine and hip. The ISCD task force for QCT reviewed the evidence for clinical applications and presented a report with recommendations at the 2015 ISCD Position Development Conference. Here we discuss the agreed upon ISCD official positions with supporting medical evidence, rationale, controversy, and suggestions for further study. Parts I and III address the clinical use of QCT of the hip, and the clinical feasibility of existing techniques for opportunistic screening of osteoporosis using CT scans obtained for other diagnosis such as colonography was addressed.
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multicenter precision of cortical and trabecular bone quality measures assessed by high resolution peripheral Quantitative Computed Tomography
Journal of Bone and Mineral Research, 2013Co-Authors: Andrew J Burghardt, Stephanie Boutroy, Klaus Engelke, Galateia J Kazakia, Janina M Patsch, Jeanbaptiste Pialat, Alexander ValentinitschAbstract:High-resolution peripheral Quantitative Computed Tomography (HR-pQCT) has recently been introduced as a clinical research tool for in vivo assessment of bone quality. The utility of this technology to address important skeletal health questions requires translation to standardized multicenter data pools. Our goal was to evaluate the feasibility of pooling data in multicenter HR-pQCT imaging trials. Reproducibility imaging experiments were performed using structure and composition-realistic phantoms constructed from cadaveric radii. Single-center precision was determined by repeat scanning over short-term (<72 hours), intermediate-term (3–5 months), and long-term intervals (28 months). Multicenter precision was determined by imaging the phantoms at nine different HR-pQCT centers. Least significant change (LSC) and root mean squared coefficient of variation (RMSCV) for each interval and across centers was calculated for bone density, geometry, microstructure, and biomechanical parameters. Single-center short-term RMSCVs were <1% for all parameters except cortical thickness (Ct.Th) (1.1%), spatial variability in cortical thickness (Ct.Th.SD) (2.6%), standard deviation of trabecular separation (Tb.Sp.SD) (1.8%), and porosity measures (6% to 8%). Intermediate-term RMSCVs were generally not statistically different from short-term values. Long-term variability was significantly greater for all density measures (0.7% to 2.0%; p < 0.05 versus short-term) and several structure measures: cortical thickness (Ct.Th) (3.4%; p < 0.01 versus short-term), cortical porosity (Ct.Po) (15.4%; p < 0.01 versus short-term), and trabecular thickness (Tb.Th) (2.2%; p < 0.01 versus short-term). Multicenter RMSCVs were also significantly higher than short-term values: 2% to 4% for density and micro–finite element analysis (µFE) measures (p < 0.0001), 2.6% to 5.3% for morphometric measures (p < 0.001), whereas Ct.Po was 16.2% (p < 0.001). In the absence of subject motion, multicenter precision errors for HR-pQCT parameters were generally less than 5%. Phantom-based multicenter precision was comparable to previously reported in in vivo single-center precision errors, although this was approximately two to five times worse than ex vivo short-term precision. The data generated from this study will contribute to the future design and validation of standardized procedures that are broadly translatable to multicenter study designs. © 2013 American Society for Bone and Mineral Research.
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in vivo discrimination of hip fracture with Quantitative Computed Tomography results from the prospective european femur fracture study effect
Journal of Bone and Mineral Research, 2011Co-Authors: Valerie Bousson, C Bergot, Klaus Engelke, Judith E Adams, Mounir Aout, Martine Cohensolal, Didier Haguenauer, Daniele Goldberg, Karine Champion, Redha AksouhAbstract:In assessing osteoporotic fractures of the proximal femur, the main objective of this in vivo case-control study was to evaluate the performance of Quantitative Computed Tomography (QCT) and a dedicated 3D image analysis tool [Medical Image Analysis Framework—Femur option (MIAF-Femur)] in differentiating hip fracture and non–hip fracture subjects. One-hundred and seven women were recruited in the study, 47 women (mean age 81.6 years) with low-energy hip fractures and 60 female non–hip fracture control subjects (mean age 73.4 years). Bone mineral density (BMD) and geometric variables of cortical and trabecular bone in the femoral head and neck, trochanteric, and intertrochanteric regions and proximal shaft were assessed using QCT and MIAF-Femur. Areal BMD (aBMD) was assessed using dual-energy X-ray absorptiometry (DXA) in 96 (37 hip fracture and 59 non–hip fracture subjects) of the 107 patients. Logistic regressions were Computed to extract the best discriminates of hip fracture, and area under the receiver characteristic operating curve (AUC) was calculated. Three logistic models that discriminated the occurrence of hip fracture with QCT variables were obtained (AUC = 0.84). All three models combined one densitometric variable—a trabecular BMD (measured in the femoral head or in the trochanteric region)—and one geometric variable—a cortical thickness value (measured in the femoral neck or proximal shaft). The best discriminant using DXA variables was obtained with total femur aBMD (AUC = 0.80, p = .003). Results highlight a synergistic contribution of trabecular and cortical components in hip fracture risk and the utility of assessing QCT BMD of the femoral head for improved understanding and possible insights into prevention of hip fractures. © 2011 American Society for Bone and Mineral Research.
Andrew J Burghardt - One of the best experts on this subject based on the ideXlab platform.
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longitudinal evolution of bone microarchitecture and bone strength in type 2 diabetic postmenopausal women with and without history of fragility fractures a 5 year follow up study using high resolution peripheral Quantitative Computed Tomography
Frontiers in Endocrinology, 2021Co-Authors: Julio Carballidogamio, Ursula Heilmeier, Gabby B Joseph, Courtney Pasco, Nhan Dinh, Soheyla Torabi, K Darakananda, Jiwon Youm, Andrew J BurghardtAbstract:Introduction Diabetic bone disease is characterized by an increased fracture risk which may be partly attributed to deficits in cortical bone quality such as higher cortical porosity. However, the temporal evolution of bone microarchitecture, strength, and particularly of cortical porosity in diabetic bone disease is still unknown. Here, we aimed to prospectively characterize the 5-year changes in bone microarchitecture, strength, and cortical porosity in type 2 diabetic (T2D) postmenopausal women with (DMFx) and without history of fragility fractures (DM) and to compare those to nondiabetic fracture free controls (Co) using high resolution peripheral Quantitative Computed Tomography (HR-pQCT).
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consensus approach for 3d joint space width of metacarpophalangeal joints of rheumatoid arthritis patients using high resolution peripheral Quantitative Computed Tomography
Quantitative imaging in medicine and surgery, 2020Co-Authors: Kathryn S Stok, Andrew J Burghardt, Stephanie Boutroy, Sarah L Manske, M Peters, Vincent A Stadelmann, Nicolas Vilayphiou, Joop P W Van Den Bergh, Piet Geusens, X LiAbstract:Background: Joint space assessment for rheumatoid arthritis (RA) by ordinal conventional radiographic scales is susceptible to floor and ceiling effects. High-resolution peripheral Quantitative Computed Tomography (HR-pQCT) provides superior resolution, and may detect earlier changes. The goal of this work was to compare existing 3D methods to calculate joint space width (JSW) metrics in human metacarpophalangeal (MCP) joints with HR-pQCT and reach consensus for future studies. Using the consensus method, we established reproducibility with repositioning as well as feasibility for use in second-generation HR-pQCT scanners. Methods: Three published JSW methods were compared using datasets from individuals with RA from three research centers. A SPECTRA consensus method was developed to take advantage of strengths of the individual methods. Using the SPECTRA method, reproducibility after repositioning was tested and agreement between scanner generations was also established. Results: When comparing existing JSW methods, excellent agreement was shown for JSW minimum and mean (ICC 0.987-0.996) but not maximum and volume (ICC 0.000-0.897). Differences were identified as variations in volume definitions and algorithmic differences that generated high sensitivity to boundary conditions. The SPECTRA consensus method reduced this sensitivity, demonstrating good scan-rescan reliability (ICC >0.911) except for minimum JSW (ICC 0.656). There was strong agreement between results from first- and second-generation HR-pQCT (ICC >0.833). Conclusions: The SPECTRA consensus method combines unique strengths of three independently-developed algorithms and leverages underlying software updates to provide a mature analysis to measure 3D JSW. This method is robust with respect to repositioning and scanner generations, suggesting its suitability for detecting change.
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guidelines for the assessment of bone density and microarchitecture in vivo using high resolution peripheral Quantitative Computed Tomography
Osteoporosis International, 2020Co-Authors: Danielle E Whittier, Andrew J Burghardt, Steven K Boyd, Julien Paccou, Ali Ghasemzadeh, Roland Chapurlat, Klaus Engelke, Mary L BouxseinAbstract:The application of high-resolution peripheral Quantitative Computed Tomography (HR-pQCT) to assess bone microarchitecture has grown rapidly since its introduction in 2005. As the use of HR-pQCT for clinical research continues to grow, there is an urgent need to form a consensus on imaging and analysis methodologies so that studies can be appropriately compared. In addition, with the recent introduction of the second-generation HrpQCT, which differs from the first-generation HR-pQCT in scan region, resolution, and morphological measurement techniques, there is a need for guidelines on appropriate reporting of results and considerations as the field adopts newer systems. A joint working group between the International Osteoporosis Foundation, American Society of Bone and Mineral Research, and European Calcified Tissue Society convened in person and by teleconference over several years to produce the guidelines and recommendations presented in this document. An overview and discussion is provided for (1) standardized protocol for imaging distal radius and tibia sites using HR-pQCT, with the importance of quality control and operator training discussed; (2) standardized terminology and recommendations on reporting results; (3) factors influencing accuracy and precision error, with considerations for longitudinal and multi-center study designs; and finally (4) comparison between scanner generations and other high-resolution CT systems. This article addresses the need for standardization of HR-pQCT imaging techniques and terminology, provides guidance on interpretation and reporting of results, and discusses unresolved issues in the field.
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Quantitative characterization of metacarpal and radial bone in rheumatoid arthritis using high resolution peripheral Quantitative Computed Tomography
International Journal of Rheumatic Diseases, 2017Co-Authors: Andrew J Burghardt, Haitao Yang, Warapat Virayavanich, Thomas M Link, John B ImbodenAbstract:Aim The objectives of this study were: (i) to develop a standardized method of quantifying bone mineral density (BMD) and microarchitecture in the hand and wrist bones of patients with rheumatoid arthritis (RA) using high resolution- peripheral Quantitative Computed Tomography (HR-pQCT); (ii) to compare Quantitative bone parameters between RA and post-menopausal osteopenic (PM-OP) subjects; and (iii) to correlate Quantitative bone parameters at the distal radius with those at the metacarpal heads in RA subjects. Methods HR-pQCT imaging of the dominant hand and wrist was performed in 12 female RA patients. BMD and trabecular parameters for the 2–12% head region of the second and third metacarpals were calculated and compared between RA patients and healthy controls. Bone parameters were also calculated for 110 slices of the distal radius in RA patients and compared to data from controls and PM-OP women from a previous study. Results Compared to controls, RA patients had significantly decreased BMD, trabecular volume and number, and increased trabecular heterogeneity in the third metacarpal and distal radius. Significantly lower trabecular number and significantly higher ratio of outer annular trabecular BMD to inner trabecular BMD were observed in patients with RA, compared to patients with osteopenia (P < 0.05). Trabecular BMD in the third metacarpal and in the distal radius were significantly correlated (ρ = 0.918, P < 0.0001) in RA patients. Conclusion This study established a standardized method for quantifying bone density and trabecular properties in the hand and wrist bones of RA patients using HR-pQCT. Deterioration of bone structure in RA patients was found comparable to that in osteopenic women, and trabecular bone loss near affected joints was found to be correlated with bone loss away from joints.
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determining metacarpophalangeal flexion angle tolerance for reliable volumetric joint space measurements by high resolution peripheral Quantitative Computed Tomography
The Journal of Rheumatology, 2016Co-Authors: Stephanie Tom, Andrew J Burghardt, Steven K Boyd, Mark Frayne, Sarah L Manske, Kathryn S Stok, Cheryl BarnabeAbstract:Objective. The position-dependence of a method to measure the joint space of metacarpophalangeal (MCP) joints using high-resolution peripheral Quantitative Computed Tomography (HR-pQCT) was studied. Methods. Cadaveric MCP were imaged at 7 flexion angles between 0 and 30 degrees. The variability in reproducibility for mean, minimum, and maximum joint space widths and volume measurements was calculated for increasing degrees of flexion. Results. Root mean square coefficient of variance values were < 5% under 20 degrees of flexion for mean, maximum, and volumetric joint spaces. Values for minimum joint space width were optimized under 10 degrees of flexion. Conclusion. MCP joint space measurements should be acquired at < 10 degrees of flexion in longitudinal studies.
Mary L Bouxsein - One of the best experts on this subject based on the ideXlab platform.
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guidelines for the assessment of bone density and microarchitecture in vivo using high resolution peripheral Quantitative Computed Tomography
Osteoporosis International, 2020Co-Authors: Danielle E Whittier, Andrew J Burghardt, Steven K Boyd, Julien Paccou, Ali Ghasemzadeh, Roland Chapurlat, Klaus Engelke, Mary L BouxseinAbstract:The application of high-resolution peripheral Quantitative Computed Tomography (HR-pQCT) to assess bone microarchitecture has grown rapidly since its introduction in 2005. As the use of HR-pQCT for clinical research continues to grow, there is an urgent need to form a consensus on imaging and analysis methodologies so that studies can be appropriately compared. In addition, with the recent introduction of the second-generation HrpQCT, which differs from the first-generation HR-pQCT in scan region, resolution, and morphological measurement techniques, there is a need for guidelines on appropriate reporting of results and considerations as the field adopts newer systems. A joint working group between the International Osteoporosis Foundation, American Society of Bone and Mineral Research, and European Calcified Tissue Society convened in person and by teleconference over several years to produce the guidelines and recommendations presented in this document. An overview and discussion is provided for (1) standardized protocol for imaging distal radius and tibia sites using HR-pQCT, with the importance of quality control and operator training discussed; (2) standardized terminology and recommendations on reporting results; (3) factors influencing accuracy and precision error, with considerations for longitudinal and multi-center study designs; and finally (4) comparison between scanner generations and other high-resolution CT systems. This article addresses the need for standardization of HR-pQCT imaging techniques and terminology, provides guidance on interpretation and reporting of results, and discusses unresolved issues in the field.
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influence of soft tissue on bone density and microarchitecture measurements by high resolution peripheral Quantitative Computed Tomography
Bone, 2019Co-Authors: Signe Caksa, Mary L Bouxsein, Amy Yuan, Sara Rudolph, Elaine Yu, Kristin L PoppAbstract:Abstract High-resolution peripheral Quantitative Computed Tomography (HR-pQCT) is a non-invasive method of measuring volumetric bone mineral density (vBMD) and microarchitecture at the distal radius and tibia. With increasing use of this technology, it is crucial to understand the potential impact of overlying soft tissue on the accuracy of HR-pQCT measures. Thus, we examined the effects of a simulated increase in adiposity (via 6- and 12-mm thick layers of overlying circumferential fat) on HR-pQCT measures of a hydroxyapatite (HA) phantom and in women (n = 20, aged 18–75 years). In the phantom, increasing the amount of overlying fat tissue led to a corresponding decrease in the mean measured density for each HA rod. In women, fat-layering led to a decrease in total vBMD (−2.9 to −3.7%, p
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harmonizing finite element modelling for non invasive strength estimation by high resolution peripheral Quantitative Computed Tomography
Journal of Biomechanics, 2018Co-Authors: Danielle E Whittier, Sarah L Manske, Mary L Bouxsein, Douglas P Kiel, Steven K BoydAbstract:Abstract The finite element (FE) method based on high-resolution peripheral Quantitative Computed Tomography (HR-pQCT) use a variety of tissue constitutive properties and boundary conditions at different laboratories making comparison of mechanical properties difficult. Furthermore, the advent of a second-generation HR-pQCT poses challenges due to improved resolution and a larger region of interest (ROI). This study addresses the need to harmonize results across FE models. The aims are to establish the relationship between FE results as a function of boundary conditions and a range of tissue properties for the first-generation HR-pQCT system, and to determine appropriate model parameters for the second-generation HR-pQCT system. We implemented common boundary conditions and tissue properties on a large cohort (N = 1371), and showed the relationships were highly linear (R2 > 0.99) for yield strength and reaction force between FE models. Cadaver radii measured on both generation HR-pQCT with matched ROIs were used to back-calculate a tissue modulus that accounts for the increased resolution (61 µm versus 82 µm), resulting in a modulus of 8748 MPa for second-generation HR-pQCT to produce bone yield strength and reaction force equivalent to using 6829 MPa for first-generation HR-pQCT. Finally, in vivo scans (N = 61) conducted on both generations demonstrated that the larger ROI in the second-generation system results in stronger bone outcome measures, suggesting it is not advisable to convert FE results across HR-pQCT generations without matching ROIs. Together, these findings harmonize FE results by providing a means to compare findings with different boundary conditions and tissue properties, and across scanner generations.
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clinical use of Quantitative Computed Tomography and peripheral Quantitative Computed Tomography in the management of osteoporosis in adults the 2007 iscd official positions
Journal of Clinical Densitometry, 2008Co-Authors: Klaus Engelke, Mary L Bouxsein, Judith E Adams, Gabriele Armbrecht, Peter Augat, Cesar E Bogado, Dieter Felsenberg, Masako Ito, Sven Prevrhal, Didier HansAbstract:The International Society for Clinical Densitometry (ISCD) has developed Official Positions for the clinical use of dual-energy X-ray absorptiometry (DXA) and non-DXA technologies. While only DXA can be used for diagnostic classification according to criteria established by the World Health Organization, DXA and some other technologies may predict fracture risk and be used to monitor skeletal changes over time. ISCD task forces reviewed the evidence for clinical applications of non-DXA techniques and presented reports with recommendations at the 2007 ISCD Position Development Conference. Here we present the ISCD Official Positions for Quantitative Computed Tomography (QCT) and peripheral QCT (pQCT), with supporting medical evidence, rationale, controversy, and suggestions for further study. QCT is available for bone mineral density measurements at the spine, hip, forearm, and tibia. The ISCD Official Positions presented here focus on QCT of the spine and pQCT of the forearm. Measurements at the hip may have clinical relevance, as this is an important fracture site; however, due to limited medical evidence, definitive advice on its use in clinical practice cannot be provided until more data emerge.
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in vivo assessment of trabecular bone microarchitecture by high resolution peripheral Quantitative Computed Tomography
The Journal of Clinical Endocrinology and Metabolism, 2005Co-Authors: Stephanie Boutroy, Mary L Bouxsein, Francoise Munoz, Pierre D DelmasAbstract:Context: Assessment of trabecular microarchitecture may enhance the prediction of fracture risk and improve monitoring of treatment response. A new high-resolution peripheral Quantitative Computed Tomography (HR-pQCT) system permits in vivo assessment of trabecular architecture and volumetric bone mineral density (BMD) at the distal radius and tibia with a voxel size of 82 μm3. Objective and Patients: We determined the short-term reproducibility of this device by measuring 15 healthy volunteers three times each. We compared HR-pQCT measurements in 108 healthy premenopausal, 113 postmenopausal osteopenic, and 35 postmenopausal osteoporotic women. Furthermore, we compared values in postmenopausal osteopenic women with (n = 35) and without previous fracture history (n = 78). Design and Setting: We conducted a cross-sectional study in a private clinical research center. Intervention and Main Outcome Measure: We took HR-pQCT measurements of the radius and tibia. Femoral neck and spine BMD were measured in post...
John T Schousboe - One of the best experts on this subject based on the ideXlab platform.
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clinical use of Quantitative Computed Tomography qct of the hip in the management of osteoporosis in adults the 2015 iscd official positions part i
Journal of Clinical Densitometry, 2015Co-Authors: Thomas Lang, Sundeep Khosla, Ling Qin, Klaus Engelke, Philippe K Zysset, William D Leslie, John A Shepherd, John T SchousboeAbstract:The International Society for Clinical Densitometry (ISCD) has developed new official positions for the clinical use of Quantitative Computed Tomography of the hip. The ISCD task force for Quantitative Computed Tomography reviewed the evidence for clinical applications and presented a report with recommendations at the 2015 ISCD Position Development Conference. Here, we discuss the agreed on ISCD official positions with supporting medical evidence, rationale, controversy, and suggestions for further study. Parts II and III address the advanced techniques of finite element analysis applied to Computed Tomography scans and the clinical feasibility of existing techniques for opportunistic screening of osteoporosis using Computed Tomography scans obtained for other diagnosis such as colonography was addressed.
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clinical use of Quantitative Computed Tomography based finite element analysis of the hip and spine in the management of osteoporosis in adults the 2015 iscd official positions part ii
Journal of Clinical Densitometry, 2015Co-Authors: Philippe K Zysset, Thomas Lang, Sundeep Khosla, Ling Qin, Klaus Engelke, William D Leslie, John A Shepherd, John T SchousboeAbstract:The International Society for Clinical Densitometry (ISCD) has developed new official positions for the clinical use of Quantitative Computed Tomography (QCT)-based finite element analysis of the spine and hip. The ISCD task force for QCT reviewed the evidence for clinical applications and presented a report with recommendations at the 2015 ISCD Position Development Conference. Here we discuss the agreed upon ISCD official positions with supporting medical evidence, rationale, controversy, and suggestions for further study. Parts I and III address the clinical use of QCT of the hip, and the clinical feasibility of existing techniques for opportunistic screening of osteoporosis using CT scans obtained for other diagnosis such as colonography was addressed.
Steven K Boyd - One of the best experts on this subject based on the ideXlab platform.
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guidelines for the assessment of bone density and microarchitecture in vivo using high resolution peripheral Quantitative Computed Tomography
Osteoporosis International, 2020Co-Authors: Danielle E Whittier, Andrew J Burghardt, Steven K Boyd, Julien Paccou, Ali Ghasemzadeh, Roland Chapurlat, Klaus Engelke, Mary L BouxseinAbstract:The application of high-resolution peripheral Quantitative Computed Tomography (HR-pQCT) to assess bone microarchitecture has grown rapidly since its introduction in 2005. As the use of HR-pQCT for clinical research continues to grow, there is an urgent need to form a consensus on imaging and analysis methodologies so that studies can be appropriately compared. In addition, with the recent introduction of the second-generation HrpQCT, which differs from the first-generation HR-pQCT in scan region, resolution, and morphological measurement techniques, there is a need for guidelines on appropriate reporting of results and considerations as the field adopts newer systems. A joint working group between the International Osteoporosis Foundation, American Society of Bone and Mineral Research, and European Calcified Tissue Society convened in person and by teleconference over several years to produce the guidelines and recommendations presented in this document. An overview and discussion is provided for (1) standardized protocol for imaging distal radius and tibia sites using HR-pQCT, with the importance of quality control and operator training discussed; (2) standardized terminology and recommendations on reporting results; (3) factors influencing accuracy and precision error, with considerations for longitudinal and multi-center study designs; and finally (4) comparison between scanner generations and other high-resolution CT systems. This article addresses the need for standardization of HR-pQCT imaging techniques and terminology, provides guidance on interpretation and reporting of results, and discusses unresolved issues in the field.
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the spectra collaboration omeract working group construct validity of joint space outcomes with high resolution peripheral Quantitative Computed Tomography
The Journal of Rheumatology, 2019Co-Authors: Sarah L Manske, Steven K Boyd, Kathryn S Stok, Scott C Brunet, Stephanie Finzel, Philip G Conaghan, Cheryl BarnabeAbstract:Objective We assessed construct validity of high-resolution peripheral Quantitative Computed Tomography (HR-pQCT) joint space outcomes by comparison with radiographs in patients with rheumatoid arthritis. Methods In 43 patients, Quantitative, volumetric, HR-pQCT measurements were compared with ordinal Sharp/van der Heijde scoring (SvdH) in the 2nd and 3rd metacarpophalangeal joints. Results Generalized estimating equations showed that joint space minimum, SD, and asymmetry by HR-pQCT were associated with SvdH scores (p Conclusion HR-pQCT demonstrated construct validity outcomes and provides improved 3-D visualization of joint space.
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harmonizing finite element modelling for non invasive strength estimation by high resolution peripheral Quantitative Computed Tomography
Journal of Biomechanics, 2018Co-Authors: Danielle E Whittier, Sarah L Manske, Mary L Bouxsein, Douglas P Kiel, Steven K BoydAbstract:Abstract The finite element (FE) method based on high-resolution peripheral Quantitative Computed Tomography (HR-pQCT) use a variety of tissue constitutive properties and boundary conditions at different laboratories making comparison of mechanical properties difficult. Furthermore, the advent of a second-generation HR-pQCT poses challenges due to improved resolution and a larger region of interest (ROI). This study addresses the need to harmonize results across FE models. The aims are to establish the relationship between FE results as a function of boundary conditions and a range of tissue properties for the first-generation HR-pQCT system, and to determine appropriate model parameters for the second-generation HR-pQCT system. We implemented common boundary conditions and tissue properties on a large cohort (N = 1371), and showed the relationships were highly linear (R2 > 0.99) for yield strength and reaction force between FE models. Cadaver radii measured on both generation HR-pQCT with matched ROIs were used to back-calculate a tissue modulus that accounts for the increased resolution (61 µm versus 82 µm), resulting in a modulus of 8748 MPa for second-generation HR-pQCT to produce bone yield strength and reaction force equivalent to using 6829 MPa for first-generation HR-pQCT. Finally, in vivo scans (N = 61) conducted on both generations demonstrated that the larger ROI in the second-generation system results in stronger bone outcome measures, suggesting it is not advisable to convert FE results across HR-pQCT generations without matching ROIs. Together, these findings harmonize FE results by providing a means to compare findings with different boundary conditions and tissue properties, and across scanner generations.
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determining metacarpophalangeal flexion angle tolerance for reliable volumetric joint space measurements by high resolution peripheral Quantitative Computed Tomography
The Journal of Rheumatology, 2016Co-Authors: Stephanie Tom, Andrew J Burghardt, Steven K Boyd, Mark Frayne, Sarah L Manske, Kathryn S Stok, Cheryl BarnabeAbstract:Objective. The position-dependence of a method to measure the joint space of metacarpophalangeal (MCP) joints using high-resolution peripheral Quantitative Computed Tomography (HR-pQCT) was studied. Methods. Cadaveric MCP were imaged at 7 flexion angles between 0 and 30 degrees. The variability in reproducibility for mean, minimum, and maximum joint space widths and volume measurements was calculated for increasing degrees of flexion. Results. Root mean square coefficient of variance values were < 5% under 20 degrees of flexion for mean, maximum, and volumetric joint spaces. Values for minimum joint space width were optimized under 10 degrees of flexion. Conclusion. MCP joint space measurements should be acquired at < 10 degrees of flexion in longitudinal studies.
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reproducible metacarpal joint space width measurements using 3d analysis of images acquired with high resolution peripheral Quantitative Computed Tomography
Medical Engineering & Physics, 2013Co-Authors: Cheryl Barnabe, Helen R Buie, Michelle Kan, Eva Szabo, Susan G Barr, Liam Martin, Steven K BoydAbstract:Abstract Objective Joint space narrowing is an important feature of progressive joint damage and functional impairment in rheumatoid arthritis (RA). Methods to provide a continuous measurement of joint space width have not been adopted in research or clinical settings. High-resolution peripheral Quantitative Computed Tomography (HR-pQCT) (Scanco Medical AG, Bruttisellen, Switzerland) accurately and reproducibly images bone microstructure at a nominal isotropic voxel dimension of 82μm. Given the ability of HR-pQCT to detect bone margins with high precision, we developed methodology to measure a three-dimensional (3D) metacarpophalangeal (MCP) joint space width and tested the reproducibility of the scan protocol with hand repositioning. Materials and methods Consecutive HR-pQCT scans of the 2nd and 3rd MCP joints of ten subjects with early RA (70% female, mean age 45 years), with repositioning between scans, were obtained. The periosteal edges of the metacarpal head and proximal phalanx base were detected using the μCT Evaluation Program V6.0 (Scanco Medical AG). Using the method of ‘fitting maximal spheres', the joint space width and distribution of joint space thickness was estimated. Results The mean minimum joint space width of the 2nd MCP was 1.82mm (SD 0.20) and of the 3rd MCP 1.84mm (SD 0.23). Reproducibility with repositioning was reliable, with overlapping filtered histograms and a root square mean coefficient of variance of 4.8%. Conclusions We provide reproducible methodology for evaluating the joint space width of the MCP joints. When combined with the assessment of erosions and periarticular bone density, HR-pQCT may be the ideal technology to assess disease activity and progression in RA.
